acceleration
MOYD1
LCLS-II commissioning results
13
LCLS-2 should be completed in 2022, producing first light from its new SC linac. The status of beam commissioning and the performance of the new SC CW linac should be shown in detail. Performance should be compared with the design values and an outlook to further steps should be shown.
Paper: MOYD1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOYD1
About: Received: 03 May 2023 — Revised: 05 Jun 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
MOYD2
LIPAc (linear IFMIF prototype accelerator) beam commissioning & future plans
15
The Linear IFMIF Prototype Accelerator (LIPAc) has been constructed in Rokkasho, Japan to demonstrate the validity of the low energy section of an IFMIF deuteron accelerator up to 9 MeV with a beam current of 125 mA in continuous wave (CW) under the joint collaboration between EU and Japan. The short-pulse 125-mA deuteron beam acceleration to 5 MeV was successfully demonstrated in 2019. Now LIPAc is under commissioning toward the CW beam acceleration. The effort to realize the high-current CW beam, e.g. the commissioning of the ion source at high-current, CW and the conditioning of the RFQ cavity at CW, and the result of the beam commissioning campaign will be presented.
Paper: MOYD2
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOYD2
About: Received: 03 May 2023 — Revised: 13 Jun 2023 — Accepted: 12 Jun 2023 — Issue date: 26 Sep 2023
MOYD3
R&D in superconducting RF: thin film capabilities as a game changer for future sustainability
21
Superconducting RF thin film (SRF-TF) technology for RF cavities has only recently began to achieve accelerator field gradients and Q-factors close to that of bulk niobium SRF cavities. These thin films (such as Nb3Sn, NbTiN, Mg2B and multilayer structures) offer the ability to operate at higher temperatures (4.2 K instead of 1.9 K) thereby increasing the operating efficiency of the RF system and also the potential for achieving higher operating gradients (>50 MV/m) thereby reducing the practical accelerator footprint, both of which aiming to help maximise future sustainability. Much more development however is needed to optimise and master the thin film deposition process on RF cavities, as well as to understand the fundamental RF performance of these enhanced films. In order to develop SRF-TF capabilities beyond current limits, there are a number of international collaborations ongoing which will be described, in Europe it is being conducted under the umbrella of the H2020 ARIES and IFAST programmes.
Paper: MOYD3
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOYD3
About: Received: 03 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
MOZD2
EuPRAXIA and its italian construction site
27
The European Eupraxia project has recently been included in the ESFRI roadmap. EuPRAXIA is a world-wide first, new kind of compact facility and will be constructed at two European sites. One of the two sites for Eupraxia will be the INFN LNF at Frascati. The facility will be integrated with the already planned 1GeV linear accelerator. This talk will cover the status of the technical design of the accelerator, general infrastructure plans and future pilot applications in the user community.
Paper: MOZD2
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOZD2
About: Received: 21 May 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
MOZG1
Electron beam test facilities for novel applications
32
Delivering and tailoring high brightness electron beams for a wide range of novel applications is a challenging task in single pass accelerator test facilities. This paper will review beam dynamics challenges at single pass accelerator test facilities in Europe to generate, transport and tailor low- to medium-energy high brightness electron beams for a range of novel applications.
Paper: MOZG1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOZG1
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOOD1
Time-drift aware RF optimization with machine learning techniques
38
The Fermilab Linac delivers 400 MeV H- beam to the rest of the accelerator chain. We are exploring several machine learning (ML) techniques for automated RF tuning, with an emphasis on time-evolving modeling that can account for parameter drift. Providing stable intensity, energy, and emittance is key since it directly affects downstream machines. To operate high current beam, accelerators must minimize uncontrolled particle loss; this ca be accomplished by minimizing beam longitudinal emittance via RF parameter optimization. However, RF tuning is required daily since the resonance frequency of the accelerating cavities is affected by ambient temperature and humidity variations and thus drifts with time. In addition, the energy and phase space distribution of particles emerging from the ion source are subject to fluctuations. Such drift is not unique to Fermilab, but rather affects most laboratories. Our methods include several variations of RF system modeling based on diagnostics data from beam position monitors (transverse positions and longitudinal phase). We will present the status of each approach and future plans.
Paper: MOOD1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOOD1
About: Received: 12 May 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
MOOG1
X-band activities at INFN-LNF
42
The Eupraxia@SPARC_LAB project, foreseen a 1GeV Linac based on a X-band booster composed by 16 accelerating structures working at the nominal gradient of 60MV/m. In this framework, an intense activity has started in the last years in order to prove the reliability and functionality of the X-band technology at very high peak power. The main step of this activity has been the implementation of a X-band test station TEX, based on an RF power source capable to deliver 50MW RF pulses that are used for accelerating structures and RF components conditioning and testing. This test facility has been successfully commissioned and entered into operation at the end of 2022. Together with the source commissioning different RF components in X-band, necessary for the Eupraxia Linac, have been developed and will be tested soon at the nominal peak power in the TEX facility. In this article the status and operation of the TEX facility is reported together with a report on the main activities on the X-band technology performed at INFN-LNF.
Paper: MOOG1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOOG1
About: Received: 03 May 2023 — Revised: 19 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOOG3
Additive manufacturing of copper RF structures for particle accelerator applications
53
Particle accelerators, relevant to LANL’s mission spaces will rely on the use of copper based rf structure for charged particle acceleration. Additively manufactured (AM) copper structures offer the usual well-known advantages in terms of relaxation of physical design (shape) constraints, and thus hold the promise of making complex shaped rf structures. To rapidly demonstrate the potential to additively manufacture accelerator structures with existing technology, a bound metal deposition (BMD) metal 3D printer will be used to build a scaled design and the results of this effort will be presented.
Paper: MOOG3
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOOG3
About: Received: 03 May 2023 — Revised: 15 Jun 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
MOPA002
Sextupole optimization at rapid cycling synchrotron in China Spallation Neutron Source
60
China Spallation Neutron Source (CSNS) is a high density complex with a high repetion rate of 25Hz. The Rapid Cycling Synchrotron is the key part of the CSNS. By adopting the sextupoles with pulsed beam power system, CSNS has been operating steadily at 140kW. The CSNSII is aim to deliever above 500kW with the upgrations of many aspects of the accelerator. The sextupoles upgration is very important for CSNSII. By optimization the location of the sextupoles with MOGA algorithm, the dynamic aperture of RCS is increased impressively. In this paper, we will review the operation status of the sextupoles and give some proposals about sextupole upgration plans.
Paper: MOPA002
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA002
About: Received: 09 May 2023 — Revised: 24 May 2023 — Accepted: 24 May 2023 — Issue date: 26 Sep 2023
MOPA011
Detailed design studies of the high energy beam transport line of the Minerva Project at SCK CEN
69
MYRRHA will be a research infrastructure focussed on the construction of a first prototype of an accelerator driven sub-critical nuclear reactor (ADS). The driver ac-celerator will deliver a 600 MeV, 4 mA Proton beam to the reactor core. The first phase called MINERVA aims for the construction of a 100 MeV, 4 mA proton linear accel-erator with a focus on reliability. Attached to this 100 MeV linear accelerator are a Proton Target Facility (PTF), which is essentially a high power Isotope Separation On-Line (ISOL) Facility, and a Full Power Facility (FPF) for fusion material research. This paper presents the status of the beam optic studies and overall layout of the Protons Target line towards the PTF, the Full Power line towards the FPF and the beam line towards an energy tuning beam dump.
Paper: MOPA011
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA011
About: Received: 09 Apr 2023 — Revised: 12 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPA016
Design and optimization of an ERL for cooling EIC hadron beams
73
**The baseline scheme for hadron beam cooling in the Electron Ion Collider (EIC) calls for Coherent electron Cooling (CeC) of the hadrons with non-magnetized electrons at high energy (150 MeV electrons), and additional cooling via conventional bunched beam cooling using a precooler system. The electron beam parameters for these concepts are at or beyond the current state of the art, with electron bunch charges of the order of 1 nC and average currents on the order of 100 mA and require an Energy Recovery Linac (ERL) to produce such beams. Using specifications provided by BNL and Jefferson Lab, physicists and engineers at Xelera Research are working on a complete design of an ERL system capable of satisfying such a cooler.**
Paper: MOPA016
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA016
About: Received: 08 May 2023 — Revised: 10 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
MOPA018
High order mode analysis in energy recovery linac based on an energy budget model
77
Energy Recovery linear accelerator (ERL) light source facilities based on superconducting radiofrequency (SRF) are deemed of the most resplendent techniques in the future of accelerator physics. Running in a continuous waves mode with a high repetition rate for a long timescale, we discuss High order modes (HOMs) analysis in a two-pass two-way ERL scheme where acceleration and deceleration of electron bunches are supported by a standing wave structure of the RF cavity. The analysis reported in this paper is based on differential equations that describe the beam dynamics (BD) to overcome the limitations imposed by high currents and insure energy recuperation over millions of interactions.
Paper: MOPA018
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA018
About: Received: 03 May 2023 — Revised: 07 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPA019
Achromatic low energy merger for energy recovery linacs
81
Nowadays, Energy Recovery Linacs (ERLs) became really appealing thanks to their low environmental impact and high sustainability. ERLs require a special low energy injector, usually named merger. The energy at merger exit is clearly the energy that can’t be recycled in the ERL machine and is the amount dumped at the end. The lower the injection energy is the more efficient is the energy recovery process. A physiological issue of low energy ERL injection is the presence of space charge in the dispersive section that introduces to dispersion leaks. Worldwide ad hoc solutions for mergers beamlines design have been studied to address this problem. Here we present a different approach that allowed us to exploit a standard dogleg to design a very low energy merger for an ERL. This has been made possible thanks to the application of the GIOTTO AI code that optimizes of the optics setting finding a proper achromatic configuration.
Paper: MOPA019
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA019
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPA023
Magnetic design of the commutational magnet and quadrupoles for PERLE accelerator
85
PERLE (Powerful Energy Recovery LINAC for Experiment) is a high-power Energy Recovery LINAC (ERL) facility with 20 mA beam current and beam energy from 250 MeV to 500 MeV featuring three passes through two cryomodules. It is a hub for validation of the ERL technology development towards future energy and intensity frontier machines. Design challenges of PERLE and its beam parameters make it a testbed to validate multi-turn high current ERL operation for the LHeC. It will be the first ERL for some pioneering experiment of the eN interaction with radioactive nuclei. In this work, design and optimization of the commutational magnet (B-com) used to spread/combine the three beams and one series of the quadrupole magnet is discussed. It gives the design parameters including: yoke geometry, pole profile, and material, and calculation of the excitation current needed to drive the magnet, the coil parameters and the number of turns. The B-com magnet is optimized for a 30° bending angle with magnetic field of 0.88 T along the magnet length and a harmonic content of 0.036%. The quadrupole magnet is designed for a gradient field of 34.15 T/m and experiences saturation above this value. Further studies to avoid saturation and achieve the maximum gradient of 44.1 T/m required by the beam dynamics is undergoing.
Paper: MOPA023
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA023
About: Received: 28 Mar 2023 — Revised: 10 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
MOPA035
Progress on the electron ion collider’s RCS RF ramp development
101
We report on progress developing the Energy and RF ramp for the EIC’s Rapid Cycling Synchrotron (RCS). The development of the RF voltage and phase ramp from injection energy at 400 MeV to 5, 10 and 18 GeV extraction energy requires control of the bunch’s longitudinal aspect ratio to avoid both collective instabilities, RF bucket height and width as well as lattice dynamic aperture limits. Further the ramp profile must meet the technical limits for the current super conducting cavity design.
Paper: MOPA035
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA035
About: Received: 01 May 2023 — Revised: 12 Jun 2023 — Accepted: 12 Jun 2023 — Issue date: 26 Sep 2023
MOPA056
Transition jump system of the hadron storage ring of the electron ion collider
155
Matched first order transition crossing in the Relativistic Heavy Ion Collider (RHIC) is performed by using two families of jump quadrupoles when ramping species through transition to storage energy. The jump quadrupole families control $\gamma$ transition and the working point of the accelerator by compensating for the tune shift from the jump and minimizing optical distortions. After transition, amplitude and phase of the RF cavities need to be rematched to maintain constant acceleration. This configuration has proven to be effective in maintaining beam quality and reducing beam loss. The Hadron Storage Ring (HSR) retains the arcs and most of the insertion regions of RHIC. This paper discusses the gamma transition crossing of the HSR by the implementation of a matched first order transition jump.
Paper: MOPA056
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA056
About: Received: 02 May 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
MOPA059
Installation of a new low energy line (LEBTO3) at CNAO
159
CNAO is one the six centers all around the world able to treat patients affected from cancer by proton and carbon ions beams. Beams are produced by a synchrotron equipped with two sources. A third source has been recently installed in order to produce new species that will be interesting both for clinical and R&D purposes. A new low energy line has been designed, installed and commissioned to transport beams from the new source to the accelerator. In this paper the new line, called LEBTO3, is presented.
Paper: MOPA059
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA059
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPA060
Design and commissioning of the RF-KO extraction at CNAO
162
CNAO is one the six hadrontherapy centers all around the world that produce both proton and carbon ions beams. It is based on a synchrotron in which the beams are extracted by a slow extraction mechanism that uses a betatron core. In the last years an electrostatic exciter has been installed along the ring in order to allow beam extraction using the RF-KO method. The system has been commissioned and allows extraction according to the clinical beam parameters. The paper illustrates how the RF-KO method has been implemented in CNAO under the hardware and software point of view. The characteristics of the proton and carbon beams will be also presented.
Paper: MOPA060
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA060
About: Received: 03 May 2023 — Revised: 06 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
MOPA062
Technological features and status of the new heavy ions synchrotron SIS100 at FAIR
165
SIS100 is a new superconducting heavy ion synchrotron optimized for the acceleration of high intensity heavy ion beams. Most crucial intensity limitation for heavy ion beams in SIS100 is the dynamic vacuum and corresponding beam loss by projectile ionization. Ionization loss and ion induced desorption drive the residual gas pressure into an instability, generating an intensity barrier at much lower intensity levels than any space charge limit. Technologies for stabilizing the dynamic vacuum, such as extensive charge separator lattice, pumping by cryogenic magnet chambers, cryo-adsorption pumps and cryo-ion catchers had to be implemented. SIS100 will also be the first user synchrotron comprising a laser cooling system for cooling at relativistic beam energies. Combined with a strong bunch compression system, laser cooling will support the generation of short ion bunches. Meanwhile, a large amount of the SIS100 components have been delivered and preparations for installation are launched. The shell construction of SIS100 underground tunnel is completed. Installation of the technical building infrastructure and the cryogenic distribution system are ongoing.
Paper: MOPA062
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA062
About: Received: 02 May 2023 — Revised: 08 Jun 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
MOPA065
Electrostatic dust lofting: a possible cause for beam losses at CERN’s LHC
177
Dust particles interacting with the proton beams have caused many thousand beam-loss events at CERN's Large Hadron Collider (LHC), some of which led to premature beam dumps and even magnet quenches. It has been hypothesized that dust particles on the vacuum chamber wall of the LHC are negatively charged due to electron clouds and can detach from the chamber wall by the electric field of the beam. To test this hypothesis, we performed experiments to study the electrostatic lofting of dust particles from a conducting surface. A monolayer of SiO2 particles with a diameter of <44 um is deposited on such a surface and exposed to an electron beam of 80-140 eV. An external electric field of up to 3 kV/cm is then applied. The properties of dust charging and levitation are characterized from recorded high-speed videos. We observed that dust particles are lofted both during electron beam charging and during the application of the external electric field. Our results provide experimental evidence that dust particles can be detached from a conducting surface and help to understand the mechanism of how dust particles can enter the LHC beam.
Paper: MOPA065
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA065
About: Received: 03 May 2023 — Revised: 30 Jun 2023 — Accepted: 30 Jun 2023 — Issue date: 26 Sep 2023
MOPA075
Modernization of the NSC KIPT hard X-ray source facility
203
To satisfy up-to-date technical requirements NSC KIPT hard X-ray source on the base of Compton scattering NESTOR should be modified. Essential modernization should be done in accelerator-injector, lattice of the storage ring, RF and optical systems. In the paper the technical proposals of the facility modernizations and results of beam dynamic simulations in the modified facility are presented and described.
Paper: MOPA075
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA075
About: Received: 09 May 2023 — Revised: 10 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
MOPA078
Design status of RF system for the Korea 4th generation storage ring
212
A new fourth-generation synchrotron radiation source(4GSR) will be built in Ochang, South Korea by 2027. A technical design review for the Korea 4GSR is currently in progress and is expected to be completed in mid-2023. The storage ring has a circumference of 800 m. It has been designed for a maximum current of 400 mA at 4 GeV electron beam energy. A target emittance is 58 pm-rad, 100 times less than PLS-II that is 3rd generation light source in Korea. The RF system for the Korea 4GSR consists of 10 or more normal conducting cavities, a low-level RF(LLRF) system, a high-power RF(HPRF) system and so on. In order for the beam stability highly-HOM damped cavities will be indispensible. Subsidary the feedback system such as a longitudinal feedback system(LFS) and transverse feedback system(TFS) will be installed in the storage ring. Additionally we are planning to install harmonic cavities for Landau damping, on the other hand for improving of beam life time and less wake field. In case of the LLRF, we would try to apply new digital feedback control scheme. And the HPRF is taking account of solid state RF power amplifier. This presentation shows the current status and plans of the RF system for the Korea 4GSR.
Paper: MOPA078
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA078
About: Received: 12 May 2023 — Revised: 05 Jun 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPA081
Data analysis and control of an MeV ultrafast electron diffraction system and a photocathode laser and gun system using machine learning
222
An MeV ultrafast electron diffraction (MUED) instrument system, such as is located at the Accelerator Test Facility (ATF) of Brookhaven National Laboratory, is a structural characterization technique suited to investigate dynamics in the ultrashort range in a variety of materials via a laser pump method. It is a unique characterization technique especially suitable for highly correlated materials. This technology can be advanced further into a turnkey instrument by using data science and artificial intelligence (AI) mechanisms in conjunction with high-performance computing. This can facilitate automated operation, data acquisition, and real-time or near-real-time processing. The AI-based system controls can provide real-time feedback on the electron beam or provide virtual diagnostics of the beam. Deep learning can be applied to the MUED diffraction patterns to recover valuable information on subtle lattice variations that can lead to a greater understanding of a wide range of material systems. A data-science-enabled MUED facility will also facilitate the application of this technique, expand its user base, and provide a fully automated state-of-the-art instrument. Another beamline enhancement planned is the extension of the beamline sample area to include additional instrumentation for simultaneous measurement of a standard baseline sample. EM modeling of the beamline components facilitates this. Updates on research and development for the MUED instrument are presented.
Paper: MOPA081
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA081
About: Received: 08 May 2023 — Revised: 12 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
MOPA082
Design of a permanent quadrupole magnet with adjustable magnetic field gradient
226
As compared to traditional magnets, permanent magnets can effectively reduce energy consumption and eliminate the impact of current ripple and the wa-ter cooling system on beam current. The use of perma-nent magnets in accelerators has become a new trend as permanent magnet technology has advanced. In HALF, we have designed a permanent magnet based on the quadrupole magnet, and the central magnetic field strength of the permanent magnet can be adjusted, indicating that single or multiple permanent magnets can be developed to replace different sizes of quadru-pole magnets in accelerators, greatly improving sys-tematization. The magnet’s mechanical design has been finalized, and the prototype of the permanent magnet will be manufactured and tested soon.
Paper: MOPA082
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA082
About: Received: 27 Apr 2023 — Revised: 11 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPA089
Earthquake measurements and those analysis on ir components and Belle II detector in KEK
249
We frequently experience earthquakes in Japan. Even though countermeasures against earthquake is deeply considered and well carried out, sometime troubles are occurred on facilities or experimental devices. When we focus on the relative displacement due to an earthquake, it is possible to cause damage of a beam pipe bellows or interference by disappearing tolerance between the sub-detectors. And magnet quenches have been triggered due to relative displacement of magnetic fields between three superconducting solenoids, i.e., the detector solenoid and two compensating solenoids in each final focus magnets, when earthquake occurred. So, we set acceleration sensors, the relative displacements had been measured. And also, laser distance sensors and gap sensors mounting on the final focus magnets were referred for this study. From these measurement data, characteristics of earthquakes were analyzed. Measurement acceleration data was also applied for response spectrum analysis. In this presentation, we will present the measurements and analysis results, and comparison between the measurements and the FEM calculations are shown.
Paper: MOPA089
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA089
About: Received: 08 May 2023 — Revised: 09 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
MOPA098
Demonstration of non-local crystal shadowing at the CERN SPS
271
The main SPS users are the experiments installed in North experimental Area (NA) which are served with a continuous 4.8 s long spill of protons and heavy ions. A third-integer resonant slow extraction is used to provide a uniform, long spill. Such a technique comes at the cost of particles directly hitting the electrostatic septum wires and activating the surrounding of the extraction channel. In recent years, silicon bent crystals have been exploited to shadow the wires of the septum blade and reduce the beam induced activation. It was then demonstrated the experimental success of local shadowing in the SPS and a way to further reduce losses with a non-local installation of the crystal. After the last yearly stop, a new Si bent crystal was installed in LSS4 of the SPS. In this paper, the first results from measurements with beam are reported together with limitations and possible upgrades of the present installation.
Paper: MOPA098
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA098
About: Received: 02 May 2023 — Revised: 08 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
MOPA102
Design of the new 18 MeV electron injection line for AWAKE Run2c
287
The Advanced Wakefield Experiment (AWAKE) has demonstrated during its first run (Run1, concluded in 2018) the capability of accelerating electrons up to the energy of 2 GeV using proton driven plasma wakefield acceleration. AWAKE Run 2 has started and during the third phase of the program, Run 2c, which aims to demonstrate stable accelerating gradients of 0.5-1 GV/m and emittance preservation of the electron bunches during acceleration, the layout of the experiment will be modified to accommodate a second plasma cell. Among the many changes, the position of the primary 18 MeV electron beam line will be shifted. The beam line layout and optics will need, therefore, to be redesigned to fit the new footprint constraints and match the new beam requirements. This paper presents the proposed layout of the new 18 MeV line, detailing the constraints and specifications, describing the design procedure and showing the main results.
Paper: MOPA102
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA102
About: Received: 03 May 2023 — Revised: 15 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
MOPA108
Vertical bump orbit study on emittance of injection beam in transport line for the SuperKEKB main ring
298
The SuperKEKB accelerator, a 7 GeV electron and a 4 GeV positron double-ring collider, is in progress in order to explore the new physics beyond the standard model. The next milestone is to obtain integrated luminosity of 15 /ab data in the next decade, so that the luminosity should exceed 2 x 10^35 /cm^2/s in several years. One of the essential issues is the injection performances for both rings to be capable of storing beams of a few amperes due to overcoming their short lifetimes. To preserve the emittance of the injection beam passing through the transport line is very important for the injection performances. However, the large emittance growths have been observed in the both of electron and positron beam transport lines. After many efforts on the research this issue from both sides of the simulations and measurements, finally the coherent synchrotron radiation (CSR) wakefields has gotten to be suspected as the cause of the emittance growths. According to the parallel conducting plates model, CSR wakefields are reduced when the beam passes through the offset position from the median plane surface of the plates. In this study, it will be reported that the measured emittance variation of the injection beam with the bump orbit at the arc section of transport line for the SuperKEKB 7 GeV electron ring.
Paper: MOPA108
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA108
About: Received: 01 May 2023 — Revised: 11 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
MOPA115
Beam delivery of high-energy ion beams for irradiation experiments at the CERN Proton Synchrotron
315
Heavy-ion single event effect (SEE) test facilities are critical in the development of microelectronic components that will be exposed to the ionizing particles present in the hostile environment of space. CHARM High-energy Ions for Micro Electronics Reliability Assurance (CHIMERA) and HEARTS have developed a high-energy ion beam capable of scanning a wide range of Linear Energy Transfer (LET) at low intensities to study ionization effects on space-bound technology using CERN's Proton Synchrotron (PS). This contribution describes the extraction and transport of low-intensity lead ions at multiple energies to the CHARM facility at the East Area of CERN. Furthermore, it discusses the implementation of a Radio Frequency Knockout (RFKO) technique that streamlines beam extraction and enhances particle flux control and reproducibility across different energies, thereby improving performance and reliability in SEE testing.
Paper: MOPA115
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA115
About: Received: 21 Apr 2023 — Revised: 15 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
MOPA116
RF techniques for spill quality improvement in the SPS
319
The CERN Super Proton Synchrotron (SPS) aims at providing stable proton spills of several seconds to the North Area (NA) fixed target experiments via third-integer resonant slow extraction. However, low-frequency power converter ripple (primarily at 50 and 100 Hz) and high-frequency structures (mainly at harmonics of the revolution frequency) modulate the extracted intensity, which can compromise the performance of the data acquisition systems of the NA experiments. In this contribution, the implementation of Radio Frequency (RF) techniques for spill quality improvement is explored, with particular focus on empty bucket channelling. It is shown that both the main RF systems (at 200 and 800 MHz) can be successfully exploited to improve the SPS slow extraction.
Paper: MOPA116
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA116
About: Received: 26 Apr 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPA121
Status of plasma diagnostics on the prototype plasma lens for optical matching at the ILC e+ source
334
In recent years, high-gradient, symmetric focusing with active plasma lenses has regained significant interest due to its potential advantages in compactness and beam dynamics compared to conventional focusing elements. A promising application could be optical matching of highly divergent positrons from the undulator-based ILC positron source into the downstream accelerating structures to increase the positron yield. In a collaboration between University Hamburg and DESY Hamburg a downscaled prototype for this application has been developed and constructed. Here, we present the current status of the prototype development.
Paper: MOPA121
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA121
About: Received: 02 May 2023 — Revised: 11 May 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
MOPA132
Status of hydrodynamic simulations of a tapered plasma lens for optical matching at the ILC e+ source
364
The International Linear Collider is a proposed electron-positron linear collider, where the positron beam is generated by undulator radiation hitting a target. The resulting, highly divergent positron beam requires immediate optical matching to improve the luminosity and ensure the success of the intended collision experiments. Here, optical matching refers to the process of capturing particles and making them available for downstream beamline elements like accelerators. In the past, this has been done with sophisticated coils, but more recently the usage of a current-carrying plasma, a so-called plasma lens, has been proposed as an alternative. For the International Linear Collider, idealised particle tracking simulations have already been done in the past with the purpose of finding the optimal plasma lens design with respect to the captured positron yield. The proposed design is conical in shape to accommodate for the large beam divergence [1]. Now further research and development of this design is required, including both experiments with a downscaled prototype set-up as well as corresponding simulations modelling the hydrodynamics of the current-carrying plasma. The accuracy of the latter will benefit greatly from the former. In this work, first preliminary hydrodynamic simulations instil confidence into further endeavours.
Paper: MOPA132
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA132
About: Received: 03 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
MOPA142
Commissioning simulations tools based on python Accelerator Toolbox
386
Storage ring commissioning-like simulations are necessary to assess the feasibility of proposed future lattice designs. This paper proposes a python package for commissioning-like simulations based on python accelerator toolbox (pyAT). The software includes: 1) errors definition, 2) correction routines from open trajectory to optics and coupling correction and 3) the evaluation of the relevant parameters, such as dynamic aperture, injection efficiency and Touschek lifetime. The software is fully exploiting parallel resources (local or on a computing cluster) and is thought to be easily configured for any machine (examples are given for EBS DBA and HMBA, for PETRA IV and for FCC-ee). Whenever possible analytic formulas are made available to the user. Several examples are detailed in this paper and included in the code as demonstrations of use.
Paper: MOPA142
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA142
About: Received: 08 May 2023 — Revised: 15 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
MOPA146
Feasibility study of fast beam-based alignment using ac excitations in the HEPS
398
To improve the performance of beam orbit correction, it is necessary to perform beam-based alignment in modern storage ring light sources. For the High Energy Photon Source (HEPS), a 4th generation storage ring light source being built in China, because of the large number of BPMs in storage ring, it may take dozens of hours to complete the alignment with a conventional BBA algorithm. To reduce the time cost, it has been proposed to use ac excitation for fast beam-based alignment. We tested the feasibility of applying this method to the HEPS storage ring through numerical simulations. In the following, we will introduce the simulation settings and the corresponding results.
Paper: MOPA146
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA146
About: Received: 05 May 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPA166
Protection of insertion devices against radiation damage at ESRF-EBS
445
The user service mode of ESRF started in August 2020 after the installation of the new EBS machine, replacing the original ESRF DBA storage ring. All the insertion devices (IDs) were stored and re-installed to be available from day-1 of the accelerator commissioning. A major concern was, and still is, to preserve them as much as possible from demagnetization, both low gap in-vacuum devices and in-air undulators. This paper presents the strategy put in place for the commissioning, and in a longer term over the first years of operation, to reduce the risk of radiation damage of the IDs.
Paper: MOPA166
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA166
About: Received: 28 Apr 2023 — Revised: 19 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
MOPA179
Modification of beam transport line design for simultaneous top-up injection to PF and PF-AR
468
KEK has two light sources: Photon Factory (PF, 2.5 GeV) and Photon Factory Advanced Ring (PF-AR, 6.5 GeV). In 2017, the use of a new beam transport line (BT) of PF-AR was started, and the simultaneous top-up injection for both PF and PF-AR was realized. These days, there have been strong demands for the reduction of the operating cost of accelerators, and its importance is greater in PF-AR with higher ring-energy. In 2019, the 5 GeV operation was started in PF-AR. However, the new BT of PF-AR (ARBT) was designed for the energy of 6.5 GeV, then the simultaneous top-up injection is no longer available under the condition of 5 GeV operation of PF-AR and 2.5 GeV operation of PF. In order to mitigate this impact, the pseudo-top-top injection has been employed by fine-tuning the current of a common DC bending magnet placed at the intersection of ARBT and the BT of PF (PFBT) within a given time frame. However, this scheme limits the operation schedules, and will not be able to respond adequately to low emittance optics of PF-AR that may bring the shorter beam lifetime. In order to realize true-top-up injection, a modification of BTs’ optics design was carried out. This time, details of modified design of BTs’ optics and its extended plan will be presented.
Paper: MOPA179
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA179
About: Received: 31 Mar 2023 — Revised: 24 May 2023 — Accepted: 24 May 2023 — Issue date: 26 Sep 2023
MOPA180
Construction and beam commissioning of the GeV-range test beamline at KEK PF-AR
471
Commissioning a test beamline in KEK Photon Factory Advanced Ring (PF-AR, 6.5GeV and 5.0GeV) is proceeded under cooperation with the KEK Institute for Particle and Nuclear Studies (IPNS) to use electron beams in the GeV-range for the development of detectors in particle physics experiments. The inauguration of the project which was mainly directed by the IPNS was launched back in 2014, but the project progressed after the budgeting in FY2020, and the construction was completed in the summer of 2021. The electron for beam test can be obtained from gamma-rays emitted by collisions between the halo of a stored beam, which is the synchrotron radiation source in PF-AR, and a wire target using a copper converter to electron-positron pair creation. A yielded monochromatic electron beam is guided to the test area by quadrupole magnets and a bending magnet on the test beamline; the first interaction test between the wire target and the stored beam was successfully performed in the fall of 2021 and the trial of long user operation with top-up injection was completed in the fall of 2022. In this presentation, we will report on the overview of the construction and the beam commissioning of the test beam line.
Paper: MOPA180
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA180
About: Received: 28 Apr 2023 — Revised: 11 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
MOPA186
Sorting of sextupole and octupole magnets in the HEPS storage ring
489
The High Energy Photon Source (HEPS) is a 6 GeV diffraction-limited storage ring light source, which started construction in 2019. The sextupole and octupole magnets in the storage ring of HEPS are divided into several groups, and each group of magnets shares one power supply. In the lattice design, magnets in the same group are identical, but the real magnets have errors, which violate the symmetry of the lattice. To optimize the performance of HEPS, it is necessary to carry out sorting of these magnets. By doing simulations with elegant, we studied the effect of sorting on the performance of the nonlinear beam dynamics. The details are presented in this paper.
Paper: MOPA186
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA186
About: Received: 03 May 2023 — Revised: 06 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPA188
Design of a 250 linac injector for the Southern Advanced Photon Source
496
The Southern Advanced Photon Source (SAPS) is a 4th generation storage ring based light source under design started several years ago, which is planned to be constructed at Guangdong province at China. The equilibrium emittance of the storage ring will be below 100 pm.rad and the beam energy is determined to be 3.5 GeV. During the past two years, the nominal current of the storage ring was increased from 200 to 500 mA, so the injector system has to provide more bunch charge. Besides, the injection beam energy for the booster was increased from 150 to 250 MeV, which means two more accelerating cavities have to been added. In this paper, the update of the linac injector is presented, which consists of a thermionic electron gun, a bunching system, a 200 MeV linac. The beam transfer line from linac to booster is also presented
Paper: MOPA188
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA188
About: Received: 31 Mar 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPL011
Strategy for proton polarization in the Electron Ion Collider
523
The Electron Ion Collier (EIC) will utilize highly polarized electron and ion beams. To preserve polarization through numerous depolarizing resonances over the whole EIC hadron accelerator chain, harmonic orbit correction, partial snakes,horizontal tune jump system and full snakes have been used. A new scheme using skew quadrupoles to compensate horizontal intrinsic resonances is under development. In addition, close attentions have been paid to betatron tune control, orbit control and beam line alignment. The polarization of 60% at 255 GeV has been delivered to experiments with 1.8E11 bunch intensity. For the EIC era, the beam brightness has to be maintained to reach the desired luminosity.This will be achieved by electron cooling at injection of EIC hadron storage ring. Since we only have one hadron ring in the EIC era, existing spin rotator and snakes can be converted to six snake configuration for one hadron ring. The number of snakes can be increased. With properly arranged snakes in EIC and reduction of emittance, the polarization can reach 70% at 275 GeV. The general strategy of polarization preservation scheme in the injectors and hadron ring of the EIC is described in this paper.
Paper: MOPL011
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL011
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPL028
Configuration management of the CERN accelerators complex on the road to long shutdown 3
579
The Configuration Management of the LHC and its injectors ensures a clear and coherent representation of the CERN accelerators at a given point in time. It has been evolving steadily. The methodology has been continuously improved, incorporating best practices and was also extended to the injectors to face the Long Shutdown 2 (LS2) with a set of rigorous and homogenised processes for the entire accelerator complex. Lessons learnt from the LS2 provide a strong basis to further improve the effectiveness of the change management process. This paper describes the action plan, concerning the processes and engineering tools, to further improve configuration management efficiency to face the numerous changes foreseen during the Long Shutdown 3 (LS3), with principally the equipment installation foreseen by the HL-LHC project. In addition, it reports on the smooth transition between the LHC and HL-LHC configuration teams to ensure the long-term operation and maintenance of the LHC.
Paper: MOPL028
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL028
About: Received: 28 Apr 2023 — Revised: 08 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPL040
Experience from the US contribution to HL-LHC: Nb3Sn focusing quadrupoles and SRF crab cavities
622
The Interaction Regions (IR) of many colliders benefit from the application of leading-edge technologies to ensure the highest possible luminosity delivered to the experiments. Leading-edge low-beta focusing magnets and crab cavities to handle individual bunches are critically important to increase the instantaneous and integrated luminosity in future Colliders. The High-Luminosity LHC Upgrade, HL-LHC, with Nb3Sn Magnets (called MQXF) and Superconducting Radio Frequency (SRF) crab cavities (of two types, called DQW and RFD) is a world-wide collaborative project under construction in this decade to utilize the solutions mentioned above as key ingredients to increase tenfold the integrated luminosity delivered to the CMS and ATLAS experiments in the next decade. The HL-LHC AUP is the US effort to contribute approximately 50% of the low-beta focusing magnets and crab cavities for the HL-LHC. In this contribution we present the valuable lessons learned by the US efforts in the procurement, construction, and testing phases of the Nb3Sn focusing magnets and SRF crab cavities. We will report on the experience gathered by HL-LHC AUP in the production of the first half of deliverables (magnets MQXFA03 to MQXFA13). We will also report on the test of the first cryoassemblies and the status of the cavities’ development, production and testing. Both the technical and project management lessons-learned will inform applications of these technologies to future colliders and projects.
Paper: MOPL040
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL040
About: Received: 01 May 2023 — Revised: 23 Jun 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
MOPL042
Nonlinearity optimization for the 125 TeV SPPC collider ring lattice
630
As an energy frontier machine, the proposed Super Proton-Proton Collider (SPPC) will have the capability to explore a much larger region of new physics models with center of energy around 125 TeV and circumference 100 km. The nonlinearity optimization of the SPPC collider ring lattice is essential to get a high peak luminosity and lifetime of the beams. In this paper, a collider ring lattice based on the CDR one will be presented. Then, the nonlinearity of the bare lattice was optimized using Lie map analysis and frequency map analysis. With the optimization, the lattice aberration at the interaction points and dynamic aperture of whole ring were improved. Finally, the alignment tolerances and field error tolerances for the SPPC are evaluated. The correction scheme of the lattice with errors will be presented.
Paper: MOPL042
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL042
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPL046
Thermionic sources for electron cooling at IOTA
646
A new electron cooling experiment is being planned at the Integrable Optics Test Accelerator (IOTA) at Fermilab for cooling ~2.5 MeV protons in the presence of intense space-charge. Electron cooling is integral to the study of beam dynamics and has valuable applications for producing high-intensity hadron beams in particle accelerators. For such goals, an electron lens to be placed in the IOTA ring will be used for electron cooling, space-charge compensation, and non-linear dynamics. Here we present the simulations and designs of two thermionic electron sources for the cooling at IOTA. One cooler is a basic electron source and will be used for cooling the proton beam and as a tool for other experiments at IOTA. The other cooler is a strong electron source, which will be used for studying effects of electron cooling in ion beams with intense space-charge. We particularly discuss parameters of the thermionic sources’ electrodes, as well as the simulation results. We also present a new electron source test-stand at the University of Chicago, which will be used to test the thermionic electron sources. We also discuss the results from analyzing the test stand operations with a currently existing electron source. Furthermore, we present future steps for production and commissioning of these thermionic sources at IOTA.
Paper: MOPL046
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL046
About: Received: 06 May 2023 — Revised: 16 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPL053
A booster free from spin resonances for future 100 km-scale circular e+e- colliders
662
Acceleration of polarized electron and positron beams to ultra-high beam energies is of interests for polarized beam applications in future 100km-scale e+e- circular colliders. However, it was widely envisaged that crossing hundreds of spin depolarization resonances would lead to severe depolarization during the energy ramp in the booster synchrotron. In this work, we have studied the spin resonance structure of a booster lattice for the Circular Electron Positron Collider (CEPC). The 100 km-scale booster lattice has a periodicity of 8 and each arc region contains hundreds of FODO cells. We show that the first super strong depolarization resonances only occur beyond 120 GeV, and other resonances are much weaker, due to the effectively very high periodicity of the lattice structure in terms of spin resonances. This finding is similar to the concept of ``Spin resonance free injector’’ for the Electron Ion Collider [V. Ranjbar, Phys. Rev. Accel. Beams, 20, 111003, 2018]. Spin tracking simulations verify that beam polarization can be mostly maintained in the fast ramping to 45.6 GeV and 80 GeV beam energies, without using special hardware like Siberian snakes. We also discuss possible measures to maintain beam polarization up to 120 GeV. This study opens the way for injection of highly polarized beams generated from the source into the collider rings, to enable resonant depolarization measurements as well as longitudinally polarized colliding beam experiments.
Paper: MOPL053
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL053
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPL061
FCC-ee arc half-cell: preliminary design & integration studies, with ideas for a mock-up
678
During 2022, a dedicated study was undertaken at CERN, together with FCC Feasibility Study collaborators, aimed at proposing a robust configuration for the FCC-ee arc half cell. The proposed configuration takes into account integration aspects of the elements in the arc cross section, both for the booster and the collider, as well as aspects related to powering, cooling and ventilation, supporting and alignment, optics, instrumentation, handling and installation. The interfaces between the arc elements and the straight sections have also been analyzed. This paper summarizes the main conclusions of the assessment, and reports the preliminary engineering analyses performed to design the supporting system of the booster and of the collider. A proposal for a possible mock-up of the arc half-cell, to be built at CERN in the next years, is also presented.
Paper: MOPL061
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL061
About: Received: 10 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
MOPL068
Dark sector searches based on dielectric laser acceleration
702
We discuss the beam requirements for indirect searches of dark matter and feebly coupled particles using advanced accelerator concepts. A parameter comparison reveals dielectric laser acceleration as a promising candidate for delivering the needed single-electron beams in the 5-100 GeV energy range or beyond. We suggest a parameter set for a baseline DLA-based dark sector accelerator. Enhancements through combining dielectric laser deflectors with a segmented detector or by making the dielectric structure be part of the laser oscillator could offer a performance significantly exceeding the ``Extended LDMX'' proposal based on LCLS-II.
Paper: MOPL068
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL068
About: Received: 26 Apr 2023 — Revised: 05 Jun 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
MOPL074
Modeling SuperKEKB backgrounds with the Belle II electromagnetic calorimeter
724
The largest current obstacle to SuperKEKB's luminosity goals is currently beam-related backgrounds occurring during accelerator operation. Thus, understanding the level of these backgrounds is of crucial importance for the future of the facility. In this work, we take advantage of the Belle II Electromagnetic Calorimeter's near-total coverage of the interaction region to create a spatial model of beam-induced backgrounds with the aim of providing fast feedback to improve accelerator conditions.
Paper: MOPL074
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL074
About: Received: 11 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPL086
On positron beam dynamics an initial part of a large aperture FCC-ee capture linac
760
The application of HTS coils as a matching device and a large-aperture L-band linac make it possible to transport a substantial part of positrons generated in a positron production target through a capture linac. It raises a question of how to manage their large phase space to provide bunches matched to the damping ring acceptance. This paper presents the beam dynamics studies of the FCC-ee positron linac consisting of an adiabatic matching device (AMD) with theoretical field distribution combined with constant solenoidal field along $\frac{9}{10}\pi$ large aperture L-band accelerating sections. AMD field drop rate, as well as the RF field phase and accelerating section length, were varied to find features of a bunch formation. It was shown that 5D normalized beam brightness is a useful parameter to optimize the initial part of the capture linac. A higher beam brightness can be obtained for the higher AMD field drop rate. Starting from some accelerating section length, two peak structure appears in the normalized brightness dependence on the RF field phase. The peaks correspond to the acceleration of the head or the tail of the initial positron longitudinal distribution. The last one provides a higher positron yield.
Paper: MOPL086
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL086
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
MOPL089
Design and optimisation of an 800 MHz 5-cell elliptical SRF cavity for T¯t working point of the future circular Electron-Positron Collider
764
The Future Circular electron-positron Collider (FCC-ee) is planned to operate with beam energies from 45.6 to 182.5 GeV and beam currents from 5 to 1400 mA. This will enable precision physics at the four operational points, Z, W and Higgs boson and the top and anti-top quarks. This work will focus on the RF structure design for the ttbar operation point to reach a beam energy and current of 182.5 GeV and 5 mA, respectively. A 5-cell elliptical SRF cavity operating at 801.58 MHz is designed and optimized with a strong focus on minimizing higher-order modes impedances.
Paper: MOPL089
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL089
About: Received: 03 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
MOPL098
Helen: Traveling wave SRF Linear Collider Higgs factory
788
Travelling wave (TW) SRF accelerating structures offer several advantages over the traditional standing wave structures: substantially lower Hpk/Eacc and lower Epk/Eacc, ratios of peak magnetic field and peak electric field to the accelerating gradient, respectively, together with substantially higher R/Q. In this paper we discuss how a linear collider Higgs factory HELEN can be built using TW-based SRF linacs. We cover a plan to address technological challenges and describe potential ways to upgrade the collider luminosity and energy.
Paper: MOPL098
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL098
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
MOPL100
Beam loading compensation of traveling wave LINAC to a multi-bunch pulse with gaps
796
In the electron-driven ILC positron source, the positron is generated a multi-bunch format with gaps, because it corresponds to a part of the damping ring fill pattern. The beam loading is compensated by amplitude modulation on the input RF (*). In this article, we derive the exact solution for the compensation with gaps. In addition, we evaluate the effect of the time constant (delay) of the input RF modulation due to klystron Q-value.
Paper: MOPL100
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL100
About: Received: 01 Apr 2023 — Revised: 10 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPL101
Design, testing, and validating the CLIC module pre-alignment and alignment systems
800
In order to produce a high luminosity at the interaction point, the Compact Linear Collider (CLIC) accelerators must preserve low emittance beams along both the main 22km linacs. A key factor in preserving a low emittance beam is the mechanical alignment and stability of the accelerator components. The CLIC accelerators are divided into `Two Beam Modules’ (TBMs) which integrate a section of the power-delivering Drive Beam and the accelerating Main Beam. The Main Beam is accelerated within Acceleration Structures that require prealignment to within 14 µm of the Metrological Reference Network (MRN). To prevent a greater than 1% luminosity loss, the vertical jitter of the accelerator components must be kept below 1.4µm RMS when the TBMs are exposed to the ground noise within the tunnel, and other sources of vibration. A design of the TBMs is presented which includes active alignment, passive prealignment, and sufficient mechanical stability to meet the specification. Finite Element Analyses (FEA) are used to demonstrate the suitability of this design. The results of the testing of prototype SAS prealignment and active TBM positioning systems are discussed and shown to meet the CLIC alignment requirements. Opportunities for future testing and areas for further optimisation are identified and discussed.
Paper: MOPL101
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL101
About: Received: 06 Apr 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
MOPL105
Orbit correction studies for the MINERVA 100 MeV proton accelerator
806
MINERVA entails the first phase of the MYRRHA programme, which aims at driving a nuclear reactor with a high-power proton accelerator, commonly referred to as an Accelerator Driven System(ADS). The purpose of MINERVA is to demonstrate the reliability requirements that are needed for a stable ADS, by the realization of a 100 MeV, 4mA proton beam. In order to transport the proton beam with minimal losses, a strategic placement and usage of orbit correctors, i.e. steering magnets, and Beam Position Monitors (BPMs) along the accelerator is paramount. With this in mind, error studies were carried out with TraceWin to determine an optimal steering strategy and put forward requirements on magnet design and alignment. In addition, orbit correction studies were performed with an in-house developed beam dynamics simulation code, PyAccel. Comparison of the results obtained with both software packages serves as an important benchmark towards future developments.
Paper: MOPL105
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL105
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPL112
MAD-NG for final focus design
818
The CLIC Beam Delivery System (BDS) transports the lepton beams from the exit of the Main Linac to the Interaction Point (IP). The Final Focus System (FFS) is the last part of the BDS and its role is to focus the beam to the required size at the IP and to cancel the chromaticity of the Final Doublet (FD). MAD-X and MAD-NG are simulation codes for beam dynamics and optics that are used for particle accelerator design and optimization. This paper presents a comparison between the two codes to achieve the best performance of the design of the FFS, including the optimization methods, the speed performance and the physics accuracy.
Paper: MOPL112
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL112
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPL118
Status of the hydrogen gas stripper at the UNILAC at GSI
826
High intensity heavy ion beams are a main constituent of the FAIR research program. They will be provided by the UNILAC via the high current injector HSI. Generated in high current sources, these ions originally have low charge states. To allow for efficient acceleration in the UNILAC and SIS18, a gas stripper is located at the end of the HSI to reduce the mass-to-charge ratio below 8.5. An effort has been made to enhance the stripping by introducing hydrogen instead of nitrogen as stripping target, thereby increasing the stripping efficiency by up to 60%. The main focus of the project is now on transforming the experimental setup into a system suitable for regular operation. In 2022 the main effort was on the finalization of the technical and safety concept, which had been thoroughly revised last year and was awaiting final risk assessment. Additionally, solutions to some details had to be left open for discussion and decision with the help of external specialists. Both objectives were achieved and the technical and safety concept was approved with some modifications. Some of the planned safety measures were found to be unnecessary, resulting in a minor reduction of complexity and cost. The risk assessment was documented and the explosion safety document, relevant for later operation, compiled. Based on the design now being approved, the residual parts necessary for the gas stripper facility may be specified and procured and will be presented in this publication.
Paper: MOPL118
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL118
About: Received: 02 May 2023 — Revised: 12 May 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
MOPL122
Design of a 10.156 MHz pre-buncher for a heavy ion RFQ
836
LEAF (Low Energy heavy ion Accelerator Facility) is a low-energy high-intensity heavy-ion LINAC complex for multidiscipline research. At present, the beam repetition rate is the same as the LINAC frequency of 81.25 MHz. A lower frequency would be desirable for many types of experiments employing time of flight data acquisitions. A method of increasing the bunch spacing to 98 ns by combining a 10.156 MHz pre-buncher before the RFQ and an RF chopper after the RFQ has been proposed. This paper reports the design studies of such a low-frequency pre-buncher. A resonator-based buncher is the best choice since lumped circuit-based buncher cannot provide the high voltage we expect for the efficient bunching of ion beams with an A/q of 7. According to the simulation result, the bunching efficiency of a 3-harmonic buncher will merely increase by 1% compared to a 2-harmonic buncher. We decide to design a two-harmonic buncher based on the little improvement in bunching efficiency. We optimize the length of electrodes so that the utilization of the parasitic field is maximized. The beam dynamics analysis indicates that the voltage amplitude and the RF power can be lowered by 1.3 times and 2.2 times by optimizing the electrode length.
Paper: MOPL122
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL122
About: Received: 25 Apr 2023 — Revised: 08 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPL125
750 MHz IH-DTL for a proton therpy linac
844
750 MHz IH-DTL with the capability to accelerate protons from 3 to 10 MeV was proposed for the compact therpy linac that now under development in IMP. Four drift tube sections were housed in a single vacuum chamber and coupled with three large drift tubes which housing focusing triplet lens inside. In each drift tube section, there were 9 to 10 drift tubes, supported by the separated ridges. This cavity will be powered by a 1 MW klystron at 0.1% duty cycle, the kp factor is about 1.7 at the operation power level. The tank is now under construction and expected to be ready for beam commissioning in the middle of 2023. The overall cavity design and the status of the power cavity are presented in this paper.
Paper: MOPL125
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL125
About: Received: 02 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
MOPL127
Status and overview of the activities on ESS DTLs
851
The Drift Tube Linac (DTL) for the ESS Linac will accelerate H+ beams of up to 62.5 mA peak current from 3.62 to 90 MeV. The structure consists of five cavities. The first cavity (DTL1, 21 MeV) has been commissioned with beam in summer 2022. DTL2, 3 and 4 are installed in the tunnel since the end of 2022, ready for the conditioning and commissioning starting in 2023. DTL5 is under assembly and will be transported to the tunnel after the completion of beam commissioning up to 74 MeV. The paper wants to give an overview of the activities already done and ongoing on the five DTLs: from assembly to tuning, from conditioning to beam commissioning.
Paper: MOPL127
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL127
About: Received: 02 May 2023 — Revised: 09 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
MOPL128
The IFMIF RFQ as a resonant combiner: equivalent circuit and operational scenarios
855
The IFMIF RFQ has to accelerate a D+ beam of 125 mA from the source energy of 100 keV to its final energy of 5 MeV. For such a purpose, the needed RF power (approximately 600 kW dissipated power and 600 kW beam power) is injected in the RFQ from 8 amplifier chains with 8 coupling loops. In order to quantitatively understand the different circumstances which can occur, an equivalent circuit of the RFQ (that can be generalized to a generic multple-feed cavity) with all the feed lines and couplers will be described, and the expressions for cavity and reflected voltages and powers will be derived. Moreover, some operational scenarios that can occur will be analyzed. In particular errors in amplitude phase and coupling of each of the 8 feed lines of the RFQ itself will be introduced. This analysis is also useful as a guideline in determining the basic architecture of the amplitude/phase controls of the cavity feeds, for a given set of amplifier amplitude/phase characteristics.
Paper: MOPL128
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL128
About: Received: 03 May 2023 — Revised: 07 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPL144
Steering to a wakefield reduced trajectory using RF kick data in the SLAC linac
880
Wakefields kick the electron bunch to a non-linear tilt causing emittance growth. Any additional correlation like an energy chirp (energy vs z dependence) will filament the disturbance further causing a nearly unrecoverable bigger emittance. For C3 (Cool Copper Collider) the emittance preservation numbers seems to be about 1000 times more stringent than achieved. It is actually "only" about 30 times trickier (square root of 1000) which is still a big number. During two-bunch setups for LCLS (Linac Coherent Light Source) it was observed that the same transverse beam offset reduced the wakefield kick and at the same time the RF kick from the most probably misaligned accelerating structure. To turn this around an RF kick can be easily measured with RF on and off, or a phase scan using a single bunch. The plan is to test this at FACET-II where the emittance growth is quite high due to a high charge. Experimental results where RF kicks are locally minimized and therefore give a better starting value for emittance tuning will be presented in a later paper.
Paper: MOPL144
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL144
About: Received: 02 May 2023 — Revised: 11 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
MOPL148
Study and simulation of cryogenic bi-periodic accelerating structure with TM02 mode
886
To further enhance the accelerating gradient of accelerators, we designed a cryogenic C-band standing wave bi-periodic accelerating structure for the Shanghai Soft X-ray Free Electron Laser Facility (SXFEL). According to the low-temperature environment, material characteristics and technological conditions, the design is completed and it is decided to design the accelerating structure into a bi-periodic magnetic coupling structure. It is a 17-cell structure consisting of 9 accelerating cavities and 8 coupling cavities. To guarantee the symmetry of the field, the structure is doubly-fed. Operating with the $\pi/2$ mode standing wave, it is much less sensitive than the standing-wave structure of $\pi$-mode. Additionally, the microwave mode is TM02 in coupling cavities that are larger and even less sensitive than the traditional bi-periodic structure. The shape of the coupling cavity can be redesigned to make it tunable.
Paper: MOPL148
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL148
About: Received: 20 Mar 2023 — Revised: 13 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPL154
Electromagnetic simulation of LANSCE chopper structure
900
An electromagnetic chopper is an important component of particle accelerators. It helps to provide users with different time structure beams. It is usually placed in the low energy beam sections of accelerators. In general, the chopper has rise and fall times of the order of a few nanoseconds. Due to this rise and fall time, post-chopper beam dynamics are affected. As part of this master thesis, the dependence of the beam parameter on the WNR chopper model (rise time, fall time, flat peak time) will be explored and CST software will be used for beam dynamics simulations.
Paper: MOPL154
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL154
About: Received: 06 May 2023 — Revised: 30 Jun 2023 — Accepted: 12 Jun 2023 — Issue date: 26 Sep 2023
MOPL162
Parameter ranges for a chain of rapid cycling synchrotrons for a muon collider complex
913
A facility for a muon collider brings the big advantages of a compact lepton collider and a collision energy up to several TeV, well above the energy reach of conventional electron circular accelerators. However, the short lifetime of muons drives the design of the accelerator complex and collider, which makes this complex unique. A high muon survival rate and luminosity requires an extremely fast energy increase in combination with intense and ultra-short bunches. The International Muon Collider Collaboration proposes a chain of rapid cycling synchrotrons (RCS) for acceleration from several tens of GeV to several TeV. The minimization of the muon decay during the acceleration process is driven by technological limitations like the maximum magnet ramp and field, and cavity gradient. We will consider different scenarios to reuse as much as possible the existing infrastructure at CERN. We will give some scaling laws for a hybrid RCS to evaluate the frequency shift due to a path variation and the trajectory variation. Finally, we will propose a preliminary parameter range for the different stages of an RCS chain.
Paper: MOPL162
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL162
About: Received: 27 Apr 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPL172
Prototyping of a disk-loaded structure for muon acceleration
933
The muon linear accelerator is under development at J-PARC for precise measurement of muon anomalous magnetic moment and electric dipole moment. Four 2592 MHz disk-loaded structures (DLSs) operating in the TM01-2pi/3 mode take charge of the acceleration of high-velocity muon from 70% to 94% of the speed of light. They have disk-iris apertures tapered to generate a quasi-constant gradient of 20 MV/m. Gradual variation in disk space at each cell is one of the structural features of the DLS for muon to synchronize the accelerating phase with the changing speed of muon. Therefore, the dimensions of both end cells are significantly different. Two prototypes of RF couplers and two 9-cell reference cavities with shapes of the end cells of the DLS at the first stage have been fabricated and tested. We validate our design RF parameters and establish a method for tuning the DLS in this paper.
Paper: MOPL172
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL172
About: Received: 03 May 2023 — Revised: 06 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
MOPL173
Development of the diagnostic beamline for muon acceleration test with APF IH-DTL
937
The muon-dedicated linear accelerator is being developed for the muon g-2/EDM experiment at J-PARC. To suppress the decay loss during acceleration, the alternative phase focusing (APF) method inter-digital H-mode drift tube linac (IH-DTL) is adopted in the low-velocity region following a radio-frequency quadrupole linac (RFQ). We are planning to accelerate muons in 2024 using the RFQ and the IH-DTL which will accelerate muons from 8% to 30% of the speed of light with an operating frequency of 324 MHz. After the IH-DTL, a diagnostic beamline will be placed to measure the beam energy and quality after acceleration, and its design, which consists of magnets and bunchers, is underway. In this poster, we will report on the development status of the diagnostic beamline.
Paper: MOPL173
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL173
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
MOPL176
Slow Extraction Techniques from Fixed Field Accelerators
945
Fixed Field Accelerators are a candidate for future hadron cancer therapy facilities as their high repetition rate and large energy acceptance enables novel treatment modalities such as high dose rate FLASH. However, conventional dose delivery mechanisms are still necessary, requiring continuous beam delivery over 1--30s. This work is the first study of slow extraction from a scaling Fixed Field Accelerator, using the LhARA facility for baseline parameters. At a horizontal tune of 10/3, the intrinsic sextupole strength of the nonlinear FFA magnetic field is sufficient to excite the resonance, although extraction is better controlled using an additional excitation sextupole at a tune close to 8/3, with radiofrequency knock-out extraction. Including considerations of issues due to nonlinear fields and limitations required to keep the tune energy-independent, slow extraction from Fixed Field Accelerators is successfully demonstrated.
Paper: MOPL176
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL176
About: Received: 31 Mar 2023 — Revised: 16 Jun 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPL177
Status of error correction studies in support of FFA@CEBAF
949
In this work, we examine the beam correction requirements for the FFA@CEBAF energy upgrade. Both hardware and software diagnostic and corrector components are under investigation; in particular the relationship between hardware and software optimization will be developed. To generate a representative sample of errors---from the machine lattice and other beam properties---we construct a Markov Chain Monte Carlo (MCMC) sampler which considers different probability distributions for different types of errors. This sample is used to investigate the statistical sensitivity of the beam to various diagnostic and corrective schema. Once statistics are acquired, we plan to use a variety of optimization techniques to minimize correction time for the electron beam in the FFA arcs designed for the CEBAF upgrade.
Paper: MOPL177
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL177
About: Received: 02 May 2023 — Revised: 07 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPL178
Short pulsed beam extraction from Kurns FFAG
952
Short pulsed proton beams of 8 ns has been extracted from FFAG accelerator in KURNS. Bunch rotation after adiabatic debunching was used at highest energy orbit.
Paper: MOPL178
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL178
About: Received: 03 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
MOPL180
Proton and electron RLA optics design
958
We describe optics designs of the key components of proton and electron Recirculating Linear Accelerators (RLAs). They are presented in the context of a high-power hadron accelerator being considered at ORNL and a CEBAF electron energy doubling study, FFA@CEBAF, being developed at Jefferson Lab. Both concepts rely on the Fixed-Field Alternating gradient (FFA) arc optics designs where multiple beam passes are transported by a single beam line.
Paper: MOPL180
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL180
About: Received: 13 May 2023 — Revised: 16 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPL182
CEBAF 22 GeV FFA energy upgrade
962
Extending the energy reach of CEBAF by increasing the number of recirculations, while using the existing linacs is explored. This energy upgrade is based on the multi-pass acceleration of electrons in a single non-scaling Fixed Field Alternating Gradient (FFA) beam line, using Halbach-style permanent magnets. Encouraged by the recent successful demonstration of CBETA, a proposal was formulated to nearly double the energy of CEBAF from 12 to 22~GeV by replacing the highest energy arcs with FFA transport. The new FFA arcs would support simultaneous transport of an additional 6 passes spanning roughly a factor of two in energy. One of the challenges of the multi-pass (11) linac optics is to assure uniform focusing over a wide range of energies. Here, we propose a triplet lattice that provides a stable periodic solution covering an energy ratio of 1:33. The current CEBAF injection at 123 MeV, makes optical matching in the first linac impossible due to the extremely high energy ratio (1:175). Replacement of the current injector with a 650 MeV recirculating injector will alleviate this issue. Orbital and optical matching from the FFA arcs to the linacs is implemented as a compact non-adiabatic insert. The design presented here is anticipated to deliver a 22 GeV beam with normalized emittance of 76 mm·mrad and a relative energy spread of 1×10^{-3}. Further recirculation beyond 22 GeV is limited by the large (974 MeV per electron) energy loss due to synchrotron radiation.
Paper: MOPL182
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL182
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPL183
Designing the spreaders and splitters for the FFA@CEBAF energy upgrade
965
The FFA@CEBAF energy upgrade study aims to approximately double the final energy of the electron beam at the Continuous Electron Beam Accelerator Facility (CEBAF). It will do this by replacing the highest-energy recirculating arcs with fixed-field alternating gradient (FFA) arcs, allowing for several more passes to circulate through the machine. This upgrade necessitates the re-design of the vertical spreader sections, which separate each pass into different recirculation arcs. Additionally, the FFA arcs will need horizontal splitter lines to correct for time of flight and R56. This work will present the current state of the spreader re-design and splitter design.
Paper: MOPL183
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL183
About: Received: 02 May 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
MOPL184
Multicell dielectric disk accelerating structure design and low power results
969
Utilizing short RF pulses ($\sim$9 ns) with Dielectric Disk Accelerators (DDA) is a way to improve the energy efficiency of a linear accelerator and decrease the required footprint while still achieving large energies. A DDA is an accelerating structure that utilizes dielectric disks to improve the shunt impedance while still achieving large accelerating gradients. A single cell clamped DDA structure was designed and high power tested at the Argonne Wakefield Accelerator, reaching an accelerating gradient of 102~MV/m. A multicell clamped DDA structure has been designed and fabricated. Simulation results for this new structure show a 108~MV/m accelerating gradient with 400~MW of input power with a high shunt impedance and group velocity. Engineering designs have been improved from the single cell structure to improve the consistency of clamping over the entire structure. The multicell structure has been fabricated, assembled, and low power tested with high power testing to come.
Paper: MOPL184
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL184
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
MOPM009
Status of the ALS-U accumulator ring installation
988
The ALS-U project is an upgrade to the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory that aims to deliver diffraction-limited x-ray beams with an increased beam brightness of two orders of magnitude for soft x-rays compared to the current ALS facility. A nine-bend achromat lattice Storage Ring (SR) and a three-bend achromat Accumulator Ring (AR) will be installed in the facility. The project has recently received federal approval to start construction for the new storage ring. The accumulator ring (AR) has received early funding and is currently being installed in the ALS facility during its regularly planned shutdowns. This paper describes the status of the accumulator ring installation.
Paper: MOPM009
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM009
About: Received: 05 May 2023 — Revised: 08 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPM024
Slow orbit feedback correction using extra-windings at the SAGA-LS
1035
The periodic orbit change caused by the temperature fluctuation of the cooling water at the SAGA-LS storage ring was suppressed by the slow orbit feedback correction system using newly equipped extra-windings on 8 steering magnets. In recent years, the amplitude growth of temperature fluctuation of the cooling water caused maximally 40 micrometer periodic orbit change at the SAGA-LS storage ring, which affected some synchrotron radiation experiments. We equipped new extra-windings on 8 steering magnets to compensate the periodic orbit change, since the existing steering magnets for global orbit correction did not provide sufficient resolution for this small orbit change. By applying the slow orbit feedback correction system using the extra-windings, the periodic orbit change was suppressed satisfactorily. In this conference, we will also discuss about the mechanism by which the temperature fluctuation of the cooling water causes the orbit change at the SAGA-LS storage ring.
Paper: MOPM024
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM024
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPM028
Upgrades of beam diagnostics for linac of Siam Photon Source
1046
Siam Photon Source (SPS) is an existing synchrotron light source in Thailand, which has been operated and provided synchrotron radiation for user beam service for more than 20 years. The SPS accelerator system con-sists of a 40-MeV linac, a 1.2-GeV booster synchrotron and a storage ring with double bend achromat (DBA) lattice. The linac is one of the most critical parts of the SPS machine in which its performance affects beam injection and hence to the beam service. Beam diagnostics of the SPS linac has been upgraded in order to allow better beam monitoring and become a crucial part for linac optimization to achieve higher machine performance. In this paper, upgrades of beam diagnostics of the SPS linac will be discussed.
Paper: MOPM028
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM028
About: Received: 02 May 2023 — Revised: 19 May 2023 — Accepted: 19 May 2023 — Issue date: 26 Sep 2023
MOPM045
Development of single mode cavity at 1.5 GHz for the third harmonic RF-system in PETRA IV
1091
The PETRA IV storage ring currently under development at DESY will require a third harmonic 1.5 GHz RF-system to prevent negative effects on both, lifetime and emittance, caused by Touschek effect and Intrabeam scattering. These cavities lengthen the bunches and thereby reduce their charge density. For this 3rd harmonic system, a one-cell single-mode cavity with a simple mechanical and electrical structure is under design that should also reduce Higher Order Modes (HOMs) to a quality factor less than 100. Therefore, the well-known approach of the Choke Mode Cavity was chosen, that use a radial line damper to attenuate the HOMs and a radial choke that traps the acceleration mode. The general behaviour of the choke mode structure was simulated, discussed and optimized for the requirements of a one-cell cavity with high effective shunt impedance, high-quality factor and simple manufacturing.
Paper: MOPM045
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM045
About: Received: 28 Apr 2023 — Revised: 16 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPM051
Broad band impedance effects on Elettra 2.0
1110
Due to the reduced diameters of the vacuum chambers and of the other equipment, the performance of the next generation light sources can be greatly affected resulting in a reduction of the intensity in both single and multi-bunch operations. This is particularly important for Elettra 2.0 since there are plans to incorporate bunch compression schemes for providing very short photon pulses. In this study, the resistive wall and single bunch instabilities are investigated by tracking in order to define their thresholds.
Paper: MOPM051
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM051
About: Received: 23 Apr 2023 — Revised: 11 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
MOPM108
A THz superconducting undulator for flute - Design parameters and layout
1226
The far-infrared linac and test experiment (FLUTE) serves as an accelerator test facility for a variety of accelerator physics studies. FLUTE is foreseen to provide coherent radiation in ultra-short, very intense light pulses in the terahertz (THz) and far-infrared spectral range. A superconducting undulator in the accelerator structure after bunch compression offers the possibility to generate high-energy, pulsed radiation between 4 THz and 12 THz corresponding to photon energies between 16.5 meV and 50 meV. This energy range, for instance, is of high interest for interaction and reaction studies of liquids, especially in water, and thus for materials and medical research. In this contribution we describe the specific design parameters and the general layout of the THz superconducting undulator to reach the envisioned scientific goals.
Paper: MOPM108
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM108
About: Received: 05 May 2023 — Revised: 08 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPM138
Assembly, alignment and tuning of the XiPAF DTL
1284
A 7 MeV Alvarez-type drift tube linac (DTL) had been designed and machined in the past few years for Xi'an 200 MeV proton application facility (XiPAF). This paper presents the assembly, alignment, error analysis and tuning results of the DTL. After all these tasks were completed at Tsinghua University, the DTL cavity had been transported to Xi'an for repetition measurement and test. It has been aligned on the beamline for RF conditioning and beam commissioning.
Paper: MOPM138
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM138
About: Received: 05 May 2023 — Revised: 23 Jun 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
MOPM140
X-band electron linear accelerator design for intraoperative radiotherapy
1288
In intraoperative radiation therapy (IORT), accelerators typically consist of two or more tubes to achieve adjusta-ble electron energy. To simplify the accelerator structure and meet the demand for convenient adjustment of elec-tron energy, we propose an X-band electron linear accel-erator for IORT, composed of 102 cavities. This accelera-tor can adjust the output electron energy over a large range solely by varying the input power, providing elec-trons with energy exceeding 13MeV at maximum and approximately 5.5MeV at minimum, which satisfies the requirements of electron IORT. We also measured the field distribution and S-parameters at low power, and the ener-gy spectrum distribution also was measured at different input powers. This accelerator design provides a feasible and simple solution for IORT-specific accelerators.
Paper: MOPM140
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM140
About: Received: 30 Apr 2023 — Revised: 07 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
TUODA3
New techniques for the LNL superconductive linac ALPI beam dynamics simulations and commissioning
1307
The superconductive quarter wave cavities hadron Linac ALPI is the final acceleration stage at the Legnaro National Laboratories. It can accelerate heavy ions from carbon to uranium up to 10 MeV/u for nuclear and applied physics experiments. It is also planned to use it for re-acceleration of the radioactive ion beams for the SPES (Selective Production of Exotic Species) project. The linac was designed in 90’ with the available techniques and it was one of the peak technologies of this kind in Europe at those times. However, the improvements on the cavity fields increased the real-estate gain and the energy output, at the price of lattice periodicity and non-linear RF defocusing. This fact turned out to be troublesome for the operations and delayed the nominal transmission achievement. In this paper we will present the innovative results obtained with swarm intelligence algorithms, in simulations and commissioning. In particular, the increment of the longitudinal acceptance for RIB (Radioactive Ion Beams) acceleration, managing 84 independent cavity phases, and beam orbit correction without the beam first order measurements will be discussed.
Paper: TUODA3
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUODA3
About: Received: 03 May 2023 — Revised: 20 Jun 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUOGA2
Laser cooling taken to the extreme: cold relativistic intense beams of highly-charged heavy ions
1314
Recent storage ring experiments have demonstrated the power and the potential of laser cooling of bunched relativistic ion beams. Encouraged by this, the heavy-ion synchrotron SIS100 at FAIR (Darmstadt, Germany) will be equipped with a truly unique laser cooling facility. A sophisticated combination of 3 newly developed UV (257 nm) laser systems and modest rf-bunching will allow for fast cooling of injected intense heavy-ion beams. There will be two powerful pulsed laser systems with MHz repetition rates and variable pulse duration (1-50 ps and 50-740 ps) and one powerful tunable cw laser system. The picosecond laser pulses are broad in frequency and will enable fast cooling of injected ion beams with a large initial longitudinal momentum spread. The cw laser can be rapidly tuned over a large frequency range and has high spectral power density, forcing the ion beams to remain cold during storage. This combination of 3 UV laser beams should be up to the challenge of suppressing intra-beam scattering and space charge effects. We will present new experimental results from the ESR storage ring and the status of the SIS100 laser cooling facility.
Paper: TUOGA2
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUOGA2
About: Received: 02 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
TUOGA3
Experimental measuremnet of quadrupole beam oscillating frequency at CSNS RCS
1319
In high intensity proton synchrotrons, space charges effects will cause tune shift of the beam. When the betatron tune spreads over a resonance line, the betatron oscillation amplitude will get larger, causing large beam loss. Through the quadrupolar beam transfer function, the coherent space-charge tune shift of quadrupolar beam oscillations can be derived with quadrupole oscillating frequency. China Spallation Neutron Source (CSNS) is a high intensity accelerator based facility consists of linear accelerator and the Rapid Cycle Synchrotron (RCS). A quadrupolar BPM is already installed at RCS for obtaining quadrupolar beam oscillating information this year. This paper will present the experimental data during accelerator commissioning and how to obtain the quadrupole beam oscillating frequency on CSNS/RCS.
Paper: TUOGA3
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUOGA3
About: Received: 03 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
TUODB1
Recent experimental results from the dielectric wakefield acceleration program at CLARA facility
1328
Dielectric wakefield acceleration (DWA) is a high gradient novel acceleration concept. To realise this concept for future high energy facilities, scalable models of the transverse and longitudinal beam dynamics from these wakefields must be created and experimentally verified. We present a summary of results from the recent experimental run at the CLARA facility. This study used both circular and planar quartz DWA structures and was performed with 100 pC bunch charge and 35 MeV beam energy. The effect of dipole-like and quadrupole-like wakefields from both structures were studied in detail for a variety of beam distributions. These results were used for the benchmarking a highly scalable simulation code which was developed in-house.
Paper: TUODB1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUODB1
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
TUODB2
Dielectric laser acceleration for dark sector studies
1332
For the purpose of indirect search of dark matter, we designed laterally driven Dielectric Laser Acceleration (DLA) structure that achieves 1.2 MeV energy gain in 6 mm length together with 6D confinement. The design originated from a relativistic DLA structure and was supplemented with non-homogeneous shapes following the APF segments and optimized using a genetic algorithm together with the DLAtrack6D tracker. The achieved throughput could be increased to 98%.
Paper: TUODB2
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUODB2
About: Received: 03 May 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
TUODC2
Fabrication, conditioning, installation and commissioning with the beam of the first High Gradient (HG) module for the FERMI linac upgrade
1347
FERMI is the seeded Free Electron Laser (FEL) user facility at Elettra laboratory in Trieste, operating in the VUV to soft X-rays spectral range. In order to extend the FEL spectral range to shorter wavelengths, an upgrade plan for increasing the Linac energy from 1.5 GeV to 2.0 GeV is actually going on. After the successful testing of the short prototype of the new high gradient (HG) S-band accelerating structure up to an accelerating gradient of 40 MV/m, two full-length 3.0 m HG structures have been built and installed at the FERMI linac. In this paper, we report the low power measurement, conditioning results, and commissioning with the beam of the first HG module.
Paper: TUODC2
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUODC2
About: Received: 28 Apr 2023 — Revised: 05 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
TUPA001
Copper surface treatment with deep UV ultrafast laser for improved photocathode photoemissive properties
1350
Surface nanostructuring is a promising approach when it comes to improving the quantum efficiency (QE) of materials for electron accelerator purposes at CERN. This is due to the plasmonic effect taking place in metallic materials at the nanoscale, when an electromagnetic wave interacts with a sub-wavelength feature. Ultrafast laser surface nanopatterning can be an efficient and times saving method for producing such nanostructures. We conducted a study of nanostructuring of copper surfaces with a deep-UV femtosecond laser. A wide range of fabrication parameters (speed, laser fluence and repetition rate) were tested. At different energy regimes we were able to produce Laser Induced Periodic Surface Structures (LIPSS), as well as spherical nanoparticles of tunable size and other types of periodic nanoscale features. Sub-wavelength periodic structures yield higher exaltation of surface plasmons under matching excitation wavelength, resulting in a potentially significant increase in QE of copper photocathodes. Moreover, by using the same laser source for nanomachining and photoemission, one can easily integrate the technology in and existing photoinjector.
Paper: TUPA001
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA001
About: Received: 13 May 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
TUPA006
Activities at INFN LASA on ESS Medium Beta Cavities
1362
To complete the Italian In-Kind contribution to the ESS SRF Linac, we are working on the qualification of the last eight missing cavities. To achieve this, we are proceeding with reprocessing of not yet qualified cavities and, as a mitigation, we are constructing at the vendor four more cavities. In this paper, we report on the actual status of both of these activities with the most recent results.
Paper: TUPA006
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA006
About: Received: 03 May 2023 — Revised: 07 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
TUPA032
Copper photocathodes for the modified 10 Hz gun on the CLARA accelerator
1408
During the last run, the CLARA accelerator* ran with a 2.5 cell 10 Hz S-band RF gun which had a modified back plate to allow the use of INFN-style photocathode pucks. Previously this gun had used a solid wall back plate that also acted as the photocathode**. This presentation describes the different photocathodes that were used during the run and the various methods employed to prepare them for use. An initial cathode which was based on a solid Mo puck with the thin film of Cu grown using magnetron sputtering was seen to give high initial QE but a very fast degradation rate. Subsequent cathodes were hybrids with a Mo body and a solid copper tip for the active area. Several cathodes prepared using alternative techniques were employed, giving varied initial QE and lifetime. The final cathode used had satisfactory QE and a long enough lifetime to deliver a six month period of beam exploitation for external facility users. * D. Angal-Kalinin, et al, ‘Design, specifications, and first beam measurements of the compact linear accelerator for research and applications front end’ Physical Review Accelerators and Beams 23 (2020) 044801 ** T.C.Q. Noakes, et al, ‘Photocathode preparation and characteristics of the electron source for the VELA/CLARA facility’ Proceedings of the International Particle Accelerator Conference 2018 (IPAC-18), THPMK063, 2018, Vancouver, Canada
Paper: TUPA032
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA032
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
TUPA040
Longitudinal beam dynamics and RF requirements for a chain of muon RCSs
1428
A facility for the collision of muons offers a unique path to a compact lepton collider with an energy reach in the multi-TeV regime, well beyond the possibilities of conventional electron accelerators. However, due to the short lifetime of muons, the constraints for acceleration and collisions are very different. An extremely fast energy increase in combination with intense and ultra-short bunches is essential for a high muon survival rate and luminosity. A chain of rapid cycling synchrotrons (RCS) for acceleration from around 60 GeV to several TeV is proposed by the International Muon Collider Collaboration. We study the longitudinal beam dynamics and radio-frequency (RF) requirements for these RCSs with respect to induced voltages from intensity effects. A high synchrotron tune due to the large RF voltages is a particular challenge. We present simulation results of the longitudinal bunch distribution to determine the number of RF stations distributed over the RCS to mitigate that large tune. The impact of the induced voltages from short-range wakefields and single- as well as multi-turn beam loading is analyzed, for both fundamental and higher-order modes.
Paper: TUPA040
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA040
About: Received: 28 Apr 2023 — Revised: 11 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPA043
An electron model of vertical FFA accelerator for Harmonytron
1434
A new type of accelerator called Harmonytron has been proposed. The Harmonytron is based on a scheme of vertical Fixed-Field Alternating gradient (vFFA) focusing with harmonic number jump beam acceleration. An electron model of vFFA accelerator is under development at Kyushu University. The current status of the vFFA accelerator will be discussed.
Paper: TUPA043
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA043
About: Received: 02 May 2023 — Revised: 15 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPA044
FFA design study for a high intensity proton driver
1437
As an option for the proton driver for the next generation spallation neutron source (ISIS-II) at the Rutherford Appleton Laboratory (RAL), a Fixed Field Alternating Gradient Accelerator (FFA) is being considered. A prototype accelerator has been designed, referred to as FETS-FFA, to demonstrate flexible handling of beam repetition for users and high intensity operation with minimum beam loss. FETS-FFA takes the 3 MeV beams from RAL's Front End Test Stand (FETS) linac and accelerates them to 12 MeV. FD spiral optics have been adopted as the basic focusing structure, which allows the operating point to be chosen along the diagonal in tune space. Flexible beam repetition will be demonstrated by RF beam stacking at the extraction energy, which enables users to choose different (lower) repetition rates independent of the acceleration cycle. For high intensity beam study, several schemes of injection painting are being considered. At the injection energy, the space charge tune shift can be easily exceed -0.3. This paper discusses the overall design, while further details of each aspect of the accelerator, including hardware, are presented in separate conference papers.
Paper: TUPA044
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA044
About: Received: 02 May 2023 — Revised: 05 Jun 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
TUPA045
High-energy single-cycle terahertz sources for compact particle accelerators and manipulators
1440
Novel accelerator concepts such as all-optical terahertz (THz) based compact accelerators demand high-power THz sources that are robust in order to enable reliable testing. THz sources based on the tilted-pulse front scheme have become the method of choice for table-top, high-energy, single-cycle (SC) THz generation due to both their versatility and scalability. However, due to the noncollinear interaction geometry, fine-tuning of the performance and tailoring of the THz beam properties requires a detailed understanding of the dependences on the setup parameters. Here, we present on the use of multi-dimensional parameter scans to systematically map out sensitivities of such THz sources on the primary interaction parameters and show experimental characterization of a robust, high-energy, single-cycle THz source designed and constructed based on these findings. This setup delivers pulses centered at 300 GHz with pulse energies exceeding 400 µJ at 52 Hz repetition rate and a shot-to-shot rms stability < 3.8%. Such robust, high-energy THz sources are crucial for the development of next generation THz-driven particle accelerators and manipulators.
Paper: TUPA045
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA045
About: Received: 10 May 2023 — Revised: 10 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
TUPA047
3D polarisation of a structured laser beam and prospects for its application to charged particle acceleration
1443
A Structured Laser Beam (SLB) is a type of optical beam with spatially inhomogeneous 3D polarisation structures. Generating SLBs from vector beams allows the creation of Hollow Structured Laser Beams (HSLB) with a dark central core. In this way, atypical electric and magnetic field vectors, which are purely longitudinally polarized in the dark zones of the beam, are obtained. The SLB spatial distribution can also include regions with both the electric and magnetic fields longitudinally polarized and oriented in the same or opposite directions. The SLB has a transverse distribution similar to that of a Bessel beam but can theoretically propagate to infinity, therefore giving the potential to generate strong, longitudinally oriented electric fields over long distances, which could possibly allow the acceleration of charged particles. The results of the study of this phenomenon, including simulations of the spatial distribution of the electromagnetic field components, are presented in this paper.
Paper: TUPA047
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA047
About: Received: 10 May 2023 — Revised: 11 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUPA049
Design of an E x B chopper based on permanent magnets
1446
Chopper systems are typically used to provide beam time structure and ensure the safety of accelerator operations by deflecting the beam away. The reliability of conventional chopper is entirely based on high-voltage (HV) pulsed power supplies, and when it fails to charge the electrostatic deflection plate, the beam cannot be cut off and will enters the downstream accelerator. To meet the strict beam stopping time requirements of the China Initiative Accelerator Driven System (CiADS), improvements in safety are necessary. To address this issue, a novel E × B chopper has been physically designed, which is based on a permanent magnet and an electrostatic deflection plate. This design ensures the safety of the accelerator while providing the necessary pulse waveform. The device is small and highly reliable, making it suitable for use in most accelerators. The device is small and highly reliable, making it suitable for use in most accelerators. Moreover, beam dynamics simulations of the chopper have been conducted to determine its influence on beam quality, and beam cutting capability analysis has been performed.
Paper: TUPA049
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA049
About: Received: 03 May 2023 — Revised: 25 May 2023 — Accepted: 25 May 2023 — Issue date: 26 Sep 2023
TUPA052
Driver-witness configuration in CNT array-based acceleration
1457
Solid-state plasma wakefield acceleration might be an alternative to accelerate particles with ultra-high accelerating gradients, in the order of TV/m. In addition, due to their thermodynamic properties, 2D carbon-based materials, such as graphene layers and/or carbon nanotubes (CNT) are good candidates to be used as the media to sustain such ultra-high gradients. In particular, due to their cylindrical symmetry, multi-nm-aperture targets, made of CNT bundles or arrays may facilitate particle channelling through the crystalline structure. In this work, a two-bunch, driver-and-witness configuration is proposed to demonstrate the potential to achieve particle acceleration as the bunches propagate along a CNT-array structure. Particle-in-cell simulations have been performed using the VSIM code in a 2D Cartesian geometry to study the acceleration of the second (witness) bunch caused by the wakefield driven by the first (driver) bunch. The effective plasma-density approach was adopted to estimate the wakefield wavelength, which was used to identify the ideal separation between the two bunches, aiming to optimize the witness-bunch acceleration and focusing. Simulation results show the high acceleration gradient obtained, and the energy transfer from the driver to the witness bunch.
Paper: TUPA052
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA052
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
TUPA059
Study of the transfer and matching line for a PWFA-driven FEL
1461
The development of compact accelerator facilities providing high-brightness beams is one of the most challenging tasks in the field of next-generation compact and cost affordable particle accelerators. Recent results obtained at SPARC_LAB show evidence of the FEL laser by a compact (3 cm) particle beam plasma accelerator. This work is carried out in the framework of the SPARC_LAB activities concerning the R&D on particle-driven plasma wakefield accelerators for the realization of new compact plasma based facilities i.e EuPRAXIA@SPARC_LAB. The work here presented is a theoretical study demonstrating a possible scheme concerning the implementation of an innovative array of discharge capillaries, operating as active-plasma lenses, and one collimator to build an unconventional transport line for bunches outgoing from plasma accelerating module. Taking advantage of the symmetric and linear focusing provided by an active-plasma lens, the witness is captured and transported along the array without affecting its quality at the exit of the plasma module. At the same time the driver, being over-focused in the same array, can be removed by means of a collimator.
Paper: TUPA059
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA059
About: Received: 03 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
TUPA060
Laser source and Gabor lens for use within LhARA
1465
The ‘Laser-hybrid Accelerator for Radiobiological Applications’, LhARA*, facility is conceived to study the biological response to ionising radiation, specifically focussing upon the co-called ‘FLASH’ (>40 Gy/min) regime. A high repetition laser, directed at a thin target, will generate high intensity, ultra-short, particle bunches, at up to 15 MeV/u (and subsequent acceleration up to 127 MeV/u, as required). These particles will be guided to one of several end-stations, whereby the effects can be studied via in-vitro or in-vivo experiments using newly developed detectors, existing phantoms, and test samples. The laser driven ion source and capture systems are key technologies for LhARA. We will discuss ongoing R&D into delivery of a laser driven ion source with the required beam parameters, stability and repetition rate. Following the idea originally outlined by Gabor**, the current plan and status of using large volume, high-density, low-temperature, non-neutral plasmas as beam optics within the capture system will also be presented.
Paper: TUPA060
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA060
About: Received: 12 May 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
TUPA061
TWAC : EIC Pathfinder Open European project on Novel dielectric acceleration
1468
Particle accelerators are devices of primary importance in a large range of applications such as fundamental particle physics, nuclear physics, light sources, imaging, neutron sources, and transmutation of nuclear waste. They are also used every day for cargo inspection, medical diagnostics, and radiotherapy worldwide. Electron is the easiest particle to produce and manipulate, resulting in unequaled energy over cost ratio. However, there is an urgent and growing need to reduce the footprint of accelerators in order to lower their cost and environmental impact, from the future high-energy colliders to the portable relativistic electron source for industrial and societal applications. The radical new vision we propose will revolutionize the use of accelerators in terms of footprint, beam time delivery, and electron beam properties (stability, reproducibility, monochromaticity, femtosecond-scale bunch duration), which is today only a dream for a wide range of users. We propose developing a new structure sustaining the accelerating wave pushing up the particle energy, which will enable democratizing the access to femtosecond-scale electron bunch for ultrafast phenomena studies. This light and compact accelerator, for which we propose breaking through the current technological barriers, will open the way toward compact accelerators with an energy gain gradient of more than 100 MeV/m and enlarge time access in the medical environment (preclinical and clinical phase studies).
Paper: TUPA061
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA061
About: Received: 05 May 2023 — Revised: 19 May 2023 — Accepted: 19 May 2023 — Issue date: 26 Sep 2023
TUPA062
Cyclotron resonance accelerator for electron beams
1472
Abstract: Electron Cyclotron Resonance Accelerator (eCRA) simulation results are presented for realistic TE111 cavity geometry and finite space-charge beams that confirm the single-particle idealized solutions. The simulations include cavity openings for RF inputs, beam injection, and pumping; RF input couplings that maximize efficiency; a thin window for exit of the accelerated beam; realistic magnetic field profiles; finite diameter multi-Ampere beams. One simulated example is for a copper cavity with Q0 of about 19,000, with RF input power at each port of 12.5 MW, an 8.0-A, 100 keV beam was found to be accelerated to 2.2 MeV, for a pulsed beam power of 17.6 MW at an efficiency of 67%. A wide variety of applications can be envisioned for MW-class eCRA beams with energies in the range 1-10 MeV. Our first proof-of-principle demonstration of eCRA is to provide beams to generate intense X-ray fluxes to enable the replacement of radioactive sources now widely used for sterilization of medical supplies and foodstuffs. This demonstration will be based on use of available S-band components, although the optimal operating frequency for eCRA could be about 1000 MHz. In any case, the possibility of MW-level average power eCRA beams—even with predicted efficiencies >80%--will depend upon the availability of the required RF sources to drive eCRA.
Paper: TUPA062
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA062
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUPA066
Hydrodynamic model for particle beam-driven wakefield in carbon nanotubes
1480
Charged particles moving through a carbon nanotube may be used to excite electromagnetic modes in the electron gas produced in the cylindrical graphene shell that makes up a nanotube wall. This effect has recently been proposed as a potential novel method of short-wavelength-high-gradient particle acceleration. In this contribution, the existing theory based on a linearised hydrodynamic model for a localised point-charge propagating in a single wall nanotube (SWNT) is reviewed. In this model, the electron gas is treated as a plasma with additional contributions to the fluid momentum equation from specific solid-state properties of the gas. The governing set of differential equations is formed by the continuity and momentum equations for the involved species. These equations are then coupled by Maxwell’s equations. The differential equation system is solved applying a modified Fourier-Bessel transform. An analysis has been realised to determine the plasma modes able to excite a longitudinal electrical wakefield component in the SWNT to accelerate test charges. Numerical results are obtained showing the influence of the damping factor, the velocity of the driver, the nanotube radius, and the particle position on the excited wakefields. A discussion is presented on the suitability and possible limitations of using this method for modelling CNT-based particle acceleration.
Paper: TUPA066
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA066
About: Received: 07 May 2023 — Revised: 16 Jun 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
TUPA070
MeV-scale simulations and fabrication tests of woodpile-based waveguide for dielectric laser accelerators
1484
Hollow-core dielectric Electromagnetic Band Gap (EBG) microstructures powered by lasers represent a new and promising area of accelerator research since, thanks to the short optical wavelength and to the dielectric's high damage threshold greater accelerating gradients, with respect to the metallic counterparts, can be achieved. In this paper, we present MeV-scale beam-dynamics simulations and fabrication results relative to a silicon, woodpile-based travelling-wave structure operating at the wavelength 𝜆0 = 5 μm. The simulated CST and HFSS electric field has been evaluated and used as input for a space charge tracking code, in order to perform beam-dynamics evaluations on the beam injection and extraction into the proposed structure as well as the evolution of the main beam parameters. We also report on the fabrication of first Si prototypes of the woodpile structure that are obtained by the innovative Two Photon Polymerization fabrication process. This technique allows to reach resolutions down to hundreds of nanometers, offering the possibility to print Si-rich structures, or woodpile skeletons to be infiltrated with Si by CVD technique.
Paper: TUPA070
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA070
About: Received: 28 Apr 2023 — Revised: 11 May 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
TUPA071
Simulation of tapered co-propagating structures for dielectric laser accelerator
1488
One of the key aspects to provide on chip acceleration in Dielectric Laser Accelerators (DLA) from tens of keV up to MeV energies is the phase velocity tapering. This paper presents the simulated performance of sub-relativistic structures, based on tapered slot waveguides. We engineered channel/defect modification in order to obtain a variable phase velocity matched to the increasing velocity of the accelerated particles. Additionally, we present a hollow-core relativistic electromagnetic band gap (EGB) accelerating waveguide. In DLA structures co-propagating schemes are employed for higher efficiency and smaller footprint compared to the cross-propagating schemes. In this respect, we envisage tapered continuous copropagating structures that simultaneously allow wave launching/coupling, beam acceleration, and transverse focusing. The main figures of merit, such as the accelerating gradient, the total energy gain, and the transverse focusing/defocusing forces, are evaluated and used to guide the optimization of the channel/defect modification. Index terms: Dielectric Laser Accelerators (DLA), Photonic Crystal, Dielectric Waveguides
Paper: TUPA071
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA071
About: Received: 04 May 2023 — Revised: 09 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
TUPA075
A w-band corrugated waveguide for wakefield acceleration at the AWA emittance exchange beamline
1492
High gradient radio-frequency structures are of considerable interest in ongoing structure wakefield acceleration research. The prospect of economical accelerators with a small footprint in the sub-terahertz regime shows promise in achieving high gradient and high efficiency, and in that vein, we present a design for a metallic corrugated waveguide designed at 110 GHz. This W-band structure has been optimized in the CST Studio Suite for the maximum achievable gradient of 84.6 MV/m from a nominal Argonne Wakefield Accelerator (AWA) electron bunch at 65 MeV, with a charge of 10 nC and an RMS length of 0.5 mm. When the developed structure is excited with a shaped electron bunch, higher gradient and longer beam propagation distance could be achieved. Simulations are ongoing to test the effects of bunch shaping on the structure's performance, and structure fabrication and cold tests are underway in preparation for a collinear wakefield acceleration experiment at AWA.
Paper: TUPA075
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA075
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPA076
Design and test of a metamaterial accelerating structure for Wakefield acceleration
1496
Structure-based wakefield acceleration with nanosecond-long RF pulses is a promising advanced accelerator concept to mitigate the risks of RF breakdown. Advanced structures are required to satisfy the need of a high transient gradient with a short pulse length. A metamaterial (MTM) structure, as a subwavelength periodic structure exhibiting a negative group velocity, could have a higher shunt impedance, thus a higher gradient, compared to structures with the same but positive group velocities. An X-band ‘wagon wheel’ structure has been designed and tested as an accelerating structure for two-beam acceleration. Up to 200 MV/m of gradient has been achieved with an input power extracted from the 65 MeV drive beam at AWA, with a peak power of 115 MW, and a pulse length of 6 ns (FWHM). Evidence has been found towards a new accelerating regime, the breakdown insensitive accelerating regime (BIAR), where breakdown was only observed in the secondary pulse of the transmitted RF signal while the primary pulse (useful for acceleration) was not interrupted. This experiment could lead to high-gradient wakefield acceleration and new knowledge in the breakdown physics in the short-pulse regime.
Paper: TUPA076
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA076
About: Received: 03 May 2023 — Revised: 19 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUPA077
Design and modeling of dielectric a wakefield accelerator with plasma ionized witness bunch
1499
A planned experiment at the Argonne Wakefield Accelerator (AWA) facility will demonstrate the plasma photocathode concept, wherein precise laser-based ionization of neutral gas within the wakefield driven by a relativistic particle beam generates a high brightness witness beam, which is accelerated in the wakefield. Replacing the plasma wakefield acceleration component with a dielectric wakefield acceleration scheme can simplify experimental realization by relaxing requirements on synchronization and alignment at the expense of accelerating gradient. However, this places rigorous constraints on drive beam dynamics, specifically charge, size, and relative separation. This paper presents progress on the design of such a hybrid scheme, including improved simulations accounting for anticipated beam properties and revised structure characteristics.
Paper: TUPA077
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA077
About: Received: 04 May 2023 — Revised: 19 May 2023 — Accepted: 19 May 2023 — Issue date: 26 Sep 2023
TUPA080
Demonstration of transverse stability in an alternating symmetry planar dielectric structure
1502
Dielectric wakefield acceleration (DWA) is a promising approach to particle acceleration, offering high gradients and compact sizes. However, beam instabilities can limit its effectiveness. In this work, we present the result of a DWA design that uses alternating gradients to counteract quadrupole-mode induced instabilities in the drive beam. Through simulation and experimental results, we show that this approach is effective at suppressing beam breakup, allowing for longer accelerating structures. We have designed and fabricated a new apparatus for positioning the DWA components in our setup. This allows us to precisely and independently control the gap in both transverse dimensions and consequently the strength of the destabilizing fields. Our results show that the use of alternating gradient structures in DWA can significantly improve its performance, offering a promising path forward for high-gradient particle acceleration.
Paper: TUPA080
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA080
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPA089
EARLI: design of a laser wakefield accelerator for AWAKE
1529
Following the successful Run 1 experiment, AWAKE has developed a program for Run2 that requires designing and implementing a compact electron source (150 MeV, >= 100 pC) for external injection. The baseline design uses a S- and X-band RF photo-injector gun system. The project EARLI investigates the feasibility of an alternative electron source system using a laser wakefield accelerator (LWFA) to produce this electron bunch. Currently, the EARLI project is in the design phase backed by the preparation of experimental demonstrations to prove the feasibility of this accelerator. The main originality of the chosen approach is that the focus is made exclusively on the final beam-targeted characteristics and the reliability and repeatability of the beam quality. EARLI is a stand-alone injector that consists of three main parts: a laser system, a plasma cell and a transfer line, at the end of which the electron beam is injected in a plasma wave driven by a self-modulated proton bunch. Methods from conventional accelerators are applied to LWFA physics. Each part requires specific expertise, that must be investigated in close coupling with the others. A massive campaign of simulations and optimizations with PIC codes is ongoing while the design of the transfer line, the plasma chamber, diagnostics and the laser are carried out in parallel.
Paper: TUPA089
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA089
About: Received: 08 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
TUPA093
Efficient simulation of multistage plasma accelerators
1533
Plasma accelerators can sustain accelerating gradients of up to ~100 GeV/m. However, reaching the high energies required for future particle colliders requires the acceleration to be performed in multiple plasma stages. Solving the challenges posed by multistage acceleration, such a beam quality preservation, requires the capability of simulating large chains of accelerating stages, something that is typically limited by the high cost of full 3D particle-in-cell codes. Thus, there is a growing need for the development of more efficient models that allow for inexpensive collider studies with reduced physics or dimensionality. Here, we present the implementation of a novel gridless quasistatic algorithm in the Wake-T code that, coupled with a laser envelope solver, allows for accurate and efficient simulations of multistage laser-plasma accelerators with axial symmetry, a critical step toward their realization.
Paper: TUPA093
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA093
About: Received: 03 May 2023 — Revised: 19 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
TUPA097
Characterization of plasma-discharge capillaries for plasma-based particle acceleration
1545
Novel particle accelerators based on plasma technology allow a drastic reduction in size, due to the high accelerating field established inside plasmas, which are created and confined by specific devices. Plasma Wakefield Acceleration experiments are performed at the SPARC_LAB test facility (Laboratori Nazionali di Frascati - INFN) by using gas-filled capillaries, in which the plasma formation is achieved by ionizing hydrogen gas through high voltage pulses. In this work, the characterization of gas-filled plasma-discharge capillaries is presented. Several geometrical configurations are tested, including capillaries with different channel shapes and arrangement of inlets positions for the gas injection. Such configurations are designed in order to enhance the uniformity of the plasma density distribution along the plasma channel, which is necessary to improve particle beam acceleration. Plasma sources are characterized by means of the spectroscopic technique based on the Stark broadening method, which allows to measure the evolution of the plasma density profile along the channel. In addition, the CFD software OpenFoam is used to simulate the dynamics of the neutral gas during the filling of the capillary.
Paper: TUPA097
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA097
About: Received: 06 May 2023 — Revised: 08 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
TUPA104
Status and first results from FACET-II towards the demonstration of plasma wakefield acceleration, coherent radiation generation, and probing strong-field QED
1549
FACET-II is a National User Facility at SLAC National Accelerator Laboratory with the goal to develop advanced acceleration and coherent radiation techniques using a 10 GeV electron beam of unprecedented beam intensity with >100 kA peak current and <10 µm spot size, a 10 TW experimental laser system, and a variety of solid, gas and plasma targets. A diverse experimental program will investigate beam-driven plasma wakefield acceleration (PWFA), injection, and control with the aim of demonstrating efficient multi-GeV/m PWFA while preserving emittance and narrow energy spread – as is required to reach the beam parameters for a future linear collider. Complimentary research programs into the application of machine learning for accelerator diagnostics and control, novel techniques for the generation of intense coherent radiation, and probing strong-field quantum electrodynamics (QED) also make use of the facility’s unique beam intensity and laser capabilities. The first year of beam delivery to experiments has focused on user assisted commissioning of beam delivery and experimental systems, including a novel EOS BPM with 10 fs bunch length and 5 µm transverse resolution. This contribution will describe the status of the facility, experimental systems, and novel diagnostics, in addition to reviewing the first scientific developments from User programs including initial progress towards beam-driven PWFA.
Paper: TUPA104
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA104
About: Received: 07 May 2023 — Revised: 14 Jun 2023 — Accepted: 14 Jun 2023 — Issue date: 26 Sep 2023
TUPA106
Machine learning-based reconstruction of electron radiation spectra
1557
The photon flux resulting from a high energy electron beam's interaction with a target, such as in the upcoming FACET-II experiments at SLAC National Accelerator Laboratory, should yield, through its spectral and angular characteristics, information about the electron beam's underlying dynamics at the interaction point. This project utilizes data from simulated plasma wakefield acceleration-derived betatron radiation experiments and high-field laser-electron-based radiation production to determine which methods could most reliably reconstruct these key properties. The data from these two cases provide a large range of photon energies; this variation of photon characteristics increases confidence in each analysis method. This work aims to compare several reconstruction methods and determine which best predicts original energy distributions based on simulated spectra.
Paper: TUPA106
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA106
About: Received: 03 May 2023 — Revised: 07 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
TUPA108
Simulation study of betatron radiation for perturbed beams in plasma
1564
Plasma wakefield acceleration (PWFA) is a method for accelerating charged particles using large electric fields sustained by plasma waves (up to hundreds of GV m−1) for the accelerating longitudinal fields. In this project, we will evaluate the impact of perturbations on basic particle motion. These perturbations are affected by any number of terms of the equations of motion. The most important perturbations derive from the fact that the particle beams are not quite monochromatic, the finite spread of energies about the nominal energy. We will discuss the hosing which is a transverse instability due to perturbations. The prototypical parameter set was perturbed in several ways. The main goal of this research is to be able to diagnose the parameters of a beam from the spectral and angular distribution of the betatron radiation which encodes information about the beam-plasma interaction.
Paper: TUPA108
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA108
About: Received: 03 May 2023 — Revised: 18 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUPA109
EuPRAXIA doctoral network
1567
EuPRAXIA is the first European project that develops a dedicated particle accelerator research infrastructure based on novel plasma acceleration concepts and laser technology. It focuses on the development of electron accelerators and underlying technologies, their user communities, and the exploitation of existing accelerator infrastructures in Europe. It was accepted onto the ESFRI roadmap for strategically important research infrastructures in June 2021 as a European priority. To fully exploit the potential of this breakthrough facility, advances are urgently required in plasma and laser R&D, studies into facility design and optimization, along a coordinated push for novel applications. EuPRAXIA-DN is a new MSCA Doctoral Network for a cohort of 12 Fellows between universities, research centers and industry that will carry out an interdisciplinary and cross-sector plasma accelerator research and training program for this new research infrastructure. This contribution gives an overview of this interdisciplinary network and its research.
Paper: TUPA109
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA109
About: Received: 30 Apr 2023 — Revised: 12 Jun 2023 — Accepted: 12 Jun 2023 — Issue date: 26 Sep 2023
TUPA111
Plasma wakefields produced by transversely asymmetric beams
1571
Particle beams with highly asymmetric emittance ratios are employed at accelerator facilities and are expected at the interaction point of high energy colliders. These asymmetric beams can be used to drive high gradient wakefields in plasmas. In plasma, the high aspect ratio of the drive beam can create a transversely elliptical blowout cavity and the asymmetry in the ion column creates asymmetric focusing in the two transverse planes. The ellipticity of the blowout depends on the ellipticity and normalized charge density of the beam. Simulations are performed to investigate the ellipticity of the wakefield based on the initial driver beam parameters and the corresponding beam transport is discussed.
Paper: TUPA111
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA111
About: Received: 04 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
TUPA114
Extraction of high-charge state neon and krypton from the D-Pace Penning ion source test stand
1574
D-Pace has a self-heated hot-cathode Penning ion source test stand at their Ion Source Test Facility (ISTF). High-charge state production of boron, arsenic, and phosphorous is interesting to the ion implantation industry, as it allows for higher energy implants of these dopants using the same accelerating gradient in a given accelerator system. We use Neon and Krypton as proxy gases to investigate whether the Penning ion source could be used for high-charge state production in ion implanters. We were able to produce charge states up to Ne$^{3+}$ ($>$ 200 $e \mu$A) and Kr$^{6+}$ ($>$ 7 $e \mu$A). The obstacles in using the current Penning ion source test stand are discussed, with comments on how to potentially increase the current output, stability, and lifetime of this ion source.
Paper: TUPA114
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA114
About: Received: 27 Apr 2023 — Revised: 11 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
TUPA120
Fabrication progress of the prototype spoke cavity for the JAEA-ADS linac
1588
The Japan Atomic Energy Agency (JAEA) has been proposing an accelerator-driven system (ADS) as a future nuclear system to efficiently reduce high-level radioactive waste generated in nuclear power plants. As a first step toward the full-scale design of the CW proton linac for the JAEA-ADS, we are now prototyping a low-beta (around 0.2) single-spoke cavity. The actual cavity fabrication started in 2020. Most of the cavity parts were shaped in fiscal year 2020 by press-forming and machining. In 2021, we started welding the shaped cavity parts together. By preliminarily investigating the optimum welding conditions using mock-up test pieces, each cavity part was joined with a smooth welding bead. So far, we have fabricated the body section and the beam port section of the cavity. By measuring the resonant frequency of the temporarily assembled cavity, we have confirmed that there is no significant problem with the cavity fabrication. In this paper, fabrication progress of the prototype spoke cavity is presented.
Paper: TUPA120
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA120
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
TUPA147
The results of the NSC KIPT subcritical assembly neutron source facility physical start up
1633
Subcritical Assembly Neutron Source facility of the National Science Center “Kharkiv Institute of Physics & Technology” (NSC KIPT), Kharkov, Ukraine is Accelerator Driven System with tungsten or uranium neutron generating target and 100MeV/100kW electron linear accelerator as a driver. The facility physical start up was started in the middle of 2020 fnd completed in August 2022. The program of the facility physical start-up supposes to operate with tungsten neutron generating target and to carry out stepwise fuel element loadings with neutron multiplication factor and reactivity measurements at the end of each loading step. During the physical start up it was supposed to load 38 fuel elements in several loading steps. 200 W electron beam was used for neutron multiplication factor and reactivity measurements. After loading of 37 fuel assemblies the measured value of neutron multiplication factor was 0.941. Because of nuclear safety reasons it was decided to complete the facility physical start up and make some clarifying simulation for 38 loaded in the core fuel assemblies taking into account tolerances for fuel mass, geometry and nuclei data uncertainty to be sure that the value of multiplication factor will be not higher than 0.96. During the the facility start up the results of the reactivity and neutron multiplication factor measurements were in a good agreement with results of Monte-Carlo simulations for NSC KIPT SCA Neutron Source facility.
Paper: TUPA147
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA147
About: Received: 09 May 2023 — Revised: 10 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
TUPA153
Investigations of losses on the CERN SPS flat bottom with HL-LHC type beams
1652
The High-Luminosity LHC (HL-LHC) project at CERN aims at doubling the beam intensity and the brightness. To achieve this unprecedented performance, the LHC injectors were upgraded during the Long Shutdown 2 (2019-2021) to overcome limitations such as space charge and beam instabilities. Despite these upgrades, the reduction of beam loss on the flat bottom in the Super Proton Synchrotron (SPS) to reach the target beam parameters remains a challenge, avoiding unnecessary activation. Losses are due to several factors: uncaptured beam in the SPS due to the bunch rotation in the Proton Synchrotron (PS) prior to the transfer, large transient beam loading during multiple SPS injections, and transverse tails reaching aperture limitations. Investigations were conducted with HL-LHC beam parameters, aiming at disentangling the different sources of losses and defining specific observables. Finally, refining the optimal beam parameters for improved transfer between PS and SPS is the objective of the study, as well as the possible need for new hardware such as an additional RF system for beam stability and capture or a dedicated collimation system.
Paper: TUPA153
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA153
About: Received: 02 May 2023 — Revised: 20 Jun 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUPA154
Project management structures, processes, and tools for the HL-LHC project
1656
At its restart after a major shutdown in 2029, the LHC will see its interaction regions upgraded by the installation of the HL-LHC equipment, with new Nb3Sn triplets and cold powering system, crab-cavities for crossing angle compensation and luminosity levelling, an upgraded collimation system, and fully remote alignment for the final focusing region. In the following operational runs, the LHC will aim at a tenfold increase of the integrated luminosity compared to the original design. The HL-LHC project features a light project management (PM) structure, with strong delegation of PM tasks to the 19 work-packages structuring the project by expertise areas. Unified processes align the community around a common configuration and performance, while shared tools are applied to budget and schedule management . The paper describes committees and processes applied to run this complex project, within the overall organization and planning of CERN. We explain the procedures ruling decisions and change management in configuration, cost and schedule, detail the responsibility share between project and work-packages and explain how quality standards build a common language across the project.
Paper: TUPA154
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA154
About: Received: 02 May 2023 — Revised: 08 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPA156
An improved procedure for energy matching between PS and SPS at CERN
1663
Energy matching between two hadron synchrotrons is the adjustment of the magnetic bending fields and beam momentum to obtain a correct transfer between the two. Conventionally, energy matching is achieved by turning off the RF system and measuring the revolution frequency of the de-bunching beam in the receiving accelerator. For an ideal circumference ratio, the orbits would then be centred in the two rings. However, this procedure is non transparent, seen that the de-bunched beam cannot be accelerated anymore. Thanks to the Low-Level RF (LLRF) upgrade in the Super Proton Synchrotron (SPS) during the 2019-2021 long shutdown, most LLRF signals have become available in digital form, allowing easy online display, analysis, and storage. In this contribution, we look at the possibility of performing energy matching between the PS and the SPS in a more transparent way, without disabling the RF system. The signals from the beam phase and synchronization loops reveal information on the energy of the beam injected into the SPS. This allows to continuously monitor the transfer frequency error, as well as identify and correct potential long-term drifts.
Paper: TUPA156
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA156
About: Received: 01 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPA157
SPS fixed target spill quality improvements in the longitudinal plane
1667
The SPS proton fixed target beams are spilled via a third integer resonant extraction, for which high momentum spread is beneficial. To increase the momentum spread prior to the slow extraction, the bunches are stretched at the unstable phase by inverting the sign of the RF voltage. The RF phase is then flipped back, and the voltage is turned off when the bunch distribution is rotated to the maximum momentum spread. The past production scheme additionally relied on uncontrolled longitudinal blow-up of the unstable beam during the acceleration ramp. After the major upgrade of the main RF system and a successful impedance reduction campaign, the spill quality was significantly compromised. This contribution summarizes the efforts to recover, and improve, the spill quality. The use of the fourth harmonic RF system and controlled longitudinal emittance blow-up are used for beam stabilization along the ramp. Moreover, RF counter phasing is applied during the first part of the de-bunching to profit from the cavity impedance reduction of the feedback systems.
Paper: TUPA157
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA157
About: Received: 01 May 2023 — Revised: 16 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPA158
Beam performance and operational efficiency at the CERN Proton Synchrotron
1671
The injectors for the LHC at CERN underwent a major upgrade during a recent two-year long shutdown in the framework of the LHC Injectors Upgrade (LIU) project. Following this upgrade, the Proton Synchrotron (PS) was restarted in 2021, with the same beam quality as before the upgrade quickly achieved or surpassed. This contribution details the current beam performance for fixed-target and LHC-type beams in the PS and the ongoing activities to improve the operational efficiency by means of automating routine operational tasks.
Paper: TUPA158
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA158
About: Received: 27 Apr 2023 — Revised: 10 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPA163
SIS18 operation and recent development
1683
SIS18 will be used as booster for FAIR’s main synchrotron SIS100. In addition, it provides a wide variety of ions from Protons to Uranium for users directly at GSI and FAIR. An upgrade program to enhance the overall performance for the booster operation has been carried out. Part of the upgrade program for booster operation was a complete overhaul of the control system including data supply and timing system. In addition, a new magnetic alloy cavities have been installed for h=2 operation and dual harmonic operation in conjunction with the existing H=4 cavities. The main power supplies have been upgraded to allow reduced cycle times. The vacuum system has been significantly enhanced. Further upgrades and machine studies have been performed to enhance available beam parameters and provide new features for the users. We will report about machine studies and recent operation for FAIR Phase0 experiments utilizing various upgrade measures to enhance overall machine performance.
Paper: TUPA163
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA163
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPA164
Simulation and measurement of beam loading effects in magnetic alloy RF cavity of CSNS RCS
1687
Different from the high Q value of ferrite cavity, the Q value of magnetic alloy cavity in CSNS RCS is only about 1.25, the frequency band of impedance is wide, and the beam loading effects is strong. Based on the impedance measurement results, the influence of the beam load effects on the longitudinal distribution of the magnetic alloy cavity in CSNS RCS is studied by simulation, and the induced voltage measured on the machine is consistent with it.
Paper: TUPA164
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA164
About: Received: 08 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPA166
Impact of insertion devices on the SLS 2.0 dynamic aperture
1691
Insertion devices may be also very detrimental for the dynamic aperture of storage rings, since they introduce linear and higher order perturbations on the optics of synchrotrons. It is essential to study these effects to adjust the lattice to compensate for these terms when possible (high order multipole magnets are present in the lattice of the machine), or optimize the design of the IDs to minimize the higher order effects. We applied our analysis to SLS~2.0, the upgrade of the presently running Swiss Light Source (SLS) facility at Paul Scherrer Institut. In particular, we compared the results using an approach based on the calculation of the multipoles computed on the beam reference trajectory and on the kick map calculation.
Paper: TUPA166
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA166
About: Received: 02 May 2023 — Revised: 16 Jun 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
TUPA170
Thermal and deformation analysis of a 750 MHz IH-DTL prototype for medical applications
1695
This article presents an IH-DTL prototype, capable of accelerating carbon ion beams from 5 MeV/u to 5.5 MeV/u, for manufacturing and assembling validation in a hadrontherapy linac injector. A multi-physics study is made in CST Studio concerning steady-state thermal, stress and deformation analysis. Convenient water-cooling circuits close to drift tubes are simulated to evaluate field errors and frequency detuning as they can affect directly to beam dynamics.
Paper: TUPA170
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA170
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
TUPA173
Reverse engineering on IPHI RFQ
1706
The Radio Frequency Quadrupole (RFQ) for the High-Intensity Photon Injector (IPHI) project has been designed and manufactured in the early 2000s. It is now operating at CEA Saclay since 2016 and accelerates a 100-mA continuous beam up to 3 MeV. It is a 6-meter-long, 3 segments vane RFQ, with 352.2 MHz operation frequency and non-constant voltage profile. From this RFQ, a lot of experience has been gained and, based on this feedback, other RFQ were designed at CEA, such as the one for SPIRAL2, LINAC4, or ESS, which are now operating. For maintenance purposes and to simulate the changes before we operate them, a new virtual 3D model has been developed. This model is simplified and may have the same RF performances as the existing one. This paper present this new model.
Paper: TUPA173
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA173
About: Received: 02 May 2023 — Revised: 23 Jun 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
TUPA175
Injector and synchrotron commissioning of helium ion beams at the MedAustron Ion Therapy Center
1713
MedAustron is a synchrotron-based ion cancer therapy facility located in Austria. Patients are treated with proton and carbon ion beams in an energy range of 62-252 MeV and 120-402 MeV/u, respectively. The facility features three clinical irradiation rooms, among which horizontal and vertical beam lines as well as a proton gantry are available for treatment. A fourth irradiation room is dedicated to non-clinical research. In 2021, a development project started, which aims at commissioning helium ion ($\mathrm{^{4}He^{2+}}$) beam up to the non-clinical irradiation room. A first major milestone was reached by completing the commissioning of helium in the ECR ion source branch, the LEBT and the LINAC section, where the beam is accelerated up to 7 MeV/u. In this work we discuss the challenges and main results achieved during the injector commissioning (i.e. emittance, intensity and transmission efficiency). Furthermore, recent outcomes from the injection of $\mathrm{^{4}He^{2+}}$ beam into the synchrotron as well as acceleration and extraction results are presented.
Paper: TUPA175
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA175
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
TUPA176
Alvarez drift tube linac for medical applications in the framework of HITRIplus project
1717
A first beam dynamics and RF design of an Alvarez-type drift tube linac (DTL) has been defined in the framework of the EU project, HITRIplus. Its main application is to be exploited as a carbon (12C4+) and helium (4He2+) ion injector into a compact synchrotron for patient treatment. As a second implementation, helium particle acceleration with a higher duty cycle of 10% enables the possibility for radioisotope production. The 352.2 MHz structure efficiently accelerates two ion species, for A/q=3 and 2, in the energy range of 1÷5 MeV/u and for a beam current of ~0.5 mA. The design extends to a full length of ~7 meters. Permanent magnet quadrupoles are utilized all along the DTL for focusing both ion beams. This paper presents a first-phase analysis towards a realistic DTL design capable of providing full beam transmission and minimum overall emittance increase for two ion beams.
Paper: TUPA176
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA176
About: Received: 08 May 2023 — Revised: 08 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
TUPA177
Comparison of 352 MHz LINAC structures for injection into an ion therapy accelerator
1721
In the frame of ongoing initiatives for the design of a new generation of synchrotron-based accelerators for cancer therapy with ion beams, an analysis of linac designs has been started, to address a critical element with strong impact on performance and cost of the accelerator. The goal is to identify alternatives at lower cost and similar or possibly smaller footprint than the standard 217 MHz injector presently used in all carbon therapy facilities in Europe. As an additional feature, a new linac design can be tailored to produce radioisotopes for treatment and diagnostics in parallel with operation as synchrotron injector. In this paper is analysed the attractive option of moving to 352 MHz frequency, to profit of reliable mechanical designs already developed for protons and of the cost savings that can be obtained using as RF power sources klystrons with a much lower cost per Watt than tubes or solid-state units. The paper will present a Quasi-Alvarez Drift Tube Linac (DTL) version of an injector linac for carbon ions at q/m=1/3 and compare it with recently developed DTL and IH designs. The option of a separated-IH type linac will be also discussed, together with a standard IH design at 352 MHz. Finally, a DTL design at 352 MHz for injection of fully stripped helium ions into the synchrotron will be presented.
Paper: TUPA177
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA177
About: Received: 09 May 2023 — Revised: 09 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPA180
Accelerator and beam physics challenges in support of FRIB experiments
1729
The Facility for Rare Isotope Beams (FRIB), a major nuclear physics facility for research with fast, stopped, and reaccelerated rare isotope beams, started operation in May 2022. Since then, five nuclear physics experiments have been successfully accomplished. The experiments with rare isotope beams typically last within 1-2 weeks. Each experiment requires a different primary beam and its energy. It is critical to shortening the accelerator and fragment separator setup time to meet the requirements of the FRIB Users community. Currently, the primary focus in the linac is to reduce the accelerator setup time and ramp up beam power. Many physics applications, including Machine Learning, have been developed and used to set up the accelerator and beamlines. The simultaneous acceleration of multiple charge states of heavy ion beams is routinely used to minimize the beam power deposition on the charge selector slits after the stripper. The challenges in the fragment separator are related to the highly non-linear beam physics due to the large emittance and momentum spread of the isotope beams. Since the iron-dominated SC magnets operate near saturation, the optimization process includes field distributions at different excitation currents. This paper discusses the theoretical and experimental procedures to improve the linac and fragment separator performance.
Paper: TUPA180
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA180
About: Received: 28 Apr 2023 — Revised: 12 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
TUPA181
Linear accelerator for a next generation rare isotope facility
1733
We propose a linear accelerator concept for a Next Generation Nuclear Physics Accelerator Facility - a versatile User Facility with a wide variety and high availability of its instruments and beam time. The concept is based on the simultaneous acceleration of light and heavy ion primary beams. It improves the utilization of the superconducting driver-accelerator capabilities and allows for the simultaneous and complementary rare isotope production in two different targets, namely a thin target for fragmentation of accelerated heavy ion beams, and a thick spallation target for an isotope separation on-line (ISOL) system driven by light ion beams. This approach supports the multi-user operation of the facility, and enables other research driven by light ion beams. The concept is presented as an upgrade of the Facility for Rare Isotope Beams (FRIB, MSU) with a 60-MV compact room-temperature continuous-wave light ion injector. The funneling of the light and heavy ion beams as well as their distribution to production targets is discussed.
Paper: TUPA181
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA181
About: Received: 27 Apr 2023 — Revised: 08 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
TUPA183
IOTA Proton Injector Beamline Installation
1737
The IOTA Proton Injector (IPI), currently under installation at the Fermilab Accelerator Science and Technology facility, is a beamline capable of delivering 20-mA pulses of protons at 2.5 MeV to the Integrable Optics Test Accelerator (IOTA) ring. First beam in the IPI beamline is anticipated in 2023, when it will operate alongside the existing electron injector beamline to facilitate further fundamental physics research and continued development of novel accelerator technologies in the IOTA ring. This report details the expected operational profile, known challenges, and the current state of installation.
Paper: TUPA183
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA183
About: Received: 03 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
TUPA186
Advanced basic layout of the Helmholtz LInear Accelerator for cw heavy ion beams at GSI
1747
The design and construction of continuous wave (cw) superconducting (sc) high intensity linacs is a crucial goal of worldwide accelerator technology development. The standalone sc cw heavy ion HElmholtz LInear ACcelerator (HELIAC) is a common project of GSI Helmholtz Centre for Heavy Ion Research and Helmholtz Institute Mainz (HIM) under key support of Goethe University Frankfurt (IAP). In 2017 the first section of the linac has been successfully commissioned and extensively tested with heavy ion beam at GSI, featuring the capability of 216.816 MHz multi-gap Crossbar H-mode (CH) DTL-structures. At present, the first fully equipped cryomodule of the HELIAC is under construction. Six further superconducting CH cavities are being procured. The HELIAC beam dynamics concept foresees a total of twelve CH-cavities in order to accelerate ions with a mass-to-charge ratio of 6 up to a smoothly variable energy in the range 3.5 - 7.5 MeV/u. In this paper, an advanced compact and less complex layout is presented, where the same number of accelerating cavities can be accommodated in three instead of four cryomodules, thus also reducing the number of solenoids and rebunchers, required for beam focusing. In addition, the integration and linking of the HELIAC to the GSI accelerator facility will be outlined.
Paper: TUPA186
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA186
About: Received: 25 Apr 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
TUPA189
Operation of copper cavities at cryogenic temperatures
1754
This work is focused on the anomalous skin effect in copper and how it affects the efficiency of copper-cavities in the temperature range 40-50 K. The quality factor Q of three coaxial cavities was measured over the temperature range from 10 K to room temperature in the experiment. The three coaxial cavities have the same structure, but different lengths, which correspond to resonant frequencies: around 100 MHz, 220 MHz and 340 MHz. Furthermore, the effects of copper-plating and additional baking in the vacuum oven on the quality factor Q are studied in the experiment. A “geometric model” based on a spherical Fermi - surface and using the equivalent skin layer model is presented in the paper to calculate the surface resistance which is relevant for the RF power losses in the cavity walls. Finally, Cavity cooling process about the pulsed heat transport from the surface into the bulk copper is simulated. The motivation is to check the feasibility of an efficient, pulsed, ion linac, operated at cryogenic temperatures.
Paper: TUPA189
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA189
About: Received: 02 May 2023 — Revised: 23 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPA190
The double drift harmonic buncher (DDHB) and acceptance investigations at linac and cyclotron injections
1758
Particle accelerators demand high particle transmission and reduced longitudinal emittance; hence, effective bunching systems are requested. The concept based on an efficient, compact design called “Double Drift Harmonic Buncher - DDHB” fulfills these two requirements for a c.w. or pulsed beam injection into an RFQ, a DTL, or a cyclotron. The proposal is associated with two buncher cavities separated by a drift space and an additional drift at the end of the system for a longitudinal beam focus at the entrance of the next accelerator unit, whose candidates can be one of those mentioned above. The investigations are focused on exploring accurate acceptance rates. To obtain successful and understandable outputs from the DDHB concept, a new multi-particle tracking beam dynamics code called “Bunch Creation from a DC beam - BCDC” has been developed for detailed investigations of space charge effects. It allows to calculate the transformation of intense dc beams into particle bunches in detail with a selectable degree of space charge compensation at every location. This paper presents the results from various investigations with and without space charge effects.
Paper: TUPA190
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA190
About: Received: 03 May 2023 — Revised: 04 Jun 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
TUPA192
Strategies for SPIRAL2 linac heavy-ion beam tuning
1762
Heavy ions have been accelerated for the first time by SPIRAL2 in 2022. A fast method to tune the linac cavities has been used (< 1 hour by now, < 10’ in the future) to obtain a 7 MeV/A 18O6+ beam (50 microA CW). Then an automatic Q/M beam change procedure has been successfully used to directly produce a 18O7+ beam. The goal was to demonstrate the possibility to tune a beam even if its intensity is too low (<10 microA) to be seen by phasemeters (BPM) along the linac. The linac transmission was ~ 100% for both beams and, as expected, the measured output energy was the same. The same oxygen reference beam tuning has been also used to obtain 80 microA of 40Ar14+ at 7 MeV/A. Again, the same method has been used to tune the linac cavities at the RFQ output energy beam (0.73 MeV/A, no acceleration). These different methods and the one used to tune the linac output energy are presented.
Paper: TUPA192
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA192
About: Received: 03 May 2023 — Revised: 06 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPA193
NEWGAIN project at GANIL-SPIRAL2 : design of the new heavy ion injector for the superconducting linac
1765
A new project, NEWGAIN (NEW GAnil Injector), is under development at GANIL, and aims to build a second injector for heavier beams with A/q up to 7, as an extension of the SPIRAL2 accelerator. With this upgrade, SPIRAL2 will provide high intensity beams, from proton to uranium, thus increasing GANIL international competitiveness both in fundamental science and associated applications. This paper presents the layout and describes the main technical components of the new injector, based on 2 ECR ion sources (one of them existing), two LEBT, one RFQ and a MEBT section to transport the beam into the present MEBT connected to the LINAC.
Paper: TUPA193
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA193
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
TUPA194
RF-acceleration studies for the HBS-linac applying alternating phase focusing concepts
1768
The recent layout of the Jülich High Brilliance Neutron Source (HBS) driver linac is based on short crossbar H-mode (CH) cavities operated at a fixed synchronous phase. In the last decades the computing power for the development of linacs, available to physicists and engineers, has been increased drastically. This also enabled the accelerator community to finally carry out the required R&D to generate further the idea of drift tube linacs with alternating phase focusing (APF) beam dynamics, originally proposed in the 1950s. This focusing method uses the electric fields in between the drift tubes (i.e., gaps) to provide subsequent transverse and longitudinal focusing to the beam along multiple gaps. The beam focusing properties within each gap are adjusted individually by means of the synchronous phase. As a result of the alternating phase focusing method, these linacs can operate completely without internal magnetic lenses. The R&D-program for the high brilliance neutron source HBS offered the opportunity to investigate the APF concept further in order to open this advanced concept for high duty-factor, high intensity hadron beam acceleration. Besides, a prototype APF-interdigital H-mode (IH)-cavity has been designed and is going to be build and tested in the next future.
Paper: TUPA194
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA194
About: Received: 27 Apr 2023 — Revised: 12 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPL022
Recommissioning of the FLASH injector and linac
1816
FLASH, the <strong>F</strong>ree electron <strong>LAS</strong>er in <strong>H</strong>amburg is currently undergoing a substantial refurbishment and upgrade project (FLASH2020+). A major stage was the 9 month shutdown in 2021/22. During this shutdown key components of the injector/linac where inserted, moved, rebuild or upgraded to enable the efficient and reliable preparation of electron bunches for HGHG and EEHG seeding in the FLASH1 beamline and simultaneous SASE operation in the FLASH2 beamline. In particular we have, added a new injector laser system, installed a laser heater system, moved the 1st bunch compression chicane downstream to generate space for the laser heater, replaced two old acceleration modules with modern high-gradient modules (thereby gained an additional 100 MeV of energy), replaced the 2nd bunch compression chicane with a more fancy movable one that enables variable longitudinal dispersion while allowing the compensation of bunch tilts, and saves space for an additional matching section section at the entrance to the main linac. Here we describe the more general aspects of the re-commissioning of the machine with beam which started early October 2022.
Paper: TUPL022
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL022
About: Received: 02 May 2023 — Revised: 08 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPL057
Preliminary study on THz-TBA based X-ray source
1885
Two-beam acceleration (TBA) in Terahertz (THz) regime is the natural extension of Gigahertz TBA pursued in Structure Wakefield Acceleration Community. Recently proposed CSR-free shaping technique using deflecting cavities showed the feasibility of generating a high-charge (~1 nC per bunch) bunch train compatible with THz frequency. Wakefield from THz structure with such a h high-charge bunch train has potential to reach a few GV/m accelerating gradients or a few GW THz power levels. We present a concept of a compact accelerator using THz-TBA for generating coherent X-ray.
Paper: TUPL057
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL057
About: Received: 13 Apr 2023 — Revised: 10 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUPL058
Feasibility study on multi-channel power extraction tube
1889
One of the limitations in structure wakefield acceleration is large transverse emittances of high-charge wakefield drivers. The simplest idea to avoid this issue would be to prepare multiple lower-charge drivers and apply RF power from all drivers to a single accelerating tube. However, the method has two significant drawbacks; cost and timing control. We propose a single high-charge beamline that turns a single beam into multiple transverse beamlets to drive wakefield in transverse distributed power extraction tubes. Here, we present the first feasibility study of the concept.
Paper: TUPL058
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL058
About: Received: 13 Apr 2023 — Revised: 11 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUPL100
HPC modelling of a high-gradient C-Band LINAC for applications including hard X-Ray FREE-Electron Lasers
1958
The production of soft to hard x-rays (up to 25 keV) at XFEL (x-ray free-electron laser) facilities has enabled new developments in a host of disciplines. However, there is great potential for new scientific discovery at even higher energies (42+ keV), such as those provided by MaRIE (Matter-Radiation Interactions in Extremes) at Los Alamos National Laboratory. These instruments can require a large amount of real estate, which quickly escalates costs: The driver of the FEL is typically an electron beam linear accelerator (LINAC) and the need for higher electron beam energies capable of generating higher energy X-rays can dictate that the LINAC becomes longer. State of art accelerating technology is required to reduce the LINAC length by reducing the size of the cavities, which in turn provides for a high gradient of acceleration. Compact accelerating structures are also high-frequency (S, C, and X-bands). Here, we describe using the Argonne Leadership Computing Facility (ALCF) ), located at Argonne National Laboratory to facilitate our investigations into design concepts for future XFEL high-gradient LINAC's in the C-band (~4-8 GHz). We investigate a Disk Loaded Wave Guide (DLWG) and an elliptical traveling wave (TW) structure modeled for operation at f =5.712 GHz at the ALCF using VSim software. We used an existing account under the ALCF LIGHTCONTROL project.
Paper: TUPL100
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL100
About: Received: 07 May 2023 — Revised: 12 Jun 2023 — Accepted: 12 Jun 2023 — Issue date: 26 Sep 2023
TUPL105
Fabrication and evaluation of the PEM for the fuel cell by irradiation graft polymerization using electron beam accelerator
1975
Our laboratory has been studying about polymer electrolyte membrane (PEM) for polymer electrolyte fuel cell (PEFC) by irradiation graft polymerization using electron beam accelerator. Irradiation graft polymerization can reduce the production cost of the PEM compared with the current product, perfluoro-sulfonic acid (PFSA) ionomer such as Nafion®︎ by DuPont. We have two methods to fabricate high-performance PEMs using the accelerator. One is to give the micro-structure of hydrophilic and hydrophobic region to the PEM. The other is to generate the concentration gradient of hydrophilic region inside of the PEM. Both methods were able to generate high power density as much as Nafion®︎. In previous study, we used ion beam to give these characteristics. Ion beam has highly straightness and easy to create micro-structure and the concentration gradient of hydrophilic region inside of the PEM. But, its production equipment costs too much. Therefore, in this study, we use electron beam that production equipment costs less than ion beam and fabricate the PEM which has above both methods for advanced application of the electron beam accelerator.
Paper: TUPL105
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL105
About: Received: 24 Apr 2023 — Revised: 07 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPL111
Start-to-end simulation of the full energy linac injector for the Southern Advanced Photon Source
1992
Southern Advanced Photon Source (SAPS) is a 3.5 GeV diffraction limited storage ring, being planned to be built near the site of the China Spallation Neutron Source (CSNS). Full energy Linac injector reserves the possibility of using the Linac for free electron laser application in a future upgrade. In this paper, the start-to-end simulation of the full energy Linac working on the ring injection mode are given.
Paper: TUPL111
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL111
About: Received: 03 May 2023 — Revised: 06 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPL112
A C-band test platform for the development of RF photo cathode and high gradient accelerating structures
1995
In order to promote the studies of low emittance RF photo cathode and high gradient accelerating structures, a C-band test platform has been initialized since late 2021. In this paper, an overview of the present status and future plans of this platform is given, including a 3.6-cell C-band RF photo cathode and a C-band RF traveling-wave accelerating structure. In addition, other on-going studies on this platform, such as the test of a cryo-copper accelerating structure and the development of short pulse high gradient parallel-coupled structures, are briefly introduced.
Paper: TUPL112
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL112
About: Received: 10 May 2023 — Revised: 13 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPL117
Energy saving measures in the high-power RF system of the European XFEL
2006
The high-voltage modulators of the 26 klystrons in the XFEL represent the largest power consumer of the accelerator facility. The beam energy is usually 14 GeV, but a few weeks a year, lower and higher beam energies are also produced. For example, 11.5 and 16.3 GeV. Until mid-2022, the modulator voltages were set so that enough RF power for 16.3 GeV beam energy could be provided at all times. In order to save energy, the modulator voltages will now be lowered to a sufficient level for beam energies of ≤ 14 GeV. In this way, the previous power consumption of the modulators of 5 MW can be reduced up to 1 MW depending on the operation mode. Over the course of a year, this will save several GWh of energy. In the following, the relationship between the output voltage and the power consumption of the modulators is described. Afterwards, it is reported how the power consumption was reduced in various operating conditions in 2022.
Paper: TUPL117
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL117
About: Received: 04 May 2023 — Revised: 08 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPL125
Physical design of a 10 MeV electron linac for industrial application and material irradiation effect research
2020
A 35MeV/2 mA S-band electron linear accelerator used to interact with solid targets to generate neutrons, gamma rays, and X-rays has been proposed to provide a scientific research platform for nuclear energy development, material development, biomedicine, deep space exploration besides other industrial applications. The accelerator has a three-stage accelerating structure, after the first-stage of structure, the beam energy can reach 10MeV, and then completes 270° vertical bend and 45° horizontal bend, respectively, for industrial applications and material irradiation effect research. This paper presents the first-stage acceleration of the linac and its bend branch, including a pre-buncher, an acceleration structure (provides beam energy 10MeV and average current 2mA), 270° and 45° bend magnets, with beam loss rate less than 15%. A detailed physical design and dynamics simulation results are presented and discussed.
Paper: TUPL125
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL125
About: Received: 02 Apr 2023 — Revised: 11 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
TUPL126
Beam commissioning of the HEPS Linac
2023
The High Energy Photon Source (HEPS) is a synchrotron radiation source of ultrahigh brightness being built in China. Its accelerator complex is composed of a 6-GeV storage ring, a full energy booster, a 500-MeV Linac, and three transfer lines. The Linac is an S-band normal conducting electron linear accelerator with available bunch charge from 0.5 nC up to about 10 nC. The Linac installation was completed in July 2022 and high-power RF conditioning was finished in September 2022. Physics quantity based high-level applications have been developed for the HEPS Linac using our own platform Pyapas. The beam commissioning of the Linac is scheduled from December 2022 to March 2023. Detailed beam commissioning experiences and results of the HEPS Linac will be presented in this paper.
Paper: TUPL126
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL126
About: Received: 02 May 2023 — Revised: 16 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
TUPL128
Construction, assembly and measurements of the SPES RFQ
2027
The SPES RFQ is designed in order to accelerate beams in CW with A/q ratios from 3 to 7 from the Charge Breeder through the MRMS and the selection and injection lines up to the MEBT (Medium Energy Beam Transport). The RFQ is composed of 6 modules about 1.2 m long each, made of a Stainless Steel Tank and four OFE Copper Electrodes. A copper layer is plated on the tank inner surface and a spring joint between tank and electrode is used in order to seal the RF. In this article, the main results related to the the module assembly and related RF and mechanical measurements are shown.
Paper: TUPL128
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL128
About: Received: 03 May 2023 — Revised: 07 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPL130
Electron beam analysis and sensitivity studies for the EuPRAXIA@SPARC_LAB RF injector
2034
The interest in plasma-based accelerators as drivers of user facilities is growing worldwide thanks to their compactness and reduced costs. The EuPRAXIA@SPARC_LAB collaboration is preparing a technical design report for a multi-GeV plasma-based accelerator with outstanding electron beam quality to pilot an X-ray FEL, the most demanding in terms of beam brightness. The beam dynamics has been studied aiming to a reliable operation of the RF injector to generate a so-called comb-beam with 500 MeV energy suitable as driver of the Beam-driven Plasma Wakefield Accelerator. A case of interest is the generation of a trailing bunch with 1 GeV energy, less than 1 mm-mrad transverse emittance and up to 2 kA peak current at the undulator entrance. The comb-beam is generated through the velocity bunching technique, an RF compression tool that enables high brightness beams within relatively compact machine. Since it is based on a rotation of the beam phase space inside the external RF fields, it could be particularly sensitive to amplitude and phase jitters in the RF injector. The electron beam dynamics and the machine sensitivity to the possible jitters are presented in terms of effect on the beam quality so to provide the basis for the alignment procedure and jitter tolerances. Numerical studies have been consolidated with experimental results obtained at SPARC_LAB, a test facility currently oriented to plasma acceleration physics where the velocity bunching scheme is routinely applied.
Paper: TUPL130
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL130
About: Received: 11 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
TUPL131
Recent experimental results on the particle driven acceleration at the SPARC_LAB test facility
2038
Plasma accelerators are emerging as formidable and innovative technology for the creation of table-top devices thanks to the possibility to sustain several GV/m accelerating gradients at normal conducting temperature. Among others, the particle-driven configuration has been successfully tested at the SPARC_LAB test facility also demonstrating the emission of plasma-based FEL radiation in SASE and seeding operation. Recently we have performed further experimentals devoted to heightening the accelerating gradient in the plasma. The so-called comb beam has been set up with a 500pC driver followed by a 50pC trailing bunch. The maximum measured energy gain in the plasma has been of almost 30 MeV turning in an accelerating gradient of the order of 1.2 GV/m. The result represents a fundamental achievement also looking at the forthcoming EuPRAXIA@SPARC_LAB plasma-based user facility. Further experimental runs are planned for the next year on the measurements of transverse quality of the electron beam and its eventual preservation. The paper reports on the obtained experimental results and on the numerical studies for the next future experiment at the SPARC_LAB test-facility.
Paper: TUPL131
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL131
About: Received: 19 Apr 2023 — Revised: 05 Jun 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
TUPL132
Numerical studies for EuPRAXIA@SPARC_LAB plasma beam driven working point
2042
The realization of a plasma based user facility on the model of EuPRAXIA@SPARC_LAB requires to design a working point for the operation that allows to get an high accelerating gradient preserving a low emittance and low energy spread of the accelerated beam. Such beam is supposed to pilot a soft x-ray free electron laser, a device with very challenging requirements in terms of brightness and energy spread. The external injection beam driven scheme by means of an RF photoinjector allows a fine tuning of the working point parameters at the injection, but the high beam current dictates the maximum accelerating gradient that can be obtained while preserving energy spread. These parameters are mostly connected to each other depending on the plasma wavelength and on the separation phase between driver and witness. In this work several simulation scans are presented, varying at the same time the plasma density and driver-witness separation in order to show that, in a realistic working point for EuPRAXIA@SPARC_LAB, it is possible to find an ideal compromise for a witness with a peak current >1kA that allows to preserve the energy spread of the core (80% of the charge) below 0.1%, while maintaining an accelerating gradient of the order of GV/m. The study is completed with a parametric analysis with the aim of establishing the stability requirements of the RF working point and the plasma channel in order to preserve the energy jitter at the same level of the energy spread.
Paper: TUPL132
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL132
About: Received: 01 Apr 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
TUPL135
Beam Dynamics Optimization of an Electron Linac Using the Multi-Objective Genetic Algorithm
2049
A beam dynamics optimization study of an electron injector linear accelerator including an RF photoinjector gun was performed using MOGA (Multi-Objective Genetic Algorithm). To meet the requirements of electron beam characteristics at the linac end, the optimization goal was to minimize transverse beam emittance and energy spread. The transverse and longitudinal beam sizes were constrained to find Pareto fronts effectively. Parameters to be optimized were the input phases of the RF gun cavity and accelerator column cavity as well as the strength and position of the focusing solenoids. In addition to finding physical optimization parameters, we also investigated hyper-parameters in optimization simulations such as population, offsprings, generations, etc. This paper presents the optimization results of the linac design.
Paper: TUPL135
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL135
About: Received: 01 May 2023 — Revised: 20 Jun 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUPL136
Study of HOM couplers for the c-band accelerating structure
2053
Cryo-cooled C-band (5.7 GHz) copper distributed-coupling cavities are a new approach to the structure-based accelerators for the future multi-TeV energy range linear collider. It provides numerous degrees of freedom to optimize the cavity geometry to achieve high gradient and high-power in the linear collider. In this study, we analyze the dipole modes of C-band 20-cells cavity and calculate the wall loss Q-factors, shunt impedance, and the impact of transverse wakefields in the frequency range up to 40 GHz by using ACE3P code (Omega3P and ACD tools). Next, we equip each cavity with four waveguide manifolds with damping loads to suppress undesirable higher-order-modes (HOM). The results of ACE3P simulations are compared with the CST microwave studio simulations.
Paper: TUPL136
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL136
About: Received: 03 May 2023 — Revised: 18 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
TUPL138
Update on the status of the C-band high gradient program at LANL
2057
This talk will report on the status C-band high gradient research program at Los Alamos National Laboratory (LANL). The program is being built around two test facilities: C-band Engineering Research Facility in New Mexico (CERF-NM), and Cathodes And Radio-frequency Interactions in Extremes (CARIE). Modern applications require accelerators with optimized cost of construction and operation, naturally calling for high-gradient acceleration. At LANL we commissioned a high gradient test stand powered by a 50 MW, 5.712 GHz Canon klystron. The test stand is capable of conditioning accelerating cavities for operation at surface electric fields higher than 300 MV/m. CERF-NM is the first high gradient C-band test facility in the US. CERF-NM was fully commissioned in 2021. In the last several years, multiple C-band high gradient cavities and components were tested at CERF-NM. Currently we work to implement several updates to the test stand including the ability to autonomously operate at high gradient for the round-the-clock high gradient conditioning. Adding capability to operate at cryogenic temperatures is considered. The construction of CARIE began in October of 2022. CARIE will house a cryo-cooled copper RF photoinjector with a high quantum-efficiency cathode and produce an ultra-bright 250 pC electron beam accelerated to the energy of 10 MeV. The status of the facility, the designs of the photoinjector and the beamline, and plans for photocathode testing will be presented.
Paper: TUPL138
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL138
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
TUPL139
C-band photoinjector radiofrequency cavity design for enhanced beam generation
2061
We present our 1.6-cell radiofrequency cavity design for a photoinjector under development for producing intense electron bunches with 250-pC beam charge and normalized emittance below 100 nm rad for cryogenic temperature operation. The cavity cell profile was designed by SLAC and UCLA, optimized for maximal shunt impedance and minimal peak magnitude of the electric and magnetic field. The pi-mode accelerating fields are established in the cells with power coupled into each cell individually through the slot on the sidewall, and the peak electric field magnitude has been tuned to be equal in the two cells. The coupling waveguide network was designed to achieve critical coupling into the port of the input power waveguide and to achieve the desired power distribution. The cavity design has been completed for initial high-gradient test at room temperature.
Paper: TUPL139
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL139
About: Received: 02 May 2023 — Revised: 08 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
TUPL141
Distributed coupling linac for efficient acceleration of high charge electron bunches
2064
Future colliders will require injector linacs to accelerate large electron bunches over a wide range of energies. For example the Electron Ion Collider requires a pre-injector linac from 4 MeV up to 400 MeV over 35 m [1]. Currently this linac is being designed with 3 m long traveling wave structures, which provide a gradient of 16 MV/m. We propose the use of a 1 m distributed coupling design as a potential alternative and future upgrade path to this design. Distributed coupling allows power to be fed into each cavity directly via a waveguide manifold, avoiding on-axis coupling [2]. A distributed coupling structure at S-band was designed to optimize for shunt impedance and large aperture size. This design provides greater efficiency, thereby lowering the number of klystrons required to power the full linac. In addition, particle tracking analysis shows that this linac maintains lower emittance as bunch charge increases to 14 nC and wakefields become more prevalent. We present the design of this distributed coupling structure, as well as cold test data and plans for higher power tests to verify on the structure’s real world performance.
Paper: TUPL141
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL141
About: Received: 02 May 2023 — Revised: 09 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPL143
Jitter tolerance for the FEBE beamline on CLARA
2071
CLARA at STFC Daresbury Laboratory is a test facility for FEL research and novel accelerator technologies, providing high-quality electron bunches with charges up to 250 pC. Phase two of CLARA, which will bring the accelerator to its design energy (250 MeV) and repetition rate (100 Hz), is expected to begin commissioning in 2024. To maximise exploitation of the upgraded accelerator, a dedicated Full Energy Beam Exploitation (FEBE) beamline is currently being installed, featuring two large chambers where a high-power laser and advanced diagnostics will be available for user experiments that include investigation of novel plasma acceleration methods. Many experiments planned for CLARA-FEBE will require a high level of shot-to-shot beam stability, placing particular importance on the bunch time of arrival (tens of femtoseconds) and peak current (several kiloamperes). Accurate modelling of beam jitter will therefore be critical for the purposes of planning user experiments, and for future work to mitigate the dominant jitter sources in the machine. In this contribution, we investigate the jitter tolerance of CLARA-FEBE using start-to-end simulations of the accelerator complex.
Paper: TUPL143
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL143
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
TUPL148
Design, fabrication and cold-test of an x-band accelerating structure for linearizer
2083
X-band high gradient accelerating technology is a challenging and important technology in advanced electron linear accelerator facilities. The X-band accelerating structure can provide harmonic compensation to eliminate non-linear energy spread and realize linear compression of bunch in linac. In this paper, a special X-band traveling-wave accelerating structure is designed for linearizer, with accelerating gradient of 20 MV/m under the input power below 5 MW according to the requirement of Dalian Coherent Light Source. The fabrication and cold-test of the structure are successfully completed and the transmission efficiency of power is about 0.38.
Paper: TUPL148
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL148
About: Received: 04 Apr 2023 — Revised: 15 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUPL149
Dark current in the LCLS-II-HE superconducting injector
2086
In high-gradient accelerator structures, field emission produces dark current that behaves much differently than the main photobeam current. This dark current can damage accelerator components and increase the radiation dose in the surrounding area. Thus it is important to analyze its behavior when designing a new accelerator or subsystem, such as the superconducting low-emittance injector (LEI) currently under development for the LCLS-II high-energy upgrade (LCLS-II-HE). In principle, the emission of dark current is governed by the Fowler-Nordheim (FN) equation*. In practice, variations in surface quality result in localized emission sites at locations that are not predictable a priori. Since the superconducting gun for the LEI does not exist yet, particles must be tracked from a dense array of initial positions and times on all likely emission surfaces and assigned weights according to the FN equation in the early design phases to inform the placement of collimators. We present the results of tracking studies using BMAD** and Python to analyze dark current in the LEI.
Paper: TUPL149
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL149
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
TUPL151
Evaluation of a compact electron preinjector using a low beta acceptance X-band accelerating structure
2089
At the University of Melbourne X-LAB we are investigating the use of a low \(\beta\) acceptance X-band accelerating structure as part of the design of an all X-band RF electron preinjector optimised for the production of low emittance electron bunches for medical physics applications and compact light source development. In this work we will elaborate on the estimated performance, design issues, and optimisation methodology of the preinjector beamline.
Paper: TUPL151
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL151
About: Received: 01 Apr 2023 — Revised: 10 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPL153
Beam dynamics optimization of a modular and versatile linear accelerator-based system exploiting C-Band technology for VHEE FLASH Applications
2097
In the framework of a collaboration between Sapienza University of Rome, the Italian Institute for Nuclear Research (INFN) and the Curie Institute, the proposal of a new facility dedicated to the Very High Electron Energy (VHEE) FLASH irradiation is in progress. The aim is to exploit the promising VHEE regime for the translation of electron FLASH radiotherapy into clinical practice in order to treat deep tumors. For the translation to clinical practice, the electron energy should be varied in the 60-160 MeV range. The needed electron peak current is the order of 200 mA, that is 200 nC per 1 $\mu$s pulse. The irradiation system also requires compactness for the installation inside a hospital or treatment facility. In order to satisfy both requirements, i.e. high energy and compact system, we propose a radio-frequency (RF) linear accelerator-based electron-beam source working in C-band at 5.712 GHz. In particular, we present the beam dynamics of the optimized high-gradient C-band linear accelerating system for the transport of high beam current beams for FLASH applications.
Paper: TUPL153
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL153
About: Received: 01 May 2023 — Revised: 24 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
TUPL154
Planning, installation and testing of the RF system for the upgrade of the Star facility
2101
In 2021, the Italian Institute for Nuclear Physics (INFN) was awarded the project for installing, testing and commissioning the energy upgrade of the Southern European Thomson back-scattering source for Applied Research (STAR) which is currently installed at the University of Calabria (UniCal). The STAR high-energy Linac, STAR-HEL, consists in a layout comprising RF accelerating structures (linacs), with relative magnetic optics components, in order to boost the electron beam energy from 65 MeV up to 150 MeV. In this paper, we discuss the status of the planning, installation and testing of the RF system (accelerating structures, power, network and LLRF) based on C-band (i.e. 5712 MHz RF frequency) technology. For this purpose, two C-band linacs are installed and are independently powered by two RF power stations, located aside the present S-band RF power station, which will deliver 42 MW (nominal) peak power RF pulses of 1us width and up to 100 Hz repetition rate. Operation in C-band permits acceleration with higher gradients, resulting in a more compact linac footprint.
Paper: TUPL154
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL154
About: Received: 02 May 2023 — Revised: 18 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
TUPL155
High power test results of diode E-Gun based 4-6 MeV Accelerator Beam Centerline (ABC)
2104
Varex Imaging High Energy Sources Group has developed, built, and tested a Diode Electron Gun (DEG) based 6 MeV Accelerator Beam Centerline ABC-6-S-X-D, which showed excellent performance results, and has been entered into a serial production. The ABC is very similar in performance to its Varian-produced counterpart and may be used as its drop-in replacement in the existing installed Varex linac system base, which exceeds 1000 units. While we intend to utilize a Triode Electron Gun (TEG) based ABC in all new products, this DEG based design can also be used in linac systems for security screening, non-destructive testing, and medical applications. This paper presents high power test results of the developed ABC-6-S-X-D.
Paper: TUPL155
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL155
About: Received: 26 Apr 2023 — Revised: 28 Jun 2023 — Accepted: 28 Jun 2023 — Issue date: 26 Sep 2023
TUPL156
High voltage e-gun for LINAC
2106
A typical commercially available thermionic triode e-gun operates in 10-15 kV range. Certain linac accelerating structures may benefit from higher voltage injection. Based on commercially available low voltage e-guns Varex Imaging High Energy Sources Group has developed an e-gun that could be operated in extended range of voltages of 10-40 kV, provides high adjustability of injecting beam parameters. The new e-gun can be utilized with both triode and diode options
Paper: TUPL156
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL156
About: Received: 26 Apr 2023 — Revised: 28 Jun 2023 — Accepted: 28 Jun 2023 — Issue date: 26 Sep 2023
TUPL160
Accelerator physics experiments at the versatile SRF photoinjector of SEALab
2115
The superconducting radio-frequency photoelectron injector (SRF photoinjector), now under commissioning at the SEALab accelerator test facility, has the potential to cover a fast area of beam parameters. Electron bunches from fs to ps length, with fC to nC charge can be accelerated to a couple of MeV beam energy. The legacy from the energy-recovery linac (ERL) test facility bERLinPro, the foundation of SEALab, allows us to operate the SRF photoinjector at very high repetition rate, with energy recovery (ERL), in a sustainable way for fundamental accelerator research into novel, energy-efficient electron accelerators. In this paper preparatory work for two applications is detailed. One is the use of the SRF photoinjector as a direct beam source for ultrafast scattering experiments with high 6D coherence, the other are experiments towards an ERL application for high-energy physics at high average current.
Paper: TUPL160
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL160
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUPL162
Brixsino high-flux dual X-ray and THz radiation source based on energy recovery linacs
2123
We present the conceptual design of a compact light source named BriXSinO. BriXSinO was born as a demonstrator of the Marix project, but contains also a dual high flux radiation source Inverse Compton Source (ICS) of X-ray and a Free-Electron Laser Oscillator of THz spectral range radiation conceived for medica applications and general applied research. The accelerator is a push-pull CW-SC Energy Recovery Linac (ERL) based on the technology of superconducting cavities and allows to sustain MW-class beam power with al-most just one hundred kW active power dissipation/consumption. ICS line produces 33 keV monochromatic X-Rays via Compton scattering of the electron beam with a laser system in Fabry-Pérot cavity at a repetition rate of 100 MHz. The THz FEL oscillator is based on an undulator imbedded in optical cavity and generates THz wavelengths from 15 to 50 micron. The possibility of generating in the FEL cavity also synchronized X radiation is also shown.
Paper: TUPL162
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL162
About: Received: 03 May 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
TUPL165
Dosimetry and first radiobiological assay of multi-Gy, multi-MeV TNSA proton beam with ultrahigh dose-rate
2131
Background and aim: The potential of a compact, laser-based ion accelerator for radiobiological and medical applications relies heavily on the control of the laser-target source and on the use of custom beam transport and delivery to the final target. Here we show the results of an experimental campaign dedicated to the dosimetry of the beam at the crosswire and the first radiobiological micronuclei (MN) assay study in the regime of ultra-high dose rate at selected proton energies at multi-MeV. Methods: We have developed a proton beamline based on the so-called Target Normal Sheath Acceleration (TNSA) to deliver a proton beam radiobiological applications. We use TNSA driven by a 200 TW ultra intense laser to accelerate protons with a cut-off energy of up to 10 MeV. We use permanent magnet quadrupoles to select protons at 6 MeV and transport them, in the form of a collimated beam, to the final target position in air. Results: We measured the spectrum and the deliverable dose of the proton beam at the sample position for each shot. We also evaluated uniformity across the beam and shot by shot fluctuations. We carried out dosimetric measurements that show a ultra-high instantaneous dose rate, with good uniformity over a cm-scale dimension and good shot to shot reproducibility. A preliminary measurement of radiation damage vs dose based on the MN assay was successfully carried out and compared with conventional X-ray source.
Paper: TUPL165
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL165
About: Received: 03 May 2023 — Revised: 25 Jul 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
TUPL169
Studies on a triple-turn energy-recovery mode at the S-DALINAC
2143
The electron accelerator S-DALINAC at TU Darmstadt was successfully operated in single and double-turn energy-recovery mode. The latter was realized using a shared beam-transport where two beams are superimposed in the first recirculation beamline. Due to its current design, the S-DALINAC can be upgraded with reasonable effort to be operated in triple-turn energy-recovery mode with shared beam-transport. Here, two beams are superimposed in both, the first and the second recirculation beamline. This mode is particularly challenging due to a reduced number of degrees of freedom compared to an individual beam-transport. Therefore, the triple-turn energy-recovery mode requires precise determination of the accelerator setup obtained from beam-dynamics simulations prior to beam-tuning. The results of the necessary beam-dynamics simulations for this mode are presented.
Paper: TUPL169
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL169
About: Received: 03 May 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
TUPL170
Modeling of standing wave RF cavities for tracking through multi-pass energy recovery linac
2147
Short bunches, high current and multiple linac pass are all characteristics of Energy Recovery Linacs (ERLs), which may result in collective effects. They in turn, may affect the beam, degrading its quality, or even yield to instabilities causing a beam loss. To study and mitigate these effects one needs a numerical simulation code, that can take into account both the collective effects, as well as, particular ERL features, such as a multi-turn design that does not reach a steady state or the multiple passages of the beam through Radio-Frequency (RF) cavities at different energies. CODAL [1], a code developed by SOLEIL in collaboration with IJCLab, enables such studies. It is a 6 dimensional (6D) tracking code applying 'kicks' based on the integration of the local Hamiltonian for each element of the lattice. It is also capable of simulating space charge, wakefields and coherent synchrotron radiation. However, to correctly take into account the ERL dynamics, an upgrade had to be made to include the effect of a standing wave RF cavity in 6D. In this paper, we will concentrate on the implementation and benchmarking (with DESY’s tracking code ASTRA [2]) of both the longitudinal and the transverse models (by J.B. Rosenzweig and L. Serafini [3]), which we use to carry out tracking of fully analytical 6D RF cavity.
Paper: TUPL170
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL170
About: Received: 03 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
TUPL171
Lattice design of 250 MeV version of Perle
2151
The PERLE (Powerful Energy Recovery LINAC for Experiment) collaboration is developing a high power energy recuperation linac facility with three acceleration (up to 500 MeV) and three deceleration passes through two cryo-modules at an injection current of 20 mA. Here we present the lattice design of the first stage of this machine with one cryo-module that would demonstrate the six-passes operation with a maximal energy of 250 MeV at a high current. This lattice has a simpler design with less elements therefore it requires lower initial expenses and shorter construction and commissioning times. All the magnets and the cryo-module are chosen to be compatible with both stages to minimise the costs of upgrade to a final one.
Paper: TUPL171
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL171
About: Received: 03 May 2023 — Revised: 07 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
TUPM001
Beam test of physics applications at the beam commissioning of the RAON accelerator
2189
The RAON accelerator has been constructed for various fields of science programs since 2011. The installation of the low-energy superconducting accelerator section (SCL3) had finished at the end of 2021, and the cooling of the cryogenics system started in early 2022. Prior to the SCL3, the beam commissioning has been carried out at the injector section of the RAON accelerator since 2020, and the beam was successfully accelerated with five quarter-wave resonator (QWR) cavities at the front of the SCL3 in October 2022. For successful and efficient beam commissioning, various beam physics studies have been conducted for several years, and physics applications have been also developed. Here we will introduce various physics applications used for beam commissioning and show the results of these beam tests.
Paper: TUPM001
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM001
About: Received: 25 Apr 2023 — Revised: 10 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPM002
Commissioning status of the RAON superconducting accelerator
2192
The Rare isotope Accelerator Complex for ON-line experiments (RAON) has been proposed as a multi-purpose accelerator facility for providing beams of exotic rare isotopes of various energies. It can deliver ions from hydrogen (proton) to uranium. Protons and uranium ions are accelerated up to 600 MeV and 200 MeV/u respectively. It can provide various rare isotope beams which are produced by isotope separator on-line system. The RAON injector was successfully commissioned in 2022 to study the beam parameters from the main technical systems, such as the ECR ion source and RFQ, and to find the optimized LEBT and MEBT setpoints and matching conditions. In addition, the low-energy superconducting linac (SCL3) is under commissioning. In this paper, we present the current beam commissioning status of the RAON injector and superconducting accelerator.
Paper: TUPM002
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM002
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPM003
Optimizing coupling slot design for pi-mode structure cavity in CSNS II debuncher
2195
This paper proposes a new coupling slots design for the Pi-Mode structure high-frequency cavity in the China Spallation Neutron Source (CSNS) Phase II. Through simulation calculations and experimental verification, it was found that the new coupling slots design significantly improves the Q value and transmission efficiency of the high-frequency cavity. This study is of great significance for improving the performance of the high-frequency cavity in CSNS II, and thus improving the accuracy and efficiency of neutron scattering experiments.
Paper: TUPM003
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM003
About: Received: 04 May 2023 — Revised: 30 Jun 2023 — Accepted: 30 Jun 2023 — Issue date: 26 Sep 2023
TUPM004
Upgrade of the heavy ion accelerator complex at INFN-LNL
2198
LNL heavy ion accelerator complex is based on three main accelerators: Tandem, ALPI and PIAVE. The Tandem XTU is a Van de Graaff accelerator normally operated at terminal voltages of up to about 14 MV. It can be operated in stand–alone mode or as an injector for the linac booster ALPI. The linear accelerator ALPI is built of superconducting resonant cavities and consists of a low–beta branch, particularly important for the acceleration of the heavier mass ions, a medium–beta branch, and a high–beta branch. ALPI can be operated also with the PIAVE injector that consists of a superconducting RFQ and an ECR source. In the last two years, accelerator complex underwent special maintenance to improve its availability and reliability in view of the operation with both Uranium and radioactive beams. In this framework, the main improvements that will be presented will concern Tandem injector and laddertron system, PIAVE ECR source, cryogenic control system and SRFQ tuning system, ALPI low and medium beta design, vacuum control system and new techniques for beam dynamic simulation and commissioning.
Paper: TUPM004
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM004
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
TUPM005
Prototyping of permanent magnet based drift tube for KOMAC 100-MeV DTL
2202
A high-power proton linac at KOMAC uses a drift tube linac structure to accelerate protons up to 100 MeV. Currently, a total of 148 drift tubes with electromagnetic quadrupoles are used in DTL sections for accelerating protons from 3 MeV to 20 MeV. A drift tube based on a permanent magnet quadrupole has been designed and prototyped to replace the EMQ-based drift tube to enhance the DTL reliability. A designed PMQ with an integrated field gradient of 1.6 T is assembled from 16 segments, which are made of Sm2Co17 magnetic material for its radiation hardness. Details of the prototyping study on the PMQ including design, fabrication, and test along with the beam dynamics effects are given in this presentation.
Paper: TUPM005
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM005
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
TUPM007
High-gradient accelerating structures for proton radiography booster linac
2205
Increasing energy of proton beam at the Los Alamos Neutron Science Center (LANSCE) from 800 MeV to 3 GeV will improve radiography resolution ten-fold. This energy boost can be achieved with a compact cost-effective linac based on normal conducting high-gradient (HG) RF accelerating structures. Such an unusual booster is feasible for proton radiography (pRad), which operates with short beam pulses at very low duty. The pRad booster starts with a short L-band section to capture and compress the 800-MeV proton beam from the existing linac. The main HG linac is based on S- and C-band cavities. An L-band de-buncher at the booster end reduces the beam energy spread at 3 GeV three times below that at the exit of the existing 800-MeV linac. We continue developing proton HG standing-wave structures with distributed RF coupling for the booster. Results of measurements for a two-cell test cavity at the LANL C-band RF Test Stand and a comparison with conventional traveling-wave structures are presented.
Paper: TUPM007
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM007
About: Received: 02 May 2023 — Revised: 05 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
TUPM010
Novel multi-beam front end for LANSCE accelerator facility
2212
The LANSCE accelerator facility has been in operation for 50 years performing important scientific support for national security. The unique feature of the LANSCE accelerator facility is multi-beam operation, delivering beams to five experimental areas. To reduce long-term operational risks and to realize future beam performance goals in support of the laboratory missions, we develop a novel high-brightness Front End injector. Proposed injector includes two independent low-energy transports for H+ and H- ions merging beams at the entrance of a single RFQ. These beamlines also perform preliminary beam bunching before RFQ. The challenge of the present project is associated with simultaneous acceleration of protons and H- ions with multiple beam flavors in a single RFQ, which has never been done before. Proposed injector must provide better than existing beam parameters while beam intensity is supposed to be increased by a factor of two and injection energy is reduced from 750 keV to 100 keV. The paper discusses details of beam physics design and presents injector parameters.
Paper: TUPM010
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM010
About: Received: 01 May 2023 — Revised: 26 Jun 2023 — Accepted: 26 Jun 2023 — Issue date: 26 Sep 2023
TUPM012
High-energy beamline for delivering H- laser stripped proton beam to LANSCE experimental area
2216
A unique feature of the current LANSCE accelerator facility is acceleration of four H- beams (differing in time structure) and one H+ beam. This is achieved by utilization of an injector system based on two ion sources (H+/H-), and a combination of chopper and RF bunchers in the Low Energy Beam Transports. Since the end of 1990’s, the large LANSCE experimental, Area-A, has been largely unused. In order to restore usage of Area-A, we have been exploring the possibilities of bringing low-intensity power beams into Area-A*. The proposal is based on partial stripping of the 800 MeV H- beam that is transported to the Weapons Neutron Research Facility, and to deliver the resulting 10 – 100 nA proton beam to Area-A. The appropriate place for generating proton beam was found to be the beginning of Line D after LANSCE Switchyard by first neutralizing the beam from H- to neutral hydrogen beam ahead of the bending magnet using a laser, and then by fully stripping the neutral hydrogen beam to protons utilizing a stripper foil. The paper discusses design details of the proposed high-energy beamline and beam parameters.
Paper: TUPM012
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM012
About: Received: 01 May 2023 — Revised: 17 May 2023 — Accepted: 17 May 2023 — Issue date: 26 Sep 2023
TUPM015
Comparison of design and production RF settings at SNS normal temperature linac
2219
The beam optics in the SNS normal conducting linac is analyzed for the 1.4 MW beam-on-target operation settings. The first section is a room temperature copper linac which include Medium Energy Beam Transport (MEBT) section with four re-bunching radio-frequency (RF) cavities, Drift Tube Linac (DTL), and Coupled Cavity Linac (CCL). The Radio Frequency (RF) cavities in this section accelerate H- beam to 185.5 MeV. For production runs the parameters of RF cavities in this section are chosen by using combination of models and empirical tuning providing low beam loss and low rate of discharge events inside the cavities. For some cavities the set parameters are significantly different form the design values. The paper discusses accuracy of these settings and discrepancies between design and real-life high-power production settings in the warm linac section of SNS.
Paper: TUPM015
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM015
About: Received: 01 May 2023 — Revised: 05 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
TUPM018
Implementation of the Additive Manufacturing for metals approach: the production of the acceleration grids for DTT NBI project
2230
Acceleration grids of the Neutral Beam Injector in nuclear fusion reactors must be extremely accurate and satisfy specific geometrical requirements to work properly. The implementation of the additive manufacturing technology was proposed since 2017 starting the characterization of pure copper up to the recent excellent results in terms of density, process reliability and repeatability. To assure the required performance and maximize the beam optics and the overall system efficiency, an intense study of the geometry of these components was performed, adopting a spherical aspect of planes. The material selection was also an important step of the work. An integrated cooling system, peculiar of the AM technology, was optimized, ensuring a relevant reduction of temperature peaks. Pure copper and CuCrZr alloy were investigated for reaching the best material properties: parameters optimization was executed using different machines and laser beams, and several post processes were assessed, such as surface treatments to smooth the cooling ducts. After the material characterization, which was focused on the evaluation of density, thermal conductivity and mechanical strength of the AMed parts. Lastly, several prototypes were produced and power tests were carried out.
Paper: TUPM018
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM018
About: Received: 05 May 2023 — Revised: 05 Jun 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
TUPM019
Configuration and engineering integration in the IFMIF-DONES project
2234
The IFMIF-DONES facility (International Fusion Materials Irradiation Facility – DEMO Oriented Neutron Source) is currently under design and being prepared for the construction phase within the framework of a EUROfusion Consortium work package. Its location will be in Escúzar, Granada and it will be the largest science and technology infrastructure project developed in Spain. Its objective is the study and certification of irradiated fusion materials by the generation of a neutron flux with a broad energy distribution covering the typical neutron spectrum of a (D-T) fusion reactor. For this purpose, a facility which accommodates a 40 MeV at 125mA deuteron Linac, a liquid lithium target and test module are being undertaken. Building and conventional plant systems are also designed to house, serve and allow main systems correct operation. Due to the complexity and high number of collaborators involved, it is of utmost importance to properly manage design and configuration integration activities. This paper describes current CAD management approaches and methodology followed in the project to coherently arrange Structures, Systems and Components (SSCs) throughout the facility’s lifecycle, easing identification of potential design inconsistencies and interferences as early as possible to actively resolve them and speed-up development of the project towards a ready-to-construct status, minimizing future construction, commissioning and operation issues and associated cost-overruns.
Paper: TUPM019
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM019
About: Received: 05 May 2023 — Revised: 20 Jun 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUPM026
Incoherent dynamics of intense proton beams under electron cooling
2237
The minimum emittance of ion beams achieved using electron cooling is limited by the heating processes of Intra Beam Scattering and diffusion driven by resonance crossing of particles due to space-charge. We describe a new experiment to explore the intense space-charge regime with a transverse tune shift approaching -0.5 using 2.5 MeV protons at the Integrable Optics Test Accelerator (IOTA) at Fermilab. We also report on the results from PyORBIT simulations incorporating transverse space-charge and electron cooling with emphasis on the incoherent dynamics of the particles.
Paper: TUPM026
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM026
About: Received: 04 May 2023 — Revised: 18 May 2023 — Accepted: 18 May 2023 — Issue date: 26 Sep 2023
TUPM031
Non-scaling fixed-field proton accelerator with constant tunes
2257
Recent studies by Dejan Trbojevic have confirmed that Non-Scaling Fixed Field Accelerators (NS-FFAs) can have their tune dependence on momentum flattened by adding non-linear components to the magnet fields, although not necessarily for an unlimited momentum range. This paper presents such a cell suitable for the proposed 3-12MeV FETS-FFA proton R&D ring at RAL. The nonlinear magnetic field components are found automatically using an optimiser and settings covering a ring tune range of one unit in both planes independently are attainable. A fully configurable magnet with multiple windings across its horizontal aperture has been designed in 2D using Poisson, which can produce the required nonlinear fields without exceeding 5A/mm^2 current density.
Paper: TUPM031
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM031
About: Received: 20 Apr 2023 — Revised: 05 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPM032
FFA magnet prototype for high intensity pulsed proton driver
2261
Fixed field Alternating gradient (FFA) accelerator is an option as a proton driver for the next generation spallation neutron source (ISIS-II). To demonstrate FFA suitability for high intensity operation, a 3 to 12 MeV proton prototype ring is planned at RAL, called FETS-FFA. The main magnets are a critical part of the machine, and several characteristics of these magnets require development. First the doublet spiral structure has never been designed before, and the essential feature of operational flexibility in terms of machine optics requires a wide range of changes for the field gradient. Finally, control of the fringe field is a challenge both mechanically and from the nonlinear optics point of view. This paper will discuss the design of the prototype magnet for FETS-FFA ring.
Paper: TUPM032
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM032
About: Received: 03 May 2023 — Revised: 14 Jun 2023 — Accepted: 14 Jun 2023 — Issue date: 26 Sep 2023
TUPM033
Adiabatic capture in the FETS-FFA ring
2265
Adiabatic capture of a coasting beam can be used to minimise the emittance of the resulting bunched beam – for example to capture the injected beam at the start of the acceleration cycle. In some cases, the voltage follows the so-called iso-adiabatic voltage law in order maintain the same adiabaticity throughout capture. Here we show that a linear evolution can result in a smaller final emittance than an iso-adiabatic scheme. This is shown by tracking a distribution through various capture schemes, taking as our example capture at injection in the FETS-FFA proton ring. We include preliminary results on the effects of longitudinal space charge which can be significant in this ring.
Paper: TUPM033
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM033
About: Received: 03 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
TUPM034
Dynamic aperture studies for vertical fixed field accelerators
2269
Vertical orbit excursion Fixed Field Accelerators (vFFAs) feature highly non-linear magnetic fields and strong transverse motion coupling. The detailed study of their Dynamic Aperture (DA) requires computation codes allowing long-term tracking and advanced analysis tools to take the transverse motion linear and non-linear coupling into account. This coupling completely transforms the beam dynamics compared to a linear uncoupled motion, and an explicit definition of the DA is needed to characterize the performance and limitations of these lattices. A complete study of the DA in the 4D phase space in highly non-linear and strongly coupled machines must give a measure of the stability domain but also means to assess the operating performance in the physical coupled space. This work presents a complete set of methods to perform such detailed analysis. These methods were explored and compared to compute and characterize the DA of an example vFFA lattice. The whole procedure can be further applied to evaluate DA using realistic models of the magnetic fields, including fringe fields and errors.
Paper: TUPM034
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM034
About: Received: 10 May 2023 — Revised: 13 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPM041
Status of 70 MeV Cyclotron at Laboratori Nazionali of Legnaro
2293
The 70MeV cyclotron at Laboratori Nazionali di Legnaro was installed and commissioned in 2017 and the accelerator was operational until March 2021. The shut down was foreseen in order to permit the completion of the SPES facility, while the resume of activities is expected on 2023. The status of the cyclotron and related high intensity beamlines will be presented as well as the last performance achieved in terms of accelerated current up to 1 MeV. Moreover the program of upgrade of the ancillary systems shall be discussed.
Paper: TUPM041
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM041
About: Received: 03 May 2023 — Revised: 18 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
TUPM046
Study for space charge effect in tune space at CSNS-II/RCS
2299
CSNSII is an upgrade project of China Spallation Neutron Source (CSNS), which needs to increase the beam power from 100kW to 500kW. In order to find a suitable working point area in advance and evaluate the influence of space charge effect on CSNSII, the measurements of beam loss with different tunes on CSNS was carried out and beam loss simulation in transverse tune space on CSNSII has been performed using PyORBIT code. We gave the relationship between the beam survival rate and the working point, compared four groups of candidate working points and confirmed the influence of the fourth-order resonance on the beam through the single particle model.
Paper: TUPM046
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM046
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
TUPM048
The development of aggregation diagrams for high-level planning at the ESS
2305
Accelerator facilities are among the most complex projects, integrating advanced engineering systems and components. At the ESS, the need to visualise the intricate integration activities has led to the development of Aggregation Diagrams (ADs). The diagrams follow the facility breakdown structure with sections and system diagrams showing their integration of the devices with enabling and interfacing systems such as the vacuum, cooling, power suppliers and control systems. Commissioning diagrams have also been developed and are used to visualise the main steps and events in the commissioning of the accelerator. The main advantage of using ADs is to help in the activities planning, provide easy access to high-level plans and develop a standard tool that could be used among the different work packages. In this paper, we present the workflow on the development of ADs giving some examples of their use in the activities planning at the ESS.
Paper: TUPM048
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM048
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPM056
Estimation of the anode power supply current of the J-PARC MR RF system for 1.36 s cycle operation
2320
The J-PARC Main Ring (MR) delivers high-intensity proton beams for the neutrino experiment. The beam intensity delivered to the neutrino experiment reached 520kW with a cycle time of 2.48 seconds in 2021. We chose to shorten the MR cycle time to 1.36 seconds to achieve higher beam intensity. An anode power supply feeds a high-voltage DC current to the tetrode vacuum tubes, which drive the RF cavity. Beam acceleration in a shorter MR cycle requires a higher RF voltage to keep the RF bucket large enough and a larger anode power supply current for the beam loading compensation. We plan to add RF systems to achieve higher RF voltage and to manage the output current of each anode power supply under limitations. To estimate the anode power supply current with a shorter MR cycle, we derived the beam loading compensation contribution in the power supply current using the data recorded during the operation with a cycle time of 2.48 seconds. We present the estimated anode power supply current for various combinations of RF voltage and the number of RF cavities.
Paper: TUPM056
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM056
About: Received: 31 Mar 2023 — Revised: 20 Jun 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUPM060
Vacuum tube operation analysis under a positive grid biasing in J-PARC RCS
2327
> Tetrode vacuum tubes are used under the positive grid region > to accelerate a high intensity beam in the RCS. A tube amplifier is operated in push-pull mode and two tubes are installed in the amplifier. Although each control grid should be driven in counterphase for the push-pull operation, the waveform becomes asymmetric by the positive grid biasing. The vacuum tube operation analysis should include such an effect caused by the positive grid biasing. The analysis becomes complicated because the anode current and the control grid voltage waveforms interact each other under the heavy beam loading. The effects caused by the positive grid voltage are analyzed with the self-consistency. We will describe the analysis result under the positive grid biasing.
Paper: TUPM060
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM060
About: Received: 01 May 2023 — Revised: 12 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPM063
Recent status of J-PARC 3 GeV Rapid Cycling Synchrotron
2339
The 3 GeV rapid cycling synchrotron (RCS) at the Japan Proton Accelerator Research Complex (J-PARC) provides more than 800 kW beams to the Material and Life Science Facility (MLF) and Main Ring (MR). We have been continuing a beam study to achieve 1-MW, design power operation. In addition, we have also improved and maintained the accelerator components to establish a stable operation. This paper reports the status of the J-PARC RCS in recent years.
Paper: TUPM063
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM063
About: Received: 01 May 2023 — Revised: 14 Jun 2023 — Accepted: 14 Jun 2023 — Issue date: 26 Sep 2023
TUPM065
RF conditioning towards continuous wave of the RFQ of the linear IFMIF prototype accelerator
2345
The Linear IFMIF Prototype Accelerator (LIPAc) is designed to accelerate 125mA of deuteron beam to 9MeV in continuous wave (CW). The superconductive RF Linac has not yet been installed and the final accelerating stage now under commissioning is the RFQ. This system has been designed and developed by INFN (Italy) before installation in QST (Japan). The RFQ is the longest in the World with its 9.8m and requires RF power injection from 8 independent and synchronized coupler ports. LIPAc demonstrated the acceleration of 125mA deuteron beam at 5MeV for 1ms with a 1s repetition period in 2019. A fundamental milestone to extend beam operations to CW is the completion of the RFQ cavity RF conditioning up to CW. This work presents the strategy followed to successfully reach CW RF injection at 80% of the nominal 132kV vane voltage. The field distribution correction scheme (acting on cooling system at various power level) was successfully verified. We discuss as well the main challenges encountered on the way, which include updates of the RF system, failure of a circulator (by arcs) and the damages occurred on some of the RF couplers. Finally, the recent status and outlook will be provided.
Paper: TUPM065
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM065
About: Received: 08 May 2023 — Revised: 09 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
TUPM069
Studies and results of electrostatic devices for the SPIRAL2-DESIR project at GANIL Caen France
2353
The SPIRAL2 installation at GANIL, Caen France is al-ready in operation since 2019 and produce a large num-ber of new radioactive ion beams at high intensities. In 2027, the DESIR facility will receive beams from the upgraded SPIRAL1 facility of GANIL (stable beam and target fragmentation) and from the S3 Low Energy Branch (fusion-evaporation and deep-inelastic reactions). The construction of the DESIR building will start in 2023. Many parts of the process is already build and stored on site at GANIL. The DESIR facility require some long transfer beam lines and distribution lines up to ex-perimental set-ups. These lines must be very robust and will transport mono-charged radioactive ion beams up to 60keV. All along the design of the beam lines since 2012, various electrostatic systems have been design and care-fully reviewed like quadrupoles, steerers and deflectors. This paper will focus on the design of different deflector developped for the DESIR project.
Paper: TUPM069
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM069
About: Received: 26 Apr 2023 — Revised: 05 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPM073
Scheduling tools development to manage CERN accelerators programmed stops and facilities installations
2364
The Scheduling Tool Project (ST Project) is in charge of ensuring the scheduling and coordination of CERN accelerator programmed stops and facilities installation managed within the Accelerator Coordination and Engineering (ACE) Group, inside the Engineering Department (EN) at CERN, since 2019. The scheduling tools should consider all the activities, that take place in large facilities, composed of complex and interdependent systems, ensuring the safety rules and quality standards. The current goal of the ST Project is to consolidate the scheduling tools that are used, and to homogenize them through the different facilities, merging the user needs with the developer solutions. This will lead to be ready for the Long Shutdown 3 (LS3) which will start in 2026. This paper describes the tools used to manage CERN programmed stops to build a coherent schedule, follow up, and report progress. It gives the details of the requirements, code design and future works to create a linear view on a web interface and the first results. It also describes the specifications needed to implement a report indicator in this linear view (i.e., broken line curve).
Paper: TUPM073
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM073
About: Received: 02 May 2023 — Revised: 08 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
TUPM074
PLAN - from LS2 to RUN3-LS3 and outcomes from the first RUN3-LS3 PLAN exercise
2367
The CERN-wide coordination of the programmed stops requires a tool to centralize and collect all the activities at a macroscopic scale. It includes the activities foreseen during Long Shutdowns (LS) and Year End Technical Stops (YETS). The CERN tool named PLAN centralises all the activities foreseen by the Groups, to have a global strategic view, assessing priorities across CERN. Thanks to the tool, arbitration processes are possible with Programmed Stops coordination, Groups and Departments. The LS2 (2018-2022) experience and the similarity of needs made the PLAN tool the obvious choice to fulfill this function for the period following the LS2. However, this tool needs some significant changes to be adapted to the constraints defined by the Run3 (2022-2025) programmed stops and previous Shutdown completion (LS2). The paper will describe the methodology to define the changes, the improvements implemented, and future developments, to support more effectively the CERN-wide coordination.
Paper: TUPM074
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM074
About: Received: 03 May 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
TUPM075
Improved antiproton production beam at CERN
2371
Antiprotons are generated at CERN by extracting a high-intensity proton beam from the Proton Synchrotron (PS) onto a target. The resulting antiprotons are captured in the Antiproton Decelerator (AD) ring. As the AD is about three times shorter than the PS, the entire primary proton beam must be compressed to less than one third of the PS circumference. The previous batch compression brought four bunches injected from the PS Booster (PSB) into consecutive RF buckets at a harmonic number of 20. An improved injection and compression scheme has been developed and commissioned to deliver five bunches to the AD. It became feasible thanks to the upgrades of the injector complex for the High-Luminosity LHC (HL-LHC). One of the four PSB rings delivers twice higher intensity in two bunches, and an optimized sequence of nine different RF harmonics has been set up to obtain five bunches within one quarter of the PS circumference. The contribution summarizes the main changes to the antiproton production beam, as well as the experience of the first year of operation. Results of beam tests with increased total intensity are presented.
Paper: TUPM075
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM075
About: Received: 18 Apr 2023 — Revised: 20 Jun 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUPM087
Test facility supporting modernization of the LANSCE front end
2409
We present the latest developments of the test facility for LANSCE Front-End Upgrade. The upgrade will significantly improve the operations and reliability of LANSCE, with upgrade options for future capability. This effort includes a highly diagnosed ion injector, low-energy beam characterizations, and RFQ analysis. Comparisons between beamline measurements and simulations are presented.
Paper: TUPM087
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM087
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
TUPM088
Development of He2+ 10GHz ECR ion source for astatine generation accelerator
2412
Tokyo Institute of Technology is planning a linac facility to produce 211 astatine, an isotope for αemitter cancer therapy. To produce astatine, we aim to bombard a bismuth target with helium ion beam of sufficient intensity at 28 MeV. Unlike a cyclotron, this facility will be able to accelerate a milliampere class high intensity helium ion beam. In addition, the subsequent accelerator system can be made compact by providing fully stripped helium ions. For this purpose, the ECR ion source is best suited. The multiply charged ions are generated by resonant absorption of microwaves by electrons orbiting in a magnetic field and are capable of supplying high-intensity beams. The ECR ion source will use an RF frequency of 10 GHz, and a suitable magnetic field distribution will be designed to confine the plasma by a composite magnetic field consisting of a mirror field using two solenoid coils and a magnetic field generated by a sextupole magnet to increase the charge states of the ions in the chamber. The final goal is to extract He2+ at 15 mA. In this presentation, the design and magnetic field distribution are reported, including experimental results.
Paper: TUPM088
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM088
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
TUPM091
Investigating alternative extraction methods at MedAustron
2419
MedAustron is an ion therapy facility for protons and carbon ions located in Wiener Neustadt, Austria. The beam is presently extracted for clinical operation from the synchrotron with third-order resonant slow extraction via acceleration with a betatron core. However, due to the flexibility of the synchrotron operation for Non Clinical Research (NCR) purposes, other extraction methods can be investigated for potential improvement of the machine performance as presented in this work. Radio-Frequency Knock Out (RFKO) extraction was investigated by applying an RF signal voltage across the horizontal Schottky plates in the synchrotron. Different excitation signals were evaluated with the required transverse excitation frequency band applied. Investigation of the synchronous ramping of all synchrotron magnets for extraction via Constant Optics Slow Extraction operation (COSE) was undertaken for a bunched beam in order to extend the implementation of COSE with possible Multi Energy Extraction (MEE). The last extraction method presented here is via longitudinal RF manipulation in order to extract the beam by sweeping a properly configured empty bucket through the beam stack. This method is known as Phase Displacement Extraction (PDE). Extraction rates with these methods were observed which meet the clinical requirements and might also be considered compatible with FLASH.
Paper: TUPM091
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM091
About: Received: 03 May 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
TUPM092
The new proton beam delivery line of the TOP-IMPLART accelerator
2423
A new proton beam-delivery line for the TOP-IMPLART linac is under assembly and testing at the ENEA Frascati Research Center. TOP-IMPLART is an RF pulsed linear accelerator developed for medical applications, consisting of a 425 MHz, 7 MeV injector, followed by eight accelerating SCDTL modules operating at 3 GHz, driven by two 10 MW peak power klystrons. Proton beam can be accelerated at 63 MeV or 71 MeV (other energy values can be achieved by suitable degraders) in 3µs pulses with a typical repetition rate of 25 Hz. Following the experience gathered in multi-year irradiation campaigns based on the use of a passive spreading in air of the beam, the new line employs a magnetic scanning system and has been designed to accommodate the requirements of different targets, for multipurpose applications ranging from radiobiology experiments, test of innovative dosimeters, up to qualification of components in the field of aerospace. The paper describes the setup, the monitors of the parameters of interest (dose, fluence, flux) integrated in the line, the control system and the first characterization measurements of the main elements.
Paper: TUPM092
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM092
About: Received: 01 May 2023 — Revised: 11 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
TUPM108
A scheme to extract the beam in advance and transverse beam distribution measurement for the CSNS RCS
2474
The China Spallation Neutron Source (CSNS) is a large scientific facility for frontier research by using the medium energy protons bombardment of tungsten target to produce a large number of scattered neutrons. The rapid cycling synchrotron (RCS) adopts the single-turn fast extraction scheme to extract the proton beam with the energy of 1.6GeV, and the extraction repetition frequency is 25Hz. In order to optimize the painting distribution and reduce the beam loss in the beam commissioning, it is necessary to measure the transverse beam distribution during the injection and acceleration processes. In this paper, a scheme to extract the beam in advance is proposed which is performed by adjusting the extraction timing and extraction mode. By using this extraction mode, the beam can be extracted at different time and the transverse beam distribution can be measured by a multi-wire scanner located on the beam transport line from the RCS to the target (RTBT). Then, the beam distribution at the desired position on the RCS can be deduced by using the beam transfer matrix.
Paper: TUPM108
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM108
About: Received: 03 May 2023 — Revised: 18 May 2023 — Accepted: 18 May 2023 — Issue date: 26 Sep 2023
TUPM116
Benchmarking simulations of slow extraction driven by RF transverse excitation at the CERN Proton Synchrotron
2487
Resonant slow extraction is a beam extraction method which provides a continuous spill over a longer duration than can be achieved with fast single-turn or non-resonant multi-turn extraction. By using transverse excitation to drive the circulating particles onto the resonance, a beam can be delivered to stationary target experiments which require low intensity, long-duration beams. In order to accurately and efficiently simulate the extraction process over a wide range of timescales, new modelling tools and computing platforms must be explored. By utilising optimised computational hardware - such as General Purpose Graphics Processing Units (GPGPUs), and next-generation simulation software (such as Xsuite), computation times for simulations can be reduced by several orders of magnitude. This contribution presents recent developments of resonant slow extraction modelling and benchmarking with a comparison to measurements made at CERN’s Proton Synchrotron (PS), with a particular focus on understanding the dynamics of transverse RF excitation and effect on spill quality.
Paper: TUPM116
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM116
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUPM128
Commissioning status of the Frankfurt Neutron Source FRANZ LEBT and RFQ
2530
The Frankfurt Neutron Source FRANZ will be a compact accelerator driven neutron source utilizing the 7Li(p,n)^7Be reaction with a 2 MeV proton beam. Recent comissioning efforts showed succesful proton beam operation at the targeted RFQ injection energy of 60 keV up until the point of RFQ injection. The RFQ was retrofitted with new electrodes for the injection energy of 60 keV. We report on the status of comissioning of the beamline and RFQ.
Paper: TUPM128
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM128
About: Received: 02 May 2023 — Revised: 15 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPM131
Closed-orbit distortion study of XiPAF upgrading project synchrotron
2534
Xi’an 200 MeV proton application facility (XiPAF) upgrading project is now in the design phase. For the synchrotron of the project, the influence of the dipole and quadrupole errors on the closed-orbit distortion(COD) is a matter we must pay attention to. However, Before the synchrotron assembly is complete, we do not know the actual errors of magnets. So we set certain distribution for different types of magnet errors according to the previous engineering experience and then investigate the COD caused by it, and finally we use the principle of statistics to find the relationship between them. This work was carried out with MADX program. Results show that for almost all types of magnet error, the rms value of COD is in direct proportion to the rms value of magnet error, except the rotation error around the y-axis for dipoles, in which case the COD is in direct proportion to the square of the rms value of the error. In addition, the proportionality coefficient between COD and different types of magnet error varies a lot. This can guide us to restraint the error type with high coefficient strictly for better synchrotron performance and relax the requirements slightly of the error type with low coefficient for a more economic cost.
Paper: TUPM131
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM131
About: Received: 27 Apr 2023 — Revised: 10 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPM134
Research on longitudinal dynamics and design of RF parameters of synchrotron for XiPAF-upgrading project
2545
Xi 'an 200 MeV Proton Application Facility (XiPAF) will be upgraded to proton and heavy ion synchrotron recent-ly. In order to ensure the enough life of heavy ion beam, the synchrotron requires ultra-high vacuum, and the de-signed static vacuum is better than 5×10-10 Pa. In order to place enough vacuum pumps in the synchrotron, the circumference of the synchrotron was increased from 30.9m to 39.96 m. The cyclotron frequency range of heavy ions is 0.49~1.03 MHz. In order to reduce the en-gineering difficulty and improve the lower limit of fre-quency bandwidth requirement of the RF system, the harmonic of h=2 is used to capture and accelerate the heavy ions, and the frequency bandwidth range of the RF system is adjusted from 1~6 MHz to 0.8~5.0 MHz. In this paper, the longitudinal dynamics parameters of the upgraded synchrotron are designed, and the simulation calculation is carried out. Finally, the parameter require-ments of the RF system are proposed.
Paper: TUPM134
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM134
About: Received: 01 Apr 2023 — Revised: 23 Jun 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
TUPM136
Multiturn injection design and optimization for XiPAF-upgrading synchrotron
2553
XiPAF (Xi'an 200MeV proton application Facility) synchrotron is using H^- stripping injection and phase space painting scheme. With the demand of more particle species for single event effect study, XiPAF synchrotron has been upgraded to multiturn injection from stripping injection, the injection system must be redesigned. This paper report XiPAF synchrotron multiturn injection scheme, a simulation results by PyOrbit show that the injection efficiency is ~80% for proton and ~70% for heavy ions. The influence of space charge and magnet errors on accumulated particle number has been studied by simulation.
Paper: TUPM136
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM136
About: Received: 30 Apr 2023 — Revised: 18 May 2023 — Accepted: 18 May 2023 — Issue date: 26 Sep 2023
WEXG1
Towards a true diffraction limited light source
2569
Multi-bend achromat (MBA) lattices have initiated a fourth generation for storage-ring light sources with orders of magnitude increase in brightness and transverse coherence. A few MBA rings have been built, and many others are in design or construction worldwide, including upgrades of APS and ALS in the US. The Hybrid MBA (HMBA), developed for the successful ESRF–EBS MBA upgrade has proven to be very effective in addressing the nonlinear dynamics challenges associated with pushing the emittance toward the diffraction limit.
Paper: WEXG1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEXG1
About: Received: 03 May 2023 — Revised: 12 Jun 2023 — Accepted: 12 Jun 2023 — Issue date: 26 Sep 2023
WEODA1
Challenging students into developing accelerator-based innovations to protect the environment
2575
The I.FAST CBI is an immersive challenge-based innovation program funded by the H2020 I.FAST project. The 10-day face-to-face challenge brings together students of different disciplines from all over Europe to work together on innovative projects using accelerator technology applied to environmental challenges. We report on the first edition of the I.FAST CBI, the proposed projects and feedback from the students.
Paper: WEODA1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEODA1
About: Received: 07 May 2023 — Revised: 20 Jun 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
WEODA3
Accelerator operation performance during the NSC KIPT SCA neutron source physical start up
2579
To ensure physical start up of NSC KIPT SCA Neutron Source, 100 MeV/ 100 kW electron linear accelerator should provide stable operation mode with 100 MeV electron beam energy, 20 Hz repetition rate, 35-40 mA pulse beam current, ± 3 beam energy spread and about ± 3 mm beam sizes. During preparations to the facility start up the required beam parameters were adjusted and secured during the SCA facility start up. The accelerator showed stable operation performance. The procedure of the accelerator stable operation mode tuning, adjustment secure during the whole period of the facility physical start up are described in the paper.
Paper: WEODA3
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEODA3
About: Received: 10 May 2023 — Revised: 11 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEOGA3
Green-oriented upgrade of accelerator complex at the SPring-8 campus
2590
In recent years, even accelerators, which are fundamental tools for advanced researches, should be green regarding energy/resource consumption and operation efficiency. How to improve the performance of accelerators in such an environment will be a major challenge for the field of accelerator science and technology. Against this backdrop, we have developed a long-term plan to promote the green-oriented upgrade of accelerator complex at the SPring-8 campus. We have started to integrate and rationalize the two independent accelerator systems, SPring-8 and SACLA, achieving a 20 % energy saving in a synchrotron radiation facility. We will then, as a next step, renovate the current SPring-8 storage ring by incorporating cutting-edge technologies not only to improve its performance but also to significantly reduce energy consumption by half. Upgrade of current SACLA will follow the SPring-8 upgrade. This presentation will describe our strategic accelerator upgrade plan, its progress and achievements, and future developments.
Paper: WEOGA3
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEOGA3
About: Received: 01 May 2023 — Revised: 06 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEYG1
The IFMIF-DONES facility: a fusion-oriented 5 MW superconducting CW linear accelerator
2599
IFMIF-DONES (International Fusion Materials Irradiation Facility, DEMO-Oriented Neutron Early Source) – a powerful neutron irradiation facility for irradiation of materials to be used in fusion reactors – is planned as part of the European roadmap to fusion electricity. Its main goal will be to characterize and qualify materials under a neutron field similar to the one faced in a fusion reactor, developing a material database for the future fusion nuclear reactors. The facility is based on an intense neutron source produced by a high current deuteron beam impinging on a liquid lithium curtain, aiming to generate by stripping reactions neutrons with an energy spectrum and flux similar to those expected to be seen by the first wall of a fusion reactor. The IFMIF-DONES facility has accomplished the preliminary design phase and currently in its detailed design phase. The next phase will be the preparation for the construction of the facility. This contribution presents the status of IFMIF-DONES design developed in the framework of the EUROfusion work programme, integrating the lesson learnt from the IFMIF/EVEDA Project (International Fusion Materials Irradiation Facility/ Engineering Validation and Engineering Design Activities - Broader Approach (BA) Agreement signed between EURATOM and Japanese Government), through a common program which includes the different commonalties and interfaces of the two projects. An overview of the present design status of the facility will be provided putting emphasis on the design status of the high current superconducting LINAC, responsible for delivering the 5 MW D+ beam at 40 MeV with very high inherent availability, focusing on the main challenges and the related R&D programme. The prospects for the construction and the commissioning of the facility in Granada (Spain) will be also reviewed.
Paper: WEYG1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEYG1
About: Received: 04 May 2023 — Revised: 30 Jun 2023 — Accepted: 30 Jun 2023 — Issue date: 26 Sep 2023
WEODB3
Understanding the beam quality requirement for high energy electron microscopy
2609
Commercial electron microscopes with a few hundred keV energies are fundamental tools for understanding the micro- to nano-scale world. One of the frontiers in electron microscopy development is to push the beam energy to MeV range to achieve improved lateral resolution for thick samples. Here we show the theoretical and preliminary experimental analysis of the electron beam quality required in the imaging and diffraction processes with different beam energy. By correlating the diffraction and imaging modalities, we use the focused beam scheme to characterize the beam emittance of a 200 keV TEM and a MeV UED. The quantitative correlation between the measured emittance and the obtained image resolution are established. This work demonstrates a characterization technique for electron microscopy and provides a guidance for designing a MeV electron diffraction and imaging beamline.
Paper: WEODB3
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEODB3
About: Received: 01 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
WEOGB1
Status and plan of the European Spallation Source proton linac beam commissioning
2613
The European Spallation Source is a spallation neutron source driven by a superconducting proton linac and currently under construction in Lund, Sweden. The proton linac of a 5 MW design power, with a 62.5 mA peak current, 2.86 ms pulse length, and 14 Hz repetition rate, is undergoing staged beam commissioning towards the initial user operation planned in 2026 at a reduced power of 2 MW. In 2022, beam was accelerated up to 21 MeV with the first tank of a drift-tube linac (DTL), consisting of five tanks. Following the commissioning step this year (2023) up to the fourth DTL tank and 74 MeV, low power beam commissioning through superconducting structures is planned for the next year (2024), up to 570 MeV and against a beam dump. The last beam commissioning step prior to the initial user operation, when the beam is sent to the spallation target, is planned for 2026. This paper provides a summary of the past beam commissioning activities and presents the current strategy for the upcoming beam commissioning steps, including machine configuration at each step.
Paper: WEOGB1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEOGB1
About: Received: 10 May 2023 — Revised: 10 May 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
WEOGB3
Implementation status of MYRRHA phase 1 (MINERVA)
2617
The MYRRHA design for an accelerator driven system (ADS) is based on a 4mA, 600 MeV CW superconducting proton linac. The first stage towards its realization is called MINERVA and was approved in 2018 to be constructed by SCK CEN in Belgium. This consist of a 4mA 100MeV superconducting linac as well as two independent target stations, one for radio-isotope research and production of radio-isotopes for medical purposes, the other one for fusion materials research. This contribution presents the main design choices and current status of the overall project parts (civil engineering, particle accelerator and target facilities).
Paper: WEOGB3
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEOGB3
About: Received: 26 Apr 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
WEODC1
A short-length transport line for laser-plasma accelerators using HTS periodic magnets
2627
In laser-plasma accelerators (LPA), due to extremely high accelerating gradients, electron bunches are accelerated to high energies in only a few millimeters to centimeters of acceleration length. To efficiently capture and transport the LPA-generated bunches in a compact transport line, beam line designs employing high-strength combined-function magnets based on high-temperature superconductor technology have been studied. Moreover, to overcome coil winding challenges in fabricating miniature HTS magnets, novel periodic magnets have been designed, which can collimate and guide the electron beams in a well-controlled short-length transport line. In this contribution, we present the beam dynamics calculations as well as the magnet designs for a 1.4 m transport line matching the LPA-generated electron beams to a transverse-gradient undulator.
Paper: WEODC1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEODC1
About: Received: 03 May 2023 — Revised: 24 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEODC2
Novel iron lamination for fast kicker magnets with high flux density
2631
Novel iron lamination with additional interlaminar insulation has been successfully developed for magnet cores of fast kicker magnets in particle accelerators. By minimizing the eddy current induced between core laminas, a pulse profile of the excited magnetic field has been significantly improved up to a few MHz range. The magnet core is formed by alternately stacking thin steel and insulation sheets to avoid electrical contact between the steel sheets on the cutting edge. A pair of test magnets with the new iron lamination was assembled to evaluate magnet performances focusing on applications to matched kickers in the accelerators. The magnetic field pulse profiles of the two magnets have successfully proved to match below 0.1% over the entire pulse duration, which is significantly better than those with conventional iron lamination. The developed fast kicker magnets are promising for the beam injection kickers in the coming next-generation light sources and future colliders, where suppression of the transient stored-beam oscillation during beam injection is crucial.
Paper: WEODC2
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEODC2
About: Received: 21 Apr 2023 — Revised: 08 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEOGC1
The need for Nb3Sn coated Cu cavities for future accelerators
2639
Based on current efforts in the U.S. on the novel concept of parallel-feed RF accelerator structures, and in the U.S. and abroad in producing Nb3Sn films on either Cu or bronze, we rec-ommend that the Particle Physics community foster R&D in Superconducting Nb3Sn coated Cu RF Cavities instead of costly bulk Nb. The paper includes methods to process the coated cavi-ties at temperatures consistent with Cu retaining its shape. A devoted global effort in develop-ing Cu cavity structures coated with Nb3Sn would make the ILC or Higgs factories more afforda-ble and more likely to be built. Not only do parallel-feed RF structures enable both higher ac-celerating gradients and higher efficiencies, but they would be applicable to both Cu and Nb3Sn coated Cu cells. Increased effort on these two techniques would synergize expenditures to-wards progress, which will converge on the choice of technology for the RF of an ILC or any fu-ture accelerator. The current methods of Nb3Sn coatings on Cu or bronze can be geared also towards standard cavity cells. In conclusion, the use of distributed coupling structure topology within improved performance parameters together with Nb3Sn coating technology can lead to a paradigm shift for superconducting linacs, with higher gradient, higher temperature of opera-tion, and reduced overall costs for any future collider.
Paper: WEOGC1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEOGC1
About: Received: 04 May 2023 — Revised: 05 Jun 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
WEPA004
Beam-ion Instabilities and Their Mitigation for SOLEIL II
2650
Beam-ion instabilities belong to a broader class of two-beam instabilities caused by the interaction of a primary beam (electron or hadron bunches) with a secondary beam (ion or electron cloud). The transverse oscillations of these beams can couple with each other. Their amplitude will grow, leading to beam losses. These instabilities can limit the operation of fourth-generation light sources with low emittances and high intensity. Many existing light sources, including synchrotron SOLEIL, are conducting upgrade studies towards fourth-generation light source parameters. This contribution investigates beam-ion instability and potential mitigation measures in SOLEIL II. The instability threshold is determined with analytical estimations and particle tracking results. The trapping of ions in the primary electron beam is discussed for the current lattice design. Differences between different numerical models of this beam-ion interaction are briefly discussed.
Paper: WEPA004
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA004
About: Received: 03 May 2023 — Revised: 30 Jun 2023 — Accepted: 30 Jun 2023 — Issue date: 26 Sep 2023
WEPA022
Recent measurements and analyses of the beam-halo dynamics at the CERN LHC using collimator scans
2693
Controlling beam losses is of paramount importance in superconducting particle accelerators, mainly for ensuring optimal machine performance and an efficient operation. Models based on global diffusion processes, in which the form of the diffusion coefficient is the stability-time estimate of the Nekhoroshev theorem, have been studied and proposed to investigate the beam-halo dynamics. Recent measurements with collimator scans were carried out at the CERN Large Hadron Collider (LHC) with the aim of reconstructing the form of the diffusion coefficient. The results of the analyses performed are presented and discussed in detail.
Paper: WEPA022
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA022
About: Received: 30 Apr 2023 — Revised: 08 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPA024
Study of high-intensity bunch merging and its experimental application on rapid cycling synchrotrons
2701
Longitudinal beam manipulation have been widely employed for various scientific and industrial applications in many hadron (heavy ion or proton) synchrotrons. One of the most important manipulations is the longitudinal bunch merging based on the dual rf system. For high-intensity hadron beams, longitudinal space-charge matching and cavity beam loading matching and compensation are of practical concern to minimize the emittance blow-up for merging of high-intensity beams. For rapid cycling synchrotrons, a trade off should be made between the limited bunch merging time and the high-intensity effects. This paper discusses the schemes for high-intensity hadron bunch merging and proposes a fast bunch merging scheme for rapid cycling synchrotrons. Some experimental preparations for the bunch merging in the CSNS/RCS are also introduced.
Paper: WEPA024
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA024
About: Received: 23 Apr 2023 — Revised: 25 May 2023 — Accepted: 25 May 2023 — Issue date: 26 Sep 2023
WEPA026
Active deep learning for nonlinear optics design of a vertical FFA accelerator
2709
Vertical Fixed-Field Alternating Gradient (vFFA) accelerators exhibit particle orbits which move vertically during acceleration. This recently rediscovered circular accelerator type has several advantages over conventional ring accelerators, such as zero momentum compaction factor. At the same time, inherently non-planar orbits and a unique transverse coupling make controlling the beam dynamics a complex task. In general, betatron tune adjustment is crucial to avoid resonances, particularly when space charge effects are present. Due to highly nonlinear magnetic fields in the vFFA, it remains a challenging task to determine an optimal lattice design in terms of maximising the dynamic aperture. This contribution describes a deep learning based algorithm which strongly improves on regular grid scans and random search to find an optimal lattice: a surrogate model is built iteratively from simulations with varying lattice parameters to predict the dynamic aperture. The training of the model follows an active learning paradigm, which thus considerably reduces the number of samples needed from the computationally expensive simulations.
Paper: WEPA026
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA026
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPA028
Detailed characterization of a five-dimensional phase space distribution
2717
We image the five-dimensional phase space distribution of a hadron beam in unprecedented detail. The resolution and dynamic range of the measurement are sufficient to resolve sharp, high-dimensional features in low-density regions of phase space. We develop several visualization techniques, including non-planar slicing, to facilitate the identification and analysis of such features. We use these techniques to examine the transverse dependence of longitudinal hollowing and the longitudinal dependence of transverse hollowing in the distribution. Our results strengthen the claim that low-dimensional projections do not adequately characterize high-dimensional phase space distributions.
Paper: WEPA028
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA028
About: Received: 01 May 2023 — Revised: 18 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
WEPA030
Current Status of the Beam Dynamics Simulations for the HBS Drift Tube Linac
2721
As various experimental reactors in Europe are already or will be decommissioned over the next years, new neutron sources will be necessary to meet the demand for neutrons in research and development. The High Brilliance Neutron Source is an accelerator driven neutron source planned at the Forschungszentrum Jülich. The accelerator will accelerate a proton beam up to an end energy of 70 MeV, using normal conducting CH-type cavities. Because of the high beam current of 100 mA, the beam dynamics concept requires special care. In this paper, the current status of the beam dynamics for the drift tube linac is dicsussed.
Paper: WEPA030
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA030
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPA035
Polarized electron injector for positron production at CEBAF
2727
As a part of the effort to expand the capabilities of CE-BAF 12 GeV (Continuous Electron Beam Accelerator Facility) at Jefferson Lab, the addition of a polarized positron source is considered. This capability would provide acceleration of high duty-cycle polarized posi-trons, with spin >60% polarization, through the same main CEBAF accelerator machine with appropriate mag-net field reversals and linac phasing to the four CEBAF experimental halls. To produce this positron beam, a high average current (3-10 mA) highly polarized electron beam with energy of 100 – 150 MeV is required at the positron source target. The focus of this paper is the de-sign of that polarized electron beam injector. We will describe the production and delivery of a >3 mA highly polarized electron beam. We will discuss different aspects of the design, the photocathode gun, beam dynamics simulation results, spin manipulation, bunching and accelerating process and final electron beam parameters.
Paper: WEPA035
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA035
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
WEPA040
Beam dynamics optimization of EuPRAXIA@SPARC_LAB RF injector
2739
At EuPRAXIA@SPARC_LAB an X-ray FEL user facility is driven by a plasma accelerator in the particle-driven configuration where an ultra-relativistic beam, the driver, through a plasma generates a wake of charge density useful for accelerate a witness beam. The electron bunches are generated through the so-called comb technique in an RF injector that consist of a 1.6 cell S-band gun followed by four S-band TW accelerating structures. The main working point foresees a 30pC witness and a 200pC driver longitudinally compressed in the first accelerating structure operated in the velocity-bunching regime, that allows to accelerate and manipulate the beam to reach proper transverse and longitudinal parameters. The optimization of the witness emittance is performed with additional magnetic field around the gun and the S-band structures and by shaping the laser pulse at the cathode. The paper reports on beam dynamics studies performed also for beams with higher charges to maximize the transformer ratio in the plasma and the beam brightness. In addition, the insertion of an X-band RF cavity after the gun is proposed aiming to shape the beam current distribution as needed and stabilize it with respect to RF jitters.
Paper: WEPA040
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA040
About: Received: 01 Apr 2023 — Revised: 12 May 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
WEPA041
Simulation of shot noise effects in the EIC strong hadron cooling accelerator using real number of electrons
2743
The electron ion collider, the next generation nuclear physics collider is being actively studied. In order to achieve the designed luminosity 10^34/cm^2/s with a reasonable lifetime, an efficient coherent electron cooling scheme was proposed to reduce the hadron beam emittance and counter intrabeam scattering. Such a cooling scheme requires a good electron beam quality with a small energy spread. However, the shot noise in the electron beam through the accelerator might be amplified due to the microbunching instability and might degrade the electron beam quality in the modulator section of the strong hadron cooling channel and correspondingly cooling rate. In this study, we reported on a self-consistent simulation study of these effects using the real number of electrons. This captures the details of shot noise.
Paper: WEPA041
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA041
About: Received: 01 May 2023 — Revised: 07 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
WEPA042
Emittance compensation in a high charge TOPGUN photoinjector
2747
A simple acceleration of a high charge, needle-shaped electron bunch from a cathode is affected by strong correlated emittance growth due to current-dependent transverse space-charge forces. It was shown that such emittance growth could be reversed by focusing the bunch soon after it emerges from the cathode, and that one can expect to retrieve the emittance the beam was born with – the intrinsic emittance. We present a space charge emittance compensation study for a 250 pC radiofrequency photoinjector based on a 100 pC design developed by the UCLA team. We expect that a bright electron beam with an order of magnitude improvement over currently operating photoinjectors can be achieved with 250 pC electron bunches that maintain their emittance below 100 nm-rad.
Paper: WEPA042
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA042
About: Received: 03 May 2023 — Revised: 02 Jun 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
WEPA045
Arbitrary transverse and longitudinal correlation generation using transverse wiggler and wakefield structures
2759
Transverse wigglers and wakefield structures are promising candidates for imparting arbitrary correlation on transverse and longitudinal phase spaces respectively. They provide sinusoidal electromagnetic fields that become building blocks for Fourier synthesis. We present the progress of arbitrary correlation generation using transverse wiggler and wakefield structures.
Paper: WEPA045
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA045
About: Received: 13 Apr 2023 — Revised: 11 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
WEPA046
Emittance exchange with periphery cut for high-brightness beam
2763
The exchange of transverse and longitudinal emittances is a unique feature of emittance exchange (EEX) beamline, but it is also a limitation of it at the same time. Most of the modern high-brightness injectors provide much smaller emittance in the transverse plane than the longitudinal plane. Thus, a beam passing through a single EEX beamline ends up with a large transverse emittance, which significantly limits EEX beamline’s use for its various applications. Here, we present a preliminary study for avoiding this issue by optimizing the beamline for longitudinal emittance, correcting nonlinearities, and cutting the periphery of the phase space.
Paper: WEPA046
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA046
About: Received: 13 Apr 2023 — Revised: 11 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
WEPA053
Impact of multiple beam-beam encounters on LHC absolute-luminosity calibrations by the van der Meer method
2777
The LHC particle-physics program requires that the delivered luminosity be measured to an absolute accuracy in the 1% range. To this effect, the absolute luminosity scale at each interaction point (IP) is calibrated by scanning the beams across each other according to the van der Meer method. During such scans, the orbit and the shape of the colliding bunches are significantly distorted by their mutual electromagnetic interaction; the resulting biases, if left uncorrected, would absorb a major fraction of the systematic-uncertainty budget on the luminosity calibration. The present report summarizes recent studies of such biases in the single-IP configuration, and generalizes it to the more typical case where bunches collide not only at the scanning IP, but also experience additional head-on encounters at up to 3 locations around the ring. Simulations carried out with the COherent-Multibunch Beam-beam Interaction multiparticle code (COMBI) are used to characterize the dependence of beam--beam-induced luminosity-calibration biases on the phase advance between IPs, and to derive scaling laws that relate the multi-IP case to the simpler and better understood single-IP configuration.
Paper: WEPA053
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA053
About: Received: 03 May 2023 — Revised: 19 May 2023 — Accepted: 19 May 2023 — Issue date: 26 Sep 2023
WEPA054
Beam dynamics study of a CW L-band SRF gun for the high duty cycle EuXFEL
2781
The upgrade of the European XFEL to support a future high duty cycle (HDC) operation mode requires new design concepts for the photoinjector. In particular, the electron gun is crucial for achieving high quality beams at high peak currents. Among other variants, a 1.6-cell TESLA-type RF-gun is the preferable solution for the HDC EuXFEL. The SRF gun design, however, requires the application of unconventional emittance compensation schemes. One alternative is embedded RF focusing by means of a retracted cathode. Such a scheme has been previously successfully tested, e.g., at the ELBE accelerator of the HZDR. However, the beam dynamics characterization and parameter optimization for this design remains a challenge. This is primarily due to the 3D geometry of the cathode region, which cannot be easily handled by available tracking codes. In this work, we present a simulation and optimization study of the EuXFEL injector line including the geometrical and space charge effects related to a retracted-cathode SRF gun design.
Paper: WEPA054
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA054
About: Received: 03 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
WEPA064
Generalized gradient map tracking in the Siberian snakes of the AGS and RHIC
2793
Accurate and efficient particle tracking through Siberian Snakes is crucial to building comprehensive accelerator simulation model. At the Alternating Gradient Synchrotron (AGS) and Relativistic Heavy Ion Collider (RHIC), Siberian Snakes are traditionally modeled in MAD-X by Taylor map matrices generated at specific current and energy configurations. This method falls short during ramping due to the nonphysical jumps between matrices. Another common method is to use grid field maps for the Snakes, but field map files are usually very large and thus cumbersome to use. In this work, we apply a new method called the Generalized Gradient (GG) map formalism to model complex fields in Siberian Snakes. GG formalism provides an analytic function in x and y for which automatic differentiation, i.e. Differential Algebra or Truncated Power Series Algebra can find accurate high order maps. We present simulation results of the Siberian Snakes in both the AGS and RHIC using the Bmad toolkit for accelerator simulation, demonstrating that GG formalism provides accurate particle tracking results.
Paper: WEPA064
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA064
About: Received: 03 May 2023 — Revised: 06 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPA065
Towards fully differentiable accelerator modeling
2797
Optimization and design of particle accelerators is challenging due to the large number of free parameters and the corresponding lack of gradient information available to the optimizer. Thus, full optimization of large beamlines becomes infeasible due to the exponential growth of free parameter space the optimization algorithm must navigate. Providing exact or approximate gradient information to the optimizer can significantly improve convergence speed, enabling practical optimization of high-dimensional problems. To achieve this, we have leveraged state-of-the-art automatic differentiation techniques developed by the machine learning community to enable end-to-end differentiable particle tracking simulations. We demonstrate that even a simple tracking simulation with gradient information can be used to significantly improve beamline design optimization. Furthermore, we show the flexibility of our implementation with various applications that make use of different kinds of derivative information.
Paper: WEPA065
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA065
About: Received: 03 May 2023 — Revised: 18 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
WEPA067
PLACET3: 6D tracking through PETS and accelerating structures wakefields
2805
We present the latest updates to the PLACET3 tracking package which focus on the impact of both transverse and longitudinal wakefields on a beam travelling through accelerating and decelerating structures. The main focus of this update was the first implementation of 6D tracking through Power Extraction and Transfer Structures (PETS) for the Compact Linear Collider (CLIC) which is described through short and long-range longitudinal wakefields. Additionally, we present the impact of different numerical schemes on the computation of wakefields in accelerating structures.
Paper: WEPA067
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA067
About: Received: 03 May 2023 — Revised: 05 Jun 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
WEPA069
Macroparticle collisionality in PIC solver
2809
Traditionally PIC solver compute electric field created by the beam as a mean field. The effect of particle collisions is normally neglected by the algorithm. In this proceeding we address how to include the collisions between the macro particles, and discuss the computational challenges and strategies to include the collisionallity in PIC solvers as particle-particle interaction. We present simulations that benchmark our understanding and analyse potential artifacts as energy conservation or other effects.
Paper: WEPA069
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA069
About: Received: 01 Apr 2023 — Revised: 11 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
WEPA074
BDSIM v1.7.0 developments for the modelling of accelerators and their environment
2821
Beam Delivery Simulation (BDSIM) is a program based on Geant4 that creates 3D radiation transport models of accelerators from a simple optical description in a vastly reduced time with great flexibility. It also uses ROOT and CLHEP to create a single simulation model that can accurately track all particles species in an accelerator to predict and understand beam losses, secondary radiation, dosimetric quantities and their origins. We present a broad overview of new features added to BDSIM in version 1.7. In particular, the ability to transform and reflect field maps as well as visualise the fields in Geant4 are presented. A new “CT” object is introduced to allow DICOM images to be used for simulations of Phantoms in proximity to a beamline. For experiments such as FASER, SHADOWS and NA62, a muon production biasing scheme has been added and is presented.
Paper: WEPA074
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA074
About: Received: 05 May 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
WEPA078
Symplectic neural surrogate models for beam dynamics
2825
The self-consistent nonlinear dynamics of a relativistic charged particle beam interacting with its complete self-fields is a fundamental problem underpinning many of the accelerator design issues in high brightness beam applications, as well as the development of advanced accelerators. A novel self-consistent code is developed based on a Lagrangian method for the calculation of the particles’ radiation near-fields using wavefront/wavelet meshes via the Green’s function of the Maxwell equations. These fields are then interpolated onto a moving mesh for dynamic update of the beam. This method allows radiation co-propagation and self-consistent interaction with the beam in 2D/3D simulations at greatly reduced numerical errors. Multiple levels of parallelisms are inherent in this method and implemented in our code CoSyR [1] to enable at-scale simulations of nonlinear beam dynamics on modern computing platforms using MPI, multi-threading, and GPUs. Our simulations reveal the slice emittance growth in a bend and the interplay between the longitudinal and transverse dynamics that occurs in a complex manner not captured in the 1D longitudinal static-state coherent synchrotron radiation model. Finally, we show that surrogate models with symplectic neural networks can be trained from simulations with significant time-savings for the modeling of nonlinear beam dynamics effects.
Paper: WEPA078
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA078
About: Received: 10 May 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
WEPA085
Hellweg improvements for 3D traveling wave linac design with beam loading
2834
The industrial, medical and homeland security markets for low-to-moderate energy electron linacs are growing rapidly, often requiring beam currents that strongly load the accelerating fields. The two-beam accelerator (TBA) is one concept for the structure wakefield acceleration approach to an electron-positron collider. Transient beam loading effects are a significant challenge for the drive beam in a TBA structure, where energy droop in high-charge bunch trains must be understood and compensated. The Hellweg code accurately models steady state beam loading for traveling wave RF structures with a fast reduced model. The Hellweg equations of motion have recently been generalized to include arbitrary charge-to-mass ratio and to use momentum as the dynamical variable. These and other recent developments are discussed, including a new browser-based GUI. Proposed future developments include support of standing wave RF structures and transient beam loading effects.
Paper: WEPA085
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA085
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
WEPA086
PyTao: the Python interface to Tao
2838
PyTao is a Python interface to the Bmad based Tao program for accelerator design and simulation. This enables advanced design and optimization beyond the normal capabilities of Tao as well as simplifying the use of Tao as an online model for an operating accelerator. Here we will describe this interface and some of its applications, including online models for the the LCLS and LCLS-II at SLAC National Accelerator Laboratory.
Paper: WEPA086
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA086
About: Received: 11 May 2023 — Revised: 11 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPA091
Electron cloud observations and mitigation for the LHC Run 3
2850
When operated with the nominal bunch spacing of 25 ns, the Large Hadron Collider (LHC) suffers from significant electron cloud effects. During the second operational run (Run 2) of the LHC, beam-induced conditioning allowed a satisfactory exploitation of 25 ns beams for luminosity production but could not fully suppress electron cloud formation. It has since been understood that this limitation was due to a degradation of some of the beam screen surfaces that occurred with beam operation after air exposure during the first long shutdown period. In the LHC Run 3, several electron cloud effects are expected to become even more important due to the increase in bunch intensity foreseen during the run. In addition, the beam screens have again been exposed to air during the preceding shutdown period, leading to a reset of most of the conditioning acquired in Run 2 and opening the possibility for further degradation. In this contribution, we describe the experimental observations of electron cloud effects during operation with beam after the start of Run 3 in 2022 and discuss their implications for future operation and mitigation strategies for the remainder of the run.
Paper: WEPA091
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA091
About: Received: 02 May 2023 — Revised: 22 Jun 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
WEPA092
Electron cloud build-up studies for FCC-ee
2854
The Future Circular Collider (FCC) study is developing designs for a new research infrastructure to host the next generation of higher performance particle colliders to extend the research currently being conducted at CERN. In particular, FCC-ee is an electron-positron collider, which is the first stage towards a 100 TeV proton-proton collider FCC-hh. FCC-ee may be affected by electron cloud (e-cloud) and the strongest effects are foreseen for the Z configuration, due to the highest number of bunches, which corresponds to the smallest bunch spacing. The presence of a large electron density in the beam pipe can limit the achievable performance of the accelerator through different effects like transverse instabilities, transverse emittance growth, particle losses, vacuum degradation and additional heat loads of the inner surface of the vacuum chambers. In the design phase, the goal is to suppress the e-cloud effects in FCC-ee and, therefore, a preliminary study to identify the parameters, which play a significant role in the e-cloud formation has been performed. In this paper, an extensive e-cloud simulation study is presented. In particular, the impact of the e-cloud is studied for different configurations, for example: for the electron and the positron beam; in the different elements of the particle accelerator; changing the beam chamber geometry; for different values of the Secondary Emission Yield (SEY); and for different beam parameters.
Paper: WEPA092
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA092
About: Received: 11 May 2023 — Revised: 11 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPA097
Accelerating dynamic aperture evaluation using deep neural networks
2870
The Dynamic Aperture (DA) is an important concept for the study of non-linear beam dynamics in a circular accelerator. The DA is defined as the extent of the phase-space region in which the particle's motion remains bounded over a finite number of turns. Such a region is shaped by the imperfections in the magnetic fields, beam-beam effects, electron lens, electron clouds, and other nonlinear effects. The study of the DA provides insight into the mechanisms driving the time evolution of beam losses, which is essential for the operation of existing circular accelerators, such as the CERN Large Hadron Collider (LHC), as well as for the design of future ones. The standard approach for the numerical evaluation of the DA relies on the ability to accurately track initial conditions, distributed in phase space, for a realistic time scale, and this is computationally demanding. In order to accelerate the DA calculation, we propose the use of a Machine Learning (ML) technique for the DA regression based on simulated HL-LHC data. We demonstrate the implementation of a Deep Neural Network (DNN) model by measuring the time and assessing the performance of the DA regressor, as well as carrying out studies with various hardware architectures including CPU, GPU, and TPU.
Paper: WEPA097
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA097
About: Received: 11 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPA098
Injection optimization via reinforcement learning at the cooler synchrotron COSY
2874
It is crucial to have a particle beam with high intensity and small emittance in a timely manner. The main challenges restraining the availability of the beam to the user and limiting the beam intensity in storage rings are a lengthy optimization process, and the injection losses. The setup of the Injection Beam Line (IBL) depends on a large number of configurations in a complex, non-linear, and time-dependent way. Reinforcement Learning (RL) methods have shown great potential in optimizing various complex systems. However, unlike other optimization methods, RL agents are sample inefficient and have to be to be trained in simulation before running them on the real IBL. In this research, we train RL agents to learn the optimal injection strategy of the IBL for the Cooler Synchrotron (COSY) at Forschungszentrum Jülich. We address the challenge of sim-to-real transfer, where the RL agent trained in simulation does not perform well in the real world, by incorporating domain randomization. The goal is to increase the beam intensity inside COSY while decreasing the setup time required. This method has the potential to be applied in future accelerators like the FAIR facility.
Paper: WEPA098
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA098
About: Received: 29 Apr 2023 — Revised: 12 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
WEPA099
Reinforcement control for LEBT and RFQ of linear accelerators
2877
As a scientific system with many subsystems, particle accelerator system is getting more complex， due to rising demands on accelerator performance. Meanwhile, it is increasingly difficult to study such complex systems using traditional research methods based on physical models. At present, machine learning (ML) is mature enough to be applied in accelerator science such as beam diagnostics and equipment control. Compared with traditional research methods, machine learning has strong generality and high computational efficiency. However, problems such as incomplete database or insufficient test time often hinder the application of ML in accelerator operation control and optimization. To further explore the application of ML in accelerator science, in this paper, we demonstrate the feasibility of reinforcement learning in accelerator control using: 1) replacement model of linear accelerator components based on neural network; and 2) reinforcement control and fast matching of the LEBT and RFQ of the linear accelerator, which is based on reinforcement learning. These methods will be experimentally verified on a linear accelerator.
Paper: WEPA099
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA099
About: Received: 10 May 2023 — Revised: 28 May 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
WEPA100
Demonstration of Beam Emittance Optimization using Reinforcement Learning
2881
In Particle accelerators, commissioning of a complex beam line requires extensive use of computer models. When the as-built beam line cannot be exactly modeled by the simulation (due for example to mechanical errors or to the extensive usage of the non-linear focusing forces), the solution found in the simulations needs to be adjusted. Thus, it is often required to modify the settings by exploring different parameters ranges on the real accelerator. Given the high parameter space, this is a demanding task both in term of beam time and in term of required expertise. Furthermore, there is no guarantee to reach the optimal solution. This paper proposes a Reinforcement Learning approach to develop a model able to efficiently explore the parameter space of a beam line and iteratively move towards the optimal solution. The approach is first applied for the ADIGE Medium Resolution Mass Separator (MRMS) at INFN Legnaro National Laboratories (LNL), where the potentials of an electrostatic multipole must be correctly tuned to minimize the output beam emittance after the separation stage.
Paper: WEPA100
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA100
About: Received: 02 May 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPA101
Hybrid beamline element ML-training for surrogates in the impactX beam-dynamics code
2885
The modeling of current and next-generation particle accelerators is a complex endeavour, ranging from the simulation-guided exploration of advanced lattice elements, over design, to commissioning and operations. This paper explores hybrid beamline modeling, towards coupling s-based particle-in-cell beam dynamics with machine-learning (ML) surrogate models. As a first example, we train a surrogate model of an advanced accelerator element, a laser-wakefield accelerator stage, via the time-based particle-in-cell code WarpX [1]. A second example trains trains a model for the IOTA nonlinear lens via the s-based code ImpactX [2].
Paper: WEPA101
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA101
About: Received: 04 May 2023 — Revised: 18 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
WEPA104
Prediction of superconducting magnet quenches with machine learning
2889
Superconducting magnet technology is one of the foundations of large particle accelerator facilities. A challenge with operating these systems is the possibility for the magnets to quench. The ability to predict quenches and take precautionary action in advance would reduce the likelihood of a catastrophic failure and increase the lifetime operability of particle accelerators. We are developing a machine learning workflow for prediction and detection of superconducting magnet quenches. In collaboration with Brookhaven National Laboratory (BNL), our methods for algorithm development will utilize magnet data from test stands and the Relativistic Heavy Ion Collider ring magnets to allow for a robust identification of magnet quenches. Our methods divide the problem into two different aspects. First, we are developing machine learning algorithms for binary and multi-classification of the various types of quench events. Second, our prototype machine learning model will be used to predict a quench event using precursor identification. We plan to integrate and test our monitoring system at the BNL facility to perform quench identification and prediction.
Paper: WEPA104
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA104
About: Received: 03 May 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
WEPA106
Machine learning-based optimization of storage ring injection efficiency
2896
The electron injection chain of the DELTA accelerator facility starts with a 90 keV electron gun, followed by a linear accelerator (70 MeV), a first transfer line (T1) between linac and booster, a booster synchrotron (70 MeV to 1.5 GeV) and a second the transfer line (T2) connecting the booster and the storage ring (1.5 GeV). Since DELTA does not use a fast topping-up injection mode, each software-driven injection ramp cycle takes about 7 seconds. Depending on the injection efficiency, 250 to 400 ramp cycles are required to reach the maximum beam current of 130 mA in the storage ring. Therefore, for fast post-injection a high electron transfer rate is crucial. During the injection, a large number of parameters (e.g., magnet settings, timings of pulsed elements) have to be adjusted manually. The injection efficiency depends mainly on the settings of the booster extraction elements, the transfer line magnets, and the storage ring injection components. In order to automate the injection procedure and to improve the electron transfer efficiency, the application of innovative machine learning concepts (e.g., neural networks, Gaussian processes and decision trees) was studied.
Paper: WEPA106
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA106
About: Received: 27 Mar 2023 — Revised: 07 Jun 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
WEPA107
A machine learning approach to shaping magnetic fringe fields for beam dynamics control
2900
Fringe fields at the entrance and exit of multipole magnets can adversely affect the dynamics of particles in the beam, but there is also the possibility that fringe fields of the right form could be used to enhance the accelerator performance. Accelerator design work could benefit from efficient and realistic models of multipole fringe fields at an early stage in the design process. We explore novel techniques based upon analytical solutions of multipole fringe fields to produce magnets that satisfy specific requirements for the beam dynamics. Machine learning techniques are used in the design process currently being developed, to link properties of the beam dynamics to the magnet geometry in an efficient way.
Paper: WEPA107
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA107
About: Received: 13 Apr 2023 — Revised: 07 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
WEPA108
Data intensive science and particle accelerators: driving science and innovation
2904
Particle accelerators and light sources are some of the largest, most data intensive, and most complex scientific systems. The connections and relations between machine subsystems are complicated and often nonlinear with system dynamics involving large parameter spaces that evolve over multiple relevant time scales and accelerator systems. Data Intensive Science offers exciting prospects for accelerator design and operation. This includes the optimization of machine design and the reconstruction of transverse beam distributions using machine learning, as well as data analysis in high data rate monitors. This contribution presents the new Liverpool Center for Doctoral Training for Innovation in Data Intensive Science (LIV.INNO) and its exciting research and training program.
Paper: WEPA108
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA108
About: Received: 29 Apr 2023 — Revised: 05 Jun 2023 — Accepted: 05 Jun 2023 — Issue date: 26 Sep 2023
WEPA109
Parallel prediction of beam spot with neural networks and PCA at TTX
2908
At TTX, we try to use machine learning to give the virtual detection of the beam spot. The prediction of beam spot is difficult when the dimension becomes larger. We try to use PCA to make it smaller and use Neural networks to predict it. However, the weight of different dimension varies widely. We predict them parallel and get good results with easy neural networks.
Paper: WEPA109
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA109
About: Received: 19 Apr 2023 — Revised: 11 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
WEPA113
Numerical design of a compact TE11-to-TM01 mode converter for THz-driven electron acceleration
2916
In recent years the generation of high power millimeter wave and Terahertz radiation has progressed substantially, enabling electron beam manipulation and acceleration in structures with a footprint of several centimeters. However, in many experiments the external driving pulse is coupled collinearly into the waveguide structure which increases the coupling footprint relative to the wavelength tremendously (≈30 𝜆 or more) in comparison to conventional structures (≈1 𝜆 or less). Here, the design of a double-bend mode converter for 300 GHz is presented which converts the fundamental TE11 mode quasi-instantaneously to the TM01 mode for the accelerating structure. In comparison to an s-shaped converter, the present design makes an additional waveguide bend obsolete. The structure length along the beam axis is only 4 mm (4 𝜆), showing a major advance in compactness. Combined with a horn antenna for free-space to waveguide coupling, the maximum power coupled into the structure reaches 83%, while the collinear scheme does not exceed 74%.
Paper: WEPA113
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA113
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
WEPA114
RF design of the waveguide network for the klystron-based CLIC module
2920
A new RF Module was designed for the Klystron-based CLIC main linac. The new module deploys two X-band klystrons to feed eight CLIC-K accelerating structures giving a beam energy increase of 156 MeV. This module will use a double-height waveguide distribution network which can reduce the RF power loss in the network by about 37%. All the RF components were redesigned to match the double-height requirement, mainly including the 3 dB hybrid, the RF vacuum flange, the bending waveguide, correction cavies and the BOC pulse compressor. A CLIC-K accelerating structure with bended damping waveguides was designed for the new module. The result of RF design work for the klystron based CLIC module is summarized.
Paper: WEPA114
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA114
About: Received: 28 Apr 2023 — Revised: 11 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPA115
RF design of the pulse compression system for the klystron-based CLIC main linac
2924
A pulse compression system based on double-height waveguides was designed for the Klystron-based CLIC main linac. The optimized power gain of the system is 3.81 with the particular pulse shape required for the CLIC-K accelerating structure. This pulse compression system consists of a main Barrel Open Cavity (BOC)-type pulse compressor and 4 novel correction cavities. The BOC pulse compressor has the Q0 of 2.36e5 with working mode TM1,1,32 and the β of 6.6. A novel coupling waveguide network which can ease the machining procedure was designed for the BOC pulse compressor. For the correction cavities, a new method based on a single cylinder cavity and a 3-dB hybrid was studied. Each of the correction cavities has the Q0 of 5e4 and the β of about 1.3.
Paper: WEPA115
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA115
About: Received: 28 Apr 2023 — Revised: 11 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPA117
Improved waveforms for barrier-bucket systems
2928
Barrier-Bucket (BB) systems provide a method to apply a short gap to a coasting beam. This is utilized for different applications, like ion cleaning, or to compensate the medium energy loss caused by internal experiments. BB-cavities are broadband cavities, and the applied signal is commonly a short sine burst, followed by a flat section at zero voltage. Since the transfer function of the BB-system is usually neither flat nor linear, it is common to predistort the signal to obtain the desired shape at the rf gap. Nevertheless, the resulting waveform still has a ripple in the flat section. This is due to the lowpass characteristic of the amplifier and the sharp edges at the ends of the sine, which lead to an infinite number of harmonics. This paper provides better suited BB-waveforms, which are designed with a finite number of harmonics from the beginning. It is shown that a much better flatness can be achieved than for a conventional BB-waveform, without sacrificing any performance. These advanced waveforms are currently used at the hadron synchrotron COSY at Forschungszentrum Jülich, leading to improved BB-bunch shapes, in particular for electron-cooled beams.
Paper: WEPA117
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA117
About: Received: 01 May 2023 — Revised: 01 Jun 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
WEPA118
Upgrades of S-band Accelerating Structures and Pulse Compressors in the Electron and Positron Injector Linac of KEK
2932
New S-band disk-loaded TM01-2pi/3-travelling-wave structures and pulse compressors have been developed for upgrades of the injector linac for SuperKEKB and Photon-factory storage rings in KEK. The structures 2-m long have ingenious disk irises with oval fillets reducing discharge in high-power operation and modulations in radius suppressing beam break-up instabilities arising from HEM11 wakefields. The pulse compressors are of compact spherical-cavity-type resonating at the degenerate TE112 dipole modes with a high Q-value of 98,000 and yield a peak power gain of 6.2. The structures generate an acceleration gradient of 25.9 MV/m in power operation of 40 MW by using the pulse compressor and stably accelerate a two-bunch beam with a bunch charge of 4 nC.
Paper: WEPA118
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA118
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPA120
Design of a parallel-feeding deflecting cavity with variable polarization
2940
Transverse deflecting cavity (TDC) providing time-dependent kick with fixed polarization is an important tool for beam diagnostics and manipulation. Recently, several types of novel TDC with variable polarization have been developed to fulfill the requirements of multi-dimensional phase space measurement of high-quality electron beam as well as fast scanning in proton therapy. Based on the parallel feeding technology, we propose a new design with alternating racetrack cells where the two chains are fed by waveguide networks independently. Each chain provides fixed polarization in either horizontal or vertical plane and variable polarization can be achieved by adjusting the amplitude and phase of the input power to the networks. The structure has several advantages, such as compactness, tunability, high shunt impedance, etc. In this manuscript, physical and mechanical design of this TDC will be presented in detail.
Paper: WEPA120
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA120
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPA121
Magnetic alloy core loaded 2nd harmonic cavity design and testing for CSNS-II RCS
2944
In this report, we present our recent progress in the de-sign and high-power testing of the 2nd harmonic cavity for the China Spallation Neutron Source upgrade project. To achieve optimal performance, high-performance mag-netic alloy (MA) cores with dimensions of Ф850mm × Ф316mm × 25mm were meticulously developed and fabricated to serve as the load material for the radio-frequency (RF) cavity. Through rigorous testing, we were able to achieve a remarkable cavity accelerating gradient of over 40 kV/m under 15% duty cycle. To ensure opti-mal cooling efficiency, we conducted a comprehensive fluid dynamics simulation analysis and verified our re-sults through experiments. Finally, to assess the long-term stability and performance of the cavity, we conduct-ed a series of extended operation tests. These experiments successfully confirmed the high-performance capabilities and exceptional stability of the 2nd harmonic cavity.
Paper: WEPA121
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA121
About: Received: 29 Apr 2023 — Revised: 12 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
WEPA122
Dielectric Assist Accelerating structures for compact linear accelerators of low energy particles in hadrontherapy treatments
2947
Dielectric Assist Accelerating (DAA) structures based on ultralow-loss ceramic are being studied as an alternative to conventional disk-loaded copper cavities. This accelerating structure consists of dielectric disks with irises arranged periodically in metallic structures working under the TM02-π mode. Here, the numerical design of an S-band DAA structure for low beta particles, such as protons or carbon ions used for hadrontherapy treatments, is shown. Three dielectrics with different permittivity and loss tangent are studied as well as different particle velocities depending on the energy range. Through optimization, most of the RF power is stored in the vacuum space near the beam axis, leading to a significant reduction of power loss on the metallic walls. This allows to realize cavities with extremely high quality factor over 100 000 and shunt impedance over 300 MΩ/m at room temperature. The design optimization has been improved to reduce the peak electric field in certain locations of the cavity. In addition, first multipactor simulations are being carried out, using several coatings to reduce SEY, which has also been taken into account in the electromagnetic result.
Paper: WEPA122
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA122
About: Received: 02 May 2023 — Revised: 07 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPA124
RF design of a compact C-band RF pulse compressor for a VHEE linac for flash radiotherapy
2951
In this paper, the design of a compact C-band SLED RF Pulse Compressor for a Very High Electron Energy (VHEE) FLASH machine is presented. A spherical cavity RF pulse compressor - selected because of its compactness and relative ease of fabrication - is adopted to compress the 50 MW 3 µs RF pulse, down to 1 µs obtaining a peak power gain greater than 3. The main parameters – operating resonant mode, unloaded quality factor, coupling factor, peak power gain, geometry, peak surface fields - and S-parameters of the full RF design (spherical storage cavity + mode converter/polarizer) are computed and analyzed. Moreover, the pulse-compression effect on the acceleration performances is analyzed through the evaluation of the main figures of merit (charge per pulse, energy gain, accelerating gradient and efficiency)
Paper: WEPA124
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA124
About: Received: 01 May 2023 — Revised: 14 Jun 2023 — Accepted: 14 Jun 2023 — Issue date: 26 Sep 2023
WEPA132
Basic high-power design of a 1.5-GHz TM020-type harmonic cavity for the KEK future light source
2969
In ultralow-emittance synchrotron light sources, harmonic RF cavities are very useful to lengthen the beam bunches by which the adverse effects due to intrabeam scattering can be mitigated. We are developing a 1.5-GHz TM020-type normal-conducting harmonic cavity which is to be used for the KEK future light source project. The harmonic cavity using the TM020 resonant mode has distinct advantages such as: 1) small RF-voltage fluctuation under the transient beam loading, and 2) sophisticated parasitic-mode damping structure which locates at the node of the accelerating field. In our design, we optimized* the inner shape of the cavity so that the coupling impedances due to parasitic modes were minimized. To minimize the losses of accelerating field in the parasitic-mode damping structure, we arranged three frequency-tuners symmetrically and devised an optimum loop of an input coupler, by which an axial symmetry of the cavity was almost maintained. Based on these concepts, we conducted a basic design of high-power cavity including thermal-structural analysis, which will be presented in this paper.
Paper: WEPA132
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA132
About: Received: 01 May 2023 — Revised: 08 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPA134
Design, fabrication and mechanical tests of TIG-welded Ka-band accelerating structures for ultra-high gradient applications
2976
The investigation of the processes, materials, technology and welding procedures used to manufacture accelerating components for maximum accelerating gradient (>100 MV/m) and minimum RF breakdown probability has led us to the proposal of hard-copper structures in Ka-Band made of multiple parts. In this paper, we illustrate the TIG welding tests, including visual inspection and temperature monitoring, of Ka-band metallic RF cavities for the cases of two-half and four-quadrant models. The RF cavities made of multiple parts operate at ultra-high accelerating gradients (well above >100 MV/m). Therefore, the following aspects of the welding procedure were used as references for the positive outcome of the process: 1) Successful execution of each weld bead/seam in order to assure vacuum tightness of the cavity. 2) The cleanliness of the inside surfaces of the cavities: visual inspection for absence of oxidation after cutting the cavity samples; 3) The temperature of the cavity surfaces always below the annealing one (mechanical properties significantly change after heating above 590 ◦C), in order to keep the hardness of the copper.
Paper: WEPA134
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA134
About: Received: 01 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
WEPA135
Development of an S-band accelerating structure for Hefei Advanced Light Source facility
2980
The injector of Hefei Advanced Light source Facility (HALF) will choose the full energy injection method with beam energy up to 2.2 GeV by a LINAC, which will contain 40 S-band normal conducting traveling wave tubes. Quasi-symmetric single-feed racetrack couplers were used in design of TW tube utilized for reduction the field asymmetry inside the coupler cavity. The design and test result of prototype tube are discribed in this paper.
Paper: WEPA135
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA135
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
WEPA143
Design and commissioning of a new SRF cavity for a conduction-cooled system
2987
Cornell is designing a standalone superconducting radio-frequency (SRF) accelerating cryomodule which utilizes a conduction cooling scheme in place of liquid helium. A key component of this system is a new single-cell 1.3 GHz Nb$_3$Sn-coated SRF cavity. This cavity was designed based on Cornell’s ERL injector cavities in order to replicate their RF properties, such as being able to operate at high current (> 100 mA) and high average power (> 100 kW). Thermal modelling of the cavity was then used in order to optimize the design and placement of heat intercept rings to enable the use of conduction cooling. The cavity has since been fabricated and welded, and is currently undergoing chemical treatment before baseline RF tests are performed.
Paper: WEPA143
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA143
About: Received: 09 May 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPA166
RF preparation of QWR cavities for beam commissioning
3033
QWR cavities are prepared for beam commissioning. RF conditioning is performed for each QWR cavity. The total heat load including static and dynamic heat loads are measured for each cavity. The helium pressure fluctuation is reduced by changing the flow rate, supply pressure, return pressure, liquid helium level in reservoir, cryogenic valve control, etc. The cavity pressure is monitored during RF preparation. The amplitude and phase of the QWR cavity are stably controlled for beam commissioning.
Paper: WEPA166
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA166
About: Received: 25 Apr 2023 — Revised: 07 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
WEPA171
The optimization of the bronze-method Nb3Sn coatings on Cu substrates
3046
Nb3Sn thin films are mainly used on superconducting radio frequency (SRF) cavities, single-photon detectors and RF logic circuits. Copper-based Nb3Sn thin-film SRF (TFSRF) cavities are promising for particle accelerators because they may combine the advantages of high thermal conductivity and high gradient. In this paper, a bronze method, including multi-layer deposition and heat treatment, was used to generate Nb3Sn thin film on copper substrates. We first made a precursor by sputtering a niobium layer on the copper substrate and then electroplating a thicker bronze layer. Then we annealed the precursor in a vacuum tube furnace to synthesize Nb3Sn film. Considering the morphology and superconductivity of the Nb3Sn films, we compared the effects of various annealing temperatures and optimized the preparing conditions. The samples characterization of the morphology and superconductivity showed that high-quality Nb3Sn thin films had been successfully deposited on copper substrates. The superconducting transition temperature Tc can reach higher than 17.0 K. This synthesis route provides a new approach towards high-stability Nb3Sn TFSRF copper cavities.
Paper: WEPA171
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA171
About: Received: 10 May 2023 — Revised: 23 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPA176
Investigation of the fabrication method for the 3rd harmonic superconducting double-cell cavity
3053
The 3rd harmonic cavity is a key component for the 4th generation storage ring. A bunch lengthening by the harmonic cavity increases the Touschek lifetime, which can reduce the emittance in the storage ring. The resonant frequency is selected as 1500 MHz due to the resonant frequency of the main RF cavities being 500 MHz. The prototype cavity is an elliptical double-cell geometry to reduce power losses. Based on this design, three niobium cavities are fabricated. Deep drowned half-cells are welded by the electron beam welding machine after trimming at the edge of the equator and iris. The surface treatments are performed to increase the quality factor such as buffered chemical polishing, high-pressure rinsing, and annealing. In this paper, we presented the fabrication method of the 3rd harmonic superconducting cavity from niobium sheets to an elliptical double-cell cavity.
Paper: WEPA176
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA176
About: Received: 02 May 2023 — Revised: 09 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPA183
REBCO sample testing for a HTS high Q cavity
3067
Superconducting materials such as niobium have been extremely useful for rf accelerator technology but require low temperatures for operation ~2-4 K. The development of high temperature superconductors (HTS) is promising due to their transition temperature in excess of 80 K. In this work we are exploring the high-power RF performance of such materials at X-band (11.424 GHz). We are testing two kinds of REBCO coatings, deposition and tapes, on a copper substrate. Testing was done in a hemispherical cavity with a TE mode due to its ability to maximize the magnetic field on the sample and minimize electric field. We will report on the performance in terms of conductivity vs temperature at low and high power. These measurements will then be compared to the design performance of a full 3D cavity that is coated with REBCO. This cavity will utilize the TM010 mode, and we are targeting a Q of ~1 10^6 at 80 K. Such a cavity could be useful for high power rf accelerator applications. In one example, a cryogenic copper linac operating at liquid nitrogen temperature (77 K) could utilize such a high-Q cavity in its superconducting state for pulse compression.
Paper: WEPA183
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA183
About: Received: 03 May 2023 — Revised: 05 Jun 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
WEPA184
V3Si Thin Films for SRF Applications
3071
The relatively high transition temperature of A15 superconducting materials makes them a potential alternative to Nb for radio-frequency applications. We present PVD deposition of one A15 material, V$_3$Si, on Cu and sapphire substrates. The surface structure and composition of the films were characterised via SEM and EDX. The superconducting properties were investigated using a field penetration facilty, four point probe and SQUID magnetrometry. Analysis showed that the composition was slightly Si rich by a few percent with a granular suface structure. Despite this superconductivity was observed on both Cu and sapphire substrates with critical temperatures of 12.8\,K and 14\,K. Field penetration measurements were conducted through two different facilities.
Paper: WEPA184
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA184
About: Received: 02 May 2023 — Revised: 07 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPA185
Split 6GHz SRF thin film cavities
3074
Many current accelerators use cavities that are manufactured as two half cells that are electron beam welded together, across the peak surface current of the cavity. This weld can limit the performance of Thin Film (TF) coated cavities by causing an increase in the surface resistance. Many problems with the coating process for TF Superconducting Radio Frequency (SRF) cavities are also due to this weld. TF SRF cavities can perform as well as bulk niobium cavities if the cavity is manufactured seamlessly, without any weld, however, they are much more difficult and expensive to manufacture. A cavity with a split parallel to the direction of the electric field, would not need to be welded. These cavities are easier to manufacture and coat. Thus, different coating techniques may be used leading to new materials and multilayer coating options which may allow SRF cavities to operate at better parameters than current state of the art cavities. TF SRF cavities have been developed for use in particle accelerators, as they have many advantages over normal conducting and bulk niobium cavities. One such advantage is that SRF TF cavities have a lower surface resistance, below the critical temperature, than NC cavities and a higher thermal conductivity than bulk niobium cavities leading to a more uniform temperature of the superconductor. This work discusses development and testing of longitudinally split seamless TF SRF cavities at Daresbury Laboratory
Paper: WEPA185
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA185
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPA189
The collaborative effects of intrinsic and extrinsic impurities in low RRR SRF cavities
3078
The superconducting radio-frequency (SRF) community has shown that introducing certain impurities into high-purity niobium can improve quality factors and accelerating gradients. We question why some impurities improve RF performance while others hinder it. The purpose of this study is to characterize the impurity profile of niobium with a low residual resistance ratio (RRR) and correlate these impurities with the RF performance of low RRR cavities so that the mechanism of impurity-based improvements can be better understood and improved upon. The combination of RF testing and material analysis reveals a microscopic picture of why low RRR cavities experience low temperature-dependent BCS resistance behavior more prominently than their high RRR counterparts. We performed surface treatments, low temperature baking and nitrogen-doping, on low RRR cavities to evaluate how the intentional addition of oxygen and nitrogen to the RF layer further improves performance through changes in the mean free path and impurity profile. The results of this study have the potential to unlock a new understanding on SRF materials and enable the next generation of SRF surface treatments.
Paper: WEPA189
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA189
About: Received: 04 May 2023 — Revised: 12 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPA190
Origins of quench in buffered chemical polished and low temperature baked SRF cavities
3082
Electropolishing (EP) and buffered chemical polishing (BCP) are conventional surface preparation techniques for superconducting radiofrequency (SRF) cavities that remove damaged material from the cavity surface. One main issue with EP and BCP treated SRF cavities is high field Q-slope (HFQS), a drop in quality factor at high gradients that limits quench field. High gradient performance in EP cavities can be improved by applying a low temperature bake (LTB), but LTB does not consistently remove HFQS in BCP cavities. There is no consensus as to the why LTB is not effective on BCP prepared cavities, and the cause of HFQS in BCP cavities is not well understood. We examine the origins of quench in EP, BCP, EP+LTB, and BCP+LTB treated SRF cavities. We also show the effect of these treatments on the onset of HFQS, heating within the cavity up to quench, concentration of free hydrogen, and surface roughness.
Paper: WEPA190
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA190
About: Received: 03 May 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
WEPA194
Surface characterization of mid-T heat treated Nb samples to investigate the origin of residual resistance
3094
Annealing of niobium (Nb) cavities in UHV is crucial for the performance in the later cryogenic tests and operation. Recently, a so-called “mid-T bake” treatment has exhibited very high-quality factors for Nb cavities. In this way, the first set of mid-T treated samples were produced with cavities at Zanon Research & Innovation Srl. The cavity performances have been improved with lower BCS and residual resistances, however the residual resistances were varied very different between 3-12 nΩ and didn’t achieve the low values as we expected. Thus, the characterization of these samples is discussed, and the source of residual resistance mitigation has been studied here in detail. We present our investigation on potential origins. For this, we used XPS, MOKE and Auger measurements to study the surface magnetic domains and stoichiometry of structures.
Paper: WEPA194
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA194
About: Received: 12 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
WEPL002
ALBA beam lifetime optimization using RCDS
3101
The ALBA synchotron operates in a Touschek dominated lifetime regime, which depends mainly on the momentum acceptance and the transverse beam size along the machine. Although in the current ALBA machine the RF dominates the momentum acceptance, this will not be the case for the foreseen upgrade of the machine ALBA-II. For this reason, we have developed an algorithm to optimize the beam lifetime by varying the sextupole magnets. This algorithm is based on the Powell optimization of the Robust Conjugate Direct Search (RCDS) method, and several tests have been performed at the present ALBA machine. In this case the sextupole settings are first modified so that the RF is no longer the only limiting factor in the momentum acceptance. The algorithm optimizes the ALBA beam lifetime by varying the sextupoles to follow a constant chromaticity, while the skew magnets are tweaked to keep the beam sizes constant during the optimization. This paper shows the experimental results using this algorithm, and discusses its application to the ALBA-II case.
Paper: WEPL002
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL002
About: Received: 02 May 2023 — Revised: 08 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
WEPL014
Higher-order spin depolarization analysis
3133
Current and historic tracking studies of the RHIC accelerator lattice find difficulty in explaining the transmission efficiency of spin polarization from the AGS extraction to RHIC storage energies. In this paper, we discuss mechanisms that result in resonant depolarizing behavior, beyond the usual intrinsic and imperfection resonance structures. In particular, the focus of this paper will be on higher-order resonances that become apparent in the presence of snakes. The set of conditions that identify higher-order spin-orbit resonances are 𝜈 = 𝑗0 + 𝑗 ⃗ ⋅𝑄⃗for integers (𝑗0, 𝑗) ∈ ℤ^4, where 𝜈 is the spin tune and 𝑄⃗ contains the orbit tunes. Note that we do not use the closed-orbit spin tune 𝜈0 but rather the amplitude-dependent spin tune 𝜈(𝐽𝑥, 𝐽𝑦, 𝐽𝑧) that depends on the phase-space amplitudes. While Sibrian snakes keep 𝜈0 at 1/2, the amplitude-dependent spin tune can deviate from 1/2 and can cross resonances during acceleration.
Paper: WEPL014
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL014
About: Received: 03 May 2023 — Revised: 14 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
WEPL015
Generalized Gradient Field Description Using the Bmad and PTC Toolkits
3136
The Generalized Gradient (GG) formalism of Venturini and Dragt for describing static magnetic or electric fields has been implemented in the Bmad toolkit for accelerator simulations. In conjunction with this, a new method for calculating GG derivatives from a field table has been developed which avoids some of the problems of the Venturini and Dragt method. Generalized gradients are also implemented in the PTC toolkit developed by Etienne Forest which is interfaced to Bmad. This allows for construction of spin/orbital Taylor maps useful for nonlinear analysis and rapid tracking.
Paper: WEPL015
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL015
About: Received: 06 May 2023 — Revised: 06 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPL017
Orbit-response based optics corrections for FCC-ee
3143
The new generation of storage rings aims to push the limits of the luminosity and the size of the electrons beam that can be achieved. One of such planned machines is the e+/e- Future Circular Collider (FCC-ee) with 100km circumference. The FCC-ee lattice components can be subject to random misalignments and field errors. These errors can adversely affect the beam's closed orbit and beam optics properties, resulting in a significant reduction in the future collider's performance. This issue requires linear optics correction methods to be utilized, One of these methods is linear optics from closed orbit (LOCO) in which the measured ORM is fitted to the lattice model in order to determine the appropriate quadrupole strengths. n this study we demonstrate the application of closed orbit-based optics correction LOCO for FCC-ee lattices. The code was implemented using the Python accelerator toolbox (PyAT). The impact of alignment errors on FCC the lattice optics parameters were studied.
Paper: WEPL017
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL017
About: Received: 03 May 2023 — Revised: 05 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
WEPL019
BPM offset measurements at rapid cycling synchrotron in China Spallation Neutron Source
3151
The Rapid Cycling Synchrotron is the key part of the China Spallation Neutron Source with the repetion rate of 25Hz. The lattice of the RCS is based on triplet cells with the superperiod of four. Due to ultilizing the trim quadrupoles in June 2021, the BPM OffSets were carefully measured, and the beam operation is more steady. In this paper, we will review the preparation of BPM OffSets measurements with the virtual accelerator, and the results of the measurements with beam.
Paper: WEPL019
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL019
About: Received: 02 Apr 2023 — Revised: 07 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
WEPL025
Application of beam-based alignment to the CLEAR facility
3166
The CERN Linear Electron Accelerator for Research (CLEAR) has been operating since 2017 as a user facility providing beams for a large variety of experiments. Its RF photocathode-based linear accelerator can accelerate electrons up to 220 MeV with a bunch charge of 0.1-1.5nC with single or up to 150 bunches per train. The flexibility of providing various beam parameters following user demands brights drawbacks and complexity in operating the accelerator. Standard beam steering based on the sequential variation of quadrupole and corrector magnets, performed by an operator manually, results in a very time-consuming process. This paper presents a tool we developed for automatic and global Beam-Based Alignment (BBA) for CLEAR based on dispersion-free steering and one-to-one corrections to transport beams with various charges and time structures.
Paper: WEPL025
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL025
About: Received: 04 May 2023 — Revised: 14 Jun 2023 — Accepted: 14 Jun 2023 — Issue date: 26 Sep 2023
WEPL030
Beam loading simulations in PyAT for the ESRF
3181
The Extremely Brilliant Source (EBS) at the European Synchrotron Radiation Facility (ESRF) is a 4th generation light source operating with a horizontal emittance of 135 pm. This low horizontal emittance reduces the lifetime in filling modes with high current per bunch. This will be alleviated in the future with an active 4th harmonic cavity. In order to simulate the effect of the 4th harmonic cavity on the EBS performance, beam loading needed to be added included to PyAT (Python – Accelerator Toolbox). Here, we introduce the beam loading model and show the benchmarking simulations with theory and other simulation codes.
Paper: WEPL030
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL030
About: Received: 03 May 2023 — Revised: 16 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
WEPL031
Status and recent developments of python Accelerator Toolbox
3185
The Accelerator Toolbox (AT) is a multipurpose tracking and lattice design code relying on a C tracking engine. Its MATLAB interface is widely used in the light source community for beam dynamics simulation and can be integrated in control systems through the MATLAB Middle Layer. In recent years major effort was made to develop a python interface to AT: pyAT. In this framework, several features were added to pyAT, in particular, the introductions of the 6D optics dynamic aperture and lifetime calculation, single and multi-bunch collective effects simulations and parallelized tracking capabilities. A python ring simulator was also developed based on pyAT for offline modeling of the accelerator control system. Following a presentation of the structure and main features of AT, an overview of these recent developments is provided.
Paper: WEPL031
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL031
About: Received: 30 Apr 2023 — Revised: 05 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPL035
Beam dynamics in the NEWGAIN project at GANIL-SPIRAL2
3192
The NEWGAIN (NEW GAnil INjector) project aims at supplying higher mass-to-charge ratio ions (from A/Q=3 to 7) with an energy of 590 keV/A to the present SC-Linac of SPIRAL2. It comprises a new SC source, a dogleg LEBT, an 88 MHz RFQ, and a MEBT, optimized for a current of up to 350 uA of uranium. Additionally, an extension of the present LEBT is considered to merge into the new one. This paper presents the last layout and beam dynamics results for these new lines, including the mass resolution, chopping, admittance slit and tuning scheme as the Design Study Phase ends.
Paper: WEPL035
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL035
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPL038
Model-independent determination of solenoid offsets in the Sealab Injector
3204
Sealab (SRF Electron Accelerator LABoratory) is composed of an SRF photo gun and an SRF booster, followed by a diagnostic line and a recirculation path for ERL applications. It is the follow-up project of bERLinPro, which ran from 2010-2020 at HZB. In an SRF injector, a single solenoid is sufficient to optimally focus the beam for small emittance. The alignment of the solenoid is crucial, as it is the dominant source of trajectory distortions in the facility. Polynomial Chaos Expansion (PCE) is a technique developed for risk management and uncertainty quantification. It is well suited for application in accelerators, although not well known. In this paper, PCE is used to set up a surrogate model from calculated or measured data to determine the misalignment of the solenoid in Sealab.
Paper: WEPL038
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL038
About: Received: 25 Apr 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
WEPL040
Status and extended beam dynamics scenarios for the second injection beam line at MESA
3212
This report presents new investigations on beam dynamics for the separation beamline which allows to transport and compress electron bunches from the second electron source MIST to the first acceleration section of MESA. Several beamline configurations are compared concerning the capability for transport of elevated bunch charges.
Paper: WEPL040
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL040
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
WEPL042
Design of the gradient dipole magnet for LLICTF
3215
The Lanzhou Light Ion Cancer Therapy Facility (LLICTF) is a compact medical accelerator currently under construction. It is designed to treat cancer using a 230MeV, 30mA H+ beam and a 85MeV/u, 1mA 3He2+ beam. The facility comprises two ion sources, a low-energy beam-transport (LEBT), a Radio Frequency Quadrupole (RFQ), a medium-energy beam-transport (MEBT), and the main ring accelerating structure. Due to the presence of two ion sources, it is necessary to introduce a dipole magnet which is symmetrically focused as much as possible to meet the symmetrical focusing requirements of the LEBT beam. Therefore, a gradient dipole magnet has been designed to achieve this symmetrical focusing. This paper discusses the theoretical and simulated symmetric focusing of the gradient dipole magnet. It also analyzes the effect of fringe fields and space charge. Additionally, the paper presents the results of the model design with CST and the multi-particle simulation results with TraceWin.
Paper: WEPL042
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL042
About: Received: 13 May 2023 — Revised: 21 Jun 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
WEPL045
Employing octupole magnets for nonlinear optimization of Iranian Light Source Facility storage ring
3219
Limited dynamic aperture which is in the consequence of strong nonlinearities in a low emittance storage ring, is a challenging issue from beam dynamics point of view. In the present study, we have applied three families of focusing and defocusing octupoles to the storage ring lattice with the aim of increasing dynamic aperture and beam lifetime . We have discussed different methods to optimize of the position and strength of octupoles so that each octupole family fights a specific resonance driving term.
Paper: WEPL045
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL045
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPL050
Design, fabrication and measurement of a normal conducting quadrupole for a laser-plasma-accelerator-based beam transport line
3227
For an experimental setup at the laser plasma accelerator (LPA) at the JETi Laser at Jena, Germany, an energy upgrade of a linear beam transport line has been studied. The transport line, originally designed to match the LPA beam to a transverse gradient undulator (TGU) at 120 MeV and successfully experimentally tested in 2014, will be upgraded to up to 300 MeV by employing stronger focusing quadrupoles. For these high strength quadrupoles, magnetic simulations as well as cooling and electrical calculations have been done. To develop fabrication procedures and magnetic measurement techniques, a prototype of the quadrupole magnet has been manufactured and tested at Karlsruhe Institute of Technology, Germany. This paper is presenting the design, fabrication and magnetic measurement of the first prototype quadrupole magnet.
Paper: WEPL050
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL050
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPL052
Improved measurements of nonlinear integrable optics at IOTA
3230
Nonlinear integrable optics (NIO) are a promising novel approach at improving the stability of high intensity beams. Implementations of NIO based on specialized magnetic elements are being tested at the Integrable Optics Test Accelerator (IOTA) at Fermilab. One method of verifying proper implementation of these solutions is by measuring the analytic invariants predicted by theory. The initial measurements of nonlinear invariants were performed during IOTA run in 2019/20, however the covid-19 pandemic prevented the full-scale experimental program from being completed. Several important improvements were implemented in IOTA for the 2022/23 run, including the operation at higher beam energy of 150 MeV, improved optics control, and chromaticity correction. This report presents on the improved calibrations of the NIO for nonlinear invariant measurements.
Paper: WEPL052
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL052
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
WEPL053
Experimental demonstration of a straight-merger beamline
3233
Merging beams from multiple beamlines is critical to energy-recovering linear accelerators and beam-driven wakefield accelerators. Recently, a "straight-merger" beam line was proposed as a compact beamline to merge beams. The concept is based on a deflecting cavity with a superimposed dipole field. It provides a large deflecting kick at the injection phase where the RF and magnetic kicks add up ("deflecting mode") while a beam injected at a phase where the RF and magnetic field cancel out does not experience any net kick ("transparent mode"). A proof-of-principle beamline of this concept was built at the Argonne Wakefield Accelerator and experimentally tested. This contribution will discuss the experimental performances of the beamline.
Paper: WEPL053
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL053
About: Received: 10 May 2023 — Revised: 11 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
WEPL055
Beam study on low dispersion CEBAF arcs
3240
The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab employs recirculating linac SRF technology to generate a high polarization 12 GeV electron beam for nuclear physics users. New opportunities to study multipass energy recovery have also emerged with the proposal of a 5-pass energy recovery demonstration, ER@CEBAF. New beam optics with minimized beta functions have been developed and tested to avoid collective beam instabilities for multi-pass beams and meet the beam requirements of the nuclear physics community. To enable energy recovery for a common arc beam transport of five passes, achromatic and isochronous arc optics conditions were satisfied by re-designing the transverse optics of CEBAF. This paper focuses on beam studies conducted to study the newly-designed, low-dispersion, lowest energy arcs for CEBAF operations and ER@CEBAF.
Paper: WEPL055
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL055
About: Received: 03 May 2023 — Revised: 22 Jun 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
WEPL056
Re-design of CEBAF optics for ER@CEBAF
3244
ER@CEBAF is an effort to demonstrate multi-GeV multi-pass energy recovery with a low beam current in CEBAF. The race-track-shaped CEBAF geometry allows its linacs to accommodate multiple energy beams simultaneously. However, five energy recovery passes complicate the beamline optics design process. Individual recirculating arcs each transport one beam energy, and are shared between accelerating/decelerating beams. Present CEBAF optics needs to be redesigned to accommodate this additional multi-pass ER scheme. Isochronous arcs are retuned to match with the solutions obtained from optimized 10-pass beamline. In this paper, we discuss the optics redesign process with the existing beamline for ER@CEBAF.
Paper: WEPL056
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL056
About: Received: 03 May 2023 — Revised: 06 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPL067
Field-adapted coordinate transformations for rotating and accelerating beams
3260
Many accelerators employ axisymmetric structures, such as RF cavities, induction cells, and solenoids, to accelerate and transport charged particle beams. To analyze the motion of the beam in solenoids, it is common to make a transformation to the rotating Larmor frame. In the presence of an electric field, this transformation can be modified to obtain further simplifications in the equation of motion. In this paper, we explore the use of a complex Larmor phase to simplify the equations of motion in the presence of simultaneous axial electric and magnetic fields, such as those found in the induction cells of a linear induction accelerator (LIA). We also analyze the corresponding envelope equation and find that the natural emittance in this frame can be expressed in terms of familiar quantities.
Paper: WEPL067
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL067
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPL073
The MAX-IV linac with variable bunch compressors
3272
Recent studies have shown that accelerating $+19^{\circ}$ off-crest in all RF cavities in the MAX-IV linac reduces voltage-induced timing jitter from the klystrons. The current bunch compressors in the linac have fixed first-order longitudinal dispersion, and the RF phase is varied to control the amount of compression. Variable bunch compressor designs have been considered at MAX-IV in recent years, these would allow us to regain control over compression while the accelerating phase is fixed to reduce timing jitter. Particle tracking studies have been performed on the MAX-IV linac with the addition of arc-like variable bunch compressors.
Paper: WEPL073
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL073
About: Received: 01 May 2023 — Revised: 05 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPL074
High accuracy optics measurement in J-PARC MR for 1.3 MW upgrade plan
3276
J-PARC MR is a high intensity synchrotron that accelerates protons from 3 GeV to 30 GeV. In MR, beam study for 1.3 MW upgrade plan is now in progress. The upgrade is done by shortening the repetition period and increasing the number of protons, and it is crucial to understand their effects on beam motion. Especially, the betatron function is one of the most important parameters that determines the beam motion. In MR, the betatron function has been measured by using turn-by-turn signal of the beam position monitor. Betatron function has been adjusted to match with model within 3% accuracy in relative error in low energy period. However, in evaluating the effects of space charge forces and eddy currents on beam optics whose impact will be largen by the upgrade, the accuracy of betatron function measurement during the injection and acceleration period will be even more important. In this study, we have attempt to match betatron function to model within 1% accuracy in relative error both in injection and acceleration period which has never been achieved in MR, by performing beta function measurement using COD response from the steering magnets in MR.
Paper: WEPL074
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL074
About: Received: 03 May 2023 — Revised: 24 May 2023 — Accepted: 24 May 2023 — Issue date: 26 Sep 2023
WEPL075
Modeling for the phased injector upgrade for 12 GeV CEBAF
3280
As a follow on to the 12 GeV upgrade to the Continuous Electron Beam Accelerator Facility, the front end of the DC photo-gun-based injector has gone through a phased upgrade. The first phase focused on the beamline between the gun and the RF chopper system, and the second phase addresses the beamline after the RF chopper system including replacing the capture section and quarter cryomodule with a new booster module containing a 2-cell and 7-cell cavity string. Throughout the design process, we maintained and developed three models, one for the existing injector and one for each of the upgrade phases. With these models, we evaluated proposed hardware upgrades, evaluated and determined optimized beamline element positions, developed buncher voltage requirements, and settings for optimal injector running. In this paper, we will describe the models and results from these various studies and provide a brief summary of Phase 1 commissioning.
Paper: WEPL075
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL075
About: Received: 02 May 2023 — Revised: 16 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
WEPL082
Design and validation of the LEBT for the project LINAC 7, a low-current low-energy compact LINAC
3295
In this paper we present the design and validation of a compact LEBT for the LINAC 7 project. Specifically, the LINAC 7 project focuses on building a new generation, low-energy, low-current compact accelerator. The core idea is to achieve an energy of 7 MeV in less than 12 m while maintaining enough current to generate isotopes for medical uses. Through this work we explain the procedure we followed for the design, including the tests that we carried out to reach the final result. This includes the iterations we needed to overcome various problems such as how to keep the LEBT compact and deal with cooling, when is the best time for packing factor calculation, how to solve mechanical problems,... Although this LEBT is intended to be used with protons, further simulations have been carried out to show that it could be used for other species as well.
Paper: WEPL082
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL082
About: Received: 28 Mar 2023 — Revised: 13 Jun 2023 — Accepted: 13 Jun 2023 — Issue date: 26 Sep 2023
WEPL084
Benchmarking for CODAL beam dynamics code: laser-plasma accelerator case study
3298
Laser-plasma electron beams are known for their large divergence and energy spread while having ultra-short bunches, which differentiate them from standard RF accelerated beams. To study the laser-plasma beam dynamics and to design a transport line, simulations with *CODAL* [1], a code developed by SOLEIL in collaboration with IJCLab, have been used. *CODAL* is a 6D 'kick' tracking code based on the symplectic integration of the local hamiltonian for each element of the lattice. *CODAL* also includes collective effects simulations such as space charge, wakefield and coherent synchrotron radiation. To validate the studies in the framework of Laser-Plasma Acceleratior developpement, results from *CODAL* have been compared to *TraceWin* [2], a well-known tracking code developed by CEA. The comparison has been made using the outcome of Laser WakeField Acceleration (LWFA) particle-in-cell simulations as initial start particle coordinates from a case study of PALLAS project, a Laser-Plasma Accelerator test facility at IJCLab.
Paper: WEPL084
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL084
About: Received: 03 May 2023 — Revised: 02 Jun 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
WEPL091
Fast RF tracking functions
3310
The beam dynamics of a bunch both longitudinally and transversely play a major role in the design process of an RF cavity, from the feasibility of cavity lengths, to the focusing schemes required to maximise capture. Often, computer simulations track particles using computationally intensive numerical techniques, which can be extremely time-consuming to run. In this paper, we present a generalised analytical method to track macro-particles through RF structures, computing the 6D phase space elements at the end of each RF cell. The results show strong agreement with the well-benchmarked tracking code, ASTRA, however requires a significant reduction in computing power and run time. The results from this paper present a very promising means of streamlining future tracking simulations by increasing the computing efficiency with no significant detriment in accuracy.
Paper: WEPL091
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL091
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPL092
Dynamic aperture predictions with echo state networks
3313
The calculation of the volume of the phase-space stability region of hadron storage rings is currently performed through computer simulations of particles tracking in 6D coordinates, which are resource -and time- intensive processes. We have investigated in a previous paper the ability of an ensemble reservoir computing approach based on Echo State Networks to predict the long-term evolution of the radius of the phase-space region in which the motion of charged particles in hadron storage rings is bounded. Here, we perform a sensitivity analysis of the results of the Echo State Networks prediction with respect to different ways of splitting the original data set into a training, validation, and test set. This analysis confirms the validity of the splitting proposed in our previous paper and suggests that extending the validation phase too much is counterproductive.
Paper: WEPL092
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL092
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPL093
Phase space control of transverse resonance island buckets at CESR
3317
Transverse resonance island buckets (TRIBs) have been successfully observed at the Cornell Electron Storage Ring (CESR) after optimizing the distribution of seventy-six sextupoles to achieve the desired amplitude-dependent tune shift and the resonant driving term near a third-order resonant line (3vx=2). A novel knob is created to adjust the resonant driving term h22000 while minimizing the change of h30000. Interestingly found from simulation, the knob can change the TRIBs locations in the phase space, which is then confirmed experimentally at CESR. Theoretical calculation of the fixed points (stable and unstable) in the phase plots are explored with PTC, which shows excellent agreement with the tracking results and provides theoretical understanding of the TRIBs in the phase space. In addition, the island locations in the real x-y space are explored by adjusting a skew quadrupole to change the x-y coupling.
Paper: WEPL093
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL093
About: Received: 01 May 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPL097
The adiabatic theory of the nonlinear coupling resonance crossing in circular accelerators
3329
In this paper, the nonlinear coupling resonance $2 Q_x -2 Q_y = 0$ is studied by means of a Hamiltonian model. The detailed analysis of its phase-space topology unveils the possible phenomena that can occur when crossing adiabatically such a resonance. These considerations are probed by means of numerical simulations carried out using a symplectic map and the results are presented and discussed in detail.
Paper: WEPL097
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL097
About: Received: 02 May 2023 — Revised: 05 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
WEPL101
Status of MAD-X V5.09
3340
MAD-X is a popular beam optics code used to design, model and operate a large number of synchrotons and linacs. In this paper, we present the features added in the most recent versions and improvements we intend to make in future releases. Physics models have been added and improved to support the needs of the Future Circular Collider (FCC) and the Electron Ion Collider (EIC), regarding machine-detector interface, complex beamline layouts, and synchrotron radiation. More precise physics models have been implemented for some elements, and a complete set of exact coordinate frame transformations are now available. The tracking module has been extended to support frozen space-charge models. To improve interoperability with scientific ecosystems, MAD-X relies on the cpymad Python interface which offers a fine-grained control of MAD-X simulations, exceeding the capabilities of the internal MAD-X language.
Paper: WEPL101
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL101
About: Received: 02 May 2023 — Revised: 06 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPL105
Relativistic beam loading and recoil effects using a covariant, retarded-potential iterator
3352
A algorithm is demonstrated which performs first-principles tracking of relativsitic charged-particles for determining the power they deposit into their surroundings (in particular, blackbody cavities and pillbox accelerating cavities). A computationally costly, but highly accurate covariant approach is used, which employs retarded vector potentials for trajectory integration instead of performing field calculations. The peak vector potential and related Lorentz force in the direction of travel is shown to increase asymptotically for high $\beta$ particles approaching a conductive surface or another charged particle. This effect produces a very strong field distribution at small angles from the source particle's direction of travel, which, for high-intensity beams, can deposit significant power onto the surface surrounding a cavity's exit aperture. Changes in momentum of a charged particle occurring after a cut-off of external fields are shown to be non-conservative, such that any resulting power deposition causes a recoil effect on the cavity. We present benchmark cases for this framework and results for two-particle simulations as well as small-bunch simulations using a macroparticle formalism.
Paper: WEPL105
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL105
About: Received: 03 May 2023 — Revised: 18 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPL106
Analytical potential model for the Radio-Frequency Quadrupole at the European Spallation Source
3356
The potential in the Radio Frequency Quadrupole (RFQ) can be expressed as a sum of a transverse multipolar expansion: $\sum_{m=1}^\infty{A_{0m}}\left(\frac{r}{r_0}\right)^{2m}\cos(2m\theta)$, and a longitudinal term expressed as sum of Bessel functions: $\sum_{m=0}^\infty\sum_{n=1}^\infty A_{nm}I_{2m}(nkr)\cos(2m\theta)\cos(nkz)$. Since the paper of Kapchinskii and Teplyakov \cite{osti_4032849} this potential is used considering only the first term in transversal and longitudinal components, unfortunately such approximation does not reproduce properly a realistic RFQ as the one installed at the European Spallation Source (ESS). In this paper we evaluate the potential when more terms are considered and we compare it with the field map obtained from a numerical Poisson solver used at ESS.
Paper: WEPL106
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL106
About: Received: 02 May 2023 — Revised: 11 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
WEPL110
Nonlinear Dynamics of Scaling FFAs
3367
Fixed Field Alternating Gradient Accelerators (FFAs) that follow the conventional scaling law have – by definition – high order multipole components in their magnetic fields. It is the presence of these nonlinearities that in many cases determines several important properties of the machine, including amplitude-dependent tune shift and dynamic aperture. Consequently, understanding of the nonlinear dynamics in these machines can be critical to design and optimisation processes. Study of these properties is made challenging by the complicated nature of closed orbits in many FFAs and the presence of edge angle effects (which are exploited by design in certain lattice configurations, such as the F-D spiral design chosen as the baseline for the FETS-hFFA prototype ring). This poster presents a novel method of nonlinear analysis based on the combined application of harmonic analysis and truncated power series algebra-derived techniques.
Paper: WEPL110
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL110
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPL112
Simultaneous Compensation of Third-Order Resonances at the FNAL Recycler Ring
3375
Third-order resonance lines will have a detrimental effect on the high-intensity operation of the Recycler Ring (RR), under the current Proton Improvement Plan (PIP-II) for the Fermilab Accelerator Complex. Increasing intensity will increase space charge effects, leading to the excitation of normal and skew sextupole lines. Dedicated normal and skew sextupoles have been installed in order to mitigate the effect of these resonance lines. By measuring the response matrix of the third-order Resonance Driving Terms (RDTs) to the currents of these dedicated elements, this study shows how several resonance lines can be compensated simultaneously. Resonance compensation is experimentally verified through loss maps and emittance growth measurements using the Ion Profile Monitor (IPM) system in the Recycler.
Paper: WEPL112
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL112
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPL118
Adiabatic capture of longitudinal phase space
3387
Thus ends 63 years without a theory of longitudinal capture able to predict the final beam distribution and optimize the voltage law. We show the relationship between average values of the initial and final Hamiltonian is a universal function independent of voltage law, provided the adiabaticity parameter is small. The deviations from average are also given. This means the bunch profile and energy spectrum are predictable, without particle tracking. Beam measurements at the BNL AGS Booster and MedAustron are also reported.
Paper: WEPL118
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL118
About: Received: 01 May 2023 — Revised: 19 May 2023 — Accepted: 19 May 2023 — Issue date: 26 Sep 2023
WEPL123
Coupler design for THz DLW LINACs
3399
A promising approach for compact linear accelerators in the THz frequency range is based on dielectric-loaded waveguides (DLWs). Higher breakdown fields expected at THz frequencies should enable higher acceleration gradients. However, the accelerating mode of a cylindrical DLW (TM<sub>01</sub>) is not the fundamental and only mode inside the waveguide at operating frequency. Therefore, a method is required to ensure excitation of the proper mode only. Here we present a coupler design to convert the guided electromagnetic TE<sub>10</sub> mode in a rectangular waveguide to the TM<sub>01</sub> mode of a cylindrical DLW. The symmetry of the structure and its feeding waveguides allow us to suppress all undesired modes and consequently increase the coupling efficiency to the desired mode. Moreover, this configuration shows an extremely wide bandwidth and low quality factor suggesting the coupler is also suitable for short THz pulses.
Paper: WEPL123
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL123
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
WEPL124
Resistive wall impedance of multilayer beam pipes of general cross sections
3402
One of the interesting topics among accelerator physicists in the last decades has been the resistive wall impedance of vacuum chambers with general cross sections. The resistive wall impedance of a round pipe was calculated more than half a century ago, followed by parallel plates, rectangular pipes, and, in more recent years, oval shapes. Analytical solutions usually require some approximations to simplify them. It is possible to solve Maxwell's equations in the vacuum chamber with simulation codes in order to obtain an exact solution for Resistive wall impedance. Although some of them show promising results, the need for a versatile code that can calculate resistive wall impedance and wakefield in a general cross-section vacuum chamber is still necessary. VACI-suite is a finite element solver that tries to solve this problem. Compared to well-known theories and simulation codes for well-known geometries, the code's results show remarkable agreement.
Paper: WEPL124
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL124
About: Received: 10 May 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPL126
Magnetic field tools, a C++/Python library for magnetic field processing
3409
Magnetic Field Tools is an open source library being developed by the Insertion Devices and Magnets group at the ESRF. It is dedicated to the analysis of static magnetic field values obtained from simulations and measurements. Magnetic field models such as 2D and 3D multipoles in various geometries, as well as boundary element models, can be built from sets of field samples. The library was designed in order to be easily extendable to other types of field models. It is implemented in C++ and a Python binding is available. Application to undulator magnets, 3D multipole fringe fields and solenoids will be presented.
Paper: WEPL126
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL126
About: Received: 27 Apr 2023 — Revised: 08 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
WEPL127
Progress on Thor SCSI development
3413
Tracy, the code base used for designing synchrotron light sources with predictable performance, has been significantly refactored. Furthermore it now uses mad-ng gtpsa library. We describe the achieved progress, discuss its python interface. We show how to use it for achieving a robust design for a modern synchrhotron light source.
Paper: WEPL127
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL127
About: Received: 07 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
WEPL151
Update of the RF-Track particle tracking code
3462
The tracking code RF-Track has been updated to include a large set of single-particle and collective effects: beam loading in standing and travelling wave structures, coherent and incoherent synchrotron radiation, intra-beam scattering, multiple Coulomb scattering in materials, and particle lifetime. This new set of effects was focused on the simulation of high-intensity machines such as linacs for medical applications. In these apparatuses, the beam propagation into air and water significantly impacts the beam propagation to and through the patient. Now, these effects can be included by design. Additionally, RF-Track can now simulate the cooling channel of a future muon collider.
Paper: WEPL151
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL151
About: Received: 02 May 2023 — Revised: 11 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
WEPL152
Beam loading effects in standing-wave linacs and their implementation into the particle tracking code RF-Track
3466
Accelerating technology is evolving towards compactness and high intensity. In such a scenario, beam loading effects result in significant energy losses for long trains of bunches. To address these effects, we generalised the Beam Loading module of the tracking code RF-Track to allow the study of beam loading independently of the particle type and velocity or the accelerating cavity design. This paper describes the implementation of this effect in standing wave (SW) structures. Particular attention has been devoted to guns for photoinjectors, where causality plays an important role, and one must address the non-ultrarelativistic behaviour of the emitted particles. Finally, we will discuss the simulation of these effects in the CLEAR facility at CERN.
Paper: WEPL152
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL152
About: Received: 04 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
WEPL153
Impedance analysis of deformable RF contact bridges for high luminosity LHC
3470
In order to maintain the continuity of the vacuum system wall and comply with beam stability limits, radio frequency contact bridges are utilised as transitional elements in beam vacuum line interconnections. These radio frequency contact bridges must absorb and correct longitudinal, angular, and transverse misalignments brought on by mechanical motions during assembly, alignment, operating phases and thermal influences during accelerator operation. A deformable thin-walled copper beryllium structure is the foundation of a novel deformable radio frequency contact bridge concept that satisfies the above criteria without using conventional sliding contacts. To assess the feasibility of implementing such deformable radio frequency contact bridges in the High-Luminosity LHC, the longitudinal, dipolar, and quadrupolar components of the beam impedance in the two transverse planes were determined using electromagnetic simulations.
Paper: WEPL153
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL153
About: Received: 06 Apr 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
WEPL158
Characterization of transverse profiles along the LHC injector chain at CERN
3490
Following the successful implementation of the LHC Injectors Upgrade (LIU) project, the CERN injectors were re-commissioned in 2021 and have been delivering beam to the LHC since 2022. The operationally delivered beam is well within the specifications regarding its brightness. However, heavy population of non-Gaussian tails of the transverse beam profiles were observed. These tails lead to high losses at LHC injection and degrade the luminosity reach of the LHC. This paper follows the studies to characterize the transverse profiles along the accelerator chain: the Proton Synchrotron Booster (PSB), the Proton Synchrotron (PS) and the Super Proton Synchrotron (SPS). The methodology to measure the emittance and the tail population as the studies aimed at reducing this population will also be discussed.
Paper: WEPL158
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL158
About: Received: 28 Apr 2023 — Revised: 10 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPL162
Upgrade the impedance model in RCS of CSNS
3502
The Rapid Cycling Synchrotron (RCS) in China Spallation Neutron Source (CSNS) is a high intensity proton accelerator, the impedance can drive collective instabilities and limit the machine performance. Due to new component installation, the impedance model should be updated. A thorough estimation of the coupling impedance is presented and the impedance model in the RCS is obtained.
Paper: WEPL162
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL162
About: Received: 04 May 2023 — Revised: 11 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
WEPL163
The impact of the resistive-wall impedance on the ILSF storage ring
3506
The resistive contribution of the vacuum chamber is a significant part of the impedance budget. Due to the NEG-coated re-designed ILSF vacuum chamber, the resistive-wall effects must be carefully studied. The resistive impedance of the insertion devices and general cross-section of the storage ring was calculated by CST and WI2D code. In addition, the fast-correctors containing a resistive insert with a conductivity different from the rest of the pipe were simulated in CST. Finally, the not negligible effect of the heat load and threshold current was studied. The single-bunch calculations were done by ELEGANT code. The final results in longitudinal and transverse planes are presented here.
Paper: WEPL163
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL163
About: Received: 10 May 2023 — Revised: 11 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPL186
Transverse impedance and beam stability studies for the muon collider Rapid Cycling Synchrotrons
3558
The International Muon Collider Collaboration is currently investigating the possibility to build a muon collider with a center of mass energy of 3 TeV in a first phase, with an option to build a 10 TeV collider in a second phase. The muon beam decay is the global challenge of such a collider and fast acceleration is required to reach high luminosities. A series of three or four Rapid Cycling Synchrotrons are currently proposed as the last acceleration stage before injecting the muon beams into the collider ring. The transverse collective effects in these synchrotrons have been analysed in detail. Both the higher-order modes of the numerous RF cavities needed for the fast acceleration, and the ceramic chamber needed to avoid eddy current effects, have been looked at in detail along with possible mitigation measures. Promising results have been obtained considering for the moment a single muon bunch.
Paper: WEPL186
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL186
About: Received: 30 Apr 2023 — Revised: 08 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPL190
Advanced studies for the dynamics of high brightness electron beams with the code MILES
3574
High brightness electron beams enable a wide spectrum of applications ranging from short wavelength radiation sources to high gradient wakefield acceleration. The rich dynamics that are intrinsic in charged particles accelerated in complex systems require a careful description in the analysis and design of a given machine, particularly regarding its stability. Numerous computer codes are in use by the accelerator community for such purposes. In particular, MILES is a simple tracking code we have developed that allows fast evaluations of collective effects in RF linacs. In this paper we extend the simple models previously developed to describe specific, diverse applications that can benefit from the fast simulation tools developed in MILES. Examples of this kind include particle driven acceleration schemes in a plasma where driver and witness beams propagate in the ``comb" pulse-train configuration. Specifically, we investigate the self-induced fields excited within both the rf-linac stage and the capillary. Further, we discuss additional advanced topics such as wakefield effects in planar FEL undulators and the emission of coherent synchrotron radiation in a magnetic chicane.
Paper: WEPL190
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL190
About: Received: 31 Mar 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
WEPM013
HPRF SSPA System for RAON SRF cavities
3596
The heavy-ion accelerator of the Rare Isotope Science Project (RISP) in Korea has been developed. There are three types of SRF cavity, which are 81.25MHz quarter-wave resonator (QWR), 162.5MHz half-wave resonator (HWR), 325MHz single-spoke resonator (SSR). There are 22 QWRs and 102 HWRs in the superconducting linac#3 (SCL3), and 69 SSR1s and 144 SSR2s in the superconducting linac#2 (SCL2). The required RF power is 4kW for each QWR, 4kW for each HWR, 8kW for each SSR1, and 20kW for each SSR2. The high power RF SSPAs for the SRF cavities have been developed and fabricated with domestic companies. 325MHz 20kW SSPAs have been designed and fabicated to test the prototype of the SSR2 SRF cryomodule including six SSR2 cavities. They were designed to enable full-reflection operation at all times. It consists of four 6kW power-units, four 6kW circulator units, 4-way combiner, a control unit, a power distribution unit, and cooling water inlet/outlet manifolds in each 19“ rack. The power-unit has six 1.2kW pallets and circulators, and three power packs. This paper describes the design and fabrication of the SSPA systems for the RAON SRF cavities.
Paper: WEPM013
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM013
About: Received: 28 Apr 2023 — Revised: 07 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
WEPM019
Magnet system for a 1.497 GHz injection-locked magnetron
3608
An injection-locked amplitude modulated magnetron is being developed as a reliable, effi-cient RF source that could replace klystrons used in particle accelerators that have superconducting cavities. This paper will describe the magnet system which is designed to provide a reasonably uniform field over the magnetron interaction region (IR). Most of the field in the IR is provided by a large solenoid. A smaller trim coil inside the larger coil provides the ability to vary the field within a certain range. In anticipation of a large number of magnetrons needed for an accelerator the large solenoid would be replaced by permanent magnets to provide the IR field. This paper will describe the magnet system both with solenoid coils and with the permanent magnet option.
Paper: WEPM019
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM019
About: Received: 04 May 2023 — Revised: 16 Jun 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPM031
High gradient hybrid halbach quadrupoles with a novel 3-Bit gradient tuning system
3621
This paper presents the magnetic design, mechanical design and assembly tooling design for four 500T/m Hybrid Halbach Quadrupoles with an aperture radius of 4mm. The quadrupoles will be used for capture of a 1-5 GeV electron beam produced in a plasma acceleration stage at the Extreme Photonics Application Centre which is currently under construction at Rutherford Appleton Laboratory in the United Kingdom. In order to meet the stringent requirement dictated by beam dynamics studies, that the peak gradient of the four quadrupoles should vary by less than 1% in the presence of economically achievable engineering tolerances and magnetic field uniformity of the permanent magnet blocks, the design features a novel ‘3-bit tuning system’ in which three steel rods can be inserted in 8 different combinations into each steel magnet pole to tune the gradient in evenly spaced steps of 0.8% over a full range of 6%. This 3-bit tuning system can be used to ensure the specification on uniformity over the four quads is achieved.
Paper: WEPM031
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM031
About: Received: 26 Apr 2023 — Revised: 25 May 2023 — Accepted: 25 May 2023 — Issue date: 26 Sep 2023
WEPM032
Cross-talk between magnets in the H6BA-cell of PETRA IV
3624
For the upgrade of the 6 GeV synchrotron light source PETRA III into a diffraction-limited storage ring PETRA IV it is planned to replace the 23 m long double-bend achromats by hybrid six-bend achromats (H6BA). The high packing density of elements in the H6BA cells requires that the distance between magnets are small with only a few centimeters between the yokes for some of the magnets. Overlapping fringe fields of the magnets will result in substantial magnetic cross talk. The change of the main field component of quadrupoles due to magnetic interference will lead to a change of the optical functions of PETRA IV. In this paper results of magnetic field cross-talk calculations between magnets will be presented. The influence of the cross-talk on the optics of PETRA IV, its integration in the lattice model and its correction will be discussed.
Paper: WEPM032
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM032
About: Received: 03 May 2023 — Revised: 05 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPM034
Magnetic measurement systems for Elettra 2.0
3631
The Elettra 2.0 project involves the installation of more than 600 new magnets for the upgrade of the existing light source. All the magnets will be measured in house in a new magnetic measurement laboratory to be built and equipped by 2024. The measurements will be carried out over a period of two years and will consists of acceptance tests, magnetic characterization and, to meet the demanding requirements of the new machine, alignment of magnet multiplets on a common girder. We report on the design and development of the measurement systems devoted to the aforementioned tasks. Specifically, two rotating coil systems employing high quality induction coils, fabricated on printed circuit boards, will be used for acceptance tests and characterization of multipole magnets, including reverse bend and combined function magnets. A 3D magnetic field mapper based on hall sensors will be used for the characterization of dipole magnets, sector dipoles with transversal gradient and superbend magnets. Moreover, a stretched wire system will be developed for the alignment of magnet multiplets.
Paper: WEPM034
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM034
About: Received: 03 May 2023 — Revised: 06 Jun 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPM035
Installation and integrated testing of magnets for the ESS linac
3635
The European Spallation Source (ESS) linear accelerator is designed to accelerate a 62.5 mA, 2.86 ms, 14 Hz proton beam up to 2 GeV for delivery to a rotating tungsten (W) target. The beam transfer sections between linac cryomodules and approaching the target contain over 200 quadrupole, dipole and corrector magnets for beam envelope and trajectory control. In addition, a raster magnet system comprised of dual-plane dipoles is used to reduce beam density on the target. All magnets have been provided to ESS by in-kind collaborators, universities and research institutes across Europe. Following the delivery of these magnets and their respective power converters to ESS, this proceeding presents the status of the installation together with the methodology and first obtained results from integrated testing phase.
Paper: WEPM035
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM035
About: Received: 01 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
WEPM041
Magnetic measurements of the ALS-U magnets
3650
he Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBL) is going through an upgrade (ALS-U) where the ALS triple-bend achromat will be replaced by a nine-bend achromat storage ring (SR) with an on-axis injection using beam swapping from a triple-bend achromat accumulator ring (AR). About 700 magnets will be used for the ALS-U accelerator systems. The paper gives an overview of the stretched wire and rotating coil systems used for the magnetic measurements of the ALS-U magnets. We are also describing the fiducialization process, i.e. the mechanical and magnetic alignment of the magnets.
Paper: WEPM041
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM041
About: Received: 03 May 2023 — Revised: 04 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
WEPM042
Pre-study of permanent dipole magnet at NSRRC
3653
A permanent dipole magnet assembled by Sm2Co17 was fabricated and measured at NSRRC. The main magnets were consisted of several small magnet blocks. A simple coil was wound to measure the total flux of permanent magnet. The flux coil was compared and calibrated by the Helmholtz coil using small magnet block. A flux sorting process was implement to obtain more homogeneity magnetic field. A NiFe alloy was used to compensate the magnetic flux fluctuation with temperature of permanent block. These methods were use in the accelerator upgrade in the future. The magnet circuit design, magnet assembly and field measurement results of permanent dipole magnet are presented in this article.
Paper: WEPM042
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM042
About: Received: 27 Apr 2023 — Revised: 08 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPM058
Energy deposition simulations for a damage experiment with superconducting sample coils
3696
An experiment to study damage caused by the impact of 440 GeV/c protons on sample superconducting racetrack coils made from NbTi and Nb3Sn strands was recently carried out at CERN's HiRadMat facility. This paper reports on the detailed Monte Carlo simulations performed with FLUKA and Geant4 to evaluate the energy deposition of the 440 GeV/c proton beam on the sample coils positioned in the experimental setup. using the measured beam parameters during the experiment. The measured hotspot temperatures and temperature gradients reached in the sample coils are presented and compared with the simulations. In addition, comparisons between the simulation results from FLUKA and Geant4 are discussed in detail.
Paper: WEPM058
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM058
About: Received: 03 May 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
WEPM060
Status of MQXFB quadrupole magnets for HL-LHC
3704
The MQXFB magnets are superconducting quadrupoles with nominal peak field on the conductor of 11.3 T. With their magnetic length of 7.2 m, they stand as the longest Nb3Sn accelerator magnets designed and manufactured up to now. Together with the companion MQXFA 4.2 m long units, built by the US Accelerator Research Program, they are at the heart of HL-LHC, as they shall replace the inner triplet quadrupoles at either side of the ATLAS and CMS interaction regions of the LHC. This technology has benefited from many years of development, and this specific design was validated with successful short models (MQXFS, 1.2 m long). More recently, several MQXFA magnets were shown to satisfy HL-LHC requirements. In this paper, we report on the cold test results of four MQXFB magnets, focusing on performance, training, behavior after thermal and powering cycles, and field quality. We then provide an update of the overall status, including ongoing verifications of design changes at the level of the coil fabrication.
Paper: WEPM060
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM060
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
WEPM062
Magnets for a muon collider
3712
The new interest for a muon collider has motivated a renewed and thorough analysis of the accelerator technology required for this collider option at the energy frontier. Magnets, both normal- and super-conducting, are among the crucial technologies throughout the accelerator complex, from production, through acceleration and collision. In this paper we initiate a catalog of magnet specifications for a muon collider at 10 TeV center-of-mass. We take the wealth of work performed within the scope of the US-DOE Muon Accelerator Program as a starting point, update it with present demands for the increased energy reach, and focus on the magnet types and variants with most demanding performance. These represent well the envelope of issues and challenges to be addressed by future design and development. We finally give a first and indicative selection of suitable magnet technology, taking into account both established practices as well as the perspective evolution in the field of accelerator magnets.
Paper: WEPM062
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM062
About: Received: 10 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
WEPM064
20 T dipole magnet based on hybrid hts/lts cos-theta coils with stress management
3720
This paper presents the design concept of the dipole magnet with 50 mm aperture, 20 T nominal field and 13% margin based on a six-layer cos-theta (CT) hybrid coil design. Due to the high stresses and strains in the coil at high field, Stress Management (SM) elements are implemented in the CT coil geometry. The results of magnet magnetic analysis are presented and discussed. The key parameters of this design are compared with the parameters of similar magnets based on block-type and canted cos-theta coils.
Paper: WEPM064
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM064
About: Received: 30 Apr 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPM065
What is needed for BISCO to work in a dipole insert for 20 tesla hybrid accelerator magnets
3723
Developing HTS dipole inserts producing fields larger than 5 T within 15 T Nb3Sn outserts is necessary to generate 20 T or higher fields for future high energy colliders. Dipole inserts based on the cos-theta coil geometry with various stress management concepts and Bi2212 super-conducting strand and cable are being developed at Fermilab both within and beyond the U.S. national effort. On paper, the potential reach for the maximum magnetic field in existing or planned Nb3Sn outserts is close to 20 T, thanks to the progress realized in Bi2212 wires’ critical current density. To achieve the Bi2212 potential in accelerator magnets, however, a number of technological challenges still have to be faced. These for instance include the need to design billets that are adequate for Rutherford cabling; developing insulation processes and materials that prevent leaks, which reduce transport current and increase the risk of shorts; control and limit Bi2212 coils’ stresses and strains; reconsider the Split Melt Process (SMP) to lower costs and simplify the processing. This paper reviews Bi2212 conductor properties and coil technolo-gies, and proposes new ideas to face the challenges that Bi2212 still presents as an accelerator magnet conductor.
Paper: WEPM065
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM065
About: Received: 04 May 2023 — Revised: 19 Jun 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPM067
Superconducting magnets for SIS100 at FAIR – status update
3727
At the Facility for Antiproton and Ion Research in Darmstadt, Germany, fast-cycled superferric magnets will be utilised for ion optics in the main accelerator SIS100. After an intense testing campaign, the full series of dipole magnets has been equipped with cryogenic beam vacuum chambers and is ready for tunnel installation. Currently ongoing is the procurement of the quadrupole and corrector magnets. By design, each main quadrupole is combined with at least one corrector magnet to form a so-called quadrupole unit. Two of such units are then, together with further functional elements, integrated into a common cryostat to form quadrupole doublet modules. Details on the processes of production, integration, and testing as well as an update of the progress will be presented. Moreover, to sample the installation processes of SIS100, study collective effects in an module ensemble and gain experience in operation, several magnet modules and components are currently aligned at a test facility to model a cell of SIS100. An overview of this so-called String Test setup, its commissioning and first test results will be included in the presentation.
Paper: WEPM067
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM067
About: Received: 03 May 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
WEPM070
Investigations on NbTi superconducting racetrack coils under pulsed-current excitations
3735
One of the key issues in the technology of superconductors is the protection against quenches. When designing a superconductor as a magnet, a coil or even current leads, the design should be made such that the superconductor withstands all operational conditions as fast discharges, pulsed loads or even rapid transient background fields. Computational modeling of pulsed-current characterization in a self-field NbTi racetrack sample coil has been performed using the finite element modelling software Opera as a step towards understanding the thermal and electromagnetic processes during a quench. The pulse was modelled to be generated by discharging a capacitor into an RLC circuit, which includes the NbTi racetrack coil as the sample under test. The coil was driven to the resistive state and the quench occurred by applying the pulse with a peak value exceeding the critical current of the sample coil. This contribution presents the results obtained from investigating a pulsed NbTi coil in a model based on an electromagnetic analysis. In addition, a comparison to the theoretical expectations derived for the damped oscillations in the pulse-driving circuit is given. Finally, the results from a coupled analysis, where both thermal and electromagnetic properties are being considered, within a quench multi-physics study are presented.
Paper: WEPM070
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM070
About: Received: 01 Apr 2023 — Revised: 16 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPM078
A two harmonics circuit for the powering of the very fast RCS (Rapid Cycling Synchrotron) of the muon collider accelerator
3746
Acceleration for a muon collider will have to be extremely fast to ensure efficient transmission of the decaying beams, with acceleration times of the order of 1ms. One of the proposals for such a machine is centered around a rapid cycling synchrotron (RCS), a hybrid lattice of cells with alternating superconducting and resistive dipole magnets. Resistive magnets will swing from negative to positive field level, providing the magnetic flux variations (more than 3600 T/s) that are required for the quick acceleration of the muons, while the superconducting magnets will give a field offset. The resistive magnets will have to be supplied with extremely high peak power levels, in the order of few tens of GW, to provide the necessary magnetic field variations. For the extremely quick magnetic field ramp, this application is unique in the field of the RCS and related technologies. This paper analyses the application of a two harmonics circuit with additional active filter to the powering of the four RCS stages of the muon acceleration to the ultimate 10 TeV energy level
Paper: WEPM078
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM078
About: Received: 10 May 2023 — Revised: 11 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPM079
Using supervised machine learning in power converters design for particle accelerators – application to magnetic components design
3750
Volume and precision are tightly related to magnetic components that are typically necessary in a power converter for filtering (inductor) or voltage adaptation (transformer) purposes. This paper presents a methodology for creating an efficient design tool for magnetic components to be used in power electronics applications. Specifically, an air cored inductor is taken as an example. The method consists in using supervised machine learning to create a magnetic and an electrodynamics model, able to predict the inductance value and mechanical efforts on the winging, depending on dimensional input variables. The ANN model can predict the inductance value and is trained via Finite Element Analyses (FEA). Furthermore, it can predict the electrodynamic efforts in the winding, to prevent deformation (in relation to the power converter’s output current precision) or minimise acoustic noise emission. The ANN-based model is then included into an optimisation process, where the input variables (dimensions) are selected in order to minimize the volume or the mass of the inductor and respect some constraints such as the desired inductance value or deformation constraints. This means that the ANN model is evaluated many times before finding an optimal solution. In this context we demonstrate the power of an ANN model, where the computation time is reduced by 60 times compared to a FEA approach.
Paper: WEPM079
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM079
About: Received: 10 May 2023 — Revised: 11 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPM082
Upgrading magnet power supply system in J-PARC main ring
3762
The main ring (MR) of the Japan proton accelerator research complex (J-PARC) delivers the high-intensity proton beams to the T2K long-baseline neutrino experiment. To observe charge-conjugation and parity-transformation violation in the lepton sector with high accuracy, the upgrade of the MR toward the beam power of 1.3 MW is mandatory. One promising method for increasing the beam power is to shorten the repetition cycle of the MR. The crucial point in the success of this scheme is the upgrade of the magnet power supply system corresponding to the increase in the output voltages of the magnet power supplies and the power fluctuation of the electric system. During the long-term shutdown period of MR in FY2021, a wide range of works were carried out, including installations of new power supplies, rearrangement of existing power supplies, split of magnet families, and cable rewiring. The upgrade scheme of the power supply system in the J-PARC MR and the results of this upgrade will be presented.
Paper: WEPM082
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM082
About: Received: 01 May 2023 — Revised: 08 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
WEPM083
Reliability analysis of digital controller for magnet power supply based on optocoupler failure
3766
In CSNS, there are more than 350 devices in the accelerator power supply system, which respectively provide precise excitation current for the magnet load. Therefore, the stable operation of the power supply is an important prerequisite to ensure the beam quality, and also one of the necessary conditions for the normal operation of the CSNS. In accelerator power system, digital controller is widely used because of its flexibility and reliability. However, with the accumulation of running time, the failure of power supply caused by the fault of the digital controller often occurs, which affects the operation efficiency of the accelerator. Through the analysis and detection of the failed digital controller, it is found that the failure is basically caused by the optocoupler failure. In this paper, firstly, by dividing the digital controller into functional modules, it is equivalent to series system. According to the reliability principle of series system, the failure of any part will lead to the failure of the whole system. Secondly, according to the nature of the optical coupling failure is revealed, the reliability model of the controller considering the optical coupling failure is established, and the overall life evaluation of the controller is obtained. Finally, for the failure caused by optocoupler failure, a redundancy strategy is proposed for this part to improve the reliability.
Paper: WEPM083
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM083
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
WEPM084
New SiC kicker power supply for J-PARC
3769
A new kicker power supply using SiC-MOSFETs is under development at J-PARC. SiC-MOSFETs enables the fabrication of compact high-speed pulse power supplies to replace thyratrons switch power supply. The base circuit uses an induction voltage superposition circuit of the LTD method, and the semiconductor module circuit consists of a radial symmetry type that achieves low noise. The three main parts of an existing kicker power supply, the thyratron, PFN circuit, and end clipper, can be configured in a single module circuit. The power supply consists of a 1.25kV/2kA main circuit module board that forms a trapezoidal pulse and a 0.1kV/2kA correction circuit module board that compensates for droop of the flat section. The thirty-two main circuit module boards and twenty correction circuit module boards are connected in series in a hierarchical manner to achieve the waveform specifications required for J-PARC RCS kicker power supplies: output voltage of 40kV, output current of 2kA, and pulse width of 1.2us. In addition, an insulating cylinder for conductors has been developed that suppresses corona discharge and withstands continuous operation for long periods of time.
Paper: WEPM084
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM084
About: Received: 19 Apr 2023 — Revised: 10 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
WEPM100
Design of permanent magnet dipoles-quadrupoles with longitudinal gradient for the PETRA IV storage ring
3798
The PETRA IV storage ring is a project planned to upgrade the synchrotron light source PETRA III at DESY. The main aim is to decrease the horizontal emittance as low as 20 pmrad. This nominal emittance will be achieved by a hybrid six bend achromat lattice (H6BA) and a series of damping wigglers. The magnets used in this lattice will be a combination of resistive quadrupole and higher multipole magnets and permanent dipole magnets. Three different types of permanent combined-function dipole-quadrupole magnets are presently developed, including one with an additional longitudinal gradient. The design structure is a further advancement of the well-proven ESRF-EBS dipoles with longitudinal gradient. Due to its moderate value, the transverse gradient can be implemented by a slanted pole design. This contribution presents the design status of these novel magnets, discusses the expected magnetic field characteristics, and outlines the mechanical design for a prototype.
Paper: WEPM100
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM100
About: Received: 28 Apr 2023 — Revised: 10 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
WEPM110
Research on hydrostatic leveling system to provide elevation constraints for control network adjustment
3826
As the precise sensor system for monitoring the rela-tive altitude changes among multiple points, the capacity hydrostatic leveling system (HLS) is widely used in particle accelerators. To expand its application in provid-ing the elevation constraint for the control network ad-justment, the research on the issue of the HLS for alti-tude difference measurement between multiple points is carried out. Based on the working principle of the HLS sensor, a comparison system composed of dual-frequency laser interferometer, high-precision Z stage, HLS sensors and others is designed and manufactured. The system is used to control multiple sensors to observe the same liquid level in the same coordinate system. The zero-position difference among sensors can be obtained by comparison. Then the altitude difference measure-ment can be realized, and it is verified that the measure-ment accuracy is better than 5 μm. In addition, a simula-tion experiment for 3D control network measurement is run, in which the HLS system provides the elevation constraint for the adjustment processing. The results show that for the 100m linear tunnel, the errors accumu-lation in the elevation direction is significantly improved compared to the classics adjustment.
Paper: WEPM110
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM110
About: Received: 27 Apr 2023 — Revised: 05 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPM122
Reverse Engineering, a key and challenging step before the integration studies for old accelerators at CERN
3848
The accelerators constituting the LHC injectors chain have been gradually built and commissioned since the CERN foundation in the fifties. The operation of the Proton Synchrotron, the Proton Synchrotron Booster and the Super Proton Synchrotron started in 1959, 1972 and 1976 respectively. During the Long Shutdown 2 (LS2) of the CERN accelerator complex in 2019 and 2020, a large upgrade of these machines has been performed in the context of the LHC Injector Upgrade (LIU) Project and consolidation programme. This paper presents the process of reverse engineering performed by the Integration Office within 3D CAD environment during the preparation phase of the LS2 to allow the spatial integration studies of the upgrades and ensure the reliability of the installations. It describes the methodologies and technologies used from 2D drawings to 3D models and data consistency check processes in accordance with reality. Process remains ongoing to treat the enormous quantity of data.
Paper: WEPM122
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM122
About: Received: 27 Apr 2023 — Revised: 25 May 2023 — Accepted: 25 May 2023 — Issue date: 26 Sep 2023
WEPM123
Challenges and solutions in the integration studies of the future circular collider
3851
The Future Circular Collider (FCC) study is developing designs for a new research infrastructure to host the next generation of higher performance particle colliders to extend the research currently being conducted at the Large Hadron Collider (LHC) once the High-Luminosity phase (HL-LHC) reaches its conclusion around 2040. CERN’s Integration Office aims to fulfil the requirements of different stakeholders, which includes reviewing alignment defining tunnel cross sections and supporting underground civil engineering designs. After investigating different scenarios, a first layout of an FCC machine tunnel with an inner diameter of 5.5m was defined. This paper describes the integration process for future projects i.e., decisions made and challenges that had to be overcome along the integration studies, from typical cross-sectional dimensioning to 3D machine design.
Paper: WEPM123
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM123
About: Received: 27 Apr 2023 — Revised: 25 May 2023 — Accepted: 25 May 2023 — Issue date: 26 Sep 2023
WEPM124
The high luminosity Large Hadron Collider project: from project to reality at CERN
3855
The High Luminosity Large Hadron Collider (HL-LHC) project is an upgrade of the LHC aiming to increase by a factor 10 the harvested integrated luminosity foreseen early 40s. During Long Shutdown 3, scheduled to begin at the end of 2025, nearly 1.2 km of accelerator components, including a range of services spread across surface and underground facilities, will be replaced with new equipment deploying innovative key technologies. Two 300-meter-long tunnels, with access shafts and large service caverns, were excavated in parallel to the LHC machine tunnel to house the new power converters, cryogenics, and other key systems. Ten buildings were constructed on the surface to house all the necessary new services. The civil engineering design, the system definition and equipment design phase have been managed in close synergy with the HL-LHC Integration Team, responsible for optimizing the allocation of volumes between the different stakeholders in order to guarantee the efficiency of installation, the maintainability, and the operability of the different systems. This work describes the process and the challenges that had to be overcome in the integration studies to meet the targets of maturity of the project, allowing the installation phase to start on a sound and solid basis.
Paper: WEPM124
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM124
About: Received: 02 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPM125
CERN-MEDICIS: Operational indicators to support the production of new medical radionuclides by mass separation
3859
CERN-MEDICIS is an isotope mass separation facility for biomedical R&D located in a class A laboratory, receiving up to 50% of the 1.4GeV PSB protons. It was commissioned with radioactive ion beams in 2017. MEDICIS has operated for the past 5 years in batch mode, with targets irradiated in a dedicated beam dump station at HRS, and with external sources provided by cyclotrons and nuclear reactors MEDICIS partners, notably during Long Shutdown LS2 [1,2]. Recent additions to the CERN-MEDICIS facility are the MELISSA laser ion source, radiochemistry on implanted isotopes, and online gamma implantation monitoring. In 2022, we introduced key performance indicators (KPI’s) to monitor the facility for collected efficiencies, the optimization of the radiological risks and impact of modifications of the irradiation station, like the yearly integrated luminosity serves as one of the KPI's for LHC. Defined KPI’s cover different aspects in the operation cycle, such as planning in CERN schedule, target irradiations, process duration, radiological risk mitigation, facility downtime, developments and maintenance. MEDICIS KPI’s can help distinguish which of the elements in the operation and in the facility life-cycle thus requires immediate intervention, developments or consolidation. Those deal with the irradiation stations, beam-lines (parallel collections), target and ion sources (reliability), robot handling and infrastructure, or the separation process itself.
Paper: WEPM125
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM125
About: Received: 11 May 2023 — Revised: 22 Jun 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
WEPM126
The RAON integrated control system
3863
The RAON accelerator facility which is under construction in South Korea consists of many subsystems. These subsystems have many control devices such as Programmable Logic Controller, Power Supply, Motor, and FPGA. In order to integrate these devices into the main control system, the RAON integrated control system consists of three parts which are the main control room, server & storage system, and control network. All accelerator control signals are integrated into EPICS and transmitted over a 200Gbps redundant backbone control network. In addition, the control signals sent from the device are controlled and monitored with a display wall-based system composed of 36 monitors in the main control room. In this paper, we will describe a design of the RAON integrated control system and the result of a performance test.
Paper: WEPM126
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM126
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPM128
Open-midplane gradient permanent magnet with 1.53 T peak field
3870
The CEBAF energy upgrade will require magnets with high fields to bend electron beams of up to 22GeV in the 80.6m radius tunnel. A peak field in excess of 1.5T, together with a large gradient of 40T/m or more, are used in its fixed-field arc lattice to bend multiple recirculation energies in a single pipe. Additionally, the magnet must have an open midplane to allow synchrotron radiation to be absorbed by a cooling channel. A short 45mm section of NdFeB prototype has been designed and built as part of permanent magnet R&D at BNL. This satisfies all the above requirements and has had its integrated field tuned to better than 1 part in 10^3. This tuning process uses a technique with iron rods adapted from CBETA and miniaturised here, together with measurements at a new compact field-mapping stand that is accurate to 1 part in 10^4.
Paper: WEPM128
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM128
About: Received: 12 Apr 2023 — Revised: 05 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
WEPM129
Testing of a ZEPTO tuneable permanent magnet quadrupole at Diamond Light Source
3874
Electromagnets have traditionally been used in accelerators due to their wide range of tuneability with high accuracy, but are a major factor in power consumption due to resistive losses in the coils and inefficiencies in power and cooling systems. Use of permanent magnets can greatly reduce power consumption, but it has proved difficult to produce the same range of tuning with comparable field accuracy and stability. A tuneable permanent magnet quadrupole has been developed at STFC Daresbury Laboratory that moves permanent magnet blocks relative to fixed steel structures that define the field, allowing strength to be changed while suitable field homogeneity is maintained. This prototype magnet has been installed in the Diamond Light Source booster-to-storage ring transfer line, aiming to demonstrate the operation of ZEPTO (Zero-Power Tuneable Optics) technology on a real accelerator for the first time. We present results of beam-based measurements of gradient and magnetic centre and comparison with an existing electromagnet in the same transfer line, showing that it is capable of maintaining the same injection efficiency as a traditional resistive electromagnetic quadrupole during normal operation.
Paper: WEPM129
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM129
About: Received: 27 Apr 2023 — Revised: 07 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
WEPM131
Development of the first permanent bending magnet at BESSY II
3878
Permanent Magnet (PM) based bending magnets are state-of-the-art concepts to gain stable beam operation and to reduce the power consumption of the magnetic system in an accelerator. This is even more true in injector and beam transport beamlines with fixed beam parameters and low repetition rates. An example is the B2PT magnet in the BESSYII transfer beamline between booster and storage ring. It is the last dipole magnet for the final 7.8 deg bending into septum. This one meter long, compact, high current dipole will be replaced by three 300mm long Variable Permanent Hybrid Magnets. They combine a PM driven strong and stable magnetic field with a small field variability via compact corrector coils. With this new magnet we can reduce fringe fields and vibrations next to stored beam, as well as the total power consumption of the injector by almost 30 kW. In this paper, the design and construction process of the new B2PT magnet will be presented.
Paper: WEPM131
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM131
About: Received: 02 May 2023 — Revised: 09 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
WEPM133
Permanent magnet materials for green accelerator facilities
3886
Permanent Magnets (PM) and Electro Magnets (EM) with conventional resistive conductors are widely used in particle accelerator. The different applications include all types of multipoles, bending magnets, chicanes, kicker and undulators. Both types of Magnets have specific advantages and disadvantages, state of the art PM comprise expensive raw materials like Nd, Dy, Tb and Co and reach only limited flux densities. Whereas resistive Electro Magnets are comparable cheap to produce reach higher flux densities and can be easily adjusted or switched by controlling the exciting current. However running costs and energy consumption during use are much higher for the EM`s and almost zero for the PM`s. Therefore, the lifetime energy consumption and costs are lower for the PM. Both types of magnets are compared in terms of performance, production costs, running costs and CO2-emission. We discuss the latest PM materials and approaches to reduce energy consumption by substituting EM`s with PMs or to combine both types of magnets to hybrid structures.
Paper: WEPM133
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM133
About: Received: 03 May 2023 — Revised: 23 Jun 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THXD1
Towards the COXINEL seeded Free Electron Laser with a laser plasma accelerator at HZDR
3903
Developing Free Electron Lasers using Laser Plasma Acceleration open great hopes for compact laboratory scale light sources. The COXINEL line developed at Synchrotron SOLEIL (France) has been moved at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) (Germany) for using high-quality electron beam generated by the 150 TW DRACO laser. After proper electron beam transport, seed and undulator radiation temporal, spectral and spatial overlaps, the seeded Free Electron Laser driven by the DRACO laser plasma accelerator has been observed in the UV. Good agreement is found between measurements and simulations.
Paper: THXD1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THXD1
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THOGA1
Commissioning of X-LAB: a very high-capacity X-band RF test stand facility at the University of Melbourne
3912
The Compact Linear Collider (CLIC) beam-based acceleration baseline uses high-gradient travelling wave accelerating structures at a frequency of 12 GHz. In order to prove the performance of these structures at high peak power and short pulse width RF, two klystron-based test facilities will been put in operation this year. The first Southern Hemisphere X-band Laboratory for Accelerators and Beams (X-LAB) is under commission at the University of Melbourne, and it will operate half of the CERN X-band test stand system, called XBOX3. XBOX3 uses a novel way of combining relatively low peak power (6 MW) but high average power klystron units whose power is steered to feed two testing slots with RF to the required power with a repetition rate of up to 400 Hz. Besides the repetition rate, peak power, pulse length and pulse shape can be customized to fit the test requirements. This novel way of combining pulsed RF high power can eventually be used for many other applications where multiple test slots are required.
Paper: THOGA1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THOGA1
About: Received: 19 Apr 2023 — Revised: 09 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THOGA2
Robotic solutions for the remote inspection and maintenance of particle accelerators
3916
Intelligent robotic systems are becoming essential for inspection, maintenance, and repair tasks, both for the validation of systems before installation as well as during operation. Aiming to increase personnel safety and machine availability, robots can perform repetitive or dangerous tasks that humans either prefer to avoid or are unable to complete due to hazards, size or access constraints. At the European Organization for Nuclear Research (CERN), robots are regularly used for such tasks in highly radioactive beam lines, as well as for decommissioning. This work describes the state of the art industrial and experimental robotics at CERN, as well as the application of artificial intelligence to robotics activities. It includes a review of the main types of interventions undertaken, focusing on the personnel safety impact and the improvement of accelerators availability. Research and development in robotics at CERN is also described, along with the results of commissioning and operation of novel robotic controls.
Paper: THOGA2
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THOGA2
About: Received: 25 Apr 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THYD1
FAIR completion of construction works, towards commissioning and first science
3923
The international accelerator facility FAIR, one of the largest science projects worldwide, is being built in Darmstadt, Germany. At FAIR, matter that usually only exists in the depth of space will be produced in a lab for research. With the planned experiments scientists will be able to gain new insights into the structure of matter and the evolution of the universe from the Big Bang to the present. The existing GSI linac and heavy-ion synchrotron, UNILAC and SIS18 will become part of FAIR and will serve as first acceleration stage. The construction of the tunnels and buildings including the technical building infrastructure for the first project stage, including the SIS100 synchrotron and the Super-FRS (SFRS) fragment separator will be completed at the end of the year 2025. Component manufacturing, testing and delivery for the FAIR accelerator facility is progressing. Numerous components are completed, delivered and stored ready for installation. A clear plan is in place to address the replacement of the Russian in-kind contributions following the international sanctions due to the Ukraine war. Installation of accelerator components in the buildings will start at the beginning of the year 2024. Recent highlights are, for example, the progressing SIS100 string test and the successful SFRS magnet tests at CERN. A multi-stage strategy towards commissioning is under development aiming at the FAIR startup in the year 2028 with early science.
Paper: THYD1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THYD1
About: Received: 29 Apr 2023 — Revised: 12 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
THODB2
Overview and status of ESS RF systems
3932
The proton linac, for the European Spallation Source (ESS) currently in construction, will be powered by 155 high power RF systems. The RF systems will ultimately deliver in excess of 130 MW peak power, 5 MW of average power to a mixture of normal and superconducting accelerating structures at 352.21 and 704.42 MHz. ESS is a long pulse machine and will operate at 14 Hz with beam pulses of 2.86 ms. This paper will introduce the scope, system design and key technologies of the RF systems being deployed along the linac. We will present the installation and test status as well as initial experience from the operation of the first RF systems used for conditioning and first commissioning runs with beam. The RF systems have been designed to be as energy efficient as practical and we will present the results of a selection of the efficiency measures undertaken at ESS.
Paper: THODB2
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THODB2
About: Received: 08 May 2023 — Revised: 10 May 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
THODB3
Sustainability in storage ring based light sources
3936
Climate change and its consequences require strong changes in our consumption modes and approaches. Large research infrastructures consume a large amount of various energy sources, from helium to electricity. Therefore, their societal impact in the current energy crisis is tremendous, as well as their environmental impact. The Energy for Sustainable Science at Research Institutes workshop, held every two years, gathers a large panel of institutes whose efforts and ideas aim towards a less energy consuming and impactful science.
Paper: THODB3
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THODB3
About: Received: 03 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
THOGB1
Beam dynamics optimization for high gradient beam driven plasma wakefield acceleration at SPARC-Lab
3940
The SPARC\textunderscore LAB test facility at the LNF (Laboratori Nazionali di Frascati, Rome) holds a high brightness photo-injector used to investigate advanced beam manipulation techniques. High brightness electron bunch trains (so-called comb beams) can be generated striking on the photo-cathode of a Radio Frequency (RF) photo-injector with a ultra-short UV laser pulse train in tandem with the velocity bunching technique. Beam dynamics studies have been performed with the aim of optimizing the dynamics of the double beam (driver and witness) used to perform particle driven plasma wake field acceleration (PWFA). In this scenario different scans on beam parameters were carried on adopting the ASTRA simulation code, in order to optimize the witness beam quality and improve the plasma booster stage performances. A benchmark of the simulations has been then performed, reproducing the experimental data obtained from the optimization of machine performances, and a good agreement was found.
Paper: THOGB1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THOGB1
About: Received: 31 Mar 2023 — Revised: 21 Jun 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
THOGB2
Beam tomography with coupling using maximum entropy technique
3944
Current analytical beam tomography methods require an accurate representation of the beam transport matrix between the reconstruction and measurement locations. In addition, these methods need the transport matrix to be linear as the technique depends on a simple mapping of the projections between the two areas, a rotation, and a scaling. This work will explore expanding beam tomography for transversely coupled beam and non-linear beam transports.
Paper: THOGB2
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THOGB2
About: Received: 03 May 2023 — Revised: 06 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPA009
Optical pepper-pots: developing single-shot emittance diagnostics
3966
Emittance measurements are a universal requirement when operating particle accelerators. Many techniques exist to achieve these measurements, each suiting the specific requirements of a machine. Most are multi-shot or invasive, and struggle to function with low energy beams or where space-charge effects are dominant. Generally, these limitations can be restricting, but especially so in emerging sectors such as novel acceleration or energy recovery linacs. To this end, two all-optical single-shot emittance measurements are being developed. In both cases the measurement is analogous to an optical version of the common pepper-pot diagnostic. The two methods are complementary: the first uses a micro-lens array (MLA); the second a digital micro-mirror device (DMD). Both systems can operate away from a beam waist and separate the optical beam radiation into beamlets rather than the beam itself; leaving potential for a non-invasive measurement. The benefits of using optical beam radiation are reduced beam scattering, simple designs, and suitability for low-energy/space-charge dominant beams. Presented is a series of benchmarking measurements and simulations with laser sources. Initial beam simulations, plans for first measurements, and the application to a machine learning virtual diagnostic are also discussed.
Paper: THPA009
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA009
About: Received: 03 May 2023 — Revised: 24 May 2023 — Accepted: 24 May 2023 — Issue date: 26 Sep 2023
THPA012
Initial application of machine learning for beam parameter optimization at the Hefei Light Source II
3974
Machine learning techniques have developed rapidly in the last decade and are widely used to solve complex scientific and engineering problems. Many accelerator laboratories internationally have begun to experiment with machine learning and big data techniques for processing accelerations. This paper presented the application of machine learning to the Hefei Light Source. Including the simulation of the tune and the calibration of the online experiment that met the design requirements and simulation of the beta parameter correction with deep learning. Based on this, online beta calibration will be carried out in the future.
Paper: THPA012
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA012
About: Received: 02 May 2023 — Revised: 14 Jun 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPA024
First operational results of new real-time magnetic measurement systems for accelerator control
3996
A new real-time measurement system for accelerator control, named FIRESTORM (Field In Real-time Streaming from Online Reference Magnets), to measure the integrated bending field has been recently deployed and commissioned in six synchrotron rings at CERN. We present the operational experience during the preparation phase and the restart of the accelerator complex for Run 3, focusing on the metrological performance of the new sensors and electronics, and on the lessons learned during commissioning. We also discuss the prospects for the evolution of the system and its adaptation to related use cases.
Paper: THPA024
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA024
About: Received: 02 May 2023 — Revised: 05 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPA028
Development of new synchronized data system for J-PARC RCS
4004
The J-PARC 3 GeV Rapid Cycling Synchrotron (RCS) accelerates the beam pulses with different conditions to two facilities. Therefore, it is indispensable to be able to correctly monitor the beam conditions. Then, we developed the synchronized data system for RCS beam monitor. This system is enabled to provide real-time synchronized data and to also archive all synchronized data with no data loss. By this system, we could realize beam commissioning and beam supply with minimum beam loss from the beginning of RCS operation. Current system is designed using Refractive Memory (RFM). However, recently, the use of RFM has made it difficult to integrate the various data into system. In addition, it is also difficult to upgrade to a system that can support larger size data because of RFM memory size limitation. Therefore, we developed the extensible synchronized data system that has the same primary functions as the current system and can integrate the various data by data communicating via a LAN. Furthermore, this system is designed to provide and archive the larger size data. This paper presents the details of extensible synchronized data system and the results of its performance test.
Paper: THPA028
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA028
About: Received: 08 May 2023 — Revised: 09 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
THPA037
Stability analysis of double-harmonic cavity system in heavy beam loading with its feedback loops by a mathematical method based on Pedersen model
4032
With the high beam current in storage ring, it is necessary to consider the instability problem caused by the heavy beam loading effect. It has been demonstrated that direct RF feedback (DRFB), autolevel control loop (ALC) and phase-lock loop (PLL) in the main cavity can lessen the impact of the beam effect. This paper regarded the beam, main cavity, harmonic cavity and feedback loops as double harmonic cavity system, and extended the transfer functions in the Pedersen model to this system. Some quantitative evaluations of simulation results have been got and conclusions have been drawn. In the case of a passive harmonic cavity, the optimization strategy of the controller parameters in the pre-detuning , ALC and PLL, as well as the gain and phase shift of DRFB were discussed. Meanwhile, it also involved the impact of the harmonic cavity feedback loop on the system stability at the optimum stretching condition when an active harmonic cavity was present. The research results can be used as guidelines for beam operation with beam current increasing in the future.
Paper: THPA037
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA037
About: Received: 21 Mar 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
THPA038
Beam-based alignment of individual members of sextupole families
4036
In order to steer beams through the center of focusing elements, the field center with respect to adjacent Beam Position Monitors needs to be known precisely. Often individual qudrupoles are varied to find the center, where the orbit does not change, but this requires costly field control for each quadrupole. Here we analyze beam-based Alignment(BBA) techniques that utilizes sextupoles that are powered in smaller families. These methods usually involve altering the strength of a sextupole to find the center, where the tunes do not change. How- ever, these approaches do not hold up well for sextupoles powered in families, as changing the strength of one sextupole in a family also changes the strength of every other family member. To reduce the effects of other sextupoles in the same family, a new method was developed and investigated that involves creat- ing a closed three-kicker-bump around a sextupole and observing the effects of the sextupole field on the kick settings. By changing the position at which the beam enters the sextupole by controlling the bump amplitude, one can recon- struct the sextupole center. Here, we explore the precision to which this method can reconstruct the sextupole center and we derive an error equation used to explain the degree of precision expected from this method. 1
Paper: THPA038
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA038
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
THPA042
Handling the functional features of accelerator components using ISO GPS situation features
4047
The building blocks of a scientific facility based on particle beams is made of magnets and electro-magnetic devices such as accelerating cavities. The optical design usually imposes a demanding accuracy with respect to their theoretically exact position and orientation. It is however frequent that the functional features are either not clearly defined – what is the « axis » of a magnet –, or not directly used along the lifecycle of these devices. Improving the ways to handle these functional features would contribute to meeting the demanding challenges. The European Spallation Source (ESS) is aiming at providing a powerful proton linear accelerator and a target system to produce pulsed neutrons. The challenging complex design and integration yielded to introducing a tool shared in common by all stakeholders along the lifecycle: the "situation features", as defined in ISO GPS (Geometrical Product Specifications) standards. They are here developed and extended to beyond-mechanics cases. Two examples are presented: neutron beam optics; and fiducialisation and installation of quadrupole magnets. Perspectives of generic use are also highlighted.
Paper: THPA042
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA042
About: Received: 27 Apr 2023 — Revised: 03 Jul 2023 — Accepted: 03 Jul 2023 — Issue date: 26 Sep 2023
THPA046
Overview of the radiation levels in the CERN accelerator complex after LS2
4055
The PSB, PS, and SPS accelerators at CERN provide high-energy proton and ion beams to a wide range of experiments, from fixed targets to the world’s biggest particle accelerator: the Large Hadron Collider (LHC). In 2021 and 2022, their beams have reached unprecedented intensities thanks to the LHC Injectors Upgrade (LIU) undertaken during the Long Shutdown 2 (LS2) in preparation of the High-Luminosity (HL) LHC era. The operation of these accelerators results in beam losses that generate a mixed radiation field that can negatively impact the exposed electronic systems through cumulative and single event effects. To minimise the associated damage, including potential the machine downtime due to radiation effects on electronics, the evolution and distribution of radiation levels must be carefully monitored across the CERN complex to detect anomalies promptly, to propose mitigation measures to protect electronic systems when needed, and to plan the installation of new electronic systems appropriately. This contribution will give an overview of the new radiation levels across the CERN injector complex in 2021 and 2022.
Paper: THPA046
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA046
About: Received: 26 Apr 2023 — Revised: 18 May 2023 — Accepted: 18 May 2023 — Issue date: 26 Sep 2023
THPA047
Overview of total ionizing dose levels in the Large Hadron Collider during 2022 restart
4059
During the Large Hadron Collider (LHC) operation small fractions of the beam are lost continuously, leading to mixed-field radiation. Whereas the 2022 radiation environment in the majority of the locations follows expectations established both through measurements and simulations, some discrepancies with respect to the Run 2 operation (2015-2018) were detected. This work presents an overview of the 2022 Total Ionizing Dose (TID) levels as measured by the Beam Loss Monitors (BLMs) distributed along the LHC, focusing on the similarities and most prominent discrepancies with respect to the Run 2 operation.
Paper: THPA047
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA047
About: Received: 03 May 2023 — Revised: 01 Jun 2023 — Accepted: 01 Jun 2023 — Issue date: 26 Sep 2023
THPA049
The Personnel Access System for FAIR
4067
Once completed, the Facility for Antiproton and Ion Research in Europe GmbH, FAIR, is to be one of the leading nuclear physics laboratories in Europe and one of the largest and most versatile accelerator complexes worldwide. FAIR can serve a number of experiments simultaneously, using fast-cycling synchrotrons. In this context, safety of personnel has the highest priority. The essential function of the Personnel Access System (PAS) is to prevent the presence of personnel in areas with particle beam or its secondary radiation. A particular challenge for FAIR is the large number of areas where personnel can access. For efficiency, it is required that during access to some areas, the beam operation continues in other areas of FAIR. For other hazards (e.g. electrical hazards, RF, laser beams) in certain areas, the PAS ensures that only personnel with adequate authorization can access and provides a safety signal to switch off hazardous equipment. Based on safety PLCs for the control system, the PAS uses some novel technologies such as hand vein scanners and safety radar systems.
Paper: THPA049
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA049
About: Received: 02 May 2023 — Revised: 11 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
THPA050
SuperKEKB Personnel Protection System
4070
The KEKB personal protection system (PPS) takes care of not only KEKB accelerator, but also PF-AR, Positron Damping Ring and their beam transport lines. The PPS is updated step by step. The new beam transport line to the PF-AR was constructed, and it makes possible that the injector supplies the beam to the 5 storage ring (KEKB LER,HER,PF-AR,PF and Positron damping ring) simultaneously. The positron damping ring was also constructed at the middle of the injector. The injector is not only supply the beam to the damping ring, but also is receive the beam from the damping ring. In this way, the accelerator operation scheme changed dramatically. The logic of the PPS has been changed to adapt the new accelerator operation scheme.
Paper: THPA050
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA050
About: Received: 08 May 2023 — Revised: 10 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPA057
Reliability studies for CERN’s new safe machine parameter system
4085
The Safe Machine Parameter system (SMP) is a critical part of the machine protection system in CERN’s Large Hadron Collider (LHC) and the Super Proton Synchrotron (SPS). It broadcasts safety-critical parameters like beam energy, beam intensity, the beta functions and flags indicating safety levels of the beam to other machine protection elements. The current SMP will be replaced by a consolidated system during CERN’s Long Shutdown 3, foreseen to start in 2026. In this contribution the results of the reliability study of the new SMP system are presented. This study quantifies the criticality of end-users by identifying the hazard chains leading to potential damage of the involved equipment. Data-driven risk matrices are used to derive acceptable failure frequencies and reliability requirements. The study encompasses Monte Carlo simulations of sub-system level configurations to support the decision-making process in this project.
Paper: THPA057
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA057
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPA059
Upgrades and developments related to stable ion beams injectors at INFN-LNL
4093
The LNL accelerator complex is equipped with two stable ion beams injectors, employing respectively negative and positive ion sources. In particular, a sputtering-type negative ion source and an Electron Cyclotron Resonance Ion Source (ECRIS) are installed on high voltage platforms, to provide the optimum injection energy in the downstream accelerators. Recently, the two injectors have been object of upgrades and developments, in order to improve the overall safety and reliability of the two systems, as well as the beams available for the users. This contribution describes the work related to the above mentioned activities, the technical choices employed and the latest results on ion beams production.
Paper: THPA059
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA059
About: Received: 08 May 2023 — Revised: 18 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPA060
Development of a Tool for Cavity Failure Compensation in Superconducting Linacs: Progress and Comparative Study
4097
Reliability in high power hadron accelerators is a major issue, particularly for Accelerator Driven Systems (ADS). For example, the Japan Atomic Energy Agency (JAEA) ADS maximum frequency of beam trips longer than 5 min was set to 42 per year. A significant number of breakdowns are caused by the failure of accelerating cavities or by their associated systems. Hence, we studied how these can be effectively reduced. To this end, we developed the numerical tool LightWin that aims to determine the compensation settings for any superconducting (SC) linac automatically and systematically [1]. This tool has been successfully used for the MYRRHA SC linac. In this work, we applied LightWin to compensate for several failure scenarios involving the last section of the JAEA linac and compared the associated retuned settings and beam performance to those found in a previous study [2] with TraceWin.
Paper: THPA060
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA060
About: Received: 01 May 2023 — Revised: 05 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPA063
LANSCE accelerator machine protection/timing system interaction opportunities
4109
The Los Alamos Neutron Science Center (LANSCE) timing system leverages a commercial event-driven system from Micro Research Finland (MRF) which is in use at various (16+) accelerators facilities around the world. Recent upgrades to the LANSCE accelerator machine protection [Fast Protect] system utilizing MRF event receivers will address some long-standing issues that require non-intuitive work arounds to allow beam delivery. The complexity of the system stems from the fact that LANSCE is a multi-user facility which delivers uniquely time-structured pulsed beams of varying power levels “simultaneously” to up to 5 different user facilities. One of the remaining issues with the Fast Protect system is that a fault related to one user facility can, in some circumstances, prevent beam delivery to another user facility. This is caused by allowing unscheduled but permitted changes to the beam delivery destination. The paper will discuss all relevant aspects including the timing system, current fast protect implementation, observed operational issues, and proposed changes to the fast protect system which will take advantage of the existing capabilities of the timing system.
Paper: THPA063
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA063
About: Received: 02 May 2023 — Revised: 08 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPA065
MTCA.4-based clock and timing distribution for PETRA IV
4115
At DESY, the technical design phase to upgrade the PETRA III storage ring towards the 4th-generation synchrotron light source PETRA IV is ongoing. This foresees a complete renewal of the machine including its existing timing and synchronisation system. The new timing and synchronisation system needs to deliver precise clocking, which will be implemented by an application-specific hardware design. Further on, it has to provide trigger signals and beam-synchronous information to the subsystems located across the facility. The main hardware for the timing system will be based on the MTCA.4 standard. This platform has been successfully implemented here at DESY / EuXFEL. Because of new specific requirements for PETRA IV, the successor hardware has to be adapted and upgraded to a new design. This paper describes the system design and the facility-wide distribution of precise clocks, trigger signals and timing system-related meta-information. We illustrate how the new MTCA.4-based AMC card (DAMC-X3TIMER) meets the requirements for PETRA IV. Insights into ongoing lab tests on components qualification and the status of the development will be presented.
Paper: THPA065
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA065
About: Received: 02 May 2023 — Revised: 08 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPA066
Using TSN for accelerator control systems
4119
In the context of Time Sensitive Networking (TSN), the Ethernet standards are being extended with new capabilities for deterministic communication, allowing standard Ethernet to be used in new fields of application. In addition, more and more companies now offer TSN compatible devices and software tools. In accelerator control systems (ACS), which need synchronization in the range of some hundred ns, TSN provides the necessary mechanisms for a one-cable timing system with deterministic low latency and best-effort data transfer in parallel. These techniques include message-based timing and fast back channel capabilities for front-end controllers, leading to high safety in medical applications. Nowadays, time synchronisation below 100 ns of up to 250 devices can be achieved using the IEEE 802.1AS standard, based on PTP (Precision Time Protocol). Deterministic communication can be guaranteed by a time-based scheduler according to IEEE 802.1Qbv standard, protecting critical traffics. This fulfils the needs of a next generation ACS for a synchrotron-based ion beam therapy facility. Time measurement results of test set-ups, using TSN capable switches and SoMs (System-on-Modules), will be reported as well as conceptual designs, which will be realized soon to implement multi-energy operation at HIT.
Paper: THPA066
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA066
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPA078
PRAGUE (Proton Range Measurement Using Silicon Carbide): a detector to measure online the proton beam range with laser-driven proton beams
4146
Laser-driven proton beams are characterized by very high intensities per pulse with a very short duration, extremely high dose rates, and broad energy spectra. These specific features do not allow the use of the conventional dosimeters typically suggested by the international dosimetry protocols for conventional proton beams. Precise dosimetry for laser-accelerated protons is an ambitious task as well as a crucial prerequisite for successful radiobiological experiments. We will present the work done within the PRAGUE project funded by the H2020 in the framework of the MSCA-IF IV program and by the INFN. The main goal of PRAGUE was the design, simulation, realization, and characterization of a real-time depth-dose distribution detector system based on thin Silicon Carbide multilayers for conventional and laser-accelerated proton beams in the energy range between 30 MeV to 150 MeV. The detector developed was designed to work at the regime of extremely high dose rate beams and it allows the retrieval of real-time and shot-to-shot depth dose distributions with a high spatial resolution thanks to the development and use of a 10 μm, fully depleted 15x15 mm2 square SiC detector. A detector prototype was already realized, simulated, and tested with 30 and 70 MeV conventional proton beams. Potentially this newly developed detector could enable new detector technology capable of providing online information of dose delivered at a biological sample with a laser-driven proton beam.
Paper: THPA078
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA078
About: Received: 02 May 2023 — Revised: 08 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPA092
The CERN SPS Low Level RF feedback with amplitude and frequency modulation
4171
The CERN SPS Low Level RF (LLRF) has undergone a major upgrade, including the complete redesign of the 200 MHz Cavity-Controllers [1,2] and the Beam-Control [3] during the Long Shutdown two (LS2) in 2018-21. Two major goals motivated the upgrade, first the required doubling of the proton beam intensity injected from the Super Proton Synchrotron (SPS) for the High Luminosity Large Hadron Collider (HL-LHC) project, second the implementation of the slip-stacking of two families of ions bunches, 100 ns spacing, to generate a 50 ns spacing after interleaving. This paper presents new features of the 200 MHz Cavity-Controller part, that is responsible for the regulation of the accelerating field in a single SPS cavity. Unlike the pre-LS2 implementation, the new system supports 100% Amplitude modulation (AM) and Frequency Modulation (FM) for the One-Turn delay FeedBack (OTFB) and for the Feed-ForWarD (FFWD). The AM was commissioned and used with physics proton and lead ions beams during the SPS 2022 run. The new elements required for the modulations are reviewed and details are provided on the implementation: delay and phase compensations to synchronize the cavity voltage measurement for the cavity field regulation with the AM and FM, synchronization of multiple cavities, and the velocity compensation for the heavy Ion acceleration. Finally, results of the cavity field regulation with amplitude modulation in 2022 are presented.
Paper: THPA092
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA092
About: Received: 28 Apr 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
THPA096
Beam loading compensation in the CERN SPS 200 MHz cavities. Measurements and comparison with expectations
4186
The High-Luminosity LHC (HL-LHC) project requires a doubling of the proton intensity transferred from its injector (SPS). Beam loading compensation in the SPS 200 MHz cavities is essential to limit losses when the beam is transferred into the LHC 400 MHz RF system. The SPS Low Level RF (LLRF) has been completely redesigned during the LHC Long Shutdown 2 (LS2, 2019 – mid 2021). The new system relies on a One-Turn delay FeedBack (OTFB) and a Feed-Forward for regulating the cavity field. The paper presents the performances achieved with the 2023 beam and compares these to the simulations performed during LS2. It also extrapolates the 2023 results to the HL-LHC beam intensity.
Paper: THPA096
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA096
About: Received: 28 Apr 2023 — Revised: 16 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPA100
An advanced digital feedback control system design for the muon linear accelerator
4194
A unique muon linear accelerator (linac) for the muon g-2/EDM experiment at J-PARC is under development. Digital feedback (DFB) design employed in a low-level radio frequency (LLRF) control system is crucial to fulfilling the required RF amplitude and phase specifications in the RF cavities for a stable and continuous acceleration of the whole bunched particles. To this end, a micro telecommunications computing architecture.4 (MicroTCA.4)-based compact and in-house DFB design, using Vadatech commercial off-the-shelf (COTS) RF system-on-chip (RFSoC) advanced mezzanine card (AMC), is aimed for the muon linac. This feedback control system will employ a direct sampling method that reduces the project cost by requiring less hardware employment for ultra-high frequency (UHF) and L-band accelerating structures. The present status and first results of the project will be reported in this paper.
Paper: THPA100
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA100
About: Received: 02 May 2023 — Revised: 05 Jun 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
THPA101
Design study of 972-MHz RF and clock generator board at J-PARC linac
4198
In the J-PARC linac, the low-level RF (LLRF) with the digital feedback (DFB) and the digital feedforwaed (DFF) of the cPCI system had been adopted to satisfy the requirement of amplitude and phase stabilities. It has been operated without a serious problem so far. However, more than 15 years have passed since the construction of the J-PARC linac and the life of the apparatuses used since the time of construction is approaching. Some apparatuses are now discontinued and cannot be purchased, and others have problems such as software development environments that only use on older OSs. Therefore, we are starting to develop the next generation LLRF system. Currently, the 324-MHz LLRF stations, approximately half of all systems, are replaced by new DFB and DFF system based on MTCA.4. As a next step, we will develop new 972-MHz DFB and DFF system. The analog boards cannot be shared with the 324-MHz DFB and DFF system due to the different frequencies. The digital board will be re-examined to reduce the latency. In this paper, we would like to introduce the plan to replace the DFB and DFF systems at J-PARC Linac and show the design study of the RF and clock generator board.
Paper: THPA101
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA101
About: Received: 11 May 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
THPA104
Upgrade of the ALPI low and medium beta RF control system
4205
The ALPI accelerator radio frequency (RF) control system at LNL (Legnaro National Laboratories) is currently undergoing a series of upgrades which will extends its lifetime and provide enhanced performance. This is a multi-year project where the upgrades are delivered incrementally while avoiding disruptions to the accelerator schedule. The first phase includes the development of new Low Level RF (LLRF) controllers, tuner and coupler stepper motor boxes and power amplifiers interfaces. The control system software and graphical user interfaces have been completely rewritten based on EPICS, supporting both the new and old LLRF controllers. A second phase is undergoing with the installation of the new software and hardware, while still using the old LLRF controllers, on the low and medium beta cavities of the ALPI accelerator. In the next phases the upgrade of the whole accelerator to the new software will be completed and the new LLRF controllers will be installed. This paper describes the technical solutions adopted and the status of the project.
Paper: THPA104
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA104
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPA114
Evaluation of the first version of the new RFPI system dedicated to PIP-II project accelerator
4226
The Low-Level Radio Frequency (LLRF) control system is one of the most critical superconducting linac infrastructures responsible for the parameters of the beam acceleration. The LLRF system mainly focuses on the electromagnetic field parameters inside the cavity. While it incorporates fast feedback algorithms to optimize energy transfer to the passing particle beam it does not follow other cryomodule or cavity parameter changes. The Radio Frequency Protection Interlock (RFPI) system closely monitors various factors (like cryomodule vacuum, beamline vacuum, field emission probe current level, temperature, RF signal leakage, etc). Its simple but reliable logic has to provide an instant decision about the LLRF system or high-power amplifier output signal blocking in case of safety region excitation. This contribution presents a new version of the RFPI system which logic is implemented in the FPGA chip. The initial work on the prototype of the new system design resulted in the PoC (Proof of Concept) device. The PoC offers the possibility of various protection logic configurations, input signals parameters evaluation, and modularity aspects verification. The structure and test results from the device evaluation are summarized and discussed in this contribution.
Paper: THPA114
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA114
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPA119
High-rate radiation damage studies of materials with heavy ion beams
4236
The Argonne Tandem Linear Accelerator System (ATLAS) at Argonne National Lab is a superconducting ion linac capable of delivering beams ranging over all possible elements, from hydrogen to uranium, and at a wide range of beam currents and energies. The ATLAS scientific program is focused primarily on basic nuclear physics. In this contribution, we present the capabilities of ATLAS for high-rate radiation-damage studies for a variety of applications below the threshold of producing radioactivity. To date ATLAS has been used for such studies relevant to advanced reactors. These include studies of structural materials and damage induced by fission products in advanced fuel candidates. Such studies can be expanded to include in-situ measurements of response to damage in other materials used at high power densities such as for targets at spallation neutron sources and neutrino factories. ATLAS is in the process of a multi-user upgrade which adds the capability of simultaneously accelerating two ion beams and delivering them to different target stations. This enables ATLAS to deliver beams for nuclear physics research simultaneously with irradiation studies.
Paper: THPA119
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA119
About: Received: 03 May 2023 — Revised: 20 Jun 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
THPA120
ATLAS operations shift log software upgrade and implementation
4240
The Argonne Tandem Linear Accelerator System (ATLAS) at Argonne National Lab uses an electronic shift log to record machine performance, save beam tune data, relay information between shifts, and track the facility's operational status for budget reporting. In early 2021, the legacy shift log was retired and upgraded to a modern platform to increase reliability and expand functionality. This contribution details the development and implementation, future expansion plans, and discusses 2 years of operational experience.
Paper: THPA120
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA120
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPA121
A public data service for the Beam Interlock Systems at CERN - current status and future plans
4243
The Beam Interlock System (BIS) is the backbone of the machine protection system in CERN’s accelerator chain, ensuring that the beams are safely transported through the injector chain and circulated in the Large Hadron Collider. A new version of the BIS is currently under development and planned to be deployed in the SPS, LHC and the North Area experimental zone during the Long Shutdown 3 (LS3), while the recently installed BIS in LINAC4 and the PSB will remain in place. As a result, the current and the new system will be operated in parallel, and it is primordial that both systems can be supervised and monitored in the same way by the operation crews, the system experts, and reliability engineers. Consequently, it is planned to provide a data service with a unique API for both systems. This data service will leverage UCAP and chain transformations to expose data for anyone to consume, and to be logged as time series in NXCALS. This paper recalls the current implementation of the BIS supervision. It then presents the solution that was developed with UCAP and the benefits of the chain of transformations. It then reviews the performance and limitations of this implementation, and details the future plans.
Paper: THPA121
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA121
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPA137
RF characterisation of laser treated copper surfaces for the mitigation of electron cloud in accelerators
4275
In accelerator beam chambers and RF waveguides, electron cloud and multipacting can be mitigated effectively by reducing the secondary electron yield (SEY). In recent years, it has been established that laser surface structuring is a very efficient method to create a copper surface with SEY close to or even below unity. Different laser pulse durations, from nanoseconds to picoseconds, can be used to change surface morphology. Conversely, the characteristics that minimise the SEY, such as the moderately deep grooves and the redeposited nanoparticles, might have unfavourable consequences, including increased RF surface resistance. In this study, we describe the techniques used to measure the surface resistance of laser-treated copper samples using an enhanced dielectric resonator with 12 cm diameter sample sizes operating in the GHz range. The quantification basis lies in a non-contact measurement of the high-frequency losses, focusing on understanding the variation of surface resistance levels depending on the specifics of the treatment and possible post-treatment cleaning procedures.
Paper: THPA137
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA137
About: Received: 10 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPA138
Room temperature vacuum chamber with cryogenic installations
4279
The FAIR complex at the GSI Helmholtzzentrum will generate heavy ion beams of ultimate intensities. To achieve this goal, low charge states have to be used. However, the probability for charge exchange in collisions with residual gas particles of such ions is much higher than for higher charge states. In order to lower the residual gas density to extreme high vacuum conditions, 65% of the circumference of SIS18 have already been coated with NEG, which provides a high and distributed pumping speed. Nevertheless, nobel and nobel-like components, which have very high ionization cross sections, do not get pumped by this coating. A cryogenic environment at moderate temperatures, i.e. at 50-80 K, provides a high pumping speed for all heavy residual gas particles. The only typical residual gas particle that cannot be pumped at this temperature is hydrogen. With an additional NEG coating the pumping will be optimized for all residual gas particles. The installation of cryogenic surfaces in the existing room temperature synchrotron SIS18 at GSI has been investigated. Measurements on a prototype chamber and simulations of SIS18 with cryogenic surfaces based on these measurements are presented.
Paper: THPA138
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA138
About: Received: 28 Apr 2023 — Revised: 12 Jun 2023 — Accepted: 12 Jun 2023 — Issue date: 26 Sep 2023
THPA141
Evaluation of the in-situ photocathode handling for SRF photoinjector of SEALab
4291
The handling of very sensitive bi-alkali antimonide photocathodes as the electron source for the SRF photoinjector of SEAlab is a critical procedure for its operation. After the growth of the photocathode, they have to be transferred in-situ under extreme UHV conditions using a vacuum suitcase and under particulate-free conditions to avoid the contamination of the SRF cavity. Therefore, we performed an in-situ photocathode transfer between two photoelectron spectroscopy systems to study the impact of the varying vacuum conditions on the surface chemistry of the photocathode. The photocathode substrate (plug) has to be transferred from the sample holder onto the plug holder (insert) at the SRF photoinjector. At the transfer system, which was setup under particulate free conditions in the clean room, we installed an in-situ particulate counter to investigate the appearance of particulates by transferring the plug onto the insert under vacuum conditions.
Paper: THPA141
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA141
About: Received: 03 May 2023 — Revised: 01 Jun 2023 — Accepted: 01 Jun 2023 — Issue date: 26 Sep 2023
THPA145
Measurement of the Photoelectron Yield from the Synchrotron Radiation for the NEG-coated Tubes
4294
NEG-coated chambers have been adopted as the beam ducts for large particle accelerators and synchrotron light sources for the sake of the lower yields of the photon stimulated desorption (PSD) and the photoelectrons (PE) from the NEG films in addition to their pumping performance. Measurement of the photoelectron yield (PEY) was performed at the BL19B (PSD) beamline of the 1.5 GeV Taiwan Light Source (TLS) which simultaneously measures the PSD-yield. An aluminium cathode was inserted in the tubes and a positive bias of voltage for extraction of the photoelectrons applied. The PEY was obtained by dividing the photoelectron current by the photon flux of the synchrotron radiation. Measurements of the PEY include various types of NEG-coated stainless steel tubes and the bare tubes of titanium and aluminium alloys for the comparison. The experimental system and the results will be described in this presentation.
Paper: THPA145
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA145
About: Received: 26 Mar 2023 — Revised: 07 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPA154
The effect of small bends in thin non-evaporable getter coated tubes on the partial pressure ratio as a function of sticking probability
4320
Non-evaporable getter (NEG) coated vacuum cham-bers are widely used as a vacuum solution in modern particle accelerators. In the development and testing of new NEG coatings to produce better vacuum, the pumping properties are evaluated. In this paper, Test Particle Monte-Carlo Simulations are created to investigate whether small bends in sample tubes may affect the results of pumping speed measurements, and therefore lead to a set of inaccurate results. With the preference to move towards smaller beam emittance in new accelerators, the required aperture of the beam vacuum chamber is getting smaller as well. The chambers are thus becoming more delicate (less mechanically stable), and able to be bent, therefore creating the risk that when NEG-coated samples are created, a bend in the tube is skewing the results. Findings have shown that a bend of less than 1° could lead to a change in results by a factor of 10 in a sticking probability, which is a severe difference that cannot be ignored. The results have a strong correlation with the molecular beaming area from the bottom to the top of the modelled tubes. In future, it will be important to define how straight a tube must be to obtain accurate pumping property measurements.
Paper: THPA154
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA154
About: Received: 03 May 2023 — Revised: 07 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPA156
Multipurpose Vacuum Accident Scenarios (MuVacAS) prototype for the IFMIF-DONES linear accelerator
4324
IFMIF-DONES* is a key device in the EUROfusion roadmap for studying and licensing materials for future fusion reactors. It will be a unique neutron fusion-like irradiation facility equipped with a linear particle accelerator impinging an intense deuteron beam (125 mA, 40 MeV) onto a liquid lithium target. In terms of safety analysis of the facility, relevant accidental scenarios are related to the technical impossibility of having a separation window between the liquid lithium target chamber and the accelerator vacuum chambers. In case of Loss of Vacuum Accident (LOVA), such as a sudden air/water inrush or leakage in the accelerator or target vacuum chambers, the beam duct could serve as a transport line and lead to air/water contact with liquid lithium, with the risk of exothermic reaction. The use of Fast Isolation Valves (70-100 ms closing time) is envisaged as mitigation mechanism for these events. The MuVacAS Prototype is an experimental setup to study in detail these scenarios and validate the Safety Credited mitigation requirements. For this purpose, it recreates the last 30 meters of the accelerator and target vacuum chambers and, it is equipped with dedicated instrumentation and modules for simulating LOVAs. This contribution presents an overview of the experimental setup together with preliminary numerical simulation of these accidental events.
Paper: THPA156
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA156
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPA160
Thin films for the mitigation of electron multipacting
4337
For vacuum scientists and the accelerator community, it is of paramount importance to find solutions for high energy machines to mitigate : (i) pressure increases induced by the desorption of electrons, photons and ions; (ii) clouds of ions or electrons inducing beam instabilities, heat deposits on the vacuum chamber walls or stimulated molecular desorption; (iii) multipactor effect in superconducting rf cavities. The solutions call for specific surface treatments, including the use of deposits of thin films whose nature and morphology should lead to the improvement of the surface properties, in particular to reduce the secondary electron emission yield (SEY). We present a comparative study of several thin layers (CuO, TiNC, TiN, TiVZr, Zr, amorphous-C) whose SEY as well as the surface chemistry were characterized before and after conditioning by electrons. We focused in particular on the conditioning rate as a function of the nature of the thin film. This investigation highlights the influence of thickness and roughness of thin layers on the surface properties for accelerator applications.
Paper: THPA160
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA160
About: Received: 30 Apr 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPA162
New pulse forming line and transmission cables for the CERN PS booster extraction and transfer kickers
4345
The CERN PS booster features four extraction kicker systems, one for each of the four superposed rings and three transfer kicker systems for recombination of the beams when being transferred towards the PS. Each of these systems consist of SF6 gas filled Pulse Forming Lines (PFL) which are resonantly charged and then fast discharged by thyratron switches into SF6 gas filled transmission cables, transferring the pulse to the magnets. This paper outlines the future refurbishment of PFL and transmission cables with the constraint of minimizing SF6 gas usage. The pulse requirements are presented since they limit the choice of technology together with the development cost for alternative SF6 free technologies. The optimization potential regarding technical pulse requirements versus beam performance is discussed. The paper concludes with the choice made and the technical design outline for the refurbishment of the PSB transfer and extraction kickers.
Paper: THPA162
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA162
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPA163
Ultra-fast generator for impact ionization triggering
4348
Thyristors triggered in impact ionization mode find their dI/dt capability boosted by up to three orders of magnitude. This innovative triggering requires applying an important overvoltage on the anode-cathode of the thyristor with a slew rate > 1kV/ns. Compact pulse generators based on COTS components would allow the spread of this technology into numerous applications, including fast kicker generators for particle accelerators. Our approach for such a compact pulse generator begins with a HV SiC MOS with an ultra-fast super-boosting gate driver. Super boosting in the gate of a 1.7kV rated SiC MOS allows to reduce its rise time by a factor of > 25 (datasheet tr = 20ns vs. measured tr < 800ps), resulting in an output voltage slew rate > 1kV/ns and an amplitude > 1kV. Parallel MOSFETs triggered in synchronisation deliver higher current at this stage. Next, additional boosting is obtained by a Marx generator with D2PAK thyristors, reaching an output voltage slew rate > 11kV/ns. Finally, creating sufficient current necessary for the triggering of a big thyristor presents a new challenge. In this paper, we present an upgraded board design with a higher current output capacity.
Paper: THPA163
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA163
About: Received: 01 Apr 2023 — Revised: 05 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPA165
Measurement and characterization of a toroidal tape wound nano-crystalline core for the 40kV Inductive adder development at CERN
4356
CERN is currently developing a 40 kV proof of concept Inductive Adder (IA) for replacing the Proton Synchrotron (PS) complex pulse generators, which currently use 80 kV SF6 gas filled pulse forming lines. The experience gained during the design, commissioning and operation of this prototype device will be crucial for upcoming decisions on the type of future kicker pulse generators. The cross-sectional area (CSA), hysteresis curve, biasing and material of a magnetic core determines its volt-time integral. In a terminated mode IA this parameter dictates the maximum pulse width that can be delivered into the load at a certain voltage. It is therefore key to measure the magnetic core response at the expected rate of magnetization (T·𝜇s−1) to assess its capability. Measurements and analysis yield important information for choosing the core CSA per IA layer and develop an accurate simulation model. In this paper BH curve measurements under different excitations of a toroidal, tape wound, nano-crystalline core are presented and discussed. Based on the results, pulse length/amplitude limitations are outlined and the required core CSA per inductive adder layer is proposed.
Paper: THPA165
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA165
About: Received: 03 May 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
THPA177
Multi-terawatt, sub-picosecond long-wave infrared laser for next-generation particle accelerators
4381
Lambda-squared scaling of the ponderomotive potential makes long wavelengths preferable for certain regimes of laser-based particle acceleration, including the laser-wakefield acceleration of electrons at low plasma densities and the acceleration of ions from gaseous targets. Currently, multi-terawatt levels of peak power at long-wave infrared (LWIR) wavelengths around 10 μm can only be achieved via the amplification of a picosecond laser pulse in high-pressure CO2 laser amplifiers. Our state-of-the-art LWIR laser system employs chirped-pulse amplification in a mixed-isotope CO2 active medium (Oxygen-16 : Oxygen-18 ≈ 50:50) at a pressure of ~10 atmospheres to deliver up to 5 TW peak power in 2-picosecond pulses. This laser system has enabled several promising parameter-space optimization studies and proof-of-principle demonstrations of advanced techniques of particle acceleration and x-ray generation in recent years. A next-generation LWIR laser is currently under active development. It will provide a sub-picosecond pulse duration (100 fs and 500 fs with and without post-compression, respectively) and ≥15 TW of peak power. Theoretical models predict that these laser parameters will enable new acceleration regimes, such as the blow-out regime of laser-wakefield acceleration with millimeter-scale accelerating plasma structures.
Paper: THPA177
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA177
About: Received: 12 May 2023 — Revised: 04 Jun 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPA178
Study on the laser treatment of NB and Nb3Sn thin films on copper substrate with a kW nanosecond fiber laser
4384
Surface annealing using intense nanosecond laser pulses is an emerging technique for SRF cavities. This technique can effectively reduce the cavities’ surface defects and improve their RF performance. However, previous studies in this field limited themselves on solid state lasers or gas lasers, which have very low average power and are not practical for processing actual SRF cavities with ~m2 inner surface area. IMP innovatively built a practical whole-cavity processing system with a kW-level nanosecond fiber laser, which is designed to process an SRF cavity within a working day. In this work, the system design and feasibility analysis will be given, together with the comparison between pristine Nb thin film samples on copper substrates and their fiber laser processed counterparts. The results show that our fiber laser system can deliver comparable surface treatment as that from the solid-state laser system, but with higher efficiency. The authors believe such results could boost the application of laser surface annealing technique in the particle accelerator community.
Paper: THPA178
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA178
About: Received: 09 May 2023 — Revised: 12 Jun 2023 — Accepted: 12 Jun 2023 — Issue date: 26 Sep 2023
THPA179
Ion acceleration by laser-matter interaction: status and perspective with the upcoming I-LUCE facility at INFN-LNS
4386
The potential for developing compact, high-brightness particle and radiation sources has given a strong impetus to the development of the underpinning laser technology, including increasing the efficiency and repetition rate of the lasers. A result of this technological development can be seen in the new generation of ultrafast high-power laser systems working at a high repetition rate which have been built across Europe. A new high-power laser facility called I-LUCE (INFN Laser indUced radiation acCEleration) will be realized at LNS-INFN in 2024. The facility realization is funded by both EuAPS (EuPRAXIA Advanced Photon Sources) and Samothrace (Sicilian MicronanOTecH. Research And Innovation) projects financed by the PNRR Italian program. The Ti:Sapphire laser will have two outputs: the first one will be a 1 TW beam line (25fs,25-30mJ,10Hz) while the main beam line will be a 500 TW laser (25fs,10J,10Hz). I-LUCE will serve two experimental areas called E1 and E2. E2 will provide the unique worldwide combination of intense laser radiation with heavy ion beams generated with the Superconductive Cyclotron and Tandem (already installed at LNS) opening the door for interesting experiments in the field of plasma physics, nuclear physics and atomic physics. In addition, stand-alone experiments with intense laser beams will be carried out for several studies such as proton/ion acceleration laser generation. Instead, the E1 experimental room will be dedicated to electron acceleration.
Paper: THPA179
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA179
About: Received: 02 May 2023 — Revised: 06 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPA185
Effect of oxygen and other impurities on copper coating conductivity at cryogenic temperatures
4396
Theoretically copper resistivity to a good approximation may be viewed as the sum of a term phonon-electron scattering term, and a constant term. The first follows the Bloch-Gruneisen formula; goes to zero as T5 at low temperature. The constant term corresponds to scattering off defects and magnetoresistance. The defect part is due to impurities and finite crystal size. Since copper coating maybe backup to sleeve insertion in RHIC, the constant term should be kept sufficiently small. Coatings of 10 µm thick copper films were deposited on RHIC pipes; their RF conductivity measured. One deposition had RRR of 1.2, while another deposition resulted in RRR of 2.3. Multiple measurements reveal that the only difference between these copper depositions was in the miniscule quantity of oxygen contamination 0.125% versus 0.03% respectively; consistent with predictions for O; but puzzling results for other impurities. Measurement results will be presented.
Paper: THPA185
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA185
About: Received: 25 Apr 2023 — Revised: 11 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPA186
Increasing equipment availability with CERN’s enterprise asset management platform
4400
Properly managed asset and maintenance processes is key for minimizing unplanned downtime and to ensure efficient operations of any large-scale technical installation, including particle accelerator complexes. CERN has therefore over the last years significantly increased its use of a commercial EAM (Enterprise Asset Management) platform in order to support such efforts. With its advanced maintenance management functionality and built-in industrial best practices, more than 40 equipment groups at CERN are today relying on this software platform, to manage their installations. This does currently not only cover equipment inventories and work order management, but also storerooms with spare part handling and contract management capabilities for outsourced services. Several initiatives have in addition been launched to strive towards more elaborate maintenance practices such as condition-based and predictive approaches, using additional data sources including SCADA systems and IoT devices. While continuously extending and tailoring the EAM and its use at CERN, a strict policy of zero customization of it is applied, in order to stay 100% compatible with future versions.
Paper: THPA186
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA186
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
THPA187
A new product lifecycle management platform for CERN’s accelerator complex and beyond
4403
Particle accelerator projects are complex, and CERN’s current engineering tools already manage millions of documents that follow various lifecycles and workflows. Future projects will push size and complexity to yet higher levels, in addition to increased collaboration with external partners. As reliable data is critical for success of complex system design, CERN is now implementing a new PLM (Product Lifecycle Management) platform that outperforms previous disparate design data management systems in several aspects: Consolidation of legacy data in a consistent data model; Federation of data from different systems and external partners in a common structure; Processes with flexible Workflows and Lifecycles; Integration with Simulation, Manufacturing, Maintenance, and other services dealing with design and product data. The overarching goal for the new PLM platform is to act as a catalyser for improved quality and traceability of data (often known as the “Digital Thread”) and to serve as the foundation for Digital Twins of current and future accelerators with the aim to drastically reduce development times as well as operation and maintenance cost.
Paper: THPA187
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA187
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPL002
Development and commissioning of a new materials irradiation station at ATLAS
4416
A new dedicated materials irradiation beamline and target station was developed and recently commissioned at the ATLAS facility at Argonne National Laboratory. The new ATLAS Materials Irradiation Station (AMIS) is located just downstream of the first linac section (PII) and designed to receive heavy-ion beams with energies of 0.5 - 1.5 MeV/u. The main activity at AMIS is the irradiation of samples for radiation damage studies of nuclear materials. The facility will provide a unique accessible platform for accelerated testing of nuclear fuels and materials that support the testing and deployment of new materials for advanced reactors in a short period of time, which otherwise can take years of testing in conventional reactors. Although the focus of the AMIS line is to irradiate and investigate materials for nuclear energy applications, other research and applications are welcome. In particular, more beam time will be available following the completion of the ongoing ATLAS multi-user upgrade which will allow simultaneous beam sharing between different experimental stations. The development and commissioning results of the AMIS beamline will be presented and discussed.
Paper: THPL002
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL002
About: Received: 04 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
THPL004
Real-time Bayesian Optimization with Deep Kernel Learning and NN-Prior Mean for Accelerator Operations*
4420
The use of artificial intelligence (AI) has the potential to significantly reduce the time required to tune particle accelerators, such as the Argonne Tandem Linear Accelera-tor System (ATLAS). Bayesian optimization with Gauss-ian processes is a suitable AI technique for this purpose, it allows the system to learn from past observations to make predictions without explicitly learning representations of the data. In this paper, we present a Bayesian optimiza-tion method with deep kernel learning that combines the representational power of neural networks with the reliable uncertainty estimates of Gaussian processes. The kernel is first trained with physics simulations, then the model is deployed online in a real machine, in this case a subsec-tion of the ATLAS linac, to perform the optimization. In addition to the kernel, we also modelled the mean of the Gaussian process using a neural network trained with simulation data and later with experimental data. The results show that the model not only converges quickly to an optimal tune, but it also requires very little initial data to do so. These approaches have the potential of signifi-cantly improving the efficiency of particle accelerator tuning, and could have important applications in a wide range of settings.
Paper: THPL004
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL004
About: Received: 04 May 2023 — Revised: 10 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
THPL007
Robust adaptive bayesian optimization
4428
Particle accelerators require continuous adjustment to maintain beam quality. Several machine learning (ML) approaches are being explored for this task. At the Advanced Photon Source (APS), we have recently proposed the adaptive Bayesian optimization (ABO) algorithm and have shown it to be effective experimentally in the APS injector complex. Further testing has suggested several improvements, on which we report here. We introduce dynamic kernel switching, deep kernel learning, and surrogate model prior means, resulting in improved robustness. We also extend our code with multi-dimensional time kernel support and predictive constraint avoidance to make it applicable to a wider range of systems. These changes also improve the general ABO performance, but more importantly expand ABO applicability to systems with rapid or unexpected changes in either optimization parameters or time properties. Notably, this allows for rapid and automated fallback to conservative parameters when optimizer confidence degrades, with alarms raised for further operator review. These features will permit further operational ML adoption at APS.
Paper: THPL007
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL007
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPL008
Upgrades to logging and ml analytics architecture at APS
4432
Several machine learning (ML) projects on anomaly detection and optimization were recently started at the Advanced Photon Source (APS). To improve training data quality, and accommodate the upcoming APS Upgrade changes, a large increase in the number and size of log files is expected. Recent studies found performance bottlenecks in the current log analysis architecture, especially for large ML analytics tasks. We explored several approaches to improve both data density and throughput. First, we swapped lzma compression algorithm for modern alternatives like zstd and lz4, scanning presets to find an optimal one that increased decompression throughput by 10x for a 20\% file size increase. Several lossy compression schemes were attempted to take advantage of limited device resolution and ML quantization, yielding further size decreases with reasonable fidelity losses. Finally, we tested several analytics and time-series databases, finding them faster for both linear and random-access reads while maintaining good compression ratios. They also enabled offloading analytics computations to server nodes, reducing network load. Our results indicate that with some effort, it is possible to increase the amount of logged data significantly while improving ML analytics performance.
Paper: THPL008
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL008
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPL009
AGS booster beam-based main quadrupole transfer function measurements
4436
Physics models, particularly for online operations, such as for our MAD-X or Bmad models, depend on a good understanding of the magnet characteristics. While we often measure the magnets or some subset of the magnets, those measurements are only meant to verify that the magnets meet specifications before being installed. We often have magnets that are not precisely understood. As a result, we end up adjusting the coefficients in our models to match beam-based measurements with little or no theoretical basis. In this work, we present a new method for deriving these coefficients using orbit response matrix (ORM) methods. This new approach utilizes a neural network (NN) surrogate model to establish the mapping between ORM measurements and quadrupole kicks. The NN model is trained to identify quadrupole kick as a source of error by observing the difference between measured ORM and model ORM with no quadrupole kick. With actual kick values from the NN model and power supply current values from the control system, we can calculate the magnet transfer function coefficients using a polynomial fit. We will present results from preliminary beam studies in the AGS Booster.
Paper: THPL009
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL009
About: Received: 02 May 2023 — Revised: 04 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPL010
Summary of the 3rd ICFA Beam Dynamics Mini-Workshop on Machine Learning Applications for Particle Accelerators
4440
The 3rd ICFA Beam Dynamics Mini-Workshop on Machine Learning (ML) Applications for Particle Accelerators was held in Chicago, Il, USA, on November 1-4, 2022. This was an in-person workshop focused on ML techniques as applied to accelerator operations, design, and simulations. There were 76 attendees representing 26 institutions from around the world. A total of 59 abstracts were submitted allowing us to build a diverse program with both oral and poster presentations. The workshop was sponsored by the Center for Bright Beams (CBB), with support from the National Science Foundation and by RadiaSoft, an industry leader in high-level research and design and scientific consulting for beamline physics and machine learning. CBB supported eight graduate students for this meeting. The workshop was approved as a mini workshop by the International Committee for Future Accelerators (ICFA) Beam Dynamics Panel. We will provide a summary of the work presented at the workshop and the outlook for future efforts.
Paper: THPL010
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL010
About: Received: 03 May 2023 — Revised: 06 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPL013
Initial results of applying an autoencoder to detect anomalies in the air conditioning systems of the Brookhaven accelerator complex
4448
The Collider Accelerator Complex at Brookhaven National Lab (BNL) contains millions of control points. Monitoring tolerances for these control points is crucial for the system and is a challenging task. Catching early signs of failures in those systems will be very beneficial as they can save extensive downtime. Anomaly detection in particle accelerators has been highlighted and can significantly impact the system. Autoencoder is one of the most commonly used techniques for detecting anomalies. In this contribution, we apply an autoencoder method to analyze the historical data for runs 21 and 22 to find precursors for trips (and actual trips) of Air Conditioning (AC) systems based on local thermostat readbacks. Results from the existing system are presented, showing that the new method can catch early signs of AC trips so that advance notices can be sent for the operators to take prompt action.
Paper: THPL013
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL013
About: Received: 27 Apr 2023 — Revised: 06 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPL017
Automating beam dump failure detection using computer vision
4456
The CERN SPS Beam Dump System (SBDS) is responsible for disposing the beam in the SPS in case of any machine malfunctioning or end of cycled operation. This is achieved by the actuation of kicker magnets with predefined pulses, which aim to: i) deviate the beam towards the absorber block (TIDVG); ii) dilute the particle density. Evidently, a malfunction of this system may have negative consequences, such as the absorber block degrading if the beam is not sufficiently diluted, unwanted activation of the surroundings or even damage to the vacuum chamber in case of complete failure. By leveraging a combination of real images from a beam screen device and data from simulations, we train an online monitoring system to identify potential failures of the SBDS from real-time images. This work improves the safety of the operation of the SPS and contributes towards the goal of automating the operation of accelerators.
Paper: THPL017
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL017
About: Received: 04 May 2023 — Revised: 08 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPL018
Machine learning applications for orbit and optics correction at the Alternating Gradient Synchrotron
4460
The Alternating Gradient Synchrotron (AGS) is a particle accelerator at Brookhaven National Laboratory (BNL) that accelerates protons and heavy ions using the strong focusing principle. In this work, we perform simulation studies on the AGS ring of a machine error detection method by comparing simulated and measured orbit response matrices (ORMs). We also present preliminary results of building two machine learning (ML) surrogate models of the AGS system. The first ML model is a surrogate model for the ORM, which describes mapping between orbit distortions and corrector settings. Building a self-adaptive model of ORM eliminates the need to re-measure ORM using the traditional time-consuming procedure. The second ML model is an error identification model, which maps the correlation between measurement errors (differences between measurement and model) and sources of such errors. The most relevant error sources for the error model are determined by performing sensitivity studies of the ORM.
Paper: THPL018
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL018
About: Received: 02 May 2023 — Revised: 07 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPL019
Machine learning for combined scalar and spectral longitudinal phase space reconstruction
4464
Longitudinal beam diagnostics are a useful aid during tuning of particle accelerators, but acquiring them usually requires destructive and time intensive measurements. In order to provide such diagnostics non-destructively, computational methods allow for the development of virtual diagnostics. Existing Fourier-based reconstruction methods for longitudinal current reconstruction, tend to be slow and struggle to reliably reconstruct phase information. We propose using an artificial neural network trained on data from a start-to-end beam dynamics simulation to combine scalar and spectral information in order to infer the longitudinal phase space of the electron beam. We demonstrate that our method can reconstruct longitudinal beam diagnostics accurately and provide the reconstructed data with adaptive resolution. Deployed to control rooms today, our method can help human operators reduce tuning times, improve repeatability and achieve pioneering working points. In the future, ML-based virtual diagnostics will help the deployment of feedbacks and autonomous tuning methods, working toward the ultimate goal of autonomous particle accelerators.
Paper: THPL019
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL019
About: Received: 02 May 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPL022
Virtual diagnostics for longitudinal phase space imaging
4471
For any linear accelerator, a thorough understanding of the Longitudinal Phase Space (LPS) of the beam is a great advantage. At the synchrotron light source MAX IV the two storage rings are injected with electrons using a 3 GeV linear accelerator, which also serves to provide beam for a short pulse facility (SPF). A newly commissioned Transverse Deflecting Cavity (TDC) is used to reconstruct the full LPS in a separate branch in the SPF after the second bunch compressor. This diagnostic performs a destructive measurement to extract the LPS and can not be used simultaneously with the beamline in the other branch in the SPF. In this paper we present a new virtual diagnostics which utilizes machine learning methods to extract the LPS information from other, non-destructive signals in the MAX IV linac. This involves simulations of the linac including the TDC response, as well as the collection of real data from the new TDC, for use in training artificial neural networks to predict the full LPS.
Paper: THPL022
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL022
About: Received: 03 May 2023 — Revised: 05 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPL025
Online fit of an analytical response matrix model for orbit correction and optical function measurement
4475
At the Karlsruhe Research Accelerator (KARA), an analytical online model of the orbit response matrix (ORM) has been developed and tested. The model, called the bilinear-exponential model with dispersion (BE+d model), is derived from the Mais-Ripken formalism describing coupled betatron motion. Compared to the standard approach of measuring the ORM, this method continuously adapts to changing beam optics without a dedicated measurement. It is especially useful for storage rings without turn-by-turn capable beam position monitors (BPMs) as the online model also gives access to estimates of the coupled optical functions. In the following, experimental orbit correction results and a comparison of fitted and simulated optical functions are presented.
Paper: THPL025
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL025
About: Received: 03 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
THPL027
A low-latency feedback system for the control of horizontal betatron oscillations
4479
Reinforcement learning (RL) algorithms are investigated at KIT as an option to control the beam dynamics at storage rings. These methods require specialized hardware to satisfy throughput and latency constraints dictated by the timescale of the relevant phenomena. The KINGFISHER platform, based on the novel Xilinx Versal Adaptive Compute and Acceleration Platform, is an ideal candidate to deploy RL-on-a-chip thanks to its ability to execute computationally intensive and low latency feedback loops in the order of tens of microseconds. In this publication, we will present the integration of the KINGFISHER system at the Karlsruhe Research Accelerator (KARA), as a proof-of-principle turn-by-turn control feedback loop, to control induced transversal oscillations of an electron beam.
Paper: THPL027
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL027
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPL028
Bayesian Optimization for SASE Tuning at the European XFEL
4483
Parameter tuning is a regular task and takes considerable time for daily operations at FEL facilities. In this contribution, we demonstrate SASE pulse energy optimization at the European XFEL with Bayesian optimization (BO) as an alternative approach to the widely used simplex method. Preliminary experimental results show that BO could reach a comparable performance as the simplex method, even with an out-of-the-box implementation. Compared to previous attempts, our version of BO does not require setting hyperparameters via additional measurements, thus effectively reducing the required effort for machine operators to use it during operation. On the other hand, BO has the potential to be further improved by introducing prior physical knowledge about the task and fine-tuning the algorithm to specific tasks. This makes BO a promising candidate for routine tuning tasks at particle accelerators in the future.
Paper: THPL028
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL028
About: Received: 02 May 2023 — Revised: 08 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPL029
Beam trajectory control with lattice-agnostic reinforcement learning
4487
In recent work, it has been shown that reinforcement learning (RL) is capable of outperforming existing methods on accelerator tuning tasks. However, RL algorithms are difficult and time-consuming to train and currently need to be retrained for every single task. This makes fast deployment in operation difficult and hinders collaborative efforts in this research area. At the same time, modern accelerators often reuse certain structures within or across facilities such as transport lines consisting of several magnets, leading to similar tuning tasks. In this contribution, we use different methods, such as domain randomization, to allow an agent trained in simulation to easily be deployed for a group of similar tasks. Preliminary results show that this training method is transferable and allows the RL agent to control the beam trajectory at similar lattice sections of two different real linear accelerators. We expect that future work in this direction will enable faster deployment of learning-based tuning routines, and lead towards the ultimate goal of autonomous operation of accelerator systems and transfer of RL methods to most accelerators.
Paper: THPL029
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL029
About: Received: 02 May 2023 — Revised: 09 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPL033
Artificial Intelligence for improved facilities operation in the FNAL LINAC
4491
The energy consumption in accelerator structures during beam downtimes is a significant fraction of the overall energy budget. Accurate prediction of downtime duration could inform actions to reduce this energy consumption. The LCAPE project started in 2020 and develops artificial intelligence to improve operations in the FNAL control room by reducing the time to identify the cause of a beam outage, improving the reproducibility of labeling it, predicting their duration and forecasting their occurrence. We present our solution for incorporating information from ~2.5k monitored devices in near-real time to distinguish between dozens of different causes of down time. We discuss the performance of different techniques for modeling the state of health of the facility and we compare unsupervised clustering techniques to distinguish between different causes of down time.
Paper: THPL033
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL033
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPL034
Machine learning for laser pulse shaping
4495
The temporal profile of the electron bunch is of critical importance in accelerator areas such as free-electron lasers and novel acceleration. In FELs, it strongly influences factors including efficiency and the profile of the photon pulse generated for user experiments, while in novel acceleration techniques it contributes to enhanced interaction of the witness beam with the driving electric field. Work is in progress at the CLARA facility at Daresbury Laboratory on temporal shaping of the ultraviolet photoinjector laser, using a fused-silica acousto-optic modulator. Generating a user-defined (programmable) time-domain target profile requires finding the corresponding spectral phase configuration of the shaper; this is a non-trivial problem for complex pulse shapes. Using a physically informed machine learning model, we demonstrate accurate and rapid shaping of the photo-injector laser to a wide range of arbitrary target temporal intensity profiles on the CLARA PI laser. Additionally, we discuss the utility of this expanded range of laser pulse shapes to potential applications in FELs and novel acceleration.
Paper: THPL034
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL034
About: Received: 04 May 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPL035
Identification of magnetic field errors in synchrotrons based on deep lie map networks
4499
Magnetic field errors pose a limitation in the performance of circular accelerators, as they excite non-systematic resonances, reduce dynamic aperture and may result in beam loss. Their effect can be compensated assuming knowledge of their location and strength. Procedures based on orbit response matrices or resonance driving terms build a field error model sequentially for different accelerator sections, whereas a method detecting field errors in parallel yields the potential to save valuable beamtime. We introduce deep Lie map networks, which enable construction of an accelerator model including multipole components for the magnetic field errors by linking charged particle dynamics with machine learning methodology in a data-driven approach. Based on simulated beam-position- monitor readings for the example case of SIS18 at GSI, we demonstrate inference of location and strengths of quadrupole and sextupole errors for all accelerator sections in parallel. The obtained refined accelerator model may support set up of corrector magnets in operations to allow precise control over tunes, chromaticities and resonance compensation.
Paper: THPL035
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL035
About: Received: 29 Apr 2023 — Revised: 10 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPL036
Optimizing the discovery of underlying nonlinear beam dynamics and moment evolution
4503
One of the Grand Challenges in beam physics relates to the use of virtual particle accelerators for beam prediction and optimization. Useful virtual accelerators rely on efficient and effective methodologies grounded in theory, simulation, and experiment. This work extends the application of the Sparse Identification of Nonlinear Dynamical systems (SINDy) algorithm, which we have previously presented at the North American Particle Accelerator Conference. The SINDy methodology promises to simplify the optimization of accelerator design and commissioning by discovery of underlying dynamics. We extend how SINDy can be used to discover and identify underlying differential systems governing the beam’s sigma matrix evolution and corresponding invariants. We compare discovered differential systems to theoretical predictions and numerical results. We then integrate the discovered differential system forward in time to evaluate model fidelity. We analyze the uncovered dynamical system and identify terms that could contribute to the growth(decay) of (un)desired beam parameters. Finally, we propose extending our methodology to the broader community's virtual and real experiments.
Paper: THPL036
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL036
About: Received: 06 May 2023 — Revised: 07 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPL037
Gradient descent optimization and resonance control of superconducting RF cavities
4507
Presently, superconducting radio frequency (SRF) cavities with high intrinsic quality factors are used in particle accelerators, as a high intrinsic quality factor allows for increased energy efficiency. As such, this technology benefits new research into light source linacs such as in the new LCLS-II system. However, due to the narrow bandwidth attributed to large quality factors, the use of these SRF cavities requires more accurate control to mitigate the effects of vibrations within the cavity and maintain a fixed frequency. In a paper by Banerjee et al., it was proposed that the current practice of actively suppressing such vibrations using fast tuners may be improved through the implementation of a narrowband active noise control algorithm (NANC) that makes use of gradient descent. It is the aim of this research to explore which gradient descent methods work best for active resonance control
Paper: THPL037
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL037
About: Received: 04 May 2023 — Revised: 11 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPL038
Ultra fast reinforcement learning demonstrated at CERN AWAKE
4510
Reinforcement learning (RL) is a promising direction in machine learning for the control and optimisation of particle accelerators since it learns directly from experience without needing a model a-priori. However, RL generally suffers from low sample efficiency and thus training from scracth on the machine is often not an option. RL agents are usually trained or pre-tuned on simulators and then transferred to the real environment. In this work we propose a model-based RL approach based on Gaussian processes (GPs) to overcome the sample efficiency limitation. Our RL agent was able to learn to control the trajectory at the CERN AWAKE (Advanced Wakefield Experiment) facility, a problem of 10 degrees of freedom, within a few interactions only. To date, numerical optimises are used to restore or increase and stabilise the performance of accelerators. A major drawback is that they must explore the optimisation space each time they are applied. Our RL approach learns as quickly as numerical optimisers for one optimisation run, but can be used afterwards as single-shot or few-shot controllers. Furthermore, it can also handle safety and time-varying systems and can be used for the online stabilisation of accelerator operation.This approach opens a new avenue for the application of RL in accelerator control and brings it into the realm of everyday applications.
Paper: THPL038
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL038
About: Received: 03 May 2023 — Revised: 23 Jun 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPL039
Surrogate Model for Linear Accelerator: A fast Neural Network approximation of ThomX's simulator
4514
Accelerator physics simulators accurately predict the propagation of a beam in a particle accelerator, taking into account the particle interactions (a.k.a. space charge) inside the beam. A precise estimation of the space charge is required to understand the potential errors causing the difference between simulations and reality. Unfortunately, the space charge is computationally expensive, needing the simulation of a few dozen thousand particles to obtain an accurate prediction. This paper presents a Machine Learning-based approximation of the simulator output, a.k.a. surrogate model. Such an inexpensive surrogate model can support multiple experiments in parallel, allowing the wide exploration of the simulator control parameters. While the state of the art is limited to considering a few such parameters with a restricted range, the proposed approach, LinacNet, scales up to one hundred parameters with wide domains. LinacNet uses a large-size particle cloud to represent the beam and estimates the particle behavior using a dedicated neural network architecture reflecting the architecture of a Linac and its different physical regimes.
Paper: THPL039
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL039
About: Received: 03 May 2023 — Revised: 16 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPL051
Automated Faraday cup readings at ATLAS
4547
Since its commissioning, operators at the Argonne Tandem Linear Accelerator System (ATLAS) have used an analog current meter to manually record beam current measurements from Faraday cups along the beamline. Recently an automated process using a digital picoammeter was developed for beam current measurements. This automation has streamlined daily operations, increased the precision of measurements, and expedited the generation of digital data for use with ongoing artificial intelligence and machine learning work (AI/ML).
Paper: THPL051
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL051
About: Received: 03 May 2023 — Revised: 12 Jun 2023 — Accepted: 12 Jun 2023 — Issue date: 26 Sep 2023
THPL052
Resonant Cavity for Beam Current Diagnostics in Medical Accelerators
4550
Beam currents of particle accelerators used for cancer treatment are often on the nanoampere level. These currents are too low for standard beam current diagnostics used in other fields of particle accelerator science, e.g. current transformers. This led to the general adoption of ionization chambers for beam current and dose rate determination in medical accelerators. However, the development of the so-called FLASH radiation therapy requires beam currents too high for normal ionization chambers yet still too low for standard current transformers. Resonant cavities have shown their capability to precisely detect nanoampere to microampere beam currents which renders them interesting for FLASH radiation therapy accelerators. After the design of a resonant cavity at Paul Scherrer Institut (PSI), a collaboration between PSI, Instrumentation Technologies, and Bergoz Instrumentation was established with the goal to develop a complete turn-key beam current diagnostics system readily available for medical accelerators. Two prototype systems were manufactured, installed, and tested at PROSCAN/PSI. We discuss the layout of the measurement systems and compare expected performance to beam current measurements.
Paper: THPL052
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL052
About: Received: 28 Apr 2023 — Revised: 10 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPL060
Impact of dipole component change on quadrupole beam-based alignment accuracy for circular accelerators
4557
Beam-based alignment (BBA) for quadrupoles is a routine process for circular accelerators to steer beam orbit through the magnetic centers such that the orbit is unperturbed when the strengths of quadrupoles are varied. The random errors associated with BBA are well known, but a type of systematic error appears to be neglected by the community. A standard measurement procedure involves variation of the quadrupole gradient. This systematic error is introduced when there is a non-zero dipole component after quadrupole strength is changed. This dipole component can be also interpreted as a shift in the magnetic center. The analytical formulas for this error and its amplification factor with respect to the magnetic center motion have been derived and confirmed with simulations. We demonstrate the significance of this error, potentially on the order of hundreds of microns, through both simulations and recent experimental results at NSLS-II. In addition, a special term in this error that is not extractable from orbit measurements alone will be discussed in detail.
Paper: THPL060
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL060
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
THPL064
Design of a broadband modular permanent magnet electron energy spectrometer for FEBE
4572
The CLARA accelerator facility at Daresbury Laboratory, UK, was originally designed to operate as a free-electron laser test facility. To improve the user exploitation of the facility a dedicated full energy beam exploitation (FEBE) area has been designed and is currently being installed in a separate experimental bunker on the CLARA accelerator. This facility will allow users to conduct experiments combining a 250 MeV electron beam of up to 250 pC bunch charge with laser pulses up to 100 TW in a large target chamber. A second downstream chamber contains room for a number of diagnostics that are customisable to the experiments being conducted. The ability to combine a laser and electron beam in FEBE presents the possibility of novel acceleration experiments. FEBE is designed to allow user experiments which aim to further accelerate the electron beam from 250 MeV to 600 MeV, or 2 GeV at a reduced repetition rate. To measure the output of these experiments an innovative in-vacuum permanent magnet spectrometer dipole has been designed with modular construction to measure broadband electron energy spectra. The modular nature allows the length of the installed dipole to be tailored to the experiment, allowing room for additional diagnostics in experiments where maximum energies below 2 GeV are expected.
Paper: THPL064
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL064
About: Received: 27 Apr 2023 — Revised: 07 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPL067
Development and testing of quantum gas jet beam profile scanner
4584
A quantum gas jet-based beam scanner is under development at the Cockcroft Institute (CI) in the UK. This device is based on detecting the ionisation induced in a gas jet by a beam of charged particles. It aims at generating a dense gas jet with a diameter of less than 100 μm by exploiting the quantum wave nature of neutral gas atoms to generate an interference pattern with a single maximum. Work analogously to a mechanical wire scanner while being minimally interceptive, a tightly focused gas jet promises superior position resolution and high signal intensity. This contribution gives an overview of the design and functioning principle of the monitor, presents initial modification in the system for gas density measurement, as well as results from beam profile measurements obtained with a 5 keV electron beam.
Paper: THPL067
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL067
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPL068
Characterisation and analysis of supersonic gas jets using interferometric measurement methods
4588
Supersonic gas jets are useful tools in particle accelerators used in both scientific and medical applications. They can provide real-time, longitudinal and transverse beam profile measurements for charged particle beams in accelerators and are also being used as a plasma source in wakefield accelerators. For gas jets to be used effectively as beam profile monitors, the density profile of the jet must also be well-known. This can be calculated by measuring the phase shift produced by the gas jet inside a laser beam due to the difference in density between the gas and the surrounding vacuum environment from the Lorentz-Lorenz relation. In this contribution, multiple techniques for measuring gas jet profile and density will be compared and analysed; Mach-Zehnder and Nomarski interferometry. A 532 nm laser will be used for both of these methods, with a gas jet backing pressure of 7 bar. Multi-pass interferometry will also be used to increase the phase shifts by a factor of 4, and therefore sensitivity to lower density gas jets. This method involves retro-reflecting the interferometry beams, passing them through the gas jet multiple times. These techniques will be compared and their suitability for gas jet density characterisation will be assessed.
Paper: THPL068
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL068
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
THPL093
The ionization profile monitors in the recycler ring
4669
Ion profile monitors (IPM) are used to measure the beam size in synchrotrons. Both the Fermilab Recycler and Main Injector (MI) machines have IPMs. However, they were not well understood enough to provide confidence in their measurements. Accurately measuring beam size through the IPMs was crucial to recognize the loss mechanisms for accelerators and to keep the beam loss to a minimum. Thus, performing measurements with different parameters using the IPMs led to a better analysis on how changes in conditions affect the beam size. The IPM measurements are compared with that of multi-wires in the upstream transfer line after applying corrections. The results were compared with other diagnostics and the change in the beam size for different parameters are presented in this paper.
Paper: THPL093
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL093
About: Received: 04 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
THPL095
Measurement of beam energy in the Fermilab's Linac taken at the transfer line
4676
Linac is the first machine in the accelerator chain at Fermilab where H$^{-}$ ions are accelerated from 35 keV to 401.5\,MeV and then injected into a synchronton known as Booster where they are stripped of their electrons to become protons. One of the tools used during tuning of the Linac extraction energy is two beam pickups known as Griffin Detectors. Our goal is to control the output energy using machine learning techniques to increase the reliability and quality of the beam delivered from Linac. The first step is to understand the data from the diagnostics to develop reliable and accurate energy measurement, and control methods before implementing machine learning techniques. Two methods of energy measurement were studied, and their results are compared. The first method was the time of flight measurement using Beam Position Monitors that provide beam phase measurement. The second method used the relation between beam transverse positions and dispersion values to calculate momentum variation. The results of these two measurement methods are found to be consistent.
Paper: THPL095
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL095
About: Received: 12 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
THPL099
GNU Radio 4.0 for real-time signal-processing and feedback applications at FAIR
4688
At FAIR, GNU Radio* is being used as part of the generic monitoring and first-line diagnostics for acceleratorrelated devices, and to further support equipment experts, operation, and FAIR users in developing basic to advanced top-level measurement and control loops. GNU Radio is a free and open-source software development toolkit supporting hundreds of low-cost to high-performance industrial digitizers with sampling frequencies ranging from a few MS/s to GS/s~\cite{gnuradio, gnuradio_github, gnuradio4_github, FAIR_Digitizer, FAIR_Digitizer2}. At its core are directed signal flow graphs expressing arbitrary post-processing and feedback control loop logic that are both numerically highly efficient as well as providing an intuitive yet detailed nuts-and-bolts representation. This facilitates to inspect and/or to reconfigure existing systems by accelerator-, control- or other system domain-experts alike with little to no prior required programming experience. This contribution describes the community-driven improvement and modernisation process leading to GNU Radio 4.0 supporting improved type-safety, improved performance, and new features such as event-driven data processing, nanosecond-level synchronisation using White-Rabbit, and slow feedback loops.
Paper: THPL099
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL099
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPL100
Raspberry Pi cameras as beam induced fluorescence monitors for low and high energy beams
4692
Miniature single-board cameras have been used for several years to monitor beam-induced residual gas fluorescence. This work gives an overview of the use of so-called Raspberry Pi cameras in accelerator experiments. These devices are installed in vacuum at hard-to-reach locations. They have been tested in strong magnetic fields with low energy proton beams from 2 keV to 60 keV. They have also been tested in the high energy range with 4.8 MeV/u, $^{48}Ca^{10+}$ beams. Nitrogen and argon were used as residual gas and the pressure was varied from $1\cdot10^{-5}mbar$ to $1 mbar$.
Paper: THPL100
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL100
About: Received: 03 May 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
THPL103
Instrumentation and operation modes for the commissioning phase of the SEALab SRF photoinjector
4703
Superconducting radio-frequency (SRF) photoinjectors offer a broad range of electron beam parameters and are therefore suitable for many applications such as energy recovery linac (ERL) driven lightsources, particle colliders, or for ultrafast electron scattering experiments. We are now nearing completion of the setup a SRF photoinjector with a SRF gun and SRF booster linac at the SEALAb accelerator test facility at HZB. The goal here is to realize an electron source with high brightness and high average current. In this work, the general planning for the commissioning phase, the operation modes and investigations into the diagnostic tools for achieving the expected beam parameters will be presented. The focus of the instrumentation is to provide information on the beam parameters at large dynamic range and on mechanisms for beam loss generation.
Paper: THPL103
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL103
About: Received: 03 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
THPL104
Recovery and check of the switching relay in the BPMs in the J-PARC MR
4706
The present BPMs of the J-PARC Main Ring have adopted mechanical relays in its processing circuits. Frequency range is limited less than 10 MHz by LPFs. Mechanical relay is chosen due to its good isolation. But the drawback is contact failures due to insulating materials after long suspension period of months. Methods of recovery and checking are reported. Recovery of contacts are performed with injecting dummy pulses. Contact is checked examining consistency comparing four independent position pairs (x, y) calculated from 3 electrodes out of four electrodes. The hermetically seal reed relays will be implemented in the new processing circuits under development.
Paper: THPL104
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL104
About: Received: 09 May 2023 — Revised: 19 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPL106
Three-stage simulation for the development of an ion-acoustic dose-deposition mapping system for LhARA
4714
LhARA, the Laser-hybrid Accelerator for Radiobiological Applications*, is a proposed facility for the study of proton and ion radiation biology. The accelerator is designed to deliver a variety of ion species over a wide range of spatial and temporal profiles at ultra-high dose rates. The facility requires that the deposited dose distribution be measured in real-time. For this purpose, an ion-acoustic dose mapping system has been developed that, exploits the ultrasound waves generated by the ion beam**. The feasibility of this approach is being evaluated using a two-stage simulation. A water phantom modelled in Geant4 with beam energies up to 250 MeV is used to calculate the energy deposited by the beam as a function of position and time. The time-dependent 3D energy distribution is then used as the source in k-Wave to simulate the ion energy generation of acoustic (pressure) waves and their propagation in the three-dimensional space. A hemispherical acoustic sensor array is also simulated and its ability to reconstruct the generated pressure distribution is evaluated. The results show that the 3D deposited-energy distribution can be reconstructed with sub-millimetre accuracy and suggest, that further development of the system can lead to real-time, non-invasive Bragg peak localization and dose deposition profile measurement during ion-beam therapy.
Paper: THPL106
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL106
About: Received: 03 May 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
THPL107
Influence of vibratory effects on the beam parameters of SuperKEKB
4718
SuperKEKB is an asymmetrical lepton collider with a circumference of 3 016 meters, which collides 7 GeV electrons with 4 GeV positrons. To optimize the luminosity, which recently reached a world record of 4.71 10^34 cm-2 s-1, all the undesirable effects on beam parameters must be analyzed in detail, especially close to the interaction point where the Belle II detector is operated. The presented study investigates the influence of mechanical vibration on the luminosity. For this purpose, four seismic sensors (Guralp 6T) were installed and collect data 24 hours a day, two on the ground and another two located on the supports of the two cantilevered cryostats, inside which the last focusing magnets on both sides of the interaction point (the most critical for vibrations) are mounted. The luminosity is measured thanks to the LumiBelle2 fast luminosity monitor, which is based on diamond detectors installed in both beam lines. Vibration-induced disturbances in the luminosity frequency spectrum are investigated for several types of perturbations, in particular the ones resulting from ground motion amplified by the dynamical behavior of the cryostat, as well as also from external vibrations sources.
Paper: THPL107
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL107
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPL115
Beam loss monitors characterization for SPES proton beam line
4736
Beam Loss Monitors will be installed along the primary SPES beam line to detect proton beam losses in the cyclotron area. They will be connected to the cyclotron Machine Protection System (MPS), as it is significant for the proper management of the accelerator during the operation. This report shows the work of characterization of such devices. Preliminarily, the characteristics of models used in other facilities with features similar to SPES (Proton beam energy= 40-70 MeV and current= 200-500 μA) were analyzed. Instrumentation Technologies-Libera, a company that makes potentially suitable devices for the SPES facility, was contacted as a possible supplier. They offer a system designed for beam loss measurements based on scintillators integrated on Photomultiplier, flash ADC and data acquisition. The gain is controlled by dc voltage managed by the system. Detectors and electronics have been tested in two steps: 1. Irradiation with gamma and neutrons static sources; 2. Irradiation with the CN accelerator beam (zero-degree line). From the tests, the detectors resulted very reactive to gamma and neutron radiation, so they could be suitable to be implemented at SPES as beam loss monitor purposes. Moreover, to characterize the detector on the operational conditions is fundamental. For these reasons, testing the detector’s behavior at the SPES cyclotron in normal operation (current= 200 μA and proton energy= 40 MeV) is mandatory and is planned for the next future.
Paper: THPL115
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL115
About: Received: 02 May 2023 — Revised: 09 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPL118
Beam diagnostics and instrumentation for MESA
4746
The Mainz Energy recovering Superconducting Accelerator (MESA) is currently being installed in the final area of the Institute for Nuclear Physics at Johannes Gutenberg-University in Mainz. To optimize and operate the accelerator reliably luminescence screens, wire scanners and RF cavity monitors are used. In this paper we will present the ongoing development of the beam diagnostics foreseen at MESA.
Paper: THPL118
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL118
About: Received: 03 May 2023 — Revised: 30 May 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
THPL131
Time resolved measurements of DARHT-II multi-pulse beam
4776
Using a calibrated permanent magnet spectrometer and a streak camera, a time resolved measurement is made for a multi-pulse beam. These measurements are cross calibrated with cell voltage monitors to have a reliable online energy measurement. The Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) Axis-II produces a 16 MeV, 1.65 kA electron beam. Timing on the cell voltages is changed such that the beam has a varying kinetic energy spread. Multi-pulses are produced by a kicker at varying pulse lengths and selecting out different energies from the beam. This paper reports the results of these measurements.
Paper: THPL131
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL131
About: Received: 28 Apr 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPL138
Electron gun for sheet electron probe for beam tomography
4791
In the novel device described in this presentation uses a simple, strip cathode provides a sheet beam probe for tomography instead of a scanning pencil beam that was used in previous electron probe bunch profile monitors. The apparatus with the strip cathode is smaller, has simpler design and less expensive manufacturing, has better magnetic shielding, has higher sensitivity, higher resolution, has better accuracy of measurement, and better time resolution. With this device it is possible to develop almost ideal tomography diagnostics of bunches in linear accelerators and in circular accelerators and storage rings. Currently we are planning to build a prototype tomography system will be built for testing in a proton or ion beam.
Paper: THPL138
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL138
About: Received: 04 May 2023 — Revised: 11 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPL147
Developments and characterization of a gas jet ionization imaging optical column
4810
Standard methods of measuring the transverse beam profile are not adaptable for sufficiently high-intensity beams. Therefore, the development of non-invasive techniques for extracting beam parameters is necessary. Here we present experimental progress on developing a transverse profile diagnostic that reconstructs beam parameters based on images of an ion distribution generated by beam-induced ionization. Laser-based ionization is used as an initial step to validate the electrostatic column focusing characteristics, and different modalities, including velocity map imaging. This paper focuses on measurements of the ion imaging performance, as well as the dependence of Ion intensity on gas density and incident beam current for low-energy electron beams (<10 MeV).
Paper: THPL147
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL147
About: Received: 03 May 2023 — Revised: 19 May 2023 — Accepted: 19 May 2023 — Issue date: 26 Sep 2023
THPL151
About the damage mechanisms of thin targets exposed to high-power particle beams
4824
Thin targets, in the form of wires, stripes, or foils, are often used in accelerators to measure the properties of particle beams. Motivation for a small thickness, typically between several and to hundred micrometers, is diverse and depends on a particular case. For instance, small diameters of wires allow for precision measurement because it is probing a small fraction of the beam transverse profile. In case of high-power beams, the critical argument is small energy deposits and good cooling because of the large surface-to-volume ratio. In certain beam conditions, the temperature of the target can be very high and lead to thermal damage. This paper attempts to give an overview of the conditions under which the breakage occurs and the damage mechanisms for various materials.
Paper: THPL151
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL151
About: Received: 29 Mar 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPL157
Study on transverse beam size measurement using Cherenkov diffraction radiation in low-energy electron accelerator
4836
Cherenkov Diffraction Radiation (ChDR), which is emitted when relativistic charged particles pass around dielectric materials, has recently been presented as non-invasive beam diagnostics in various studies. We intend to measure transverse beam size using ChDR in e-LABs, a 100 MeV electron experimental accelerator at the Pohang Accelerator Laboratory (PAL). The electron energy of e-LABs is low, so the intensity of photons generated by ChDR is absolutely small. Therefore, a cumulative dielectric radiator with a length of 157 mm was designed to increase the photons incident on the detector. This contribution shows the characteristics of ChDR simulated numerically at low energies. Furthermore, we present an experimental configuration for measuring transverse beam size with some considerations.
Paper: THPL157
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL157
About: Received: 11 May 2023 — Revised: 11 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPL164
Xopt: A simplified framework for optimization of accelerator problems using advanced algorithms
4847
The recent development of advanced black box optimization algorithms has promised order of magnitude improvements in optimization speed when solving accelerator physics problems. However, in practice these algorithms remain inaccessible to the general accelerator community, due to the expertise and infrastructure required to apply them towards solving optimization problems. In this work, we introduce the Python package, Xopt, which implements a simple interface for connecting arbitrarily specified optimization problems with advanced optimization algorithms. Users specify optimization problems and algorithms with a minimal python script, allowing flexible interfacing with both experimental online control and simulated design problems, while also minimizing the need for algorithmic expertise or software development. We describe case-studies where cutting-edge Bayesian optimization and genetic algorithms implemented in Xopt are used to solve online control problems at SLAC and Argonne National Laboratories. The same algorithms are also used to solve simulated optimization problems in high performance computing clusters using the same interface.
Paper: THPL164
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL164
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPL170
Transverse phase space tomography using machine learning at the CLARA accelerator test facility
4851
Phase space tomography is a powerful technique for characterising beams in particle accelerators and has found widespread use at many facilities. However, conventional tomography techniques require significant computational resources, particularly when reconstructing the charge distribution for two or more degrees of freedom. Here, we describe a novel technique that employs machine learning and image compression for transverse phase space tomography in two degrees of freedom. The use of machine learning allows the beam distribution in 4D phase space to be reconstructed more quickly than by conventional tomography techniques, while the application of image compression can dramatically reduce the size of the data sets involved in the analysis. The new method has been deployed on the CLARA accelerator at Daresbury laboratory to characterise electron bunches with moderate energy (35 MeV) and charges up to 100 pC. We compare the machine learning technique against a conventional tomography algorithm (algebraic reconstruction) applied to the same data set, and show that the results are at least as good in terms of predicting the observed beam profiles for a range of quadrupole strengths.
Paper: THPL170
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL170
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPM001
Multi-megahertz induction cell driver for the next generation compact hadron therapy system
4891
The fast cyclic synchrotron (IS) using the principle of induced acceleration was demonstrated at KEK in 2013* and is now being studied for application to a compact hadron therapy driver (ESCORT)** capable of energy swept beam extraction***. The ESCORT has the feature of avoiding instability caused by synchro-beta coupling by accelerating ions using a true variable amplitude pulse voltage that is extracted from the time varying DC voltage, rather than an equivalent variable voltage pulse system using a pulse density modulation method as used in the existing IS (KEK-DA). Furthermore, the accelerator cell driver is designed to be more compact by generating pulses at several MHz, whereas in the past, the upper frequency limit of the accelerator cell driver was set at about 1 MHz****, and multiple accelerator cells were used adapted for higher orbital frequencies. These innovations are made possible by the latest advances in power device and power electronics technology. This paper describes the development of an inductive acceleration cell driver for application to ESCORT.
Paper: THPM001
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM001
About: Received: 26 Apr 2023 — Revised: 11 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
THPM005
Design of the ESS DTL mechanical supports
4899
The Drift Tube Linac (DTL) of the European Spallation Source (ESS) is composed of 5 independent Tanks, each of which of 8 t in weight and 8 m in length, is made of 4 modules and is positioned and aligned to the Nominal Beam Line with 2 mechanical supports. The supports are designed to perform the iso-statical alignment of the tank, and to allow its longitudinal displacement for the installation and maintenance of the Intertanks. Presently, 4 of 5 Tanks have been successfully installed and aligned with respect to the Nominal Beam Line, using a Laser Tracker to monitor the position with a tolerance of 0.1 mm. This paper details the chosen kinematic configuration, the supports design, the calculation and simulations for design validation, the procedures for regulation and alignment and the achieved results.
Paper: THPM005
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM005
About: Received: 03 May 2023 — Revised: 05 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPM010
CFD studies and experimental validation of the convective heat transfer coefficient in non-fully developed flows applied to conventional geometries used in particle accelerators
4912
In the field of Particle Accelerators engineering, the design of the cooling channels of its components has been extensively based on experimental correlations for the calculation of convective heat transfer coefficients. In this scenario, this work is focused on studying whether the experimental correlations are conservative when the flow is turbulent in fully developed and non-fully developed regions. For this research, simulation models have been developed for turbulent flows in fully developed and non-fully developed regions, all of them for cooling channels with a 10 mm inner diameter. In the first case, for a circular channel, turbulence models have been studied, and comparative studies with respect to experimental correlations and previous studies performed at ALBA have been carried out. Simulation models based on the coefficients obtained from experimentally observed correlations, CFD models and an experimental validation of a mirror with inside cooling, have been performed in the second case.
Paper: THPM010
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM010
About: Received: 27 Apr 2023 — Revised: 08 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPM018
Optimization of mechanical robustness in the booster injection bumpers
4923
During the Long Shutdown 2 (LS2) at CERN, the new Linac4 (L4) accelerator has been successfully connected to the PS Booster (PSB) to inject 160 MeV H− beam into the 4 superposed PSB rings. The horizontal displacement of the circulating beam during injection relies on 4 pulsed dipole magnets. During the initial run of the new magnet system, non- conformities have been observed. These could be traced back mainly to early fatigue effects, some of which were in brazed joints on the coil cooling circuit. An extensive program has been launched to improve the brazing technology for the spare coil manufacturing. This effort has been combined with numerical computations as well as destructive and non-destructive testing of brazed joints, allowing to identify critical stress domains resulting in fatigue sensitive areas. This paper describes the applied methodology and implements measures to increase the robustness of the magnet coils. The achieved improvements have been validated by testing based on an instrumented coil, allowing to correlate stress-strain measurements with results from the structural and transient numerical computation.
Paper: THPM018
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM018
About: Received: 03 May 2023 — Revised: 22 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPM020
Pure copper and stainless steel additive manufacturing of an IH-type linac structure
4931
Additive manufacturing ("AM") has become a powerful tool for rapid prototyping and manufacturing of complex geometries. A 433 MHz IH-DTL cavity has been constructed to act as a proof of concept for direct additive manufacturing of linac components. In this case, the internal drift tube structure has been produced from 1.4404 stainless steel, as well as pure copper using AM. The Prototype cavity, as well as stainless steel AM parts have been copper plated. We present results from low level rf measurements of the cavity with and without copper plating, as well as the status of preparations for high power rf tests with a 30 kW pulsed power amplifier.
Paper: THPM020
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM020
About: Received: 01 May 2023 — Revised: 12 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPM021
Laser powder bed fusion of pure niobium for particle accelerator applications
4935
Niobium is particularly appreciated for its superconductive properties. One of the main applications of this metal in Nuclear Physics is the production of superconducting radiofrequency (SRF) cavities for particle accelerators. Additive Manufacturing (AM) gives the chance to fabricate objects with very complex shapes; also, high melting temperature and hard-to-machine materials can be easily processed. However, AM is not free from challenges, and the creation of devices such as the SRF cavities is not trivial. In this work, the characterization of pure niobium produced by Laser Powder Bed Fusion (LPBF) and a fine-tuning of the printing parameters have been carried out. Much emphasis was put on the development of innovative contactless supporting structures for improving the quality of downward-facing surfaces with very small inclination angles. A relative density higher than 99.8% was achieved and the efficiency of such innovative supports was demonstrated, as they made the fabrication of seamless SRF cavities possible. Smoothing surface treatments and performance tests on AMed cavities were also performed.
Paper: THPM021
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM021
About: Received: 04 May 2023 — Revised: 10 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPM022
Predictive capabilities in CFD simulations of additively manufactured extraction grid cooling channels for the DTT NBI system
4939
Recently, Metal Additive Manufacturing technology enables the possibility to realize cooling systems in accelerator components during the manufacturing process phase, obtaining extremely high density, high thermal, and mechanical properties in metals. In the Neutral Beam Injection for the Divertor Tokamak Test facility, the beam acceleration components are submitted to extremely high-power loads. A tailored cooling channel shape for the acceleration grids is proposed and tested. However, the roughness issue in MAM manufacturing is a problem that can strongly affect the pressure drop in long and small-section channels. CFD is a valid tool that, if properly calibrated, predicts the pressure drop and efficiency of the cooling system. In this work, different single-channel samples have been manufactured via MAM and they have been tested to characterize the pressure drop behaviour. The single-channel samples have been internally smoothed via a chemical process to reduce the pressure drop and tested again. CFD models, using Ansys Fluent software, have been calibrated to properly predict the pressure drop of the single-channel samples. The CFD models have been implemented to optimize the channel design of the Extraction Grid cooling system. The optimized shape of the EG channels has been adopted to produce different scaled AM prototypes and tested with a thermal power map, which is similar to the nominal one.
Paper: THPM022
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM022
About: Received: 05 May 2023 — Revised: 07 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPM023
Additive Manufacturing of 6 GHz seamless SRF copper cavities: printing, surface treatments and performance investigations
4943
Traditionally produced SRF cavities are characterized by many limiting drawbacks, such as welding lines and poor reproducibility of their properties. Additive Manufacturing, and in particular Laser Powder Bed Fusion (LPBF), may overcome these issues: with this technology, it is possible to create seamless components with reproducible characteristics. But 6 GHz cavities cannot see internal supports because they would not be easily removable. On the other hand, the down-skin self-supporting surfaces are extremely rough and unsuitable for the intended application. Indeed, very smooth surfaces are required since copper cavities are internally coated with superconducting materials (like Nb or Nb alloys): several surface treatments have been performed and studied; tests like tightness, resonant frequency and internal inspections have also been carried out before and after the post-printing smoothening and coating stages. Results are very promising and they will be shown in this work.
Paper: THPM023
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM023
About: Received: 02 May 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPM024
Laser powder bed fusion of CuCrZr for nuclear fusion acceleration components
4947
Copper and copper alloys are widely used in the Nuclear Fusion field for their outstanding characteristics, especially in terms of thermal and electrical conductivities. CuCrZr is peculiarly suitable and well-known in High Energy applications because it combines good conductivity and good mechanical properties. Moreover, the material properties can be tuned with thermal treatments to fit the application requirements even more. Additive manufacturing is then a revolutionizing process that permits the creation of geometrically optimized components. This near-net-shape process allows to produce seamless parts reducing material waste and saving time. We investigate the application of the Laser Powder Bed Fusion technology to produce the acceleration grids of a Neutral Beam Injector. In this work, the authors analyzed different CuCrZr powders and investigated the material properties obtained after the printing parameters optimization, in as-built conditions and after several heat treatments. The high density and high mechanical and thermal properties allowed us to proceed with the creation of the first prototypes of the acceleration components.
Paper: THPM024
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM024
About: Received: 05 May 2023 — Revised: 10 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPM030
Initial high electric field – vacuum arc breakdown test results for additively manufactured pure copper electrodes
4957
Additive Machining (AM) technology is already used in many manufacturing domains and provides many benefits such as design freedom, cooling, and performance improvements as well as significant manufacturing time reduction. AM is also being considered for the manufacture of a Radio Frequency Quadrupole, where an important unknown is the voltage holding capability of AM surfaces. To address this question a series of high electrical field tests was performed on additively manufactured (AM) pure copper electrodes using the CERN pulsed dc high-voltage system. The tests were carried out with different test surface conditions such as “rough”, as built by AM, post-processed and machined. During each test, an ultra-high vacuum was maintained, and the breakdown rate monitored by changing the electric field level and pulse structure. The initial results provide the first reference values for AM built pure copper electrodes performance under vacuum arc breakdown test. According to test results, AM process and material powder characterisation as well as post-processing will be improved in preparation for RF power and beam tests on a full RFQ prototype.
Paper: THPM030
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM030
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPM031
Evaluation of green laser source additive manufacturing technology for accelerator applications with ultra-high vacuum requirements
4960
Additive Manufacturing (AM) offers different benefits such as efficient material usage, reduced production time and design freedom. Moreover, with continuous technological developments, AM expands in versatility and different material usage capabilities. Recently new energy sources have been developed for AM – green wavelength lasers, which provide better energy absorption for pure copper. Due to high thermal and electrical conductivity of copper, this novel AM technology is highly promising for various industries, particularly, there is a huge interest to use it for accelerator applications. In particular, these AM produced accelerator components should reach the associated Ultra High Vacuum (UHV) requirements. In this study, vacuum membranes of pure copper were produced by AM using a green laser source, in different thicknesses and built angles. Furthermore, a vacuum membrane helium leak tightness test was performed at room temperature by using a high-sensitivity mass spectrometer. Comparison of these test results was performed with previously established results. Through this study, novel knowledge and initial results are provided for green laser source AM technology usage for applications for UHV accelerator components.
Paper: THPM031
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM031
About: Received: 07 May 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPM034
Beam delivery system for BNCT at Tokyo Institute of Technology
4964
Boron Neutron Capture Therapy(BNCT) is useful for cancer therapy. To generate safe and efficient neutron beams, we accelerate 2.5 MeV protons and irradiate a lithium target. This is an endothermic reaction that avoids activation of the accelerator and produces neutrons of relatively low energy. We are designing a beamline to deliver such protons to a lithium target. Tokyo Institute of Technology has been developing a high duty factor RFQ in collaboration with Time Co. A 5% demonstrator is already in practical use. This paper describes a lossless beam transport system from the RFQ to the lithium target. The beamline consists of a quadrupole magnet, a bending magnet and a multipole magnet. The bending magnets prevent the backflow of neutrons into the RFQ. The expected beam current is 20 mA. The results of the design study of this beamline will be presented at the conference.
Paper: THPM034
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM034
About: Received: 02 May 2023 — Revised: 08 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPM035
First high quality DTL cavity additively manufactured from pure copper
4967
Recently presented RF cavity prototypes printed entirely from pure copper illustrate the potential of additive manufacturing (AM), and particularly laser powder bed fusion (L-PBF), for accelerator technology. Thereby, the design freedom of L-PBF is only limited by overhanging geometries, which have to be printed with supporting structures to ensure sufficient accuracy. However, subsequent removal of these support structures is a major challenge for cm-sized GHz cavities. Therefore, our approach is to design self-supporting geometries. In this contribution we present a DTL cavity geometry as used in e.g. proton therapy linac systems that can be fabricated by L-PBF without support structures. A 5-cell prototype was manufactured from high-purity copper using L-PBF. It is shown that the developed geometry allows a print accuracy sufficient to reach the defined resonance frequency. A chemical, as well as dynamic electrochemical finishing process, was applied to optimize the prototypes surface quality. Thus, the CST simulated figures of merit (e.g., $Q_0$, ${Z_{eff}}$) were obtained for the first time with a printed cavity.
Paper: THPM035
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM035
About: Received: 19 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
THPM037
S-Band Accelerating Cells Geometry RF Measurements Technique for Pre-Tuning and Smart Combination
4971
The upgrade program for AREAL accelerator includes beam energy increase from 5 MeV up to 50 MeV. For this purpose, two 43 cells, and 1.6 m long, S-band accelerating structures are foreseen. The design and fabrication of cells are already carried out in CANDLE. For effective acceleration the tuning of phase advance and frequency of the structure is necessary. The precise geometrical dimension measurements to pick the proper sequence of cells are necessary to minimize accelerator structure tuning routine after brazing. In this paper, a method for cell geometry precise measurements is presented. The method based on TM resonance frequencies measurement for radius and length variation evaluation in µm range. The µm variation driving resonance frequency shift by few tens’ kHz, which is measurable by conventional VNA. The theoretical basis and experimental results for AREAL 50 MeV upgrade accelerator structures cells are presented.
Paper: THPM037
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM037
About: Received: 01 May 2023 — Revised: 07 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPM038
Plasma cleaning of hydrocarbon and carbon contaminated surfaces of accelerator components
4974
To achieve the vacuum quality required for the operation of particle accelerators, the surface of the vacuum vessels must be clean and free of hydrocarbons. This is usually done by wet chemistry processes, e.g. degreasing chemical baths that, in case of radioactive vessels, must be disposed accordingly. An alternative way to perform the removal of hydrocarbons exploits the oxygen plasma produced by a downstream RF plasma source. This technique offers the possibility of operating in-situ, which is an advantageous option in the case of voluminous and/or fragile components and a more sustainable alternative to large volume disposable baths. In this work, we test a commercial plasma source in a dedicated vacuum system equipped with a residual gas analyser (RGA) and quartz crystal microbalances (QCMs). The evolution of the hydrocarbon RGA peaks and the removal rates of amorphous carbon (a-C) thin films deposited on the QCMs to mimic contamination are studied. The plasma cleaning efficiency is evaluated as a function of various operational parameters and for chambers of different geometries and volumes. The studies are complemented by finite element simulations and by X-ray photoelectron spectroscopy (XPS) surface analysis. We present the results of the plasma cleaning process applied to the real case of a hydrocarbons-contaminated large vacuum vessel. The evaluation of the vessel cleanliness, based on CERN's outgassing acceptance criteria, is compared to the simulations results.
Paper: THPM038
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM038
About: Received: 08 May 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
THPM041
Magnet technology and design of superconducting magnets for heavy ion gantry for hadron therapy
4978
Various initiatives in Europe have bene launched to study superconducting magnets for a rotatable gantry suitable for delivery up to 440 MeV/A carbon ions for hadron therapy. One initiative is led by INFN inside an agreement with CERN, CNAO and MedAustron aiming at designing and manufacturing a strongly curved costheta dipole (Rbending = 1.6 m) rated for 4 T central field and a ramp rate of 0.15-0.4 T/s. Here we explore the suitability of dipole technology derived from HEP collider (use of Nb-Ti Rutherford cable, classical shell type for the coils, use of collar/yoke for force containment, etc…) for a rotatable gantry that poses severe conditions on the thermal design (conduction cooled coils). A second one, is in the frame of the European program H2020-HITRIplus-WP8, aimed at exploring the feasibility of using the novel Canted Cosine Theta (CCT) concept to produce a superconducting dipole with similar characteristics. The scope is to design and built one or two prototypes with Nb-Ti rope, to see if this route could be a viable alternative. Finally in the European collaboration H2020-I.FAST-WP8 we are exploring both CCT in combined function design (dipole + quadrupole, in Nb-Ti) and the use of HTS (REBCO tapes) with CCT dipole layout, pursuing the design manufacture of a small prototypes with European Industry. If HTS will be found successful, it will be a great benefit for the cryogenic design of the magnet system.
Paper: THPM041
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM041
About: Received: 10 May 2023 — Revised: 10 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPM042
IRIS - the Italian research infrastructure on Applied Superconductivity for Particle Accelerators and Societal Applications
4982
The Italian Minister for University and Research has recently funded a large program for an Innovative Research infrastructure on applied Superconductivity in Italy. Based on the LASA lab in Milan it is a partnership among: INFN (leader, participating with 4 labs: Frascati, Genoa, Milan, Salerno); CNR (SPIN institute in Genoa, Naples and Salerno); five Universities: Genoa, Milan, Naples, Salento and Salerno. The infrastructure will expand and coordinate existing infrastructures, with new state of the art instruments for: 1) characterization of new superconducting wires/tapes and cables at high field and large current; 2) for implementing the construction of innovative small scale superconducting magnets or accelerator, beam lines and detectors; 3) developing advanced instrumentation and measurements for magnets and accelerators; 4) for testing large superconducting magnets and high power transmission superconducting lines; 5) for characterization of new superconducting materials and magnetism in matter. IRIS will be a key feature for participation to future projects requiring advanced superconducting technology, like FCC or the Mun-Collider, and also for developing societal applications, especially in the energy domain and the medical sector, of technologies pursued for high-energy accelerators. The paper will illustrate the IRIS project, its 3-year development and the idea to make it an open-access infrastructure.
Paper: THPM042
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM042
About: Received: 10 May 2023 — Revised: 11 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPM044
Retrofit study of compressed air systems in NSRRC
4990
The aims of this work are to measure the energy consumption performance of compressed air systems, determine the weak points, implement the economic assessments and execute energy saving improvements in NSRRC. The compressed air discharge pressure is regulated in 6.0±0.5 kg/cm2. The specific energy requirement (SER) of those compressors is 7.74 ~ 20.05 kW/m3/min. Based on the performance results, we have to make a decision to repair or replace the inefficient compressors. Next, we decided three phases implements, stop leaks in phase I, replace compressor with VFD and heat-regeneration desiccant drier in phase II, connect TLS and TPS compressed air pipelines in phase III. Finally, we got great energy saving of 543,754 kWh/yr and 4.3 years pay-back time in capital investment.
Paper: THPM044
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM044
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPM046
Dose Simulation of Ultra-High Energy Electron Beams for Novel FLASH Radiation Therapy Applications
4993
The synchrotron-based ELSA facility delivers up to 3.2 GeV electrons to external experimental stations. In a new setup the irradiation of tumor cells with doses of up to 50 Gy by ultra-high energy electrons (UHEE) in time windows of microseconds up to milliseconds (FLASH) is currently investigated. This technique may enable highly efficient treatment of deep-seated tumors alongside optimal sparing and protection of healthy tissue. In a preliminary setting electrons with an energy of 1.2 GeV are used to irradiate cell samples which are located inside a water volume, representing the human body. The relative biological effectiveness (RBE) can be determined by assessing the cell survival of healthy and tumor tissues. For precise dose determination, simulations by Geant4 reproduce the electromagnetic shower process, taking the extracted electron pulse properties into account. The water volume consists of voxels of different sizes for precise investigation in the volume of interest. Various properties such as particle types, deposited energy and the energy spectra of the particle shower can be extracted. The method and first results in comparison to measured data will be presented.
Paper: THPM046
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM046
About: Received: 03 May 2023 — Revised: 06 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPM053
A novel large energy acceptance beamline for hadron therapy
5004
A design study is currently underway at the University of Melbourne for a large energy acceptance beamline to enable future hadron therapy modalities. As part of the TURBO project, a beam delivery system demonstrator is being developed for a DC Pelletron accelerator, which will provide 3 MeV H+ beams. Fixed Field Accelerator optics will be used to maximise momentum acceptance, with dispersion minimised at both ends of the transport line. This project aims to be the first `closed dispersion arc' with fixed fields ever constructed. As part of the design process, the input beam phase space from the Pelletron has been characterised. Our results show that the Pelletron beam can be injected into the novel transport line successfully, and Zgoubi simulations show that near-zero dispersion at each end will be achievable. This is supplemented by error studies and magnet investigations, demonstrating that beam transport can be achieved under realistic circumstances. This initial study establishes the feasibility of this beamline design and work is continuing toward further optimisation for implementation.
Paper: THPM053
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM053
About: Received: 02 May 2023 — Revised: 27 Jun 2023 — Accepted: 27 Jun 2023 — Issue date: 26 Sep 2023
THPM054
Impacts of strongly curved magnetic multipoles on compact synchrotron dynamics
5008
Superconducting curved magnets are able to reduce accelerator footprints by producing strong fields (>3T) for applications such as carbon ion therapy, however the effect of strongly curved magnetic multipoles and fringe fields on accelerator beam dynamics is not fully understood. This is especially important in compact synchrotrons, where fringe fields can significantly affect beam quality and long-term beam stability. To establish tolerances on these higher order harmonic errors, an electromagnetic model of a superconducting, strongly curved canted-cosine-theta (CCT) combined-function dipole is analysed. The CCT magnet is studied as a potential option for the main dipole of a 27m circumference carbon ion therapy synchrotron within the Next Ion Medical Machine Study (NIMMS) at CERN and the European project HITRIplus. Curved magnetic multipoles are modelled in MAD-X and PTC; results are presented and compared with particle tracking through the magnet’s 3D fieldmap in Zgoubi for additional investigation of non-linear effects. Preliminary assessment of the performance of the synchrotron subject to the tolerances on the harmonic errors is given with discussion for the suitability of the synchrotron for clinical applications.
Paper: THPM054
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM054
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPM056
A compact and mobile system for breast irradiation in prone position
5016
The APAM (Accelerators of Particles for Medical Application) Laboratory in the ENEA-Frascati Research Center developed a prototype of a self-shielded device dedicated to the treatment of breast cancer with the patient in prone position. It consists of a rotating X-ray source, based on a compact 3 MeV electron accelerator, placed under the patient bed which is provided with a circular opening through which the breast hangs down and can be irradiated. The system has been designed to suitably screen the patient body from the underlying accelerator. This setup improves target coverage and gives a valuable advantage in sparing healthy tissues: prone position increases the separation of the target and critical organs and in addition minimizes target motion caused by breathing. The prototype has been developed in the framework of the TECHEA (TEChnology for HEAlth) Project aimed to the realization and validation of prototype systems for applications to health protection. The paper describes the apparatus and reports the results of the experimental characterization of the X-ray source done in collaboration with the Laboratory of Medical Physics and Expert Systems of Regina Elena Hospital.
Paper: THPM056
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM056
About: Received: 26 Apr 2023 — Revised: 06 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPM057
Preparations for beam commissioning of the carbon RFQ at CERN
5020
Linear accelerators for medical applications present the possibility to reduce costs compared to cyclotrons or synchrotrons while offering higher beam stability and flexibility. In the framework of NIMMS, the Next Ion Medical Machine Study, the design of a linear accelerator for carbon ion therapy has been completed at CERN. The pre-injector is composed of a fully stripped ${}^{12}\mathrm{C}^{6+}$ carbon ion source and a 750$\,$MHz Radio Frequency Quadrupole (RFQ) accelerating the beam to 5$\,$MeV/u. The Carbon RFQ is based on a compact, successfully commissioned 750$\,$MHz RFQ presently operating for the commercial proton therapy Linac facility LIGHT. The RFQ is divided in two independent RF cavities of 2$\,$m length. The first RFQ cavity, accelerating the ions to 2.5$\,$MeV/u, is currently being built by CIEMAT and its delivery to CERN is planned for 2023. It will be commissioned initially with a proton and then a helium beam. Beam characterization is crucial to validate the transmission to the next sections of the Linac. In this paper, we describe the diagnostic test bench and highlight the necessary measurements for the acceptance of the second RFQ cavity.
Paper: THPM057
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM057
About: Received: 02 May 2023 — Revised: 06 Jun 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPM058
Conceptual design of a compact synchrotron-based facility for cancer therapy and biomedical research with helium and proton beams
5024
Thanks to their superior dose conformality and higher radiobiological effectiveness with respect to protons, helium ions are considered as the new tool of choice in the fight against cancer using particle beams. A facility to produce helium beams at therapeutical energy can also accelerate protons, at energies permitting both standardised treatment and full body radiography, and heavier ions for treatment of shallow tumours and for research. Equipped with FLASH extraction, it will be able to couple the protection to healthy tissues provided by Bragg peak and FLASH effect. This paper will present the basic layout of a facility based on a compact synchrotron of new design that can accommodate a wide research programme with patient treatment, sharing the beam between two treatment rooms and an experimental room. The linac accelerator may be designed to allow a programme for production of new radioisotopes for therapy, diagnostics and theragnostics using helium ions, in parallel with the operation as synchrotron injector. Overall cancer and conventional radiotherapy statistics, along with an estimate on the number of patients that can benefit from this facility will be presented for the case of the Baltic States, a candidate for hosting the facility.
Paper: THPM058
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM058
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPM059
Development of reliable VHEE/FLASH passive dosimetry methods and procedures at CLEAR
5028
The electron beam at CERN Linear Accelerator for Research (CLEAR) has been intensively used to study the potential use of Very High Energy Electrons (VHEE) for radiotherapy, including the so-called FLASH regime. An important part of these studies revolves around the development of reliable dosimetry methods, given that generally accepted standards are partly lacking for electron beams in the 100 MeV range and even more so in the ultra-high dose rates (UHDR) conditions needed for FLASH. Passive dosimetry methods, such as radiochromic films and alanine pellets are presumed to be energy- and dose-rate independent and constitute an indispensable tool for VHEE studies. Furthermore, the development and testing of new modalities for active UHDR dosimetry relies heavily on them for validation and cross-calibration. In this context, efforts have been made to establish reliable and systematic approaches for passive dosimetry at CLEAR. This paper describes studies related to the processing of radiochromic films, the energy dependence of the dose measurements and comparisons with alanine pellets and other media.
Paper: THPM059
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM059
About: Received: 03 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
THPM061
A new center for heavy ion research
5036
Progress in cancer therapy with ions heavier than protons, i.e., helium, carbon, oxygen and neon, requires research and development capability. Ion research activity, however, is limited from the absence of U.S. accelerator facilities offering ion beams for therapy – placing the U.S. significantly behind Europe and Asia. With dramatic advances in beam delivery and compact accelerators, the potential exists to create a facility that can play a leadership role in particle therapy and ion-based research. This paper announces summary details of a new center for ion therapy research under construction in Waco, TX, in collaboration with recognized accelerator entities both academic and industrial. The advanced accelerator technologies will produce beams for both clinical and research applications, offering a complete range of ions, intensities and energies required by the medical community, including the capability to perform ultra-high dose irradiation (FLASH) research. FLASH, a recent research initiative, which has the potential of reducing cancer treatment toxicities, is an important if not critical capability for a competitive research center – requiring beam intensities well beyond those provided by current medical accelerators. Building a state-of-the-art cancer research center within a comprehensive facility will provide the resources to promote ion therapy in the U.S, including, preclinical/clinical trials and protocols between modalities, and also support broad ion R&D.
Paper: THPM061
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM061
About: Received: 12 May 2023 — Revised: 12 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPM063
Towards multiple energy extraction operation in ion beam therapy
5039
In ion beam therapy most cancer patients are treated using the raster-scanning dose delivery method of heavy ion pencil beams, with the penetration depth determined by the ion beam energy. The beams are provided by synchrotrons, which currently have to start a new cycle to change the beam energy. The number of particles available in one cycle typically exceeds the required amount for a single energy. Thus changing the beam energy by reacceleration of the stored beam could significantly reduce the overall treatment duration. Within the HITRIplus project a novel accelerator control system will be designed, which will enable multiple reaccelerations within one synchrotron cycle. As this drastically increases the amount of parameter combinations, it is no longer feasible to use pre-calculated control data for each cycle. Instead the data will be calculated on-the-fly by the device controllers when a new energy is requested. Here, we will present the current status of the data generation strategy and the architectural model of the new accelerator control system.
Paper: THPM063
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM063
About: Received: 03 May 2023 — Revised: 15 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPM064
Beam properties beyond the therapeutic range at HIT
5042
The Heidelberg ion beam therapy facility HIT has more than ten years experience in patient treatment. More than 7800 patients have been treated with protons and heavy ions, about 700 are treated every year. Outside the beam time dedicated to therapy, quality assurance (QA) and machine tuning, we provide beams for a large spectrum of experiments in physics, biology and medicine which make use of various ion beam settings apart from the therapeutic application. By slow extraction the HIT synchrotron produces a wide range of spill lengths between a few ms and more than 10s. The intensity can be varied accordingly: For biological FLASH-radiation experiments we provide more than 2e9 carbon ions/s, still applying the high-quality raster-scanning beam delivery method. On the other hand, we deliver very stable low intensity beams in the order of 1000 ions/s if sensitive detector equipment is mounted. The layout of the facility was done for therapeutic ion beams with a maximum beam energy that corresponds to a penetration depth of ≈ 30cm in water and tissue accordingly. Especially for developments in ion beam radiography we now commissioned beams with higher energies for the light ions available at HIT (p, He). This paper summarizes the large variety of accelerator settings for the different experimental activities.
Paper: THPM064
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM064
About: Received: 03 May 2023 — Revised: 21 Jun 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
THPM066
LhARA, the laser-hybrid accelerator for radiobiological applications
5049
LhARA*, the ‘Laser-hybrid Accelerator for Radiobiological Applications’, will be a novel, uniquely flexible, facility dedicated to the study of radiobiology. LhARA will use a high-power pulsed laser to generate a short burst of protons or light ions. These will be captured using strong-focusing electron-plasma (Gabor) lenses. Acceleration using a fixed-field alternating-gradient accelerator will deliver proton beams with energies up to 127 MeV and ion beams, such as C^6+, with energies up to 33.4 MeV/nucleon. The laser-hybrid source allows high instantaneous dose rates of up to 10^9 Gy/s to be delivered in short (10–40 ns) pulses. The laser-hybrid approach will allow the exploration of the vast “terra incognita” of the mechanisms by which the biological response to radiation is modulated by the beam’s characteristics. The technologies to be demonstrated in LhARA have the potential to allow particle-beam therapy to be delivered in completely new regimens, providing a variety of ion species in a range of spatial configurations and exploiting ultra-high dose rates**. This contribution describes the status of the LhARA project in the context of the Ion Therapy Research Facility***.
Paper: THPM066
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM066
About: Received: 11 May 2023 — Revised: 05 Jun 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPM070
Design and test of C-band linac prototypes for electron flash radiotherapy
5056
The Flash Therapy is a revolution in the cancer cure, since it spares healthy tissue from the damage of the ionization radiations without decreasing its effectiveness in the tumor control. To allow the implementation of the FLASH therapy concept into actual clinical use and treat deep tumors, Very High Electron Energy (VHEE) should be achieved in range of 50-150 MeV. In the framework of VHEE project carried out at Sapienza University, in collaboration with INFN, we investigate the main issues in the design of a compact C band (5.712 GHz) electron linac for FLASH Radiotherapy. In this paper we describe the design strategy, the electromagnetic properties and the first prototype of the RF structure to be tested at Sapienza University.
Paper: THPM070
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM070
About: Received: 10 Mar 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPM083
Progress on the conceptual design of the laser-hybrid accelerator for radiobiological applications (LhARA)
5071
LhARA, the Laser-hybrid Accelerator for Radiobiological Applications, is a proposed novel facility capable of delivering high intensity beams of protons and ions that will enable radiobiological research to be carried out in completely new regimes. A two-stage facility, the first stage utilizes laser-target acceleration to produce proton bunches of energies up to 15 MeV. A series of Gabor plasma lenses will efficiently capture the beam which will be delivered to an in-vitro end station. The second stage will accelerate protons in a fixed-field alternating-gradient ring up to 127 MeV, and ions up to 33.4 MeV/nucleon. The beams will subsequently be deliverable to either an in-vivo end station or a second in-vitro end station. The technologies demonstrated in LhARA have the potential to underpin the future of hadron therapy accelerators and will be capable of delivering a wide variety of time structures and spatial configurations at instantaneous dose rates up to and significantly beyond the ultra-high dose rate FLASH regime. We present here recent progress and the current status of the LhARA accelerator as we work towards a full conceptual design.
Paper: THPM083
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM083
About: Received: 03 May 2023 — Revised: 19 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPM084
Start-to-end tracking of therapeutic ion beams in BDSIM
5075
BDSIM is a Monte Carlo simulation program for start-to-end particle tracking through 3D models of particles accelerators. Based on the Geant4 toolkit, BDSIM provides a holistic approach to accelerator modelling by using Geant4’s particle-matter interaction physics with dedicated accelerator tracking routines for beam vacuum transport. Subsequently, the ability to model the hits, losses, & energy deposition throughout a machine makes BDSIM highly suited for modelling medical accelerators where beam transmission, target dosimetry, and shielding requirements often need to be considered simultaneously. This has already been demonstrated by BDSIM’s adoption in modelling proton therapy beam lines. The growing recognition of ions as a treatment modality that offers a potentially significant improvement in relative biological effectiveness is driving an increase in the number of planned carbon ion therapy centres. The technology to deliver ion beams, however, is prohibitively expensive and remains a challenging research topic. Here, we show the first demonstrations of therapeutic ion tracking in BDSIM in an example model developed for showcasing BDSIM’s medical accelerators simulation capabilities.
Paper: THPM084
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM084
About: Received: 03 May 2023 — Revised: 19 Jun 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPM087
SAFEST: a compact C-band linear accelerator for VHEE-FLASH radiotherapy
5079
FLASH Radiotherapy is a revolutionary new technique in the cancer cure. Several pre-clinical studies have demonstrated that treatment with electron radiation delivered with mean dose rates above 100Gy/s, an ultra-high instantaneous dose rate > 106Gy/s, and total irradiation time < 100ms, significantly decreases the toxicity in the healthy tissue while keeping the same efficacy in cancer treatment. Although recent studies shed some light on the biological mechanisms and on the effects of FLASH electron beams on tissues and organs of small animals, more research investigation is necessary before the FLASH technique can be translated into clinical applications. Researchers also aim to explore the radio-therapeutic effects of high-dose beams delivered at Very High Electron Energy (VHEE), in the range 50-250 MeV, suitable for treating deep-seated tumors. We describe the project SAFEST, carried out at La Sapienza University in collaboration with INFN for the realization of a compact C-band electron linac VHEE at the energy of 60-150 MeV, able to deliver the high current up to 200mA and the very high dose rates required by the FLASH regime, and suitable for a hospital environment.
Paper: THPM087
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM087
About: Received: 05 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
THPM090
Innovations in the Next Generation Medical Accelerators for Therapy with Ion Beams
5083
Modern hadron-therapy accelerators have to provide high intensity beams for innovative dose-delivery modalities such as FLASH, pencil beams for 3D scanning, as well as multiple ions with radio-biological complementarity. They need to be compact, cheap and have a reduced energy footprint. At the same time, they need to be reliable, safe and simple to operate. Cyclotrons and compact synchrotrons are nowadays the standard for proton therapy. For heavier ions such as carbon, synchrotrons remain the most viable option, while alternative solutions based on linacs, FFAs or cyclotrons are being proposed. In this context, the European project HITRIplus studies the feasibility of an innovative super-conducting magnets synchrotron for carbon ions, with state-of-the-art multi-turn injection from a specially designed linac and advanced extraction modalities. A compact synchrotron optimized for helium ions, making use of proven normal-conducting technology, is also being designed.
Paper: THPM090
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM090
About: Received: 09 May 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPM091
Progress toward TURBO: a novel beam delivery system for charged particle therapy
5087
TURBO – Technology for Ultra Rapid Beam Operation – is a novel beam delivery system (BDS) in development at the University of Melbourne. The BDS determines several aspects of treatment delivery, where a bottleneck is the deadtime associated with beam energy variation. Beamlines at treatment facilities have a ±1% momentum acceptance range, requiring all the magnetic fields to adjust to deliver beams of different energies at multiple depths along the tumour volume. A BDS using Fixed Field Alternating Gradient optics could reduce the energy layer switching time by enabling the transport of a large range of beam energies within the same fixed fields. We present recent progress and ongoing developments with TURBO, a proof-of-concept demonstrator adapted for low energy protons. Characterisation measurements were performed to determine realistic parameters for beam transport and particle tracking modelling. Initial simulation and design studies are shown for an energy degrader, prototype magnets constructed using 3D-printed holders and considerations of canted-cosine-theta magnets for a scaled-up BDS. Future plans further explore the clinical feasibility of TURBO for charged particle therapy.
Paper: THPM091
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM091
About: Received: 08 May 2023 — Revised: 19 Jun 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPM092
Gantry design using achromatic scaling fixed-field magnets
5091
Proton therapy provides significant advantages over classic radiotherapy for specific cancerous diseases, notably by limiting the delivered dose to organs at risk (OARs). Novel treatment modalities such as flash and arc therapy require changing the energy delivered at the isocenter while providing a high dose rate. Fixed-field achromatic transport lattices satisfy both constraints, allowing ultra-fast energy modulation and excellent transmission efficiency while providing a compact footprint. Prior studies [1] have shown that lattices using scaling fixed field magnets allow the achromatic transport of energies between 70 and 230 MeV. We investigate the use of straight scaling FFAG line that uses nonlinear fields, fulfilling the straight scaling conditions for achromatic transport, to be used as a matching section for the CASPRO ("Compact Achromatic System for Proton Therapy") project.
Paper: THPM092
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM092
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPM093
Conceptual lattice design for vertical fixed field medical accelerators
5095
Hadron therapy is established as a method of choice for a number of cancerous diseases, and its advantages are well-established for specific malignancies. Modern medical particle accelerators still struggle to fulfil critical features required by advanced treatment modalities, such as variable energy beams, high repetition rate, and pulse-by-pulse intensity modulation. Fixed Field Accelerators (FFAs) are suited to tackle these challenges as they can accelerate particles over a wide energy range with fixed magnetic fields. Vertical orbit excursion FFAs feature constant tunes and a small horizontal footprint, making them excellent candidates for medical applications. We propose a conceptual design of a medical vFFA. Its linear and nonlinear beam dynamics is presented in-depth. This study demonstrates the vFFA potential to provide a new direction for the study and design of medical FFAs suitable for next-generation particle therapy systems.
Paper: THPM093
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM093
About: Received: 03 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
THPM096
Focusing of high energy electron beam using crystal lenses for applications in radiotherapy - feasibility study
5107
The two dominant radiotherapy methods are either simplified in terms of beam generation and handling, which compromises the energy deposition curve in tissues (photon therapy) or require extensive accelerator facilities and complex beam delivery systems to provide a favourable shape of the energy deposition curve (hadron therapy). The advantages of both of these methods, such as the low cost of the apparatus, ease of beam generation and a suitable shape of the energy deposition curve in tissues, can potentially be achieved by using a high-energy electron beam (beam energy in the order of a few hundreds of MeV) focused on the area of the tumour lesion. However, focusing of the beam is usually done with the use of quadrupole magnets which makes the beam delivery system complex and challenging from the engineering point of view. In this paper, we explore the feasibility of an alternative solution, where focusing is performed by a bent silicon crystal with an appropriate shape of its exit face. Such a crystal lens can be a very light object (mass in the order of grams), allowing for much simpler beam delivery systems of radiotherapy facilities.
Paper: THPM096
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM096
About: Received: 03 May 2023 — Revised: 04 Jun 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPM105
Quantitative availability modelling for the MYRRHA accelerator driven system
5114
The availability of modern accelerators has become a key performance indicator. This is especially the case for accelerator-driven-systems (ADS), such as MYRRHA, which need to deliver beam with very few interruptions longer than a few seconds over a period of several months. Quantification of such beam interruptions at other accelerators such as LINAC4 at CERN and SNS at ORNL show that their fault count would need to be reduced by more than two orders of magnitude to comply with ADS requirements. Redundancy of systems is one viable strategy to achieve this. For MYRRHA, the use of redundant low-energy injectors, modular-redundant RF power amplifiers and serial-redundant RF cavities is presently proposed. The resulting gain in the accelerator availability using these redundant systems has been quantified by simulating the operation of the MYRRHA accelerator with AvailSim4, an availability-modelling tool developed at CERN. The study results highlight the importance to focus on optimizing system design and repair strategies to maximize the effectiveness of such redundancy schemes as well as the value of powerful availability simulation tools.
Paper: THPM105
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM105
About: Received: 03 May 2023 — Revised: 07 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPM106
Mu*star: A new paradigm for nuclear reactors
5118
Commercial Nuclear Reactors have been licensed for construction and operation by the US Nuclear Regulatory Commission based on ensuring that criticality accidents and accidental releases of radioactive isotopes are acceptably unlikely. The process to get these licenses is long and expensive, involving extensive calculations and demonstrations, with explicit requirements on all reactor components that cannot be changed for the several decades that the reactor operates. The process can be replaced by 1) using accelerator-driven subcritical reactors that never contain a critical mass and 2) continuously removing volatile fission products from the molten salt reactors so that any accidental releases are insignificant. Mu*STAR Nuclear Power plants, composed of upgradable modular accelerators and reactors, can then be continuously improved using Deming’s principles of Total Quality Management.
Paper: THPM106
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM106
About: Received: 10 May 2023 — Revised: 11 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPM111
First correction to elastic scattering of electrons for microscopy
5127
Ultrafast electron microscopy (UEM) can be used to probe ultrasmall (nm scale) and ultrafast (fs scale) world. At the fundamental level, atomic potentials determine the elastic electron scattering in UEMs. Here we calculate the first correction term analytically for elastic scattering of electrons by atoms in the weak phase object approximation. Its effect varies with atom types and electron energies and may be non-negligible for electron microscopy images.
Paper: THPM111
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM111
About: Received: 08 May 2023 — Revised: 12 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
THPM113
Development of Low Energy Branch at Micro Analytical Centre, Ljubljana, Slovenia
5131
A Low Energy Branch is being built at Micro Analytical Centre * that will allow us to produce a variety of high current (up to 50 µA) ion beams, ranging from light (i.e. H, He, C, B, 15N), mid-mass (i.e. Si) to heavy (Ag, W, Pb, Bi) ion beams in the energy range of 100 eV up to 30 keV. Ions will be produced with the use of ion sources that are currently available at the facility. The branch will provide beams: a) for implantation of gases into solid targets, b) for the creation of Nitrogen-Vacancy centres in diamond ** needed for quantum computing research, c) for simulation of the effects of solar wind on the lunar surface, d) for studies of ion-gas reactions at low energies and e) for commissioning of ion optics and testing of machine learning algorithms for automatic beam control. The branch will employ electrostatic steerers for beam position control, Einzel lenses for minimising beam size, a magnetic dipole to purify the ion beam and a Wien filter to produce ion beams with the highest possible monochromaticity. The poster will present the progress and development of the ion optics, experimental stations and beam profile monitors designed for the above branch.
Paper: THPM113
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM113
About: Received: 03 May 2023 — Revised: 25 Jul 2023 — Accepted: 01 Jun 2023 — Issue date: 26 Sep 2023
THPM116
Respiratory protective equipment fit tests for researchers at the National Synchrotron Radiation Research Center
5134
Researchers at the National Synchrotron Radiation Re-search Center should use respiratory protective equip-ment to prevent respiratory damage caused by gases, steam, solvents, chemicals, materials containing toxic substances, and oxygen-deficient environments. Those working with organic matter and certain chemical sub-stances and those exposed to occupation dust should use respiratory protective gear to ensure their health. This study conducted qualitative and quantitative fit tests for various mask brands and sizes, namely 3M-9042, N95-9211, P95-8576, and 3M-6200 masks. The gear worn by all 18 participants in the qualitative fit test passed. By contrast, the gear worn by 12 of the 15 participants in the quantitative test passed; the failure of the remaining gear was due to differences in face shape. The N95-9211 mask can be used in three-piece protective gear because it exhibited a tight fit. Additionally, the 3M-6200 negative-pressure half-face mask exhibited the most satisfactory fit and can be used in protective gear.
Paper: THPM116
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM116
About: Received: 10 May 2023 — Revised: 15 Jun 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPM124
Conceptual design of the high-power electron beam irradiator using niobium-tin superconducting cavity
5153
In recent years, there has been an increasing demand for high-intensity beams related to electron beam irradiation, such as mass production of nuclear-medicine examination by using 99Mo and high-efficiency production by material modification through material irradiation. While the acceleration of high-current beams can be realized by using a superconducting cavity, a compact accelerator is desirable for general-purpose irradiation beams. In this paper, we designed a 10 MeV, 50 mA high current beam irradiator for practical use based on the experimental results of highly efficient production of nanocellulose by wood irradiation. The conceptual design of the accelerator, which consists of the electron gun, the superconducting cavity, and the irradiation section, was carried out. Especially, we designed a 10 MeV, 50 mA high-current beam accelerator by using a new Nb3Sn superconducting cavity. We estimated how compact the accelerator can be and how much the operating electrical power can be suppressed.
Paper: THPM124
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM124
About: Received: 08 May 2023 — Revised: 11 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPM125
High efficiency, 1 MW, 1 MeV accelerator for environmental applications
5157
We present design of a normal conducting, high efficiency linac that would provide a CW beam of 1 MW electrons at 1 MeV energy for various environmental applications. When a flowing sheet of wastewater is exposed to such a beam, various radiation-induced reactants are generated that lead to water purification by decomposing the chemical and biological pollutants therein. Such a linac could treat about 20 million gallons of wastewater per day with an ample dose of 1 kGy. Our linac comprises of three optimized accelerating rf cavities operating at 476 MHz. A compact rf distribution manifold splits the rf power from a 1-MW klystron in the appropriate ratio and phase for each accelerating cavity. The beam capture efficiency is 82% and the rf-to-beam efficiency is 94.5%. The total length of our accelerator is 2 m, which includes the 30 keV gun, the buncher cavity, and the accelerating cavities. In this paper, we present the corresponding beam dynamics, the implementation of rf couplers and feeding manifold, and the steady-state thermal analysis.
Paper: THPM125
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM125
About: Received: 04 May 2023 — Revised: 10 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPM127
Electron beam qualification at ENEA Frascati particle accelerators laboratory
5161
The APAM Laboratory of the ENEA Frascati Research Centre hosts two electron beam S-Band standing wave linacs. The older one, named REX, produces a 5 MeV, 150 mA electron beam with maximum PRF of 20 Hz. The second one, named TECHEA, was recently commissioned within a Research and Development program focused on breast radiotherapy applications: it produces a 3 MeV, 130 mA electron beam with maximum PRF of 100 Hz. Both plants can produce either electrons or X-rays through a conversion target with photon energies peaked at 2.5 and 1 MeV, respectively. In this contribution we report qualification activities on the electron beam properties in air (flux, uniformity and energy spectrum) at different target from source distances and at different extraction energies to assess the applicability of these facilities for multiple applications, such as sterilization, conservation of cultural heritage artifacts, material degradation, space components testing.
Paper: THPM127
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM127
About: Received: 28 Apr 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPM128
Heavy ion beam characterization for radiation effects testing at CERN using Monte Carlo simulations and experimental benchmarking
5165
The CHIMERA (up to December 2022) and HEARTS (as of January 2023) projects aim to facilitate radiation effects testing of electronics components using heavy ion beams before deployment in harsh radiation environments such as space or high energy accelerators. The required (micro-) electronics reliability assurance testing conditions can be met by using 100 MeV/n - 5 GeV/n Pb ion beams extracted from CERN’s Proton Synchrotron (PS) which have a surface Linear Energy Transfer (LET) range of 10-40 MeV cm2/mg, >1 mm penetration depth in silicon and several cm FWHM beam size. This paper gathers the results from Monte Carlo simulations in FLUKA which were used to understand the transport of ions through the T08 transfer line in the PS East Area, focusing on key effects such as energy straggling, loss of transmission (e.g. through scattering and nuclear fragmentation) and beam size. These calculations served as input for machine development activities and allow us to characterize the radiation field at the testing location, in present and future experimental configurations. The simulation results are compared to instrumentation data obtained during an experimental campaign in November 2022. Potential future upgrades and developments are also discussed.
Paper: THPM128
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM128
About: Received: 03 May 2023 — Revised: 05 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
FRXD3
Commissioning and operation of the SPIRAL2 SC linac
5187
The SPIRAL2 linac is now successfully commissioned; H+, 4He2+, D+ have been accelerated up to nominal parameters and 18O6+,7+ and 40Ar14+ beams have been also accelerated up to 7 MeV/A.The main steps with 5 mA H+, D+ beams and with 0.8 mA 18O6+ are described. The general results of the commissioning of the RF, cryogenic and diagnostics systems, as well as the preliminary results of the first experiments on NFS are presented. In addition of an improvement of the matching to the linac, the tuning procedures of the 3 Medium Energy Beam Transport (MEBT) rebunchers and 26 linac SC cavities were progressively improved to reach the nominal parameters in operation, starting from the classical “signature matching method”. The different cavity tuning methods developed to take into account our particular situation (very low energy and large phase extension) are described. The tools developed for an efficient linac tuning in operation, e.g. beam energy and intensity changes, choice of the optics to obtain the requested beam parameters on target… are also discussed.
Paper: FRXD3
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-FRXD3
About: Received: 03 May 2023 — Revised: 04 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
FRYG1
European collaboration for the realization of ESS
5199
The European Spallation Source (ESS) linear accelerator, one the largest scientific equipment under realisation in Europe, is now in the beam commissioning stage. The project is implemented thanks to the collaboration of several European countries, mostly following the scheme of the in-kind contribution, with the involvement of scientists from many European laboratories and Universities in all phases, from design to beam commissioning. The most recent achievements are described in detail. The in-kind contributions are vast and differentiated, including delivery of normal conductive and superconducting accelerating structures, ion sources, magnets, power converters, RF systems, controls, diagnostics as well as the participation to design, installation, and commissioning of the linac. Results of this collaborative effort will be shown in details.
Paper: FRYG1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-FRYG1
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
FRYG2
Accelerator driven system – a solution to multiple problems of society
5205
One of the greatest challenges for nuclear energy is how to properly manage the highly radioactive waste generated during irradiation in nuclear reactors. Accelerator Driven Systems (ADSs) is one methods of addressing the transmutation of such high level nuclear waste. ADS or accelerator driven transmutation of waste (ATW) consists of a high power proton accelerator, a heavy metal spallation target that produces neutrons when bombarded by the high power beam, and a sub-critical core that is neutronically coupled to the spallation target. This talk presents the world overview of nuclear energy that has proven to assist in dee-carbonization of energy sectors since the mid-1970s as well as the approaches to ADS being explored around the globe
Paper: FRYG2
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-FRYG2
About: Received: 12 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023