injection
MOXD1
Performance with the upgraded LHC injectors
1
The upgrade project for the LHC injectors is described in detail, highlighting the major improvements implemented in the injector chain. Lessons in technical progress, project management and planning are presented. The performance of the upgraded systems in intensity, average particle flux and beam brightness is described and compared to the upgrade goals and LHC`s original design parameters. The LHC performance with the upgraded injection chain and the luminosity achieved are presented. A future outlook to future developments is given.
Paper: MOXD1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOXD1
About: Received: 01 May 2023 — Revised: 30 Jun 2023 — Accepted: 30 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
MOPA094
Problems and Considerations about the Injection Philosophy and Timing Structure for CEPC
264
In this paper we will show the injection philosophy and the design of timing and filling scheme for high luminosity CEPC scheme under different energy modes. It is found that the RF frequency choice in CDR cannot meet the injection requirements for the bunch number at Z pole. A modified scheme was proposed to support the design luminosity,which basically meets our current design requirements and retains more flexibility for future high luminosity upgrade.
Paper: MOPA094
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA094
About: Received: 01 May 2023 — Revised: 13 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPA097
Design of a new CERN SPS injection system via numerical optimisation
267
The Super Proton Synchrotron (SPS) injection system plays a fundamental role to preserve the quality of injected high-brightness beams for the Large Hadron Collider (LHC) physics program and to maintain the maximum storable intensity. The present system is the result of years of upgrades and patches of a system not conceived for such intensities and beam qualities. In this study, we propose the design of a completely new injection system for the SPS using multi-level numerical optimisation, including realistic hardware assumptions. We also present how this hierarchical optimisation framework can be adapted to other situations for optimal accelerator system design.
Paper: MOPA097
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA097
About: Received: 25 Apr 2023 — Revised: 22 May 2023 — Accepted: 22 May 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
MOPA109
Field quality improvement of septum magnets for SuperKEKB injection system
301
The SuperKEKB accelerator, a collider consisting of 7 GeV electron and 4 GeV positron rings, is ongoing in order to supply a great number of interaction events of electrons and positrons to the Belle II detector which explores the new physics beyond the standard model. The important milestone is to obtain integrated luminosity of 15 /ab 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. The key component of the injection system is the septum magnets. It has been found that a transverse fringe field near the septum plate has sizable multipole components. A tracking simulation shows such fringe fields induce a vertical non-Gaussian tail, which could cause a beam background as well as a bad injection efficiency. Adjustment of Q-magnets for cancellation does not work perfectly for non-linear components. To reduce the multipole region contributes to the injection amplitude to be smaller, and so, that derives improvements of injection performances. This paper reports about the field quality improvement of the septum magnet for the SuperKEKB HER injection system.
Paper: MOPA109
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA109
About: Received: 28 Apr 2023 — Revised: 27 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
MOPA110
Precise control of a strong X-Y coupling beam transportation for J-PARC muon g-2/EDM experiment
304
To explore the beyond standard model of elementary physics, we proceed a new fundamental physics experiment, J-PARC muon g-2/EDM experiment. To realize very precise measurement of the muon spin precession frequency in the level of sub-ppm, a relativistic energy of muon beam is injected into a precisely adjusted storage magnet of sub-ppm uniformity by applying medical MRI magnet technologies. Three-dimensional spiral beam injection scheme is intended to storage in 0.66 m diameter compact ring, we have carefully studied of a spatial distribution of a radial magnetic field of the storage magnet and required beam phase space, especially for a strong X-Y coupling. In this presentation, we will discuss about a strategy to precise control of the X-Y coupling at the beam transport line: how to detect X-Y coupling from a beam phase space, how to control X-Y coupling with eight independent rotatable quadrupole magnets. We also discuss about how to apply fine-tuning of the beam trajectory without disturbing the magnetic field in the beam storage volume, by use of active shield multipole coils. Finally, we will report detailed studies of X-Y control at a demonstration beam line in KEK which proves the three-dimensional injection scheme is realistic one, as well as further challenges towards the original beam line at J-PARC.
Paper: MOPA110
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA110
About: Received: 01 Apr 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPA112
Damping ring and transfer lines of FCC-𝑒+𝑒− injector complex
308
The Future Circular Collider project is built around two main pillars: the construction of 100 km lepton collider running at increasing energies from the Z-pole to the t-tbar threshold (FCC-ee) followed by a hadron collider in the same tunnel (FCC-hh) to explore unprecedented energy frontier. The realization of FCC-ee relies on a very challenging injector complex that should provide the highest ever realized source of positrons, which will serve the first phase of the collider operations (Z-pole). In this contribution the relevant aspects related to the damping of the high-emittance beam coming from the positron source and the transport of the damped beam within the different LINAC of the injector complex are presented and discussed.
Paper: MOPA112
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA112
About: Received: 03 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
MOPA118
Demonstration of three-dimensional spiral injection for the J-PARC muon g-2/EDM experiment
327
In the J-PARC Muon g-2/EDM experiment, to measure muon g-2 and EDM, it is necessary to accumulate 300 MeV/c muon beams with a 66 cm diameter region with a 3 T solenoid-type magnetic field. A new three-dimensional spiral injection scheme has been invented to achieve this target. Since this is the first instance to employ this injection scheme, a scale-down experiment with an electron beam of 297 keV/c and storage beam diameter of 24 cm is established at KEK. A simplified storage beam monitor using scintillating fiber has been designed and fabricated to measure the stored beam. The 100 nanosecond width pulsed beam is injected and observed a few microsecond signals by stored beam monitor. According to this result, the beam storage is confirmed. And the recent result shows that the stored beam deviated from the design orbit and caused betatron oscillations. To measure the beam deviation quantitatively and tune the beam, the storage monitor has been updated. The data from this stored beam monitor are the primary data for considering the conceptual design of the beam monitor for the Muon g-2/EDM experiment. This talk will discuss the measurement of beam storage by three-dimensional spiral injection and beam tuning using a scintillating fiber monitor.
Paper: MOPA118
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA118
About: Received: 01 Apr 2023 — Revised: 11 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
MOPA122
A novel dual-channel kicker for the Hefei Advanced Light Facility
337
Hefei Advanced Light Facility (HALF) was designed as fourth generation light source based on the diffraction-limited storage ring (DLSR). The pre-research has been completely done, due to the smaller beam dynamic aperture, about 10mm, beam inject could not completed by the traditional bump magnet. We purposed and designed a novel dual-channel kicker, with other two traditional kicker, they were combined the new injection system. The paper presented the principle and layout and the detail of the novel dual-channel.
Paper: MOPA122
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA122
About: Received: 07 May 2023 — Revised: 08 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
MOPA143
Off-energy operation of a HMBA lattice
390
The ESRF-EBS is the first 4th generation source making use of the Hybrid Multi-Bend Achromat (HMBA) lattice cell, reaching an equilibrium horizontal emittance of 140 pm.rad in user mode (insertion devices (ID) gaps open). An off-energy operation was proposed to further reduce the equilibrium emittance by about 20 pm.rad. A first proposal rematched the HMBA optics at an energy deviation of -1\% and evaluated its dynamic aperture in the machine. Further experiments were dedicated to this study at the ESRF-EBS, including injection efficiency and lifetime optimisation.
Paper: MOPA143
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA143
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPA147
Booster conceptual design of the Southern Advanced Photon Source
400
The Southern Advanced Photon Source is a diffraction-limited storage ring at middle energy. The popular injector which includes a low energy Linac and a full energy booster is proposal. The concept design of the booster is presented in the paper. The booster is a high intensity synchrotron accelerator. The impedance model is obtained and the instability threshold is predicted.
Paper: MOPA147
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA147
About: Received: 08 May 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPA158
Updates to Diamond-II storage ring error specifications and commissioning procedures
422
The Diamond-II storage ring lattice has continued to be developed after publication of the Diamond-II’s technical design report. This study provides the updated information needed for the commissioning simulation. Firstly, changes to the reference lattice and phase-one insertion devices are briefly described. Then the error specifications are amended to be consistent with the magnet measurement and girder installation strategy. The commissioning strategy is revised accordingly with the associated errors. Finally, the commissioning simulations of multiple random machines are performed. Some of the statistical results are shown to justify the engineering feasibility of off-axis injection and beam accumulation with high injection efficiency.
Paper: MOPA158
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA158
About: Received: 02 May 2023 — Revised: 27 Jun 2023 — Accepted: 27 Jun 2023 — Issue date: 26 Sep 2023
MOPA159
Alternative Diamond-II storage ring optics with high beta section for improved injection
426
The nominal Diamond-II storage ring optics have been designed to produce a pseudo twenty-four-fold symmetry by maintaining equal phase advance across the long and standard straights [1]. In this paper, the impact of introducing a high beta section in the injection straight and reducing the ring symmetry to one have been extensively investigated. This solution does not require any additional hardware and so can be switched on or off as required. In this paper we present the optics solution and study the expected performance. [1] Diamond-II Technical Design Report, (2022).
Paper: MOPA159
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA159
About: Received: 02 May 2023 — Revised: 09 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPA168
Operation of the ESRF-EBS light source
449
The European Synchrotron Radiation Facility - Ex-tremely Brilliant Source (ESRF-EBS) is a facility upgrade allowing its scientific users to take advantage of the first high-energy 4th generation storage ring light source. In December 2018, after 30 years of operation, the beam stopped for a 12-month shutdown to dismantle the old storage ring and to install the new X-ray source. On 25th August 2020, the user programme restarted with beam parameters very close to nominal values. Since then beam is back for the users at full operation performance and with an excellent reliability. This paper reports on the present operation performance of the source, highlighting the ongoing and planned developments.
Paper: MOPA168
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA168
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 11 May 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
MOPA187
Simulation studies of first-turn commissioning for the HEPS storage ring
492
The High Energy Photon Source (HEPS), is an ultra-low emittance storage ring (USR) light source beingto be built in Beijing, China. Due to the characteristics of the compact 7BA structure with strong focusing, beam accumulation in an USR is expected to be very challenging. Our simulations confirmed the difficulty in the HEPS storage ring. This paper introduces the preparations made for the first-turns commissioning of the HEPS storage ring from the first injection to beam storage. The commissioning methods and simulation results for several key steps are discussed, including first-turns trajectory correction, RF parameters’ optimization, as well as tune measurement and adjustment in the first turns.
Paper: MOPA187
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA187
About: Received: 28 Apr 2023 — Revised: 19 Jun 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPL008
Lattice optimization for Electron Ion Collider Hadron storage ring injection
519
The Electron Ion Collider (EIC) Hadron Storage Ring (HSR) will utilize the Relativistic Heavy Ion Collider (RHIC) arcs and modified straight sections. Due to these modifications in the straight section of the on project electron Proton Ion Collider (ePIC) experiment, a new injection system needed to be built one arc downstream of the existing RHIC injection system. The new injection system will have capability of injecting 290 bunches with a maximum rigidity of ~81 Tm. In addition to the new injection system, the hydrogen jet (HJET) and proton-carbon (pC) polarimeters will be located in the straight section downstream of injection. This paper will report the modifications required to the lattice, optics, and magnets.
Paper: MOPL008
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL008
About: Received: 18 Apr 2023 — Revised: 09 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
MOPL016
Advancements in injection efficiency modelling for the Low Energy Ion Ring (LEIR) at CERN
539
The performance of the Low Energy Ion Ring (LEIR) at CERN is mainly determined by the number of charges extracted from the machine and transferred to the downstream chain of accelerators. While the required target of 9e10 charges has now been surpassed, a series of studies have been undertaken to further push the intensity reach of LEIR. In this work, we quantify the effect of the stray fields generated by the adjoining Proton Synchrotron (PS), which were recently partially shielded, and the effect of the stripper foil in the Linac supplying LEIR with its ions, Linac 3. The impact of the stray field was measured by observing the variation in injection trajectory, while that of the stripper foil was determined from the evolution of the Schottky energy profile in LEIR. Models have been developed to extrapolate the impact of these effects to the injection efficiency of LEIR, and consequently to the extracted beam intensity.
Paper: MOPL016
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL016
About: Received: 24 Apr 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
MOPL019
Mitigation of losses at injection protection devices in the CERN LHC
547
During loss maps performed with beam at injection energy in the LHC with the high octupole and chromaticity settings used for multi-train operation, large beam losses were observed at an injection protection device (TDIS). Although these losses did not present a threat to machine operation or protection, reducing them is of high importance to improve machine performance. Various strategies were developed to mitigate these losses, such as octupole setting optimization at constant Landau damping and vertical tune reduction. Further optimization of collimator settings is also considered. Results of experimental tests and first simulations are reported here together with considerations for the future.
Paper: MOPL019
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL019
About: Received: 03 May 2023 — Revised: 20 Jun 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
MOPL020
The LHC run 2022
551
Following a 3-year long shutdown for upgrade and consolidation work, the LHC was re-commissioned in spring 2022, achieving a new record of 6.8 TeV per beam. This paper will describe the beam commissioning phase, the electron cloud conditioning, and the intensity ramp-up bringing the machine to a steady production state. The main issues and achievements will be presented, including the fully automated luminosity levelling via β* adjustment. The limitations for beam intensity and peak luminosity will also be discussed.
Paper: MOPL020
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL020
About: Received: 22 Apr 2023 — Revised: 11 May 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
MOPL024
Measurement and modelling of decapole errors in the LHC from beam-based studies
567
Studies of third-order chromaticity in the LHC during its initial two runs have consistently demonstrated a substantial discrepancy between the expected Q''' at injection and that observed in beam-based measurements. In 2022 during Run 3, for the first time, studies of Q''' have been complemented by measurements of chromatic detuning, being the momentum-dependence of amplitude detuning, and the decapole resonance driving term 𝑓1004. In this paper, these beam-based measurements are presented and compared to the magnetic model. Potential sources of the previously identified Q”’ discrepancy are discussed.
Paper: MOPL024
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL024
About: Received: 24 Apr 2023 — Revised: 08 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
MOPL026
60° phase advance optics measurements in the Large Hadron Collider at CERN
571
The Large Hadron Collider (LHC) arcs have been designed for a FODO optics with roughly 90° betatron phase advance per arc cell, but not necessarily with exactly the same optics in the eight sectors of the ring. Measuring an optics with a significantly different arc cell phase advance, e.g. 60° which is at the limit for aperture at LHC injection, offers the possibility of understanding the LHC in an unprecedented depth. Furthermore, this optics would allow focusing higher energy beams, since the required quadrupole settings are lower than for the standard 90° optics for the same beam energy. Such an optics has therefore been designed, respecting all constraints for one low intensity pilot bunch per beam, and tested during commissioning of LHC Run 3 in 2022. First measurements, performed only for one beam at injection, are presented and compared to results obtained for the nominal 90° optics.
Paper: MOPL026
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL026
About: Received: 02 May 2023 — Revised: 09 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
MOPL027
First measurement of fourth and fifth order chromaticity in the LHC
575
Chromaticity up to the third order in the LHC has been well observed in the LHC’s first and second operational runs, with regular beam-based measurements performed during commissioning and machine development. In previous runs however, no higher-order chromaticity could be observed. In 2022, dedicated collimators setups meant optics measurements could benefit from an improved range of momentum-offset for the chromaticity studies. This allowed the observation of fourth and fifth order chromaticity in the LHC at 450GeV for the first time. Measurements were performed for several machine configurations. In this paper, results of the higher order non-linear chromaticity are presented and compared to predictions of the LHC magnetic model.
Paper: MOPL027
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL027
About: Received: 25 Apr 2023 — Revised: 08 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPL033
Recent updates of the layout of the lattice of the CERN hadron-hadron Future Circular Collider
598
The Future Circular Collider (FCC) study comprises two accelerators, namely a high-energy lepton collider (FCC-ee) and an energy-frontier hadron collider (FCC-hh). Both rings share the same tunnel infrastructure, analogous to LEP and LHC. We present the current design status of FCC-hh, updated from the Conceptual Design Report (CDR) and with recent developments including the new designs of the combined injection and dump insertion, combined injection and RF insertion, new collimation insertions, as well as the optimization of the arc cells and dispersion suppressors to increase the dipole filling factor.
Paper: MOPL033
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL033
About: Received: 19 Apr 2023 — Revised: 06 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPL039
Machine protection perspective on the restart of the large hadron collider after long shutdown 2
618
In 2022, the Large Hadron Collider started its third operational run. Following the three-year Long Shutdown 2, a careful re-commissioning of the machine protection system (MPS) took place. The initial hardware and beam commissioning period was followed by a 30-day-long intensity ramp-up, during which the number of circulating bunches was successively increased to 2460 bunches per beam. After each pre-defined intensity step, a detailed analysis of the functionality of the MPS was performed before advancing to the next step. It paved the way to reach a record stored energy of 400 MJ per beam in 2022. This was achieved without observing any beam-induced damage, confirming the excellent performance of the MPS. The paper reviews the strategy for the LHC re-commissioning and intensity ramp-up from a machine-protection perspective.
Paper: MOPL039
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL039
About: Received: 03 May 2023 — Revised: 16 May 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
MOPL043
NICA ion collider and its acceleration complex
634
The Nuclotron-based Ion Collider fAcility (NICA) is under construction at JINR. The NICA project goal is to provide colliding beams for studies of hot and dense strongly interacting baryonic matter and spin physics. The NICA Collider includes two rings with 503 m circumference each and the injection complex. For the heavy ion mode, the injection complex consists of following accelerators: 3.2 MeV/u linac (HILAC), 600 MeV/u (A/Z=6) superconducting booster synchrotron (Booster) and main superconducting synchrotron (Nuclotron) with kinetic energy up to 3.9 GeV/u (A/Z=2.5). The injection complex has been under commissioning for more than 2 years. The latest half-year Run ended in February of 2023. It was devoted to preparations for the collider operation and also delivered slowly extracted 3.9 GeV/u xenon beam to the BM&N experiment. Now the injection complex is shut down for its further development and an assembly of the collider. Cryogenic tests of the collider magnetic structure are expected at the end of 2023. The next run of the injection complex is aimed at an increase of ion flux by more than an order of magnitude and will be started at 2024.
Paper: MOPL043
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL043
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPL070
Status and plans for the high energy booster of the future electron-positron collider FCC-ee
708
In the context of the FCC IS European study, which investigates the feasibility of a 100 km circular $e^{+}e^{-}$ collider for the future high energy physics research, we present the status of the High Energy Booster (HEB) ring. The HEB will be located in the same tunnel as the collider and should have the same circumference. The main difference is to have a bypass near the experiments to avoid perturbing the detectors. In order to perform precision measurements of the Z, W and H bosons, as well as of the top quark, unprecedented luminosities are required. To reach this goal and to fill the collider, it is mandatory to continuously top up inject some beams with a comparable emittance and bunch length to the collider ones. One challenge of the HEB is in the fast cycling time allowing to reach the collider equilibrium emittance, especially for the Z mode. We present the status of the layout and optics design of the HEB taking into account these challenges. A special focus will be made on the cycling considerations.
Paper: MOPL070
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL070
About: Received: 27 Apr 2023 — Revised: 09 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPL071
Bunch lifetime analysis based on the injection interval at SuperKEKB
712
We carried out the study of the beam lifetime at SuperKEKB to investigate beam instabilities. We analyzed the injection interval for individual bunches to evaluate their beam lifetime ratio. SuperKEKB performed the top-up operation with the equalized bunches currents. This particular condition enables us to evaluate the lifetime ratio among all operation bunches. This report introduces the analysis results for the 2020 and 2021 data. We observed the beam lifetime has dependent on the bunch spacing and the relative position in the bunch train. Besides, in the December 2021 data, we determined the magnitude of the forward/backward asymmetry of the lifetime in the bunch train depends on the bunch current. They become good hints to understand the beam instabilities such as the electron cloud, the ion cloud, the beam-beam effect in the collision, and so on.
Paper: MOPL071
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL071
About: Received: 11 May 2023 — Revised: 24 May 2023 — Accepted: 24 May 2023 — Issue date: 26 Sep 2023
MOPL081
Transient beam loading and power analysis in the booster ring of CEPC
744
During the injection phase of the Higgs mode of CEPC, the stored energy of the cavity is low and beam loading is relatively high. The synchrotron radiation damping is weak compared to the growth rate of the untidamped mode. This will cause two types of trouble. Firstly, the transient beam loading caused phase-shift between the head and the tail of the beam will be too much. Secondly, the untidamped mode will grow too fast. Therefore, we performed a series of studies in order to put a quantified requirement on the strength of the damping mechanism and the power overhead.
Paper: MOPL081
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL081
About: Received: 04 May 2023 — Revised: 08 May 2023 — Accepted: 11 May 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
MOPL120
Beam injection issues at SuperKEKB
832
A high-charge, low-emittance injection beam is essential for SuperKEKB. For its both rings, HER and LER, the injection efficiencies and detector backgrounds have not been good enough up to the recent run. There are many reasons for the issues. For example, serious emittance growths are observed through the beam transport lines between the injector linac and both rings. It is considered that some parts of them are due to coherent synchrotron radiation as the observed horizontal emittance blowups depend on the bunch charge. Especially for the HER injection, physical aperture around the injection point and ring dynamic aperture also contribute, as both are narrower than the design. In this paper, we discuss the injection issues up to 2022 operation and outlook for the future to maximum collision currents.
Paper: MOPL120
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL120
About: Received: 03 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
MOPL123
Design of a CW RFQ as axial injector of high intensity cyclotron
840
We propose to develop a compact superconducting cyclotron to accelerate H2+ ions for isotope production since using H2+ allows the use of a stripper foil after extraction from the cyclotron to remove the binding electron, thereby doubling the electrical beam current. An RFQ, partially embedded in the cyclotron yoke, will be used to bunch and axially inject the H2+ beam into the cyclotron’s central region because RFQ has excellent bunching capability. In this paper we are presenting the design of the RFQ, including beam dynamics, electromagnetic structure and geometrical cavity.
Paper: MOPL123
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL123
About: Received: 18 Apr 2023 — Revised: 11 May 2023 — Accepted: 23 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
MOPL185
High beam energy recovery simulations for space charged based collector in Neutral beam injection application
973
Energy recovery of residual ions may be needed to increase the energy efficiency of Neutral Beam (NB) injectors for fusion plants as DEMO while a deflection-based system has been proposed. A compact beam energy recovery system, composed of 2 Farady Cups (FC) with holes for D0 passage, based on space charge effects, very effective to recover ions with low residual energy, has been proposed recently to replace the Electrostatic Residual Ion Dump (ERID) designed for ITER to dump the residual D- and D+ before the NB injection in the tokamak plasma [1]. New more accurate simulations on the proposed recovery system, however, presented some collection efficiency problems for very high initial beam kinetic energy (Eki=0.5÷ 1 MeV) when a very low residual (few keV) energy in the planned device. In this contribution, all parameter tunings for optimized simulation results are described and discussed. The collection of high Eki ions at low energy (a few percent of the full neutral beam energy Eki) remain possible although it could be done with lower efficiencies.
Paper: MOPL185
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL185
About: Received: 04 May 2023 — Revised: 12 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
MOPM002
Progress of physics studies and commissioning preparations for the High Energy Photon Source
980
The High Energy Photon Source (HEPS) is a 34-pm, 1360-m storage ring light source being built in the suburb of Beijing, China. The construction of HEPS started in mid-2019. Later, to deal with challenges emerging from the technical and engineering designs, the HEPS accelerator physics design was modified and had been finalized in 2020. Afterwards, studies on related physics issues were updated and have been basically finished. Besides, preparing studies for commissioning of the HEPS Linac, booster and storage ring were started almost at the same time, and are still underway. The commissioning of the Linac has been launched since early of 2023. In this paper, we will briefly introduce the updated studies on related physics issues and present the results of the Linac commissioning.
Paper: MOPM002
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM002
About: Received: 25 Apr 2023 — Revised: 07 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPM010
First results of automated startup and commissioning procedures at the Advanced Light Source
991
Rapid commissioning and automated start up procedures are crucial for many upcoming 4th generation storage ring light sources as their downtime demands are very challenging given their increased operational complexity. Detailed commissioning simulations as a tool of error analysis are not only used to guide the design process of new machines but also a prerequisite to implement an automated commissioning and start up procedure for the final machine. The current ALS can be used effectively to test the developed automated commissioning procedures for the ALS Upgrade because the lattice is very similar to the ALS-U Accumulator Ring, of which detailed commission simulations have been carried out. In this study we present first results including first turn beam threading and turn by turn beam based alignment procedures.
Paper: MOPM010
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM010
About: Received: 07 May 2023 — Revised: 07 Jun 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
MOPM011
First results of the multipole injection kicker in the MAX IV 1.5 GeV ring
994
A Multipole Injection Kicker (MIK) has been successfully designed, constructed, installed and commissioned with beam in the MAX IV 1.5 GeV ring. This device allowed reaching injection efficiencies as high as those obtained with the previously used conventional dipole injection kicker scheme, while at the same time providing an order of magnitude reduction in the perturbations to the stored beam resulting from the injection process. In addition, the device has had a major positive impact in allowing effective top-up injection under the strong optics perturbations generated by long-period elliptically polarizing undulators. In this paper we describe the first operations with the device and detail the process of optimisation and commissioning.
Paper: MOPM011
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM011
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPM012
A report on a lower emittance lattice at MAX IV 3 GeV storage ring
998
At MAXIV Laboratory we are continuing the efforts to reduce the emittance of 330 pm.rad of the larger storage ring (SR) operating at an energy of 3GeV. This paper details the techniques used to improve the characterization of the optics, and to optimize the injection into the SR with an emphasis on the difficulties encountered during the process and the strategies adopted to overcome them.
Paper: MOPM012
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM012
About: Received: 03 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
MOPM020
SLS 2.0 storage ring components overview before installation
1023
The Swiss Light Source SLS will have a 15 months long shutdown starting in October 2023 in order to install the new storage ring SLS 2.0. While the procurement of large series of components like magnets, power supplies, RF, vacuum chambers, … has started, the design of more specific components like the thin septum, undulators or collimators, is close to completion. The main difficulties and challenges of SLS 2.0 are common to other diffraction limited storage rings: cross talk issues due to the very short distances between magnets and especially with permanent magnets, heat dissipation issues in the small aperture vacuum chambers due to synchrotron radiation and RF heating and in general beam instabilities issues due to wakefields perturbations. Components have been designed to withstand these constrains and this paper will give an overview of the key components design and first tests before installation.
Paper: MOPM020
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM020
About: Received: 01 May 2023 — Revised: 05 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPM030
SOLEIL machine status: operation and upgrade project
1050
The synchrotron SOLEIL is both a 2.75 GeV third-generation synchrotron light source and a research laboratory at the forefront of experimental techniques dedicated to matter analysis down to the atomic scale, as well as a service platform open to all scientific and industrial communities. We present the performance of the accelerators delivering extremely stable photon beams to 29 beamlines. The beam delivery schedule and the operation have been affected by the energy crisis. Shortages of cryogenic fluids and electronic components, coupled with a high inflation, are impacting the operation budget and the related projects. The update on the construction of the new low-energy footprint cooling station is presented. Finally, new developments and testing of prototype equipment related to the upgrade of the injector complex and the main storage ring are discussed.
Paper: MOPM030
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM030
About: Received: 06 May 2023 — Revised: 12 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPM031
TDR baseline lattice for SOLEIL II upgrade project
1054
Previous TDR studies for the SOLEIL II Upgrade project have converged towards a lattice alternating 7BA and 4BA HOA type cells providing a low natural horizontal emittance value in the 80 pm.rad range at an energy of 2.75 GeV. This lattice adapts to the current tunnel geometry as well as to preserve as much as possible the present beamline positions. The new TDR lattice is an evolution including perfect straight sections alignment, better relative magnet positioning and more space for accommodating photon absorbers, BPMs and other mandatory diagnostics. The SOLEIL upgrade TDR lattice is then composed of 20 HOA cells with a two-fold symmetry, and provides 20 straight sections having five different lengths of 3.0, 3.6, 4.2, 8.0, and 9 m. This last long straight accommodates a triplet of quadrupoles to set the two low vertical beta functions and an additional canting for the two long beamlines. This paper reports the linear and the non-linear beam dynamic optimizations as well as future directions for performance improvement.
Paper: MOPM031
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM031
About: Received: 09 May 2023 — Revised: 11 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
MOPM038
Progress on the storage ring physics design of Hefei Advanced Light Facility (HALF)
1075
The Hefei Advanced Light Facility (HALF) is a soft X-ray and VUV diffraction-limited storage ring to be built in the Hefei city of China. This paper reports the recent progress on the physics design of the HALF storage ring, including lattice modification and optimization, error and insertion device effects, collective effects, injection scheme and collimation.
Paper: MOPM038
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM038
About: Received: 03 May 2023 — Revised: 16 Jun 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPM040
Beam transfer line of Wuhan Advanced Light Source
1082
Wuhan Advanced Light Source (WALS) is a fourth generation diffraction limit synchrotron radiation facility, which is composed of a full energy 1.5 GeV LINAC, a 1.5 GeV Storage Ring and 10 beamlines for its phase I project. The LINAC is 6 meters lower than the storage ring, which is connected by a 46 meters beam transfer line. The beam transfer line includes three parts, one ver-tical line between two horizontal lines. Four achromat sections are used, the first three are 30 degrees with exact same settings and the last one is matched with the storage ring injection septum and non-linear kicker. In this paper, the optic and error correction results are described in brief, especially the dispersion correction. Since there are horizontal and vertical dispersions at the same time, the correction process must correct both of them at the same time.
Paper: MOPM040
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM040
About: Received: 28 Apr 2023 — Revised: 06 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
MOPM047
RF feedback simulation for Diamond-II using ELEGANT
1099
The Diamond-II storage ring will utilise normal conducting main cavities and a passive superconducting harmonic cavity in its RF system. To evaluate the effects of bunch lengthening and lifetime gain from the harmonic cavity for different filling patterns, transient beam loading effects need to be studied. When simulating these effects with ELEGANT, RF feedback for the main cavities must be defined using sets of infinite impulse response (IIR) filters. This paper describes the method used to convert proportional-integral (PI) feedback parameters representative of the RF feedback implemented at Diamond into equivalent ELEGANT settings and presents simulation results demonstrating the effectiveness of the RF feedback. Transient beam loading effects for the standard and hybrid filling pattern are also studied.
Paper: MOPM047
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM047
About: Received: 02 May 2023 — Revised: 08 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPM060
Study of the ramping process for Korea-4GSR
1128
The Korea fourth generation storage ring (Korea-4GSR) is a 4GeV, low emittance light source to be built in Ochang, Korea. The booster ring, which consists of 26 FODO standard cells and 2 dispersion-free cells, ramps the beam energy up from 200 MeV to 4 GeV as part of the injector. The circumference and repetition rate of the booster ring is 772.9 m and 2 Hz, respectively. In this paper, the injection scheme, energy ramping curve, eddy current effect, beam parameters changing curve, and RF voltage during the energy ramping in the booster ring will be presented in detail.
Paper: MOPM060
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM060
About: Received: 28 Apr 2023 — Revised: 05 Jun 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
MOPM061
Sextupole injection at TPS
1131
The feasibility of performing sextupole injection at TPS (Taiwan Photon Source) storage ring has been demonstrated in November 2021 with 300 mA stored electron beam. In order to carry out the experiment, a sextupole and its associated pulser were fabricated according to the specifications required. The sextupole was installed during a short break in September 2021 by making use of a ceramic unit located between kicker-3 and kicker-4 at the injection straight section. Moderate adjustment of the beam injection trajectory at the BTS (booster-to-storage ring) transfer line is needed so as to avoid beam scraping off at the injection septum. A brief description of the preparation work is given and the experimental results are summarized in this report.
Paper: MOPM061
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM061
About: Received: 25 Mar 2023 — Revised: 08 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPM069
Commissioning of the ThomX Storage Ring
1141
We will report on the ongoing ThomX ring commissioning, its status, its main challenges, our results and our planning. ThomX is a compact Compton-based X-ray source under commissioning at IJCLab in Orsay (France). This facility is composed of a 50-70 MeV linac, a transfer line and a storage ring whose closed orbit is 18 m long. Compton scattering between the 50 MeV electron bunch of 1 nC and the 30 mJ laser pulses stacked in a Fabry-Perot cavity results in the production of X-rays with energy ranging between 45 keV and 90 keV. We aim at a total flux of about 10^13 X-rays per second. The injector commissioning started in the spring of 2021. The ongoing storage ring commissioning faces many challenges due to the ring’s low energy, its compactness, its non-linear beam dynamics, the time-limited beam storage and the need to achieve a very accurate and stable geometry of the collision region between the laser pulses and the electron bunch. The commissioning and operational experience is of great importance for the future Compton sources.
Paper: MOPM069
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM069
About: Received: 08 May 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
MOPM072
Dynamics of off-axis injection near the coupling resonance at PETRA IV
1148
The PETRA IV project will have a storage ring with an ultra-low natural emittance of 20 pm rad [1]. For an off-axis injection scheme with working points at the difference resonance it is important to assure the vertical excursion arising due to transversal coupling such, that injection efficiency is not compromised. In this contribution we present simulations results of an off-axis injection near the coupling resonance, which provides equal equilibrium emittances. Advantages and disadvantages of such a scheme are discussed.
Paper: MOPM072
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM072
About: Received: 08 May 2023 — Revised: 09 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPM073
Study of aperture sharing injection scheme for Diamond-II
1152
The Diamond-II storage ring has been designed to increase photon brightness by up to two orders of magnitude compared to the existing Diamond facility. A single-bunch aperture sharing injection scheme using short stripline kickers applied with high-voltage nano-second pulsers was proposed to provide both high injection efficiency and high photon beam stability in top-up mode [1]. The quasi-transparent injection process has been optimised and studied using Accelerator Toolbox. The results of these study will be presented.
Paper: MOPM073
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM073
About: Received: 28 Apr 2023 — Revised: 10 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
MOPM075
Beam-based characterization of a non-linear injection kicker at BESSY II
1156
Top-up operation at BESSY II is performed with average injection efficiencies of 98 %. However, the four-kicker bump and the septum, that form the present injection system, both contribute to a distortion of the stored beam with an amplitude of about two millimeters for several thousand turns after injection. A non-linear injection kicker (NLK) could be used to reduce the distortion due to the kicker bump by a factor of approximately 30 - a necessary condition for transparent injection. Studies with an NLK and optimized sextupole settings have shown that it is also possible to achieve injection efficiencies of up to 97 %. The NLK was characterized beam-based with regards to the application of the NLK for BESSY II user operation, a possible injection method for BESSY III and to get a better understanding of the limiting effects of the injection efficiency. Additionally, measurements and simulations were compared.
Paper: MOPM075
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM075
About: Received: 03 May 2023 — Revised: 07 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
MOPM078
Longitudinal injection for SAPS based on a double-frequency RF system
1159
In the fourth-generation storage ring light sources, the dynamic acceptance is usually small related to the extremely strong nonlinearity inherent in the multi-bend achromat design, making it difficult to implement traditional off-axis local-bump injection. It was found that a double-frequency rf system can be used for longitudinal injection with the help of rf gymnastics. However, such schemes require tuning the RF parameters during injection, which would challenge the RF hardware system and cause the bunch length shrinking of the circulated bunch. In this paper, we find that with proper parameters optimization, a double-frequency RF system with static parameters can be used for longitudinal injection. A detailed design of this scheme for the application in the Southern Advanced Photon Source (SAPS) is presented.
Paper: MOPM078
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM078
About: Received: 24 Apr 2023 — Revised: 10 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPM083
Beam injection with an anti-septum into the HALF storage ring
1170
Compared to the conventional injection scheme, the three-kicker bump injection scheme with an anti-septum has two advantages. One is less requirement of dynamic aperture thanks to the thin blade of the anti-septum, the other is less installation space requirement of the injec-tion system. Both are beneficial to the beam injection for the fourth generation light sources. In this study, the application of this injection scheme to the HALF storage ring is presented. The layout and parameters of the injec-tion system are designed and the injection process is simulated. The results of the injection efficiency and the effect on the stored beam during beam injection is shown in this paper.
Paper: MOPM083
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM083
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
MOPM085
Beam injection using a nonlinear kicker for the HLS-II storage ring
1173
The single nonlinear kicker (NLK) injection has been adopted by several synchrotron radiation light source facil- ities or their upgrades. The injected beam receives a kick from an NLK and goes into the acceptance of the storage ring while the stored beam passes through the center of the NLK where the magnetic field is almost zero. Compared with the local-bump injection, NLK injection requires less space for kickers and causes less oscillation amplitude for the stored beam during injection. Currently, a conventional local bump injection including four pulsed dipole kicker magnets is adopted in the HLS-II storage ring. In this paper, we propose an NLK injection scheme by only replacing one kicker with a pulsed NLK for HLS-II. The simulation result is also presented.
Paper: MOPM085
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM085
About: Received: 03 Apr 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPM086
Studies on beam injection system for Wuhan Advanced Light Source storage ring
1176
Wuhan Advanced Light Source (WALS) is the low-energy 4th generation advanced light source, which is proposed by Wuhan, China. WALS includes a 1.5 GeV full-energy LINAC injector, a 180 m circumference, 1.5 GeV low-emittance storage ring, and a series of start-of-the-art beam lines. The standard 7BA magnetic focusing structure is adopted for the storage ring to lower the beam natural emittance and the lattice has been well- designed and optimized by multiple-objective genetic algorithm to maximize the dynamic aperture and energy acceptance. The dynamic aperture of the storage ring at injection can reach up to 8 mm in the horizontal plane, which makes the off-axis beam injection method possible. An off-axis beam injection scheme based on the pulsed nonlinear magnet is to be employed for the storage ring. Detailed studies about the beam injection scheme, including the beam optical design, nonlinear magnet design and optimization, have been performed and multi-particle simulations have also been carried out to study the beam injection procedure, which will be presented in this paper.
Paper: MOPM086
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM086
About: Received: 27 Apr 2023 — Revised: 09 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPM130
Calibration of the 2-phase bubble tracking model for liquid mercury target simulation with machine learning surrogate models
1267
The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is one of the most powerful accelerator-driven neutron sources in the world. The intense protons strike on SNS’s mercury target to provide bright neutron beams, which also leads to severe fluid-structure interactions inside the target. Prediction of resultant loading on the target is difficult particularly when helium gas is injected into mercury to reduce the loading and mitigate the pitting damage on vessel walls. A 2-phase material model that incorporates the Rayleigh-Plesset (R-P) model is expected to address this multi-physics problem. However, several uncertain parameters in the R-P model require intensive simulations to determine their optimal values. With the help of machine learning and the measured target strain, we have studied the major uncertain parameters in this R-P model and developed a framework to identify optimal parameters that significantly reduce the discrepancy between simulations and experimental strains. The preliminary results show the possibility of using this mercury/helium mixture and surrogate models to predict a better match of target strain response when the helium gas is injected.
Paper: MOPM130
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM130
About: Received: 10 May 2023 — Revised: 19 Jun 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUODA2
Experimental confirmation of the impedance reduction campaign in the CERN SPS
1303
Measurements of the very long single bunch spectrum with RF off, were started in the SPS in 2012 to identify the main impedance sources responsible for both single and multi-bunch beam instabilities observed during operation. The impedance of the vacuum flanges with a strong peak at 1.4 GHz was identified and proven from simulations to limit the beam intensities required for the High-Luminosity LHC (HL-LHC). A shielding campaign was then initiated and applied during the long shutdown period in 2019-2020 to reduce their impedance. The same measurement technique was used recently to verify and evaluate the impedance reduction, as well as to identify other impedance sources. In this paper, the results of the new measurements are presented and compared with those found in 2012. The comparison shows that the strong impedance peak at 1.4 GHz has been fully suppressed and that the instability threshold largely increased in both optics used in measurements. Furthermore, the beam spectra evolution during the de-bunching is driven by the main 200 MHz cavity impedance, and no other dominant peak for the measured intensity range was observed.
Paper: TUODA2
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUODA2
About: Received: 02 May 2023 — Revised: 12 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUOGA1
Laser assisted charge exchange injection into the ring at the SNS
1311
A realistic laser assisted charge exchange (LACE) scheme for 1.3~GeV H- beam injection into the Ring for Spallation Neutron Source is under development. The design considered here is supposed to demonstrate the possibility of H$^-$ charge exchange injection into the SNS ring as an alternative to carbon foil stripping. A realistic stripping magnet design is considered as an integrated part of the injection area. Beam dynamics at the injection area are optimised. Laser assisted stripping, painting and beam dynamics of protons in the ring is simulated. Several alternative stripping schemes are evaluated.
Paper: TUOGA1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUOGA1
About: Received: 04 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 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
TUPA088
Feasibility investigation of a low energy laser driven plasma injector for ELSA
1526
The 3.2 GeV electron stretcher facility ELSA at the University of Bonn provides electron beams for fundamental research in hadron, detector and medical physics. The beam is extracted from a storage ring, whose injector consists of a 26 MeV linear accelerator and a 1.2 GeV booster synchrotron. The advent of functional plasma-based electron injectors in the MeV energy range raise the opportunity to replace the conventional Linac, which currently delivers electron pulses of up to 16 nC at a repetition rate of 50 Hz. We conduct a feasibility study of using a plasma based injector for the booster synchrotron. For this, we improve the diagnostic capabilities of the Linac transfer beamline and the injector synchrotron to obtain and verify its acceptance parameters which are to be matched to beam properties from contemporary operated laser plasma accelerator setups. Possible plasma-based facility operating modes are evaluated.
Paper: TUPA088
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA088
About: Received: 03 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 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
TUPA124
Latest PANTECHNIK’s ECR ion sources performances
1597
Electron Cyclotron Resonance Ion Sources (ECRIS) are commonly used as injectors in many accelerator laboratories and industries and therefore, pushing its limit towards very high charge state and intense ions for nuclear and elementary particle physics and low charge state ions for surface treatments & medical purposes. For these applications, several models of ECRIS were designed and developed by PANTECHNIK. This article presents a short description of the latest ECR ion source models delivered to the clients along with their typical beam intensities of low and high charge states of various elements. A focus will be made on our latest Supernanogan source (14.5GHz) which has just been installed at INSP, France. We will present improvements of highly charged ion production as a function of time and the efficiency of the new gas injection design.
Paper: TUPA124
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA124
About: Received: 02 May 2023 — Revised: 12 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
TUPA151
Performance of the Low Energy Ion Ring at CERN with lead ions in 2022
1648
2022 has been a performance consolidation year for the Low Energy Ion Ring (LEIR) at CERN that demonstrated its capability of delivering the target beam parameters required for high luminosity production in the LHC in a reproducible and reliable way. The main steps that have led to the high performance reach of this beam, together with the machine stability improvements deployed, are detailed in this paper.
Paper: TUPA151
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA151
About: Received: 26 Apr 2023 — Revised: 18 May 2023 — Accepted: 18 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
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
TUPA160
Validation of control loop modeling for power limitation studies with beams for HL-LHC
1679
For HL-LHC intensities, transient beam loading after injection between the Super Proton Synchrotron (SPS) and the Large Hadron Collider (LHC) is expected to push the RF power in the LHC to the limit of the installed system. A detailed understanding of this process is necessary to minimize beam losses during LHC injection. Realistic models of the local SPS and LHC cavity control systems were implemented in the Beam Longitudinal Dynamics (BLonD) simulation suite to model bucket-by-bucket and turn-by-turn transient effects. We show the results of studies and detailed benchmarks of key observables such as bunch-by-bunch spacing, RF power at 2023 beam intensity and transfer functions against theory and measurements.
Paper: TUPA160
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA160
About: Received: 29 Apr 2023 — Revised: 12 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
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
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
TUPL059
Study of an ERL-based X-ray FEL
1893
An energy-recovery-linac (ERL)-based X-ray free-electron laser (FEL) is proposed considering its three main advantages: i) shortening the linac by recirculating the electron beam by high-gradient SRF cavities, ii) saving the klystron power and reducing the beam dump power through the energy recovery in the SRFs, iii) producing a high average photon brightness with high average beam current. Such a concept has the capability of optimized high-brightness CW X-ray FEL performance at different energies with simultaneous multipole sources. In this paper, we will present the preliminary results on the optics design, parameter optimization, beam dynamics study and identification of potential R&D aspects.
Paper: TUPL059
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL059
About: Received: 01 May 2023 — Revised: 08 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
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
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
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
TUPM028
Status of the commissioning of Beam Cooler for SPES project
2245
A beam cooler device has been constructed by the Laboratories de physique corpusculaire (LPC) of Caen (France) in collaboration with Laboratori Nazionali di Legnaro (INFN) for the SPES project. The design phase started in 2018 and the construction was carried out in 2021. In 2022 the functionality test have been done at LPC and the beam commissioning started. The Beam Cooler is capable to improve the quality of ion beams at low energy in terms of reduction of the transversal emittance and decreasing the energy spread. The description of the device will be done and the result of beam test done at LPC will be reported.
Paper: TUPM028
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM028
About: Received: 03 May 2023 — Revised: 06 Jun 2023 — Accepted: 22 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
TUPM037
The C70XP injection line transverse distribution study and impact
2277
The C70XP is a cyclotron operated for production of radionuclides in nuclear medicine, for research in physics, radio-chemistry and biology. It aims at providing high intensity beams to the various experiment for long or very short time runs. The beam transverse distribution, e,g. homogeneity and emittance, has a great impact on the experiments. The ion source and subsequently the injection line, which can hold 4 types of particles (HH+, D-,He2+ and H-), being the first stage of the accelerator defining the beam, are therefore of particular focus for the beam studies. Thus, a first study of the transverse beam distribution in the injection line has been measured with an Allison-type emittance-meter. Additionally, various simple shape collimators have been used and their impact has been measured in the extraction beam line. These studies have also been combined with multiple magnets tuning simulating various operating mode. A model of the injection line based on G4Beamline has been performed. The experimental and simulation results are given in this paper as well as the on-going studies for a potential future collimator.
Paper: TUPM037
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM037
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 22 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
TUPM061
High intensity beam operation of J-PARC RCS with minimum beam loss
2331
The 3-GeV RCS at J-PARC at present operates at a relatively high intensity beam of nearly 1 MW for the spallation neutron source. The beam loss and the corresponding residual radiation, which is the key limitation against beam intensity ramp up, has been well mitigated to a minimum level in a recent series of beam studies and feedback from realistic numerical simulations. The residual beam loss even at the designed 1 MW beam power is now mostly due to the foil scattering of the circulating beam during multi-turn injection, while other beam loss sources have been well optimized to minimize the beam loss for achieving a stable operation presently at 800 kW.
Paper: TUPM061
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM061
About: Received: 25 Mar 2023 — Revised: 07 May 2023 — Accepted: 15 Jun 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
TUPM085
Metallic neutral vapours diffusion in electron cyclotron resonance ion sources : fluid dynamics and particle tracing simulations
2402
Resistive oven technique is used to inject vapours of metallic species in plasma traps, where plasma sustained by the electron cyclotron resonance (ECR) mechanism provides step-wise ionisation of neutral metals, producing charged ion beams for accelerators. We present a numerical survey of metallic species suitable for oven injection in ECR ion sources to explore neutrals diffusion and deposition, under molecular flow regime. These aspects depend on geometry of the evaporation inlet, thermodynamics, and on plasma parameters, which strongly impact on ionisation and charge-exchange rate, thus on the fraction of reacting neutrals. We considered diffusion of metals with and without plasma, and the impact of a liner for re-emitting deposited species. Numerical predictions might be relevant to reduce the metal consumption and to increase the overall efficiency. As test beams, we simulated most relevant ones for modern nuclear physics field, such as 48Ca and rare earths species.
Paper: TUPM085
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM085
About: Received: 11 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
TUPM098
Analysis of losses and protection of the electrostatic septum anode wires in SIS18
2439
The synchrotron SIS18 at GSI uses resonant extraction for slow beam extraction. Recently it was discovered that about 50% of the anode wires of the electrostatic extraction septum were broken during beam operation. In this paper, we present the analysis of the possible loss scenario that led to the anode wire damage and suggest machine protection measures to prevent future damage. The investigations revealed the importance of having access to stored data representing machine parameter settings and their changes as well as signals from devices and beam instrumentation to be able to analyse the events leading to losses. Relevant signals include beam current, beam loss monitor signals, and vacuum pressure. Systems for logging and archiving such data are under development for FAIR, but are not yet routinely available.
Paper: TUPM098
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM098
About: Received: 03 May 2023 — Revised: 05 Jun 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
TUPM115
Phase space painting of a self-consistent Danilov distribution in the SNS ring
2483
The {2, 2} Danilov distribution is self-consistent — it is a Vlasov equilibrium distribution that produces linear space charge forces. Additionally, the distribution has zero (four-dimensional) transverse emittance. Thus the Danilov distribution may be of use for overcoming space charge limitations at high intensities, increasing collider luminosity, or pushing the limits of transverse bunch compression using round-to-flat transformers. When such a distribution is matched to one of the eigenmodes of a ring it is possible to use phase space painting to build the distribution over many turns, maintaining self-consistency throughout. This provides a way to create high-intensity beams with unique properties that could increase accelerator performance, with direct implication for experiments. Here we report on the results of a proof-of-principle experiment using the flexible transverse phase space painting system at the Spallation Neutron Source to demonstrate the creation of an approximate Danilov distribution, including the effect of recently installed solenoid magnets.
Paper: TUPM115
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM115
About: Received: 03 May 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
TUPM118
Tailoring transverse beam characteristics with the new CERN PS booster charge-exchange injection system
2495
A key aspect of the LHC Injectors Upgrade project is the connection of the PSB to the newly built Linac4 and the related installation of a new 160\,MeV charge-exchange injection system. The new injection system was commissioned in winter 2020/21 and is now used operationally to tailor the transverse characteristics for the various beam types at CERN, such as high-intensity fixed target beams, LHC single bunch beams, and high-brightness beams for LHC. This contribution outlines the different injection strategies for producing the various beam types and discusses the application of numerical optimization algorithms to adjust injection settings in operation efficiently.
Paper: TUPM118
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM118
About: Received: 08 May 2023 — Revised: 05 Jun 2023 — Accepted: 22 Jun 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
WEOGA2
Status of SIRIUS operation with users
2586
SIRIUS is a green-field 4th generation Synchrotron Light Source Facility based on a 3 GeV electron storage ring with 518 m circumference and 250 pm.rad emittance. It was de- signed, built, and is operated by the Brazilian Synchrotron Light Laboratory (LNLS/CNPEM). After completion of Phase-0 commissioning of the accelerators and first beam- lines, SIRIUS is now open for external users, with 6 fully operational beamlines, 4 close to start scientific commis- sioning, and 4 in different stages of installation. We report on the status of SIRIUS operation with users in the recently implemented top-up mode, with important upgrades in the orbit feedback systems and in the reduction of transient perturbations to the stored beam during injection process.
Paper: WEOGA2
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEOGA2
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 23 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
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
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
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
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
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
WEPL001
Progress on the 6BA lattice for ALBA-II
3098
The ALBA-II upgrade lattice to a diffraction limited soft X-rays storage ring calls for an emittance smaller than 200 pm*rad in a 269 m circumference at an energy of 3 GeV. In this paper we report on progress of the 6BA lattice with distributed chromatic correction. This lattice relies on transverse gradient dipoles and reverse bends to suppress the emittance. Several modifications to the lattice presented in 2021 have been introduced in order to easy the injection with high horizontal beta function and a longer section for the septum, to make more efficient the chromaticity correction with the sextupoles, and to provide room for the orbit correctors. The last performances of the linear and non-linear beam dynamics are presented in this paper.
Paper: WEPL001
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL001
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 16 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
WEPL006
Improvements to the commissioning simulations of the APS Upgrade storage ring
3112
The commissioning of the APS Upgrade storage ring will need to be completed fast in order to minimize the dark time for APS users. To help speed up commissioning, lattice commissioning simulations were developed that allow to test commissioning algorithms and automate the entire process. In this paper, we describe recent improvements and additions to the commissioning simulations. We cover the addition of the transfer line commissioning, handling of larger than expected errors, use of survey results in the first-turn trajectory correction, and discuss lattice correction results.
Paper: WEPL006
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL006
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPL022
Emittance reduction of the actual Booster for Elettra2.0
3155
A crucial common parameter for the new 4th generation machines is the reduced dynamic aperture at injection point. Will be presented the analyzed strategies and what have already been done in order to reduce the emittance of the injected beam and garantee a good injection efficiency.
Paper: WEPL022
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL022
About: Received: 02 May 2023 — Revised: 06 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPL026
Derivation and interpretation of parameters describing betatron mismatch and chromaticity
3170
Expressions to quantify betatron mismatch and chromatic effects are frequently used in accelerator physics, but their derivations are not given in standard text books, making their interpretation difficult. First parameters describing betatron mismatch are introduced using normalization with respect to reference Twiss parameters describing a lattice. In a second step, the derivatives of these mismatch parameters with respect to the relative momentum offset are considered and lead naturally to the Montague W functions and a phase angle computed as well by standard lattice programs.
Paper: WEPL026
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL026
About: Received: 02 May 2023 — Revised: 05 Jun 2023 — Accepted: 05 Jun 2023 — Issue date: 26 Sep 2023
WEPL029
Mini-beta optics for the European Synchrotron Radiation Facility
3177
The ESRF presently operates with the HMBA lattice that features beta-functions of 6.9 m and 2.7 m in the horizontal and vertical planes at the center of the the straight sections. These are not optimal for a length of in-vacuum undulator of approximately 2 m that is used at ESRF. New optics with reduced beta functions at the center of the straight section were designed to better match the electron and photon beams, allow for a reduction of the in-vacuum undulator gap and increase the brilliance delivered to the beam line. This paper presents the optics design, brilliance calculation and plans for experimental validation at the ESRF.
Paper: WEPL029
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL029
About: Received: 30 Apr 2023 — Revised: 06 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPL034
Simulation Studies of the Particle Dynamic in Beam: Internal Target and Beam-Beam Interactions in the Figure-8 Storage Ring(F8SR)
3189
The Figure-8 storage ring (F8SR) concept for fusion reaction research in context of astrophysics is under development at Frankfurt University. In contrast to traditional storage rings, a guiding longitudinal magnetic field is used for confinement of very low energy charged particle beams continuously with high transverse momentum acceptance. Due to the strong magnetic field level (B=6 T), low energy proton and ion beams (W < 1MeV) of several amperes can be confined. Many characteristic and unique features (e.g. injection system, collider mode) and key components were developed in the past. The current developments are concentrated on the design of a beam-target area and detectors. Particle-in-cell (PIC) simulation of high current beam propagation through a target area and interaction with an internal gas target will be presented and discussed. Possible space charge compensation through confined electrons will be assessed. Investigation of the large target area for colliding beam mode will be presented and discussed as well.
Paper: WEPL034
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL034
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 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
WEPL070
Status of the SOLEIL II robustness studies
3263
SOLEIL, the French third-generation synchrotron radiation facility, is in the TDR phase of its upgrade to a new fourth-generation synchrotron light source, called SOLEIL II. Its storage ring lattice design has evolved over the last year to better adjust its parameters taking into account the results of the mechanical integration, more realistic magnet design~[1], and the geometrical constraints for the extraction of the photon beams. A new configuration of girders has been introduced, and the correction strategies have been refined. A new corrector budget and updated results with more statistics are presented in this paper.
Paper: WEPL070
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL070
About: Received: 02 May 2023 — Revised: 05 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
WEPL072
Progress on the New Booster for SOLEIL II
3267
The SOLEIL II storage ring project will require an injected beam with small transverse and longitudinal sizes. To meet this requirement, a new multi-bend 14BA Higher-Order Achromat lattice has been de-signed to reduce the booster emittance from the pre-sent 140 nm.rad to 5 nm.rad @ 2.75 GeV. In this paper we report the progress in the booster beam dynamics studies, considering the linac energy increase from 110 to 150 MeV, and all errors coming from injection mag-nets, injected beam parameters, booster magnets and RF system, whereas the resistive wall study is reported elsewhere. The progress in designing the magnets, the vacuum system, the ramped power supplies, and the diagnostics is presented.
Paper: WEPL072
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL072
About: Received: 26 Apr 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPL087
Online optimization of SIRIUS nonlinear optics
3302
SIRIUS is the 4th generation storage ring-based synchrotron light source built and operated by the Brazilian Synchrotron Light Laboratory (LNLS). Beam accumulation at SIRIUS storage ring occurs in an off-axis scheme, using a nonlinear kicker (NLK), for which the efficiency depends on a sufficiently large dynamic aperture (DA). This work reports on the application of online optimization using the Robust Conjugate direction Search (RCDS) algorithm on SIRIUS sextupoles, which resulted in improvements to injection efficiency and DA in three different machine working tunes.
Paper: WEPL087
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL087
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPL111
Amplitude dependent tune shift measurements at KARA
3371
KIT operates the storage ring KARA (Karlsruhe Research Accelerator) as an accelerator test facility, which serves as a testbed for different electron beam-based experiments. Thus, it motivates to study the beam conditions extensively. To extend the existing characterisation of non-linear parameters, the amplitude dependent tune shift (ADTS) was measured. ADTS is typically controlled by octupole magnets in a storage ring, which are not available at KARA, but the installed insertion devices exert a certain octupole component on the beam resulting in a change of the ADTS. This contribution presents measurements of the amplitude dependent tune shift for different combinations of active insertion devices.
Paper: WEPL111
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL111
About: Received: 02 May 2023 — Revised: 29 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
WEPL135
Evaluation of the impact of REBCO-coated conductors on the resistive wall impedance of the FCC-hh
3421
The beam screen for the Future Circular hadron-hadron Collider (FCC-hh) has a baseline design based on a copper (Cu) coating. Calculations have indicated that the resistive wall impedance will be the major contributor to the beam impedance for the FCC-hh at both injection and collision and that Cu might be on the limit to ensure beam stability. To increase the safety margin, it is desirable to reduce the resistive wall impedance. In this contribution, we present an approach to reduce the beam impedance based on the reduction of the surface resistance of the beam screen coating by using High-Temperature Superconductors based on REBaCu3O7-x coated conductors (REBCO-CCs). These HTS-CCs have transition temperatures around 90K, and critical current densities which are high enough even in the presence of strong magnetic field, being therefore good candidates to substitute Cu in the FCC-hh beam screen which will be operating at around 50K and under a magnetic field of 16T. Using experimental data generated on the surface impedance of REBCO-CCs, CST simulations have been performed and the beam impedance has been estimated for an elliptical beam screen with the same vertical dimensions as that of a pure Cu beam screen. A position and REBCO-CCs contribution dependence study to determine the optimum beam screen configuration will be shown. Resistive wall impedance studies using an ellipse is a step forward towards determining the performance of the REBCO-CCs on the FCC-hh beam screen.
Paper: WEPL135
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL135
About: Received: 08 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPL148
Overview of transverse instabilities in the CERN Proton Synchrotron
3450
During Long Shutdown 2 (2019-20), the injector chain of the Large Hadron Collider (LHC) has been upgraded to reach the High Luminosity LHC goals in terms of beam intensity and brightness. In the CERN Proton Synchrotron (PS), this upgrade consisted in hardware modifications to double the intensity at extraction, while preserving the transverse emittance available from the CERN PS Booster. The gradual beam brightness ramp-up in the PS after the restart in 2021 brought to light several impedance-induced instabilities. Each of these instabilities has been thoroughly studied in order to understand the impact of several key beam parameters (chromaticity, RF voltage, damper gain). Instability observations, mitigation strategies as well as comparisons with macroparticle tracking simulations will be presented in this paper.
Paper: WEPL148
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL148
About: Received: 02 May 2023 — Revised: 16 Jun 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPL149
Impedance-induced beam observables in the CERN Proton Synchrotron
3454
Impedance-induced tune shifts and instability growth rates in the CERN Proton Synchrotron are studied thanks to the recently updated impedance model of the machine. Calculation of these beam observables are obtained using both Vlasov solvers and macroparticle tracking simulations, and are compared with those observed during dedicated measurement campaigns. Thanks to improvements in the measurement procedure, including the careful monitoring of losses, bunch length, linear coupling and chromaticity, uncertainties on the tune shifts were noticeably reduced compared to previous years. Finally, the effect of linear chromaticity on tune shift slopes and growth rates has been examined, allowing for a detailed comparison with both past measurements and simulations.
Paper: WEPL149
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL149
About: Received: 02 May 2023 — Revised: 07 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPL155
Head-tail mode zero instability growth rate studies in the CERN SPS
3478
The growth rate of the Head-Tail mode 0 instability is related to the real part of the transverse beam coupling impedance. The SPS transverse impedance model, which includes the major impedance contributions in the machine, can be benchmarked through measurements of growth rates as a function of chromaticity. This paper summarizes the methodology established to explore a wider range of chromatic frequency shifts, and presents the measurements performed after the LHC Injectors Upgrade (LIU) for two sets of machine optics: nominal and low gamma transition. The measurements are compared with the current Impedance model to further study its degree of accuracy.
Paper: WEPL155
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL155
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 19 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
WEPL176
Resistive-wall instability evaluation along the ramp in the SOLEIL II booster
3526
The ultra-low emittance specification of the SOLEIL II storage ring requires a challenging lattice design of the booster that will inject the beam into it. The dimension of the vacuum chamber in the new booster must be reduced compared to that in the present machine. The resistive-wall (RW) instability is then expected to become more important than in the current booster. However, the Amplitude-Dependent Tune Shift (ADTS) is also expected to be stronger due to the strong sextupole magnets necessary for chromatic error correction in the new lattice. It could then be an important effect in fighting against this instability. Therefore, evaluating this instability is important to ensure the machine's feasibility. This work studies the beam dynamics along the ramp in the RW instability regime using the code mbtrack2. The turn-by-turn tracking allows us to see the evolution of the beam thoroughly and understand how RW, synchrotron radiation, and ADTS impact the beam stability.
Paper: WEPL176
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL176
About: Received: 24 Apr 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPL182
Coupled bunch stability with variable filling patterns in PETRA IV
3542
The PETRA IV upgrade project is aiming at building a 6 GeV diffraction-limited light source. The storage ring’s off-axis accumulation injection scheme will allow generating a wide range of filling patterns for the needs of photon science users. To preserve high beam quality and low transverse emittances it is imperative to ensure beam stability against collective effects. In this paper we investigate the impact of different filling patterns on the coupled-bunch stability in the ring using a semi-analytical Vlasov solver.
Paper: WEPL182
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL182
About: Received: 28 Apr 2023 — Revised: 06 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
WEPM018
Affordable, efficient injection-locked magnetrons for superconducting cavities
3605
The cost of a klystron for the SNS is estimated to be in the $200K range. A magnetron with the same power level is about one-fourth the cost. With ancillary equip-ment to functionally duplicate the performance of the klystron and allowing for the reduced lifetime of the magnetron compared to the klystron, about half the cost. Additional operational cost savings are related to the 805 MHz magnetron 90% efficiency, which for some applica-tions is twice that of a corresponding klystron.
Paper: WEPM018
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM018
About: Received: 04 May 2023 — Revised: 10 May 2023 — Accepted: 23 Jun 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
WEPM038
Development of an octupole ceramics chamber with integrated pulsed magnet for beam injection
3639
An air-core pulsed magnet named Ceramics chamber with integrated Pulsed Magnet (CCiPM) was developed as a fast dipole kicker at first. A prototype of a dipole CCiPM was designed and tested successfully at KEK Photon Factory (KEK-PF). Because of the feature of an air-core magnet, a CCiPM can also generate an octupole magnetic field for pulsed multipole magnet injection. Compared with the pulsed iron-core magnet, the CCiPM almost does not have eddy current effects which may induce the stored beam oscillation. One prototype has been developed for the beam injection at PF ring. To examine the performance of the octupole CCiPM, some experiments has been conducted such as durability test, current excitation test and magnetic field measurement to evaluate the mechanical performance and magnetic field quality. The design and experimental results will be reviewed.
Paper: WEPM038
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM038
About: Received: 19 Apr 2023 — Revised: 28 May 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
WEPM039
Conceptual design of multipole injection kicker magnets for the ILSF storage ring
3643
The standard injection scheme of ILSF is composed of 2 septum and 4 kicker magnets installed in a 7-meter-long straight section. Further tuning of the 4 kicker devices to reduce perturbations has proven to be almost impossible since it requires having 4 identical magnets, electronics, and Ti-coated ceramic chambers. Different from pulsed dipole kicker magnets used in a conventional local-bump injection, the single nonlinear or multipole kicker provides a nonlinear distribution of magnetic fields, which has a maximum value off the axis where the injected beam arrives and a zero or near-zero value at the center where the stored beam passes by. So, here the designs of different multipole kickers, including sextupole, octupole, and a nonlinear kicker, have been investigated and compared.
Paper: WEPM039
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM039
About: Received: 11 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPM040
DC septum magnet with low current density for the synchrotron light source
3646
We have designed and fabricated a new DC septum magnet for modern accelerators. Septum magnets feature a dipole magnetic field deflecting designated beams at one side of the septum while providing no deflecting field on the other side. Conventional direct-drive type DC septa is embedded with coils inside the magnet gap, which usually results in rather high current density in the thinner septum conductor as the septum thickness is required as thinner as possible upon request from beam trajectory design. It can, however, lead to failures in coils due to harsh heat cycles and faults in high-current power supplies. We propose an alternative septum magnet design to significantly reduce the current density by an order of magnitude. The new design has achieved a high flux density of 1.2 T with the current density of as low as 5 A/mm2 with the 5 mm thick septum that comes in a dogleg shape for optimizing the magnetic field configuration on the both sides of the septum. We present our new magnet design and the measured performance of the magnet.
Paper: WEPM040
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM040
About: Received: 02 May 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPM052
Longitudinal impedance of nonlinear kicker for Hefei advanced light facility
3674
The Hefei Advanced Light Facility (HALF) is a vacuum ultraviolet (VUV) and X-ray diffraction-limited storage ring light source. It has a relatively large dynamic aperture, and an injection scheme with a nonlinear kicker (NLK) was considered for the HALF. This kind of magnet was designed with a small gap shield in the central area to gain a flat magnetic field. A complete prototype has also been produced and the measurement of magnetic field was done. In this paper, an improved structure of the nonlinear kicker is presented based on the previous one. Simulation of the longitudinal impedance has also been done and will be given later.
Paper: WEPM052
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM052
About: Received: 24 Apr 2023 — Revised: 05 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
WEPM088
Analysis of the bi-bridge topology and power device circuit of the TPS booster dipole power supply
3779
This study primarily discusses a unique topology for constructing a double full bridge circuit. The study establishes a push-pull inverter model and analyzes the balance circuit in its architecture. This allows the power supply to initiate the balance circuit and ensures the TPS booster magnet power supply operates smoothly in a safe and balanced voltage region when magnet energy is re-covered. We employ the approach of adding Y circuits to mitigate the impact of common mode noise. Adding a Y circuit effectively suppresses the common-mode noise generation, improving the quality of the output current of the TPS dipole magnet power supply at low currents state and ramping the beam current energy from 150 MeV to 3 GeV. Furthermore, the reproducibility and stability of the injection point can enhance the injection efficiency of the TPS booster magnet power supply. This study presents the results obtained from these efforts.
Paper: WEPM088
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM088
About: Received: 28 Apr 2023 — Revised: 08 May 2023 — Accepted: 19 Jun 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
WEPM136
Lattice considerations for synchrotron of XiPAF-upgrading project
3896
The synchrotron of XiPAF (Xi'an 200MeV proton application Facility) is a compact proton synchrotron, which can accumulate and accelerate 1e11 particles for 3-order resonance slow extraction, with H^- stripping injection and phase space painting scheme. Now XiPAF is under the challenge of more particle species for single event effect study, like He+, C4+ and so on. This paper report the lattice considerations and beam dynamic study for XiPAF-Upgrading Project, shows that XiPAF synchrotron upgrade is feasible by using original dipole, quadrupole and sextupole magnets.
Paper: WEPM136
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM136
About: Received: 30 Apr 2023 — Revised: 18 May 2023 — Accepted: 18 May 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
THPA034
New injection controls environment for the Taiwan Light Source
4025
Taiwan Light Source (TLS) delivery user service since 1993. Some legacy system have been updated recently to avoid obsolesce and to provide better performance to improve operation efficiency. Proprietary designed timing modules were replaced by event based timing system recently. The magnets of the booster synchrotron configured as three White circuits and drive by resonance excitation. Original control of the White circuit include analog amplitude loop and digital phase loop for regulation were replace by full digital regulation loops. Success upgrade of both system lead easy and smooth injection control possible with functionality and flexibility enhancement. The injection control includes foreground and background processes to coordinate the operation of e-gun, linear accelerator, booster synchrotron, and storage ring by the help of timing system. Scheme of fix time interval between injection was selected to meet user requirements. Injection control GUI provide an intuitive operation interface includes parameters setting and present all necessary information display like various timing value, stored beam current/lifetime, injection efficiency, filling pattern, kickers waveform. Energy saving mode of the White circuits are supported by the injection control to save electricity. Lifetime calculation of the storage ring is also synchronized with the injection process. Detail of the implementation and operation experience will be presented.
Paper: THPA034
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA034
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPA036
New controls for white circuits power supplies for the booster synchrotron of Taiwan Light Source
4029
Controls of the White circuits for the booster synchrotron of Taiwan Light Source was developed in late 1990s. That design based on various analog circuitry to detect 10 Hz magnet amplitude and phase. The existed implementation consists of analog regulation for amplitude control and digital regulation for relative phase between magnet family. Modernized of the White circuits controls was implemented recently to avoid obsolesce of components of the existed system. Upgraded system adopt digital regulation for amplitude and phase loops. Improve performance and easy maintenance are the goals of this upgrade.
Paper: THPA036
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA036
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 19 Jun 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
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
THPA053
Dose rate and accumulated dose around the Taiwan Photon Source in various scenarios
4077
The Taiwan Photon Source (TPS) is equipped with 16 real-time radiation monitoring stations around the accelerator. Each operating scenario entails a different dose rate and accumulated dose. In this study, we assessed the beam current and injection efficiency of the accelerator and the dose rate and accumulated dose at the radiation monitoring stations in five scenarios. The background radiation level of the TPS is approximately 0.1 µSv/h. We observed that when the injection efficiency was over 85%, the accumulated dose was similar to the background level. When the injection efficient was low (~55%), the accumulated dose was high. When the beam trip focused on a hot spot, the accumulated dose was considerably high. The gamma-ray dose rate reached approximately 2,500 μSv/h. These results indicate that the machine should not be continuously operated in injection mode at low efficiency. Furthermore, in beam trip or dump beam mode, operators should pay particularly close attention to radiation safety.
Paper: THPA053
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA053
About: Received: 10 May 2023 — Revised: 11 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPA068
New event based timing system for the taiwan light source
4122
The Taiwan Light Source (TLS) is a third generation of synchrotron light source, and it has been operated since 1993. Legacy timing system of the Taiwan Light Source was delivered in early 1990s. To deal with obsolete com-ponents and improve functionality, upgrade to event-based timing system for TLS is under way. The system need coordinate the operation the linac, White Circuit based booster synchrotron, and the storage ring for beam genera-tion, injection, extraction, and beam accumulation. Sup-port top-up operation of the storage ring is needed. Due to more experiences on EPICS related framework, the cPCI (CompactPCI) based EPICS IOC (Input Output Control-ler) and expandable Fanless Embedded Computers have been adopted for new TLS Timing system to replace the existed VME based ILC (Intelligent Local Controller) to be as an easy-to-maintain control environment. Scheme deal with resonance excitation of the booster magnets with the event system need special care. Design ideas and implementation will be summarized.
Paper: THPA068
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA068
About: Received: 09 May 2023 — Revised: 09 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPA146
Study of titanium coating of multipole injection kicker by magnetron sputtering method
4298
One of the projects for upgrading at the Taiwan Photon Source (TPS) is the design and fabrication of an improved multipole injection kicker (MIK). The aim is to improve the injection efficiency using four kickers, to deliver transparent injections during the top-up operation. A uniform titanium coating on the inner surface of the ce-ramic substrate is required to reduce the impedance of the stored electron beam and to conduct the image current. The study results of the deposition of a titanium film on a ceramic substrate (30 cm × 6 cm ) in a long vacuum chamber show that the thickness uniformity of the thin film can be controlled within 5 % with an electrical resis-tivity of 2 × 10-4 ohm-cm. The adhesion between the ceramic substrate and the titanium film meet the highest ASTM-D3359 5B requirements (bonding strength 39.2 MPa). The details of the coating set-up, experimental processes and measurement method are described in this paper.
Paper: THPA146
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA146
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 11 May 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
THPA164
Operational experience of a low beam coupling impedance injection kicker magnet for the CERN SPS ring
4352
The CERN SPS injection kicker magnets (MKP) were developed in the 1970's, before beam power deposition was considered an issue. There are two types of these magnets in the SPS: MKP-S (small aperture) and MKP-L (large aperture) versions. The MKP-L magnets are very lossy from a beam impedance perspective: this would be an issue during SPS operation with the higher intensity beams needed in the future for HL-LHC. Hence, a beam screen has been developed, which is inserted in the aperture of each MKP-L module. The screen consists of silver fingers applied to alumina U-shaped chambers: the fingers have been optimized to achieve both adequately low beam induced power deposition and good high voltage (HV) behaviour. A surface coating, with a low secondary electron yield, is applied to the inner surface of the alumina chambers to reduce dynamic vacuum. The low-impedance MKP-L has been extensively HV tested in the lab before installation in the SPS. This paper briefly presents the design and focuses on the operational experience in the SPS, including heating and vacuum.
Paper: THPA164
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA164
About: Received: 03 May 2023 — Revised: 05 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPA167
Design and production of the fast HESR-injection kicker magnets
4363
The High Energy Storage Ring (HESR) has been designed for acceleration and storage of antiprotons and ions by Forschungszentrum Jülich (FZ-Jülich) for FAIR in Darmstadt. The HESR kicker magnets have been designed for the injection of charged particles with magnetic rigidity of 13 Tm. Kicker magnets shall generate a total integral field of 57.8 mT during 500 ns with rise- and fall-times of less than 220 ns. To produce the neceassary injection field, a current pulse of up to 4000A/70 kV has to be sent through the magnets. Since the injection process using longitudional stacking should not destroy the stored beam, special attention has been paid to the flatness of the current pulse at flat-top ([I-I_0]/I_0<0.08) and to the current variation after ramp down (<10 A). All the challenges of the kicker design have been successfully solved and the kicker system of the HESR has been produced. The system consist of four kicker magnets in two UHV tanks and one solid-state pulser with control system for every magnet. The pulsers, connected with magnet using a coaxial cable in Blumlein topology, are made of commercially available semiconductor based switches. Using a special tuning procedure the designed requirements for the pulse shape have been succesfully met. Main details of the designed system, achieved parametes and solutions used in the produced injection kicker system will be presented in this contribution.
Paper: THPA167
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA167
About: Received: 03 May 2023 — Revised: 22 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPA175
Pulsed Magnets and Power Supplies for Injection & Extraction in the SOLEIL II Project
4377
Electron beam injection and extraction from the various stages of the SOLEIL II accelerator complex will be performed in three different locations, as it is done today. Injection of the LINAC beam into the upgraded booster and then its extraction use traditional on-axis & on-momentum schemes with single turn kickers and septum magnets*. The main Top-Up injection scheme in the storage ring** will use an off-axis & on-momentum betatron injection scheme. In particular, this scheme requires the design of a new type of Multiple Injection Kicker (MIK) which significantly differs from the current generation. This article presents the technical proposals and design constraints for the pulsed magnets and power supplies – dipole kicker, MIK and septum magnets - foreseen in the upgrade of SOLEIL.
Paper: THPA175
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA175
About: Received: 30 Apr 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPL065
Optimisation of a gas jet-based beam profile monitor for high intensity electron beams
4576
A beam profile monitor using gas jet technology is being designed and manufactured at the Cockcroft Institute for high intensity electron beams. It generates a thin, supersonic gas sheet that traverses the beam at a 45-degree orientation and measures the beam-induced fluorescence interactions to produce a 2D beam profile image. The gas sheet acts similar to a scintillating screen, but remains non-invasive. This contribution summarises the method developed towards optimising the injection of a gas jet monitor for the example use-case of the Hollow Electron Lens. A multi-objective genetic algorithm is used with a Monte-Carlo particle tracking simulation to optimise the geometric features of the jet injection chambers. The algorithm optimises for several key features of the jet that will improve it as a diagnostic tool. Specifically, at the point of interaction, the jet’s density, uniformity and geometric dimensions are considered. The work developed in this contribution is not limited to diagnostics and can be expanded upon in other disciplines such as plasma wakefield gas injections.
Paper: THPL065
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL065
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
THPL085
Calibration of the LHC Diamond beam loss monitors for LHC Run 3
4641
A set of twelve Polycrystalline Chemical Vapour Deposition (pCVD) diamond detectors are installed in the beam injection, extraction and betatron collimation areas of the Large Hadron Collider (LHC) as fast beam loss monitoring detectors. Their high-radiation tolerance and time resolution in the order of a few ns makes them an ideal candidate to monitor bunch-by-bunch losses in the LHC beams, which have a nominal bunch separation of 25 ns. Considering their location in some of the most critical areas for beam loss studies, a signal-to-lost-particle calibration of these detectors provides a useful insight of the various LHC bunch-by-bunch beam loss mechanisms. This contribution shows the principle of the calibration of the LHC diamond Beam Loss Monitors (dBLMs) as well as a description of the machine tests run to study and perform this calibration.
Paper: THPL085
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL085
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPL105
Improvement of the longitudinal phase space tomography at the J-PARC synchrotrons
4710
The longitudinal phase space tomography, which reconstructs the phase space distribution from the one-dimensional bunch profiles, is used in various accelerators to measure longitudinal beam parameters. At the J-PARC, an implementation of the phase space tomography based on the convolution back projection method has been used to measure the momentum spread of the injected beam. The method assumes that the beam distribution rotates without significant deformation during the synchrotron oscillation. Because of the nonlinearity of synchrotron motion with sinusoidal RF voltage, the method can be used only in limited situations such as small amplitude synchrotron oscillation. Algebraic Reconstruction Techniques (ART) in conjunction with particle tracking, which is implemented in CERN's tomography code, allows accurate reconstructions even for nonlinear large amplitude synchrotron oscillations. We present the overview of the application of CERN's tomography code to the J-PARC synchrotrons. The results of benchmarking are also reported.
Paper: THPL105
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL105
About: Received: 29 Mar 2023 — Revised: 16 Jun 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPL116
Observation of beam emittance reduction due to gas sheet injection for beam profile measurement
4739
To realize more stable operation of a high-intensity ion beam accelerator with a minimum beam loss, we have developed a non-destructive beam profile monitor detecting photons produced by interaction between the beam and a gas sheet injected into the beam line. The gas-injection-type profile monitor should induce scattering of the beam particles, and the beam emittance is considered to become larger. On the other hand, the beam-gas interaction may also induce space-charge neutralization of the beam. The plasma produced by the beam-gas interaction cancels the electric potential of the beam, and emittance growth due to the beam space-charge force is inhibited; the emittance relatively becomes small. To evaluate the effect of gas sheet injection on the beam, we have measured the phase space distribution of the 3 MeV, 60 mA H- ion beam with/without the gas sheet injection. As the result, the root mean square value of the beam emittance was constant or decreased against the increase in the amount of the injected gas-sheet flux.
Paper: THPL116
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL116
About: Received: 09 Mar 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
THPL142
Bunch-by-bunch transverse position measurement during injection
4802
Bunch-by-bunch systems are developed at the Taiwan Light source and the Taiwan Photon source to monitor the transverse position and filling pattern. This system consists four channels with 500 MHz sampling rate which synchronizes with the radio frequency of the accelerator. This system is used to diagnose the injection transition due to the kick mismatch and beam oscillation coming from the damped betatron oscillation and wake field.
Paper: THPL142
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL142
About: Received: 27 Apr 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPM015
Beam-beam long range compensator mechanical demonstrator
4916
Beam-Beam Long-Range Compensators employing current-carrying wires are considered as valuable options in hadron colliders to increase dynamic aperture at small crossing angles. This paper presents a simple design proposal for application at CERN LHC. The preliminary design allows for a certain scalability of the number of modules, current flowing in the wire, and dimensions. It complies with two key requirements: (a) the use of a thin, bare metal wire that allows for movement as near to the beam as necessary while minimising interactions with beam particles and meeting the specified DC current target; and (b) a wire support that is both an electrical insulator and a thermal conductor (ceramic). A molybdenum wire, vacuum brazed on an aluminium nitride support, is proposed, and the design is conceptually proved through the realisation and extensive test of a demonstrator device. The wire brazing validation, as well as the system's heat management, which are the most critical aspects, are given particular regard.
Paper: THPM015
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM015
About: Received: 10 May 2023 — Revised: 11 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
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
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
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