quadrupole
MOPC15
Study of the corrector systems for the new lattice of the CERN hadron-hadron Future Circular Collider
79
A new layout for the energy-frontier hadron collider (FCC-hh) under study at CERN has been designed, following the constraints imposed by the outcome of recent tunnel placement studies. The new lattice and the need to maximize the dipole filling factor triggered a deep revision of the corrector systems located in the regular arcs, such as orbit, tune, linear coupling, and chromaticity correctors. The system of octupoles aimed at providing Landau damping has also been reviewed. Furthermore, the corrector package in the experimental insertion aimed at compensating the field quality of the triplet quadrupoles has been reconsidered in view of the experience gained with the design of the corresponding system developed for the CERN HL-LHC. In this paper, an account of this review is presented and discussed in detail. These estimates will need confirmation when the magnet design of the various correctors will be studied.
Paper: MOPC15
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC15
About: Received: 13 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPC64
Recycling magnets for the EIC electron storage ring
211
The Electron Storage Ring (ESR) of the Electron-Ion Collider requires some 400 quadrupoles and 200 sextupoles, plus dipole magnets and correctors. In an effort to reduce cost and relax the demand on the magnet vendor pool, used quadrupoles and sextupoles of the Advanced Photon Source at Argonne National Laboratory will be refurbished and installed in the ESR.
Paper: MOPC64
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC64
About: Received: 07 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPC75
Progress on the design of the interaction region of the Electron-Ion Collider EIC
238
We present an update on the design of the Interaction Region (IR) for the the Electron Ion Collider (EIC) being built at Brookhaven National Laboratory (BNL). The EIC will collide high energy and highly polarized hadron and electron beams with a center of mass energy up to 140 GeV with luminosities of up to 10^34 /cm^2/s. The IR, located at RHIC's IR6, is designed to meet the requirements of the nuclear physics community as outlined in [1]. A second IR is technically feasible but not part of the project. The magnet apertures are sufficiently large to allow desired collision products to reach the far-forward detectors; the electron magnet apertures in the rear direction are chosen to be large enough to pass the synchrotron radiation fan. In the forward direction the electron apertures are large enough for non-Gaussian tails. The paper discusses a number of recent recent changes to the design. The machine free region was recently increased from 9 to 9.5 m to allow for more space in the forward direction for the detector. The superconducting magnets on the forward side now operate at 1.9 K, which helps crosstalk and space issues.
Paper: MOPC75
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC75
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPC80
Global betatron coupling compensation for the hadron storage ring of the Electron-Ion Collider
258
The Electron Ion Collider (EIC), to be constructed at Brookhaven National Laboratory, will collide polarized high-energy electron beams with hadron beams, achieving luminosities up to 1e+34 cm^−2 s^−1 in the center-mass energy range of 20-140 GeV. The Hadron Storage Ring (HSR) of the EIC will utilize the arcs of the Relativistic Heavy Ion Collider (RHIC) and construct new straight sections connecting the arcs. In this article, we will examine all available skew quadrupoles currently in the HSR lattice and explore possible schemes for future global betatron coupling correction with RHIC-like decoupling feedback system. The effects of detector solenoids and quadrupole rolls are estimated at injection and stored energies. We also studied the decoupling requirements for generating and maintaining large transverse emittance ratio beams in the HSR.
Paper: MOPC80
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC80
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPC82
Dynamic aperture of the EIC electron storage ring
266
Design of the electron-ion collider (EIC) at Brookhaven National Laboratory continues to be optimized. Particularly, the collider storage ring lattices have been updated. Dynamic aperture of the evolving lattices must be kept sufficiently large, as required. In this paper, we discuss the collider Electron Storage Ring, where the lattice updates include improvements of the interaction region layout and arc dipole configuration, reduced number of magnet types, and changes related to the use of existing magnets. Optimization of non-linear chromaticity correction for an updated 18 GeV lattice and the latest estimates of dynamic aperture with errors are presented.
Paper: MOPC82
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC82
About: Received: 16 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPG02
An update on EIC rapid cycling synchrotron optics
285
The Electron-Ion Collider (EIC) requires continuous replacement of the stored electron bunches to facilitate arbitrary spin patterns in the Electron Storage Ring (ESR). This is accomplished by a dedicated, spin transparent Rapid Cycling Synchrotron (RCS). The dynamic range of the accelerator is from 400 MeV to 18 GeV. To maintain stability throughout the acceleration ramp, the linear and nonlinear optics must be tuned accordingly. In this paper, we will discuss the updated linear optics, chromaticities, and dynamic aperture of the RCS.
Paper: MOPG02
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG02
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPG08
Beam-based alignment simulations for the Future Circular Collider electron lattice
308
Parallel beam-based alignment (PBBA) techniques can be used to determine the magnetic centers for multiple magnets with simultaneous measurements and are much faster than traditional methods which target one magnet at a time. The PBBA techniques are very desirable for commissioning larger machines such as the Future Circular Collider (FCC). In this study, we applied PBBA techniques on quadrupoles and sextupole magnets for the FCC-ee lattice in simulations. Improvements to the PBBA techniques were made. It is shown that sub 10-micron accuracy for quadrupoles and sub 20-micro accuracy for sextupoles can be achieved.
Paper: MOPG08
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG08
About: Received: 10 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPG17
First commissioning of the corrector quadrupoles in the 2nd bunch compression chicane at FLASH
339
FLASH, the superconducting XUV and soft X-ray FEL is undergoing a substantial upgrade (FLASH2020+) with two long shutdowns 2021/22 and 2024/25. In the 1st shutdown, FLASH's 2nd bunch compression chicane (BC2) has been completely redesigned for the FLASH2020+ upgrade project. The redesign allowed the installation of two quad/skew-quad packs in each of the arms of the 4-dipole (C-type) chicane. With these corrector quadrupoles it should be possible to partially compensate linear correlations between the transverse centroids and the longitudinal position inside the bunch, so called bunch-tilts. During the limited commissioning/development shifts in a year of operation devoted to maximizing user hours we started measuring the impact of the quads on the bunch tilts and the unavoidable effects on dispersion closure and beam optics. In this contribution we report first results.
Paper: MOPG17
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG17
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
MOPR01
Lattice design of a pulsed synchrotron for a muon collider fitting within the Fermilab site boundary
448
A muon collider allows one to have a high energy reach for physics studies while having a relatively compact footprint. Ideally such a machine would accelerate muon beams to about 5 TeV. We present a preliminary lattice design for a pulsed synchrotron that will accelerate muon beams to their maximum collision energy and having a circumference of 16.5 km, which would allow it to fit just within the Fermilab site boundary. We wish to estimate the maximum energy that muons can be accelerated to on the Fermilab site based on a realistic lattice layout. To achieve a high average bend field, superconducting fixed field dipoles are interleaved with iron-dominated dipoles whose field is rapidly ramped from negative to positive field. Multiple RF stations are required to ensure that the beam energy and the dipole fields are reasonably well synchronized and to avoid longitudinal losses due to the large synchrotron tune. We use FODO arc cells with dispersion suppressed into the RF straights. We will discuss tradeoffs between maximum energy, energy range, and muon decays. We will consider whether to mix superconducting and iron quadrupoles like the dipoles.
Paper: MOPR01
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR01
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
MOPR10
Quadrupole field instability in cylindrical dielectric wakefield accelerators
478
Dielectric Wakefield Acceleration is a technology under active research, providing the potential to accelerate charged particle bunches with gradients much greater than conventional RF-based metallic cavities. The stability of driving bunches needs to be solved before practical applications are seen. Strong transverse fields are known to be excited in DWAs, with previous research focusing on mitigating single-beam breakup instability (BBU) induced when a beam propagates off-center due to orbit-jitter or misalignment. It is also known that quadrupole-like fields are excited in planar/slab DWA structures and research has been conducted on mitigating this effect. We present simulation results that demonstrate quadrupole-like fields are also excited in circular DLWs, induced by beam astigmatism. We have shown that this in an extra source of instability within circular DWA structures and calculate the size of the fields excited as a function of beam astigmatism.
Paper: MOPR10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR10
About: Received: 14 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
MOPR22
Microbunching instability test for emittance exchange-based photoinjector
500
Previous start-to-end simulations of an emittance exchange (EEX)-based photoinjector have demonstrated highly attractive beam properties. The EEX-based photoinjector can provide another interesting opportunity that potentially eliminate the microbunching instability issue. The space-charge and/or CSR-induced amplification occurs during density-to-energy and energy-to-density modulation conversion process. This amplification becomes particularly pronounced when multiple compressors are implemented. In contrast, the proposed EEX-based photoinjector doesn’t require additional compression process. Moreover, the initial longitudinal phase space becomes the transverse phase space, resulting in a significant reduction of space-charge and CSR’s longitudinal interaction. We present preliminary simulation results of microbunching instability in EEX-based photoinjector.
Paper: MOPR22
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR22
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPR57
Automated emittance and energy gain optimization for plasma wakefield acceleration
569
At the Facility for Advanced Accelerator Experimental Tests (FACET-II) accelerator, a pair of 10 GeV high-current electron beams is used to investigate Plasma Wakefield Acceleration (PWFA) in plasmas of different lengths. While PWFA has achieved astonishingly high accelerating gradients of tens of GeV/m, matching the electron beam into the plasma wake is necessary to achieve a beam quality required for precise tuning of future high energy linear accelerators. The purpose of this study was to explore how start-to-end simulations could be used to optimize two important measures of beam quality, namely maximizing energy gain and minimizing transverse emittance growth in a 2 cm long plasma. These two beam parameters were investigated with an in-depth model of the FACET-II accelerator using numerical optimization. The results presented in the paper demonstrate the importance of utilizing beam-transport simulations in tandem with particle-in-cell simulations and provide insight into optimizing these two important beam parameters without the need to devote significant accelerator physics time tuning the FACET-II accelerator.
Paper: MOPR57
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR57
About: Received: 14 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPR64
Flat beam transport for a PWFA experiment at AWA
580
Particle beams with asymmetric transverse emittances and profiles have been utilized in facilities for driving wakefields in dielectric waveguides and to drive plasma wakefields in plasma. The asymmetric plasma structures created by the beam produce focusing forces that are transversely asymmetric. We utilize the ellipticity of the plasma ion cavity to model the beam evolution of the flat beam driver.
Paper: MOPR64
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR64
About: Received: 17 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPS15
Symplectic modeling of ALS-U bending dipoles using 3D magnetic field data
733
The Advanced Light Source Upgrade (ALS-U) is a 2 GeV high-brightness, nine-bend achromat storage ring, designed to reduce the natural emittance relative to the existing ALS by a factor of 20 for improved x-ray coherent flux and brightness. The upgrade includes the installation of an accumulator ring of the same energy as, and slightly smaller circumference than, the storage ring. The bending dipoles provide special challenges for accurate symplectic modeling, such as the combination of large sagitta and magnet narrow vertical aperture (in the accumulator ring) and overlapping fringe fields (in the main ring). We describe a procedure for the calculation of symplectic maps for the ALS-U dipoles using robust surface-fitting methods based on 3D finite-element field data, including a discussion of vector potential gauge choice and model-dependent effects on the lattice chromaticity.
Paper: MOPS15
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS15
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPS56
Imparting arbitrary correlation on longitudinal phase space using transverse wigglers and deflecting cavities
844
Imparting designed nonlinear correlation on the longitudinal phase space is nontrivial task. While RF cavities operating at different frequencies can generate arbitrary correlation in principle, it is hard to realize such system due to the lack of RF power sources and their costs. We present a new method that may overcome such practical limitation by adopting transverse wigglers and transverse deflecting cavities. Deflecting cavities introduce and eliminate linear correlation between longitudinal and transverse coordinates. We located transverse wigglers, which impart arbitrary correlation on the transverse phase space, where the longitudinal-to-transverse correlation is maximized. In principle, this system only requires deflecting cavities operating in the same frequency and several magnets such as transverse wigglers and quadrupoles.
Paper: MOPS56
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS56
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
TUPC05
Correction of horizontal partial snake resonances with pulsed skew quadrupoles at the Brookhaven AGS
1000
Proton polarization is preserved in the AGS by using helical dipoles partial snakes to avoid depolarizing vertical resonances. These same helical dipoles also drive numerous (82) weak horizontal resonances that result in polarization loss. These horizontal resonances occur at the same energy (and therefore frequency) as depolarizing resonances driven by linear betatron coupling. A new scheme has therefore been implemented to correct the snake-driven resonances with the placement of skew quadrupoles in the AGS ring powered to cancel the resonance driving term at each horizontal resonance crossing. The skew quadrupoles are required to pulse independently for each resonance to account for the variation of drive term phasing with energy. Fifteen thin skew quadrupoles have been installed in the AGS ring to implement this correction. We describe the correction principle, the magnet design and commissioning results from RHIC Run 24.
Paper: TUPC05
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC05
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPC15
Energy dependence of PS main unit harmonics
1036
CERN Proton Synchrotron (PS) is featured with 100 C-shaped combined-function Main Units (MUs) magnets with a complicated pole shape. The operation and the modelling of the PS-MUs has been historically carried out with empirical beam-based studies. However, it would be interesting to understand whether, starting from a proper magnetic model and using the predicted harmonics as input to optics simulations, it is possible to accurately predict the beam dynamics behavior in the PS, and assess the model accuracy with respect to beam-based measurements. To evaluate the magnetic model quality and its predictions, bare-machine configurations at different energies were prepared, where only the Main Coil is powered and the additional circuits are off. In this paper, a comparison of tunes and chromaticity measurements with the predicted optics is reported, showing the saturation of the quadrupolar and sextupolar components at high energy, which affect these quantities.
Paper: TUPC15
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC15
About: Received: 13 May 2024 — Revised: 23 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
TUPC67
Progress in the design of the future circular collider FCC-ee interaction region
1156
In this paper we discuss the latest developments for the FCC-ee interaction region layout, which represents one of the key ingredients to establish the feasibility of the FCC-ee. The collider has to achieve extremely high luminosities over a wide range of center-of-mass energies with two or four interaction points. The complex final focus hosted in the detector region has to be carefully designed, and the impact of beam losses and of any type of synchrotron radiation generated in the interaction region, including beamstrahlung, have to be evaluated in detail with simulations. We give an overview of the progress of the whole machine-detector-interface-related studies, among which are the updated mechanical model of the interaction region, the plans for a novel R&D activity of a IR mockup which is just starting, the collimation scheme and evaluation of beam induced backgrounds in the detectors, evaluation of radiation dose in the experimental area, and MDI integration with the detector.
Paper: TUPC67
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC67
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC68
Alternative solenoid compensation scheme for the FCC-ee interaction region
1160
We present the optics design of the solenoid compensation scheme at the FCC-ee. The 2T solenoids from the experiments induce coupling on the beams, generating an increase on vertical emittance. This compensation scheme minimizes emittance growth, with a final value of approximately 5% of the nominal.
A screening solenoid is placed around the Final Focus Quadrupoles to protect them from the experiment’s field.
A skew quadrupole component is added to the Final Doublet, aligning the magnet axis to the rotated reference frame of the beam.
Two anti-solenoids placed approximately ±20 m from the IP are used to cancel the field integral. The vertical orbit generated by the horizontal crossing angle in the detector field is compensated by vertical correctors placed right after the beam pipe separation and next to the final focus quadrupoles.
We describe the IR optics in this scheme, including the detector solenoid and the magnetic elements used for compensation.
Paper: TUPC68
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC68
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC70
Effects of dipole power converter ripple during empty-bucket channelling
1168
In 2023, an RF technique known as empty-bucket channelling was implemented operationally at the CERN Super Proton Synchrotron (SPS) to improve the quality of the spill provided to the North Area experiments. Empty-bucket channelling suppresses particle-flux variations during resonant slow extraction by accelerating particles between empty RF buckets and rapidly displacing particles into the tune resonance via chromatic coupling. The flux variations are often caused by the power converter ripple present in the synchrotron’s magnets, which modulates the beam dynamics during the extraction process. In a chromatic extraction, the quadrupole ripple is the main contribution to the modulation as it directly perturbs the transverse tune. When empty-bucket channelling is applied, however, dipole ripple additionally modulates the size of the empty RF bucket. In this contribution, the phenomenon is explored and the consequences for empty bucket channelling in the SPS are outlined.
Paper: TUPC70
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC70
About: Received: 30 Apr 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPC71
Optics rematching between TT24 and P42 primary beam lines within the HI-ECN3 study project at CERN
1172
The High Intensity ECN3 (HI-ECN3) study project aims to increase the intensity of the proton beam delivered to a new experimental facility housed in the ECN3 underground cavern in CERN’s North Area up to the ~4e+13 ppp (protons per pulse) and up to ~4e+19 POT (protons on target) per year. The increase necessitates upgrades of the primary beam transfer lines coming from SPS directly to the new Target Complex upstream of ECN3. In this work we describe the modifications to the primary beam line optics that allow the transfer of the beam to the HI-ECN3 facility in two scenarios: shared (beam is split between the three existing production targets) and dedicated (beam goes directly to the target serving ECN3). An optimization study is presented to reduce the sensitivity of the beam optics to errors and minimize the effects of the beam’s interaction with material when transiting the existing target area between TT24 and P42, whilst respecting the different constraints needed to share the beam between ECN3 and the rest of the North Area and permit a vertical trajectory bump around the target serving EHN1.
Paper: TUPC71
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC71
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC74
Characterisation of the optics of the TT24 and P42 beamlines in the CERN SPS north area
1184
400 GeV protons extracted from the CERN SPS are transported to the T4 target via the TT20 transfer line. The P42 beamline then transports the protons that did not interact in the T4 target to the T10 target. During operation in 2021 and 2022, higher than expected beam losses were measured, in addition to an increased beam spot size that had previously been observed. It was suspected that the optics between TT24 and P42 might not be well matched but due to a lack of instrumentation this was not confirmed. The recent installation of additional beam profile monitors (BSG) in the P42 beamline has allowed the present optics to be evaluated for the first time. In addition, magnet response functions have been measured and updated. A kick response study was performed using corrector dipoles to kick the beam with the subsequent displacement measured on the BSGs. The dependence between the kick and the beam position was used to fit a MADX optics model of TT24 and P42. Quadrupole scans were then performed to determine the initial conditions of the model. These results are presented in this paper.
Paper: TUPC74
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC74
About: Received: 14 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPG10
Preliminary lattice design for Australian Synchrotron 2.0
1239
A new project is underway to develop the successor to the current Australian Synchrotron. The new storage ring is proposed to be 455 m in circumference operating at 3 GeV. A preliminary 7BA lattice has been designed which utilizes the higher-order achromat (HOA) scheme to suppress strong sextupole driving terms. The lattice has 24 sectors and a natural horizontal emittance of 50 pm-rad. This is achieved using a combination of strong combined function magnets and reverse bending magnets in the unit cell, as well as careful tuning of the bending angles to preserve positive momentum compaction factor. The dynamic aperture, momentum aperture and Touschek lifetime have been optimized by tuning the linear optics and sextupole strengths with a multi-objective genetic algorithm.
Paper: TUPG10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG10
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPG20
Numerical optimization of the Diamond-II storage ring optics
1254
The design performance of the 3.5 GeV Diamond-II low-emittance electron storage ring has been studied as a function of the linear and nonlinear lattice tuning parameters. An alternative working point has been identified which optimizes the beam lifetime and the injection efficiency for off-axis injection. The simulations include misalignment and field strength errors, with the number of machine seeds tuned to achieve converging results whilst minimizing computational time. The optimization takes care to preserve the design beam emittance, energy spread, Twiss parameters and cell tunes. The results are presented for 2D parameter scans and exploring the null space of the chromaticity response matrix.
Paper: TUPG20
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG20
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
TUPG22
Full simulations of the Diamond-II storage ring commissioning and possible improvements of procedures
1262
To provide confidence in the future commissioning of the Diamond-II storage ring, realistic specifications for the error tolerances have been established. Based on these values, commissioning simulations have been conducted starting from on-axis injection through to stored beam and finally the alleviation of beta-beating caused by insertion devices. The goal of these studies is to develop a robust commissioning procedure that stays within the magnet strength limits using the statistics of many random machines simulated. In this paper we summarize these studies and present the results at each stage. Other topics such as testing on Diamond and comparisons of alternative commissioning methods are also discussed.
Paper: TUPG22
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG22
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPG27
Parallel beam-based alignment for the EBS storage ring
1278
The parallel beam based alignment technique developped at SLAC is applied for the EBS storage ring. The results are compared with the standard beam based alignment technique used for operation.
Paper: TUPG27
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG27
About: Received: 10 May 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024
TUPG33
Investigations in turn-by-turn optics measurements at KARA
1294
The Karlsruhe Research Accelerator (KARA) is a synchrotron light source user and test facility, operating at an electron beam energy ranging from 0.5 to 2.5 GeV. Performing optics measurements and comparing with the machine model promises an improved understanding of the lattice and the underlying beam dynamics. Horizontal and vertical turn-by-turn Beam Position Monitor data are acquired and used for performing optics measurements in this storage ring. The results of these studies are presented in this paper.
Paper: TUPG33
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG33
About: Received: 13 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPG54
Comparison of BBA methods for commissioning of fourth generation light sources
1369
Beam based alignment (BBA) plays an important role in the commissioning of the fourth generation light source but it takes a lot of time with several hundreds of BPMs. To speed up BBA, a method using AC excitation, called fast BBA, has been proposed and is tested in several 3rd generation light sources. We have recently also proposed and tested a new BBA based on the neural network machine learning. In this paper, we will compare these new BBAs with conventional BBA in term of error, speed and some other aspects such as the betatron coupling.
Paper: TUPG54
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG54
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPG60
Dynamic aperture in a wiggler dominated ring electron cooler of the EIC
1390
The Ring Electron Cooler (REC) is currently under design for use in the Electron Ion Collider (EIC) for hadron cooling. In this device the hadrons are cooled by the electrons and the electrons are cooled through radiation damping, which is enhanced by a number of 4 meter-long wigglers with 2.4 T field. When optimizing the beam envelope, intra beam scattering and Touschek scattering are also considered. Using a field configuration with additional focusing to keep the emittance at an acceptable value, these wigglers make up a substantial portion of the ring, with the wiggler section contributing the majority of the ring’s chromaticity. In this paper, the effects of the REC’s unusual properties on dynamic aperture are analyzed and a correction scheme is proposed.
Paper: TUPG60
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG60
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPR40
Development of prototype magnets for the ultralow emittance storage ring ALBA II
1502
The ALBA synchrotron light source is in the process of a significant upgrade, aiming to become a fourth-generation facility by reducing its emittance by at least 20 times. The initial phase of this project involves a comprehensive prototyping program designed to validate various critical technologies, such as magnets, vacuum systems, girders, etc., essential for facilitating the impending upgrade. This paper focuses on the development of the prototype magnets to implement the MBA lattice designed by our Beam Dynamics group. The lattice presents unique challenges, notably a remarkable degree of compactness necessitating magnet-to-magnet distances of just a few centimeters. Additionally, stringent strength requirements are imposed on both the quadrupolar (up to 110 T/m) and the sextupolar (up to 5000 T/m²) magnets. In this paper we will describe the design details of the initial set of resistive-type prototypes, as well as the preliminary efforts to develop alternative designs making use of permanent magnets. This dual-track approach reflects our dedication to both conventional methods and innovative solutions for the upgraded storage ring.
Paper: TUPR40
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR40
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPR42
Design, fabrication and measurements of a quadrupole wiggler prototype
1506
A quadruple wiggler consisting of a row of alternating polarity quadrupoles is used in a collinear wakefield accelerator under development at Argonne National Laboratory. We designed such a wiggler and fabricated a prototype consisting of four quadrupoles. The permanent magnet-excited quadrupole has a bore diameter of 3 mm, a length of 25 mm, and a peak magnetic field gradient of 0.94 T/mm. Fine translational and angular adjustment mechanisms were implemented in all quadrupoles to obtain better than one-micrometer alignment of the quadrupole wiggler assembly. The quadrupole wiggler prototype was measured and aligned employing the pulsed wire technique. We describe the design, fabrication, and alignment of this quadrupole wiggler prototype and describe the influence of the ambient temperature on the quadrupole wiggler alignment.
Paper: TUPR42
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR42
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPR44
Progress on the normal conducting magnets for the Electron-Ion Collider
1514
The electron-ion collider (EIC) at Brookhaven National Laboratory (BNL) is designed to deliver a peak luminosity of 1e+34 1/cm2 1/sec. The EIC will take advantage of the existing Relativistic Heavy Ion Collider (RHIC) facility. Two additional rings will be installed: an electron storage ring (ESR) and a rapid cycling electron synchrotron ring (RCS). This paper presents an update on the normal conducting magnet designs required for both the ESR and RCS rings. The ESR will store polarized electron beams up to 18 GeV and utilizes a triplet of dipole magnets to increase the emittance at 5 GeV and generate excess bending to create additional radiation damping to allow a larger beam-beam tune shift. The RCS will accelerate single bunches of spin-polarized electrons at various energies from 5 GeV to 18 GeV, with a ramp rate of 100 ms and 1 Hz repetition rate. Both rings require dipole, quadrupole and sextupole magnets with different specifications.
Paper: TUPR44
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR44
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPR47
Magnetic design of non-linear kicker for ESRF-EBS
1524
The ESRF-EBS injection is performed with a standard off-axis injection scheme consisting of two in-air septa S1/2, one in vacuum septum S3 and four kicker magnets K1 to K4 to generate the injection bump. We can achieve 80% efficiency with this scheme. Despite many modifications and adjustments which allow the reduction of the perturbation, some beamlines are still affected. The Non-Linear Kicker could be a solution to this problem because it acts only on the injected beam. This paper reports on the magnetic design of the Non-Linear Kicker, including the octupole like Magnetic field simulations, magnetic forces calculations and mechanical tolerance optimizations.
Paper: TUPR47
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR47
About: Received: 13 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPR53
Findings of simulation studies for the fast corrector magnets of PETRA IV
1544
Fourth-generation synchrotron radiation sources, which are currently being planned in several accelerator laboratories, require fast orbit feedback systems to correct distortions in the particle orbit in order to meet stringent stability requirements. Such feedback systems feature corrector magnets powered at frequencies up to the kilohertz range, giving rise to strong eddy currents. To understand the eddy current effects and the characteristics of these fast corrector magnets, elaborate finite element simulations must be conducted. This paper gives an overview of the most important findings of our simulation studies for the fast corrector magnets of the future synchrotron radiation source PETRA IV at DESY, Hamburg, Germany. Using a homogenization technique for the laminated yokes, we simulate the magnets over a wide frequency range.
Paper: TUPR53
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR53
About: Received: 05 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPR55
Research on design of a novel permanent quadrupole magnet
1552
Research on a novel permanent quadrpole magnet (PQM) design is introduced in this paper. It can make the quadrupole magnetic field gradient continuously adjustable by modulating several permanent magnet blocks. Four poles of the magnet inform an integral whole to ensure good structural symmetry, which is essential to obtain high-quality quadrupole magnetic field permanent quadrupole magnet. Series of simula-tion calculations have been done to study the effects of four distinct types of pole position coordinate errors on the central magnetic field. By juxtaposing these results with those derived from optimal design scenario of PQM, the study underscores the critical role that pole symmetry plays in this context. Two integrated design methodologies were proposed, with one of the designs undergoing processing and coordinate detection. The results indicate that this design, is capable of meeting the specified requirements. This design effectively ad-dresses the issue of asymmetrical pole installation, thereby ensuring to a certain extent that well-machined pole can generate a high-quality magnetic field.
Paper: TUPR55
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR55
About: Received: 13 May 2024 — Revised: 19 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPS02
Impact of beam screen eddy currents on transition crossing in the EIC HSR
1626
The Electron Ion Collider (EIC) hadron storage ring (HSR) requires a beam screen made of 75 μm copper layer on top of a 1 mm thick 316LN stainless steel sheet. The eddy currents produced by the dynamic fields at the beam screens of the transition jump quadrupoles will increase the field response delay. The field response curve depends on the thickness and Residual Resistivity Ratio (RRR) value of the copper layer. Manufacturing variances of thickness and RRR in the beam screens of the gamma transition quadrupole will result in different field response delays. This paper summarizes the effects from the beam screens on transition crossing. From the varying delays, the beta-wave and eta-wave may exceed typical RHIC values. The effectiveness of the jump will be estimated using simulations of the existing RHIC lattice.
Paper: TUPS02
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS02
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPS03
An update on the transition crossing schemes for the EIC hadron storage ring
1630
The Electron Ion Collider (EIC) Hadron Storage RIng (HSR) requires the crossing of transition for all species except for protons. The current scheme for the Relativistic Heavy Ion Collider (RHIC) utilizes the gamma transition quadrupoles will be adopted for the scheme of the HSR. With rebuilt straight sections, the jump quadrupoles responsible for tune compensation will need to be placed at the proper phase advance to mitigate the beta and dispersion waves generated. As an alternative method, the beam may be nonadiabatically kicked into a stable resonance island to place the beam above transition. This paper discusses transition crossing using the matched first order method and resonance island jump schemes applied to the latest HSR lattice.
Paper: TUPS03
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS03
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS12
Final preparation of accelerated and polarised protons at COSY Jülich
1657
2023 was the last year of operation for the Cooler Synchrotron (COSY) in Jülich, Germany. To prepare for the extraction of polarized protons at a momentum of 1950 MeV/c to an external target, full advantage of the most recent developments of the COSY control system was taken along with the established hardware of COSY. Challenges in beam development included the operation close to transition energy as well as seven depolarizing resonances (4 intrinsic and 3 imperfection resonances) which have to be crossed during the acceleration. To overcome the intrinsic resonances tune jumps were carried out with the Q-jump quadrupole system of COSY*. To identify the correct time window for the jump, the precise measurement of the tune** during the acceleration ramp was used. We present how the recent developments in the control system, along with the established techniques, enabled us to successfully accelerate and extract the polarized beam.
Paper: TUPS12
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS12
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
TUPS14
Tracking error analysis on the power supply currents of J-PARC main ring main magnets
1665
The bending, quadrupole, and sextupole power supplies in the J-PARC Main Ring (MR) have been upgraded ramping up the average beam power for fast extraction (FX) operation for the neutrino oscillation experiment and slow extraction (SX) operation for the experiments in the hadron facility. The repetition cycles have been shortened from 2.48 sec. to 1.36 sec. for the FX operation and will be soon shortened from 5.2 to 4.24 sec. for the SX operation. The current ripples in the power supply generate the electric current errors of the main magnets. A tracking error can also generate the electric current deviation for the main magnets. A rather large tracking error has been observed after the power supply upgrade. An equivalent circuit analysis for the output load has been conducted to examine the cause. The impact on the beam optics for the longitudinal and transverse beam motions will be discussed. A manipulation of the power supply to improve the tracking errors is tried in the equivalent circuit analysis.
Paper: TUPS14
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS14
About: Received: 16 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPS34
Superconducting magnet string test for the SIS100 accelerator of FAIR
1718
The SIS100 accelerator, currently under construction in Darmstadt (Germany), consists of six arc and straight sections. Each of the six cryogenic arc sections comprises fourteen regularly repeating optical cells (lattice). Each standard cell includes two dipole magnets and two quadrupole units integrated in a quadrupole doublet module. The SIS100 String Test technically represents one standard cell of the arc section of the SIS100, terminated by and End Cap and a Bypass Line as a representation of the end of the arc section. The purpose of the SIS100 String Test is to validate all technical systems such as cryogenics, vacuum, interlock and quench detection and investigate their collective behavior. A wide spectrum of tests will be performed during cool down, powering at operational conditions and warm up. Additionally, the experience gained during the SIS100 String Test will be crucial for the installation, commissioning and operation of the SIS100. The planning, installation process and first experimental results of the String Test will be presented.
Paper: TUPS34
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS34
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPS36
Vertical quadrupole electric field systematics and its mitigation in the proton-EDM ring
1726
With the present proton electric dipole moment (pEDM) storage ring design [1], the counter rotating (CR) beam closed orbits will separate vertically if there is a nonzero radial magnetic field Bx. If a quadrupole electric field Ey is also present, then its direction would be opposite for the CR beams hence it becomes a potential source for a false EDM signal. In this work, we model this non-zero stray radial magnetic field Bx as a field perturbation source and it would cause the closed orbit distortion around the pEDM ring. This EDM-like background is due to the product of the electric quad multipole and the closed orbit distortion. We found the difference of the precession rates for CR beams and quadrupole magnet polarity would be a cure to this systematics.
Paper: TUPS36
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS36
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS63
Overview of machine learning based beam size control during user operation at the Advanced Light Source
1816
The Advanced Light Source (ALS) storage ring employs various feedback and feedforward systems to stabilize the circulating electron beam thus ensuring delivery of steady synchrotron radiation to the users. In particular, active correction is essential to compensate for the significant perturbations to the transverse beam size induced by user-controlled tuning of the insertion devices, which occurs continuously during normal operation. Past work at the ALS already offered a proof-of-principle demonstration that Machine Learning (ML) methods could be used successfully for this purpose. Recent work has led to the development of a more robust ML-algorithm capable of continuous retraining and its routine deployment into day-to-day machine operation. In this contribution we focus on technical aspects of gathering the training data and model analysis based on archived data from 2 years of user operation as well as on the model implementation including the interface of an EPICS Input/Output Controller (IOC) into a Phoebus Panel, enabling operator-level supervision of the Beam Size Control (BSC) tool during regular user operation.
Paper: TUPS63
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS63
About: Received: 17 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
TUPS75
Orbit response matrix correction based on exploration enhanced evolutionary algorithm
1854
For a large ring, the response matrix contains tens of thousands of data points, allowing for a comprehensive representation of the ring’s linear optics. However, when it comes to fourth-generation diffraction-limited rings that utilize strong sextupoles and octupoles, the response matrix derived from closed orbit tracking is significantly influenced by nonlinearity. This nonlinearity poses challenges for the Linear Optics from Closed Orbit (LOCO) method in terms of matching lattice parameters and correcting lattice errors. In this study, we propose the utilization of an evolutionary algorithm that integrates multiple techniques to enhance exploration capabilities. By this, we aim to find the global optimal solution, which can effectively address the issues associated with the response matrix correction and achieve a larger dynamic aperture compared to the linear LOCO approach.
Paper: TUPS75
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS75
About: Received: 08 May 2024 — Revised: 19 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
WEPC20
Experimentally verified reduction of local reflection of traveling-wave accelerating structure by output coupler undercoupling
2003
Hefei Advanced Light Facility (HALF) injector comprises 40 S-band 3-meter traveling wave accelerating structures, capable of delivering electrons of full energy 2.2 GeV into the storage ring. To mitigate the emission degradation caused by dipole and quadrupole fields in the coupler cavity, the coupler design incorporates a racetrack and a short-circuit waveguide to eliminate this impact. This article presents an introduction to design of the traveling wave structure and the results of cold and high-power testing. We performed tuning and preliminary measurements on accelerating structure, resulting in meeting the single-cell phase deviation and accumulated phase deviation requirements of the project objectives while maintaining good measurement consistency.
Paper: WEPC20
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC20
About: Received: 05 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPC27
Implementing NOECO at NSLS-II
2030
With the recently implemented lattice tool LOCOM, which combines the precision of LOCO as well as the speed of multi-frequency AC-LOCO, it takes only a few minutes for the NSLS-II lattice measurement and correction of both linear optics and coupling. Besides, LOCOM can be applied to characterize linear optics at the extremely high chromaticity condition, thus, greatly speeding up the development of a new operational mode with x/y chromaticity of +10/+10. The high chromaticity lattice could potentially enable a reliable operation of the storage ring with high single-bunch current. Moreover, to characterize the errors of chromatic sextupoles with high precision, we are in the process of implementing the NOECO based on the LOCOM method. Preliminary simulation study indicates that 1-2% precision can be achieved for the calibration of chromatic sextupole errors. If such high accuracy can be achieved, it could potentially help in resolving some long-standing challenges of NSLS-II, e.g., the discrepancy between the designed and measured tune shift with amplitude. Finally, to have an independent crosscheck, we have implemented the TBT based ICA NOECO method with a confirmed 2% accuracy.
Paper: WEPC27
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC27
About: Received: 13 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPC38
Commissioning simulation for the HALF storage ring
2043
Hefei advanced light facility (HALF) is a fourth-generation light source under construction. Its storage ring is a diffraction-limited one with an energy of 2.2 GeV and an extremely low emittance of less than 100 pm·rad. The real storage ring is different from the ideal lattice due to various kinds of errors. Those errors come from many sources, like misalignment of components, imperfect magnetic fields, RF cavity, etc. Due to the strong nonlinear nature and small dynamic aperture of the HALF storage ring, those errors significantly increase the difficulty of its commissioning. To figure out the practical performance of the lattice with those errors, a start-to-end commission simulation is performed in this study, which also helps to generate effective commissioning process for the HALF storage ring.
Paper: WEPC38
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC38
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPG11
Demonstration of time-resolved diagnostic in coherent electron cooling pop experiment
2203
We present a demonstration of time-resolved diagnostics within the Coherent Electron Cooling (CeC) Pop Experiment. This technique utilizes a combination of a focusing lattice, transverse deflecting cavity, and YAG screen, along with unique analytical techniques, to precisely measure and analyze the longitudinal profile information of the CeC electron beams. Additionally, our measurement of slice quantities contains slice emittance, slice current, and slice Twiss parameters. Through comprehensive analysis of these key parameters, we acquire essential information that aids in the detailed control of the beam instability of the CeC electron beams. This ultimately enhances our understanding of beam dynamics and contributes to the optimization of performance within the Coherent Electron Cooling system.
Paper: WEPG11
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG11
About: Received: 13 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPG12
Measurements of the transverse beam emittance at the AREAL linac
2206
One of the main tasks for advanced experiments in modern accelerators is the generation of low-energy and high-brightness beams. The Advanced Research Electron Accelerator Laboratory (AREAL) is a linear electron accelerator based on a photocathode RF gun. The basic aim of this facility is to generate electron bunches of sub-picosecond duration with an extremely small beam emittance for ultrafast processes in advanced experimental studies in the fields of accelerator technology and dynamics, material and life sciences. In this paper, the current status and plans for further upgrades of the diagnostic system, along with the techniques used for transverse beam emittance measurements, are presented.
Paper: WEPG12
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG12
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPG22
Slice energy spread measurements of a 20 MeV electron beam at PITZ
2240
Due to improvements of the performance of FELs, the measurements of the beam’s slice energy spread is becoming increasingly important for optimization of the brightness. Of particular interest are measurements of the uncorrelated energy spread near the gun as this determines the lower limit of the energy spread for the rest of the machine. At the Photo Injector Test facility at DESY in Zeuthen (PITZ), the uncorrelated energy spread is measured of an electron beam generated from an L-band electron gun and accelerated to 20 MeV with a booster cavity. The energy spread of the central time slice is measured using a transverse deflecting structure (TDS) and a dispersive arm to image the longitudinal phase space. Scans of the TDS voltage and quadrupole strengths are used to remove the contributions from the TDS, transverse emittance, and imaging resolution. Presented is an overview of the measurement procedure, resolution, and results of measurements tests.
Paper: WEPG22
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG22
About: Received: 16 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPG37
Beam tomography using MCMC
2291
Beam tomography is a method to reconstruct the higher dimensional beam from its lower dimensional projections. Previous methods to reconstruct the beam required large computer memory for high resolution; others needed differential simulations, and others did not consider beam elements' coupling. This work develops a direct 4D reconstruction algorithm using Markov Chain Monte Carlo.
Paper: WEPG37
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG37
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPG41
Fermilab Booster beam emittances from quadrupole modes measured by BPMs
2307
The measurement of beam emittances by extracting the quadrupole mode signal from a 4 plate BPM was published at least 40 years ago. Unfortunately, in practice, this method suffers from poor signal to noise ratio and requires a lot of tuning to extract out the emittances. In this paper, an improved method where multiple BPMs are used together with better mathematical analysis is described. The BPM derived emittances are then compared with those measured by the Ion Profile Monitor (IPM). Surprisingly, the BPM measured emittances behave very well and are more realistic than those measured by the IPM.
Paper: WEPG41
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG41
About: Received: 13 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPG44
Using CT algorithm to reconstruct electron beams transverse phase space in HUST-UED
2319
Accurate beam emittance and transverse phase space measurement are crucial for obtaining high-quality sample information in Ultrafast Electron Diffraction (UED). Traditional methods rely on general initial assumptions about the electron beam's phase space and lack specific distributions. The transverse phase space reconstruction technique based on the Computed Tomography (CT) algorithm eliminates the need for prior assumptions, resulting in more precise measurements. In this paper, we utilize an Algebraic Reconstruction Technique (ART) algorithm for HUST-UED, enabling the reconstruction of the beam transverse phase space distribution at the sample location and further facilitating system optimization.
Paper: WEPG44
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG44
About: Received: 06 May 2024 — Revised: 16 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPR03
Simulated performance of FCC-ee IP tuning knobs
2453
The Future Circular electron-positron Collider (FCC-ee) is a proposed accelerator with 91 kilometres circumference that should serve as a Higgs and electroweak factory, with unprecedented luminosity. Unavoidable misalignments and field errors will generate optics errors at the interaction point (IP), whose effect will be amplified by the beam-beam collisions, which will make it challenging for the collider to reach its intended luminosity goals. Hence, there is a need for correction tools that will enable the precise correction of the optics at the IP, such as linear coupling parameters and spurious dispersion. This will be essential both for FCC-ee commissioning and during routine operation. This paper describes the construction, simulated effectiveness, and constraints of IP tuning tools.
Paper: WEPR03
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR03
About: Received: 13 May 2024 — Revised: 23 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
WEPR04
Relaxed insertion region optics and linear tuning knobs for the Future Circular Collider
2457
This paper provides updates on two essential toolsets designed to facilitate the tuning and commissioning processes of the Future Circular Collider (FCC): relaxed optics and linear tuning knobs specifically for the experimental insertion regions. Motivated by the imperative need for efficient tuning strategies, we outline the construction methodology for both toolsets and present initial studies demonstrating their efficacy. The paper discusses the significance of these tools in enhancing the operational capabilities of the FCC and presents early results showcasing their potential impact on the collider's performance during tuning and commissioning phase.
Paper: WEPR04
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR04
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPR10
First FCC-ee lattice designs with Nested Magnets
2477
The Future Circular Electron-Positron Collider (FCC-ee) represents a cutting-edge particle physics facility designed to further investigate the Z, W± and Higgs boson in addition to the top quark. The implementation of Nested Magnets (NMs) in the FCC-ee arc cells would maintain high luminosity and reduce its energy consumption. The use of these special magnets induces changes in the damping partition numbers. To mitigate this the dipole fields in focusing and defocusing quadrupoles have to be different. This solution gives rise to incompatibility problems for the machine layout between the different energy configurations as the optics is also changed. This problem is tackled by defining different bending and geometric angles for the NMs. The beam dynamics and performance aspects of the new lattice are studied in this paper.
Paper: WEPR10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR10
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPR11
Parameter space for the magnetic design of Nested Magnets in the FCC-ee arc cell
2481
The Future Circular Collider (FCC-ee) is designed to explore the Z and W± bosons, along with the Higgs boson and top quark, achieving exceptionally high luminosity. In order to minimize the energy lost per turn due to Synchrotron Radiation (SR) we explore the use of Nested Magnets (NMs) into the arcs cell. For this, it is necessary to explore the possible combinations of the different magnet types in the cell, namely: dipoles, quadrupoles and sextupoles. Specifications in terms of strength and alignment tolerances are reviewed in this paper.
Paper: WEPR11
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR11
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPR21
Update in the optics design of monochromatization interaction region for direct Higgs s-channel production at FCC-ee
2520
The FCC-ee could allow the measurement of the electron Yukawa coupling via direct Higgs s-channel production at ~125 GeV centre-of-mass (CM) energy, provided that the CM energy spread of this channel, can be reduced to about 5–10 MeV to be comparable to the width of the standard model Higgs boson. The natural collision-energy spread at 125 GeV, due only to synchrotron radiation (SR), is about 50 MeV. Its reduction to the desired level can be accomplished by means of “monochromatization”, e.g., through introducing non-zero dispersion of opposite sign at the Interaction Point (IP), for the two colliding beams. This nonzero dispersion at the IP (horizontal or vertical) could be generated by different methods, requiring or not modifications of the Final Focus System (FFS) Local Chromaticity Correction (LCC) system. In this paper we report and compare the different recent Interaction Region (IR) optics design of this new possible collision mode.
Paper: WEPR21
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR21
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPR22
Review of MAD-X for FCC-ee studies
2524
The design of the electron-positron Future Circular Collider (FCC-ee) challenges the requirements on optics codes (like MAD-X) in terms of accuracy, consistency, and performance. Traditionally, MAD-X uses a transport formalism by expanding the transfer map about the origin up to second order to compute optics functions and synchrotron radiation integrals in the TWISS and EMIT modules. Conversely, particle tracking uses symplectic maps to propagate particles. These approaches solve the same problem using different approximations, resulting in a mismatch between the models used for tracking and for optics. While in a machine like LHC these differences are not relevant, for FCC-ee, given the size and the sensitivity to phase advance, the different approaches lead to important differences in the models. For instance, a tapering strategy that matches the tunes for optics needs to apply approximations that would mismatch the tune in tracking and vice versa. In this paper, we show the effectiveness of advanced methods that bring the maps used for optics and tracking closer and that will be used to reduce the gap between optics and tracking models to an acceptable level for FCC-ee studies.
Paper: WEPR22
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR22
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPR46
Experimental designs of coherent synchrotron radiation in complex beams
2601
Coherent synchrotron radiation (CSR) is one critical beam collective effect in high-energy accelerators, which impedes the generation of high-brightness beams. The Argonne Wakefield Accelerator (AWA) facility is unique in the experimental investigation of CSR effects in complex beams, offering a large parameter space for the bunch charge and size, various bunch profiles (round and flat beams), and the capability of generating shaped bunches through both laser shaping and the emittance exchange approach. This presentation will outline planned experiments at AWA and their designs, including a CSR shielding study using a dipole chamber with a variable gap size, and the effect of CSR on the beam phase space in a laser-shaped short electron bunch. This work is part of a comprehensive study involving self-consistent CSR code development and experimental investigation. The experimental component aims to provide benchmarking with the advanced codes under development, explore the boundaries of 1/2/3D CSR effects on beam dynamics, evaluate CSR effects in complex beams, and eventually propose CSR mitigation strategies.
Paper: WEPR46
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR46
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPR53
H- source characterization and transfer line studies with realistic EM fields in the ELENA decelerator at CERN
2616
A local H- /p source is operated at the CERN Extra Low Energy Antiproton (ELENA) decelerator for commissioning the ring and subsequent electrostatic transfer lines toward the experiments. For proper optics characterization, it is important to have a detailed knowledge of the H- beam parameters at the source. Phase space tomography techniques were applied to reconstruct the beam distribution at the measurement point, which was then tracked backward to the H- source using symplectic field maps to calculate the beam matrix. Due to the presence of an ion switch a highly non-linear behavior with significant deviation from the linear model was observed. The SIMPA tracking code allows EM fields in the transfer line to be treated continuously and as a whole.
Paper: WEPR53
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR53
About: Received: 08 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPR57
Simulations of incoherent effects driven by electron clouds forming in the inner triplets of the Large Hadron Collider
2627
During Run 2 and Run 3 of the Large Hadron Collider (LHC), slow losses from electron cloud (e-cloud) effects have been systematically observed during the full duration of fills with closely-spaced proton bunches. In particular, these effects had been found to depend strongly on the crossing angle of the two beams and the value of the betatron functions in the interaction points. Due to this observation, the main cause of this effect was attributed to the non-linear forces induced by electron clouds forming in the vacuum chamber of the LHC Inner Triplet quadrupole magnets. In this contribution, electron cloud buildup simulations reveal that the induced forces depend strongly on the transverse coordinates of the beam particles, on time, as well as on the longitudinal coordinate within the Inner Triplet. Finally, non-linear maps are generated based on the buildup simulations, and the effect of these forces on the motion of the protons is simulated.
Paper: WEPR57
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR57
About: Received: 14 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPR59
Developing nested auto-differentiation tracking code for beam dynamics optimization
2635
An innovative particle tracking code is in development using the Julia programming language, utilizing the power of auto-differentiation (AD). With the aid of specifically designed truncated power series algebra (TPSA) methods and built-in Julia AD packages, this code enables automatic calculation of derivatives with respect to selected parameters of interest. This tracking code provides a flexible and powerful solution for accelerator physicists applicable across various research topics, especially for beam dynamics optimization works.
Paper: WEPR59
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR59
About: Received: 13 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPR63
Development of novel magnetically-focussed minibeams for in vivo and in vitro end stations for LhARA
2649
Radiotherapy is an effective, non-invasive, widely used treatment for cancerous tumours that uses x-ray photon, electron and ion beam sources. The Laser-hybrid Accelerator for Radiobiological Applications (LhARA) is a novel laser-driven accelerator system under development that aims to prove the principle of the laser-driven approach to Particle Beam Therapy (PBT). This study aims at the development of a novel system to deliver different light ion minibeams to the in vivo and in vitro end stations. The desired minibeams will be delivered by magnetically focusing and steering the incoming proton and light ion beams, without the use of collimators. Minibeams with a diameter of approximately 1 mm spot will be delivered at an energy of 15 MeV to the in vivo and in vitro end stations. An update on the status of the development of this magnetic focusing technique will be presented here.
Paper: WEPR63
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR63
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPS62
Superconducting dipole for Elettra 2.0
2840
Elettra 2.0 is the 4th generation synchrotron light source that is going to replace Elettra, the 3rd generation light source operating for 30 years in Trieste Italy. The new ring will be giving light to the users in 2026 at 2.4 GeV. Three beam lines require very hard-x-rays i.e. photon energies at 50 keV or more with a flux of 1013 ph/sec and this can be achieved with a superconducting magnet at 6 T peak field. A new superconducting magnet is developed with an innovative compact design integrated with quadrupole side magnets. A new cryogenic solution will combine the benefits of a liquid-helium cooled inner magnet with a liquid-helium-free upper cooling stage. A C-shaped design will allow to slip in and slip out the magnet from its position on the storage ring vacuum chamber. A prototype of a new 6T superconducting magnet will be constructed and installed in the storage ring to replace a normal 1.4 T magnet allowing a full characterization of its performance. The NbTi superconducting magnet will work at 3.5K conduction cooled, using a system of heat exchanger connected to a subcooled Helium bath.
Paper: WEPS62
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS62
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
WEPS64
Measurement of integrated gradient and field quality on the first Q2 magnets for HL-LHC
2847
The Q2 insertion quadrupoles for the High Luminosity upgrade of the LHC are currently being produced and tested. The test of the first units provides valuable information about the field quality of superconducting accelerator magnets built from Nb3Sn coils. This paper presents the results of the magnetic measurements performed on the prototype and series magnets with emphasis on field quality and field repeatability. The stability of the integral gradient is analyzed in view of the final installation in the machine.
Paper: WEPS64
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS64
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPS65
The first superconducting final focus quadrupole prototype of the FCC-ee study
2851
A first FCC final focus quadrupole prototype has been designed, constructed and tested. The prototype is of a Canted Cosine Theta type using a NbTi conductor with novel features like edge compensation and wax impregnated. It has an aperture of 40 mm and a field gradient of 100 T/m. In this paper we recall the main design features and report on the test results on field quality and the powering campaign.
Paper: WEPS65
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS65
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPS67
Status of coil-dominated discrete-cosine-theta quadrupole prototype for high rigidity isotope beams
2854
Iron-dominated superconducting magnets are one of the most popular and used design choices for superconducting magnetic quadrupoles for accelerator systems. While the iron yoke and pole tips are economic and effective in shaping the field, the large amount of iron also leads to certain drawbacks, namely, unwanted harmonics from the sextupole correctors nested inside of quadrupole iron pole tips. Additional problems include the nonlinear field profile present in the high-field regime caused by the presence of steel, the cryogenic design challenges of the iron yoke being part of the cold mass, and the mechanical challenges of mounting the sextupole and octupole, which will generate significant forces for apertures of the size being proposed. The Facility for Rare Isotope Beams is developing a coil dominated quadrupole as a future upgrade, and the presented work discusses the advantages of using an iron-free quadrupole, along with the methods and choices of the design and the current status of prototype fabrication. The methods and work presented will include the model results and the aspects of the model that have been verified up to the current status of prototype fabrication.
Paper: WEPS67
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS67
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPS68
Development and test of a large-aperture Nb3Sn cos-theta dipole coil with stress management
2858
The stress-managed cos-theta (SMCT) coil is a new concept which was proposed and is being developed at Fermilab in the framework of US Magnet Development Program (US-MDP) for high-field and/or large-aperture accelerator magnets based on low-temperature and high-temperature superconductors. A 120-mm aperture two-layer Nb3Sn SMCT dipole coil has been developed at Fermilab to demonstrate and test the SMCT concept including coil design, fabrication technology and performance. The first SMCT demo coil was fabricated and assembled with 60-mm aperture Nb3Sn coil inside a dipole mirror configuration and tested separately and in series with the insert coil. This paper summarizes the design, parameters, and quench performance of the 120-mm aperture SMCT coil in a dipole mirror configuration.
Paper: WEPS68
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS68
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPS71
Superconducting magnets for SIS100 and Super-FRS at FAIR – overview and progress
2862
At the FAIR project in Darmstadt, Germany, superconducting magnets will be utilized for the main accelerator, the SIS100 heavy ion synchrotron, and for the fragment separator Super-FRS. For SIS100, the magnets are fast ramped with a rate of up to 4 T/s while large apertures are required for Super-FRS. In total, several hundred magnets need to be produced, qualified and characterized for the operation at FAIR. For both machines, series production is ongoing and testing programs at operational conditions have been established for quality assurance of the high demanding magnet modules. In the presentation, an overview is given on the design and operation principles of the various magnet types and module combinations. The complex project landscape involving several sites for production, module integration, and cold testing is pictured. The project progress and key testing results are highlighted and an outlook for the installation and commissioning plans at FAIR is given.
Paper: WEPS71
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS71
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPS72
Thermal studies of the magnet quenches of the SuperKEKB beam final focus system
2866
The beam final focus system of SuperKEKB consists of 55 superconducting magnets. They are 8 main quadrupole magnets, 43 corrector magnets and 4 compensation solenoids. During beam operation from 2018 to 2022, the superconducting magnets quenched 40 times induced by the electron or positron beam hitting the superconducting coils or the other disturbances. The temperatures of the quenched superconducting coils are being studied with the accumulated magnet quench data and the conditions of beam operation. The temperatures of the coils are evaluated with the critical temperature defined by the operation magnetic field and the transport current. The authors will report the temperature range of the superconducting coil shortly after the coil quench.
Paper: WEPS72
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS72
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPS73
Time decay effect of the superconducting final focus quadrupole fields on SuperKEKB beam operation
2868
SuperKEKB is the particle collider of electrons at 7 GeV and positrons at 4 GeV, and it is the cutting-edge collider in the luminosity frontier using the “Nano-beam scheme”. The beam colliding operation of SuperKEKB started from 2018 May, and the peak luminosity reached at 4.678×1e-34 1/cm² 1/s with quite expert beam operation. In beam operation, the vertical tune of the positron beam was measured to decline exponentially with time just after exciting the final focus quadrupole magnets. To identify the source of the tune change, we performed the magnetic field measurements of the prototype final focus quadrupole magnets, and the exponential field change with time after exciting the magnets was measured and the measured field decay rates were found to be of equal size of the measured tune change during beam operation. Because the field change is due to the magnetization decay in the superconductor, NbTi, filament, we modified the excitation pattern of the magnets and canceled the field decay. We will report the measured beam tune changes, the prototype field measurement results and the condition of beam operation with the modified excitation patterns of the quadrupole magnets.
Paper: WEPS73
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS73
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPS75
A design for very short powered quadrupoles
2875
Powered optics magnets which could be stacked in a very dense alternating pattern could enable a higher density of focusing in beamlines, with potential use for e.g. muon beams or high-current hadron beams at low energy. Here, we investigate such a design of quadrupole, where the yoke is energised by straight conductors running parallel to the beam, and does not require conductor to pass within the gap between yokes of adjacent magnets of opposite polarity. Suitable shaping and design of the steel yokes allows alternating focusing and defocusing quadrupoles, of arbitrary thickness, to be positioned with only the spacing required for constraining fringe fields. We investigate multiple thicknesses/sizes, and the use of thin field clamps to further reduce the required spacing between quadrupoles.
Paper: WEPS75
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS75
About: Received: 13 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THYN1
First results of AUP Nb3Sn quadrupole horizontal tests
2943
The Large Hadron Collider will soon undergo an upgrade to increase its luminosity by a factor of ~10. A crucial part of this upgrade will be replacement of the NbTi final focus magnets with Nb3Sn magnets that achieve a ~50% increase in the field strength. This will be the first ever large scale implementation of Nb3Sn magnets in a particle accelerator. This talk will present the program to fabricate these components and first results from horizontal tests of fully assembled cryoassemblies.
Paper: THYN1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THYN1
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPC01
Status of the ALBA-II lattice studies
2964
Due to the constrains imposed by the tight geometry of the ALBA storage ring, the initial 6BA lattice envisioned for the ALBA-II upgrade was reconsidered in favor of a more relaxed 5BA configuration. The first engineering studies of magnets and vacuum chambers made evident many short comings of the 6BA optics. The here proposed 5BA optics allows for an easier integration at cost of a small increase of the natural emittance. The employed linear and non-linear optics optimization process is here described along with the first studies about dynamic aperture and lifetime.
Paper: THPC01
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC01
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPC04
Sextupole offset effects on the storage ring linear optics
2968
Even though the strengths are weaker, different from quadrupole offsets, sextupole offsets are causing more complicated disturbances on the storage ring optics. They are making orbit distortion and quadrupole kicks as well as couplings. The offsets in chromatic sextupoles can affect the correction of chromaticity too. The closed orbit corrections in modern storage rings are fast and reliable, but their main focus is correcting the orbit to the quadrupole centers and the orbit distortion from a sextupole offset can make orbit offsets at other sextupoles which can be iterated. In this paper, we study the impact of the sextupole offsets on the linear optics in NSLS-II storage ring.
Paper: THPC04
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC04
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPC08
Beam-based alignment of magnetic system in AREAL linear accelerator
2978
In this paper the beam-based alignment for solenoid and quadrupole magnets in the AREAL linear accelerator is presented. The AREAL accelerator, at this stage, operates with one solenoid, one quadrupole, corrector, and dipole magnets. The adjustment of solenoid and quadrupole magnets is crucial for the stable operation of the accelerator and for forming the desired beam required for the AREAL upgrade program. This work also takes into account the influence of the RF field radial component on the off-axis beam parameters and trajectory due to laser spot misalignment on the cathode. The study involves theoretical, simulation, and experimental comparisons.
Paper: THPC08
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC08
About: Received: 13 May 2024 — Revised: 19 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPC13
Optics design of a compact helium synchrotron for advanced cancer therapy
2991
The design of a helium synchrotron for cancer therapy is being studied and optimized in the context of the Next Ion Medical Machine Study (NIMMS) at CERN. In particular, the effects of combined-function magnets and their geometry on the optics functions and hence on the beam size are evaluated. Moreover, the introduction of defocusing quadrupoles in the lattice is investigated as a means of better controlling the optics in both planes, while sextupoles for chromaticity control and resonant extraction are introduced. The updated lattice design is simulated to identify potential limitations in terms of nonlinear dynamics due to the low periodicity of the lattice and propose a regime for operations from the transverse beam dynamics’ perspective.
Paper: THPC13
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC13
About: Received: 13 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPC16
Sorting strategies for the new superconducting magnets for the CERN HL-LHC
3003
In a circular collider, precise control of the linear optics in the vicinity of the interaction points plays a crucial role in ensuring optimal operational performance and satisfying the machine protection constraints. Superconducting magnets are affected by unavoidable field errors that impact machine performance, and mitigation strategies are usually put in place to improve the situation. Past studies performed on the LHC have shown the benefit of magnet sorting on both initial beta-beating, through compensation of magnetic field errors, and overall correction quality of the machine optics. This work aims at extending those studies in the context of the luminosity upgrade of the LHC by considering the possible impact on performance from various sorting strategies applied to the new triplet quadrupoles for the ATLAS and CMS high-luminosity insertions.
Paper: THPC16
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC16
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPC28
Design of the H- beamline for the LANL RFQ test stand
3043
The Los Alamos Neutron Science Center (LANSCE) accelerator produces high intensity H+ and H- beams for multiple experiments in fundamental and national security science. The proposed LANSCE Modernization Project (LAMP) is evaluating necessary upgrades to enable continuous LANSCE operations in years to come. LAMP seeks to upgrade the H+ and H- 750 kV Cockcroft-Walton (CW) generators with a dual-beam, 3-MeV Radiofrequency Quadrupole (RFQ). For technology maturation and know-how associated with this concept, an RFQ test stand with LAMP-like layout is being set-up to demonstrate dual-beam operation in an RFQ with all beam patterns required by experiments. The RFQ test stand will have 35-keV H+ and H- beamlines that simultaneously inject into a 750 keV RFQ. Assembly and initial characterization of the H+ beam is under way. The H- beamline has stringent requirements and will also demonstrate systems like a beam chopper and a low frequency buncher to produce required beam patterns. We describe the design of the H- beamline based on accelerator codes Warp and Impact.
Paper: THPC28
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC28
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPC34
Linear optics correction of an asymmetric storage ring lattice
3064
The SSRF storage ring has been upgraded to an asymmetric lattice containing two super-bend cells, two double-mini-βy optics (DMB) cells and a superconducting wiggler (SCW) in 2019. Due to the destruction in structural symmetry, the restoration of linear optics becomes an essential issue in commissioning and routine beam dynamics maintenance. During the initial commissioning, the linear optics were well corrected with the LOCO method even though the SCW had not yet been installed. Recently, it has been found that the setups of some quadrupole power supplies tend to exceed the limits and deviate significantly from the intrinsic theoretical values, and the beta-functions and the tunes cannot be commendably recovered, leading to degradation of the storage ring performance. In this paper, the linear optics correction of the SSRF storage ring is introduced, the difficulties of the linear optics correction in asymmetric lattice are investigated, and the improved correction method and related application results are introduced.
Paper: THPC34
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC34
About: Received: 14 May 2024 — Revised: 19 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPC36
SOLEIL II booster robustness and emittance exchange
3071
For the injection into the SOLEIL II storage ring a beam with small transverse and longitudinal sizes is necessary, which requires the booster synchrotron to be upgraded. The new booster is designed as a multi-bend 16BA Higher-Order Achromat lattice with a small emittance of 5 nm∙rad at 2.75 GeV. Robustness of the lattice has been studied with realistic errors in magnet alignment and calibration, but also taking into account specific errors as mismatch in the RF frequency and circumference error, as RF frequency is driven by the main storage ring. Also, power supply tracking errors have been considered and their reduction will be discussed. On top of these error studies an emittance exchange is performed to allow more flexibility in the injection parameters into the storage ring. Different methods are compared within the framework of a very realistic machine.
Paper: THPC36
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC36
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPC37
Resonant matching section for CEBAF energy upgrade
3075
Thomas Jefferson National Accelerator Facility (Jefferson Lab) currently studies the feasibility of upgrading its energy to 22GeV. It considers addition of six more linac passes. The highest energy passes will share two new arcs designed using the Fixed-Field Alternating Gradient (FFA) technology. The FFA arcs are built using permanent combined-function magnets. They will be connected to the linacs through transition sections that will match the optics of all six passes to the linacs. With the high number of constraints and the limited space available, we are investigating a parametric resonance technique to match the optics quasi-independently at each energy. A resonance is excited at each individual energy to selectively control its optics. The resonant dipole and quadrupole kick harmonics are imposed for all energies simultaneously using Panofsky corrector magnets placed throughout the FFA arcs. This paper presents the current progress on that transition section design.
Paper: THPC37
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC37
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPC38
Exploratory splitter bend system designs for FFA@CEBAF
3079
An upgrade to the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility (JLAB) is anticipated to provide an electron beam of over 20 GeV using the existing superconducting-RF linear accelerator and new fixed-field alternating (FFA) gradient recirculation arcs made up of Halbach-style permanent magnets. In the current design, the FFA arcs will carry six beams with energies of approximately 11, 13, 16, 18, 20, and 22 GeV which will require horizontal splitter lines to match the beam from the preceding linac. In this paper, we describe two alternative splitter beamline designs that are tuned to match the beam's Twiss parameters, R56, time-of-flight, bend-plane offset, and dispersion into the FFA cells.
Paper: THPC38
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC38
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPC39
Horizontal splitter design for FFA@CEBAF energy upgrade: current status
3082
Thomas Jefferson National Accelerator Facility (Jefferson Lab) is currently studying the feasibility of an energy upgrade based upon Fixed-Field Alternating Gradient (FFA) permanent magnet technology. The current plan is to replace the highest-energy recirculation arcs with FFA arcs, increasing the total number of beam recirculations, thus the energy. In order to accommodate multiple passes in the FFA arcs, horizontal splitters are being designed to control the beam parameters entering the FFA arcs, as well as time-of-flight and R56. In the current design, six passes will recirculate through the FFA arcs, necessitating the design of six independent beamlines to control the optics and beam dynamics matching into the arcs. These beamlines must fit into the current CEBAF tunnel while allowing for personnel and equipment access. They must also be flexible enough to accommodate the beam under realistic operational conditions and fluctuations. The constraints on the system are highly restrictive, complicating the design. This document will describe the current state of the design and indicate the work remaining for a complete conceptual design.
Paper: THPC39
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC39
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPC48
Impedance calculation for the hadron storage ring in the Electron-Ion Collider with ECHO3D
3104
ECHO3D has been used for calculating the geometric impedance for several beamline vacuum components in the hadron storage ring (HSR) of the EIC (Electron-Ion Collider) in the past few years. In this paper, we present the geometric impedances calculated from ECHO3D for the beam screen with pump slots, the polarimeter and the bellow with pump ports in the HSR. We also discuss some findings while cross-checking these results with what calculated from GdfidL and CST.
Paper: THPC48
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC48
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPC69
Full-cycle simulations of the Fermilab booster
3183
The PIP-II project currently under construction at FNAL will replace the existing 400 MeV normal conducting linac with a 800 MeV superconducting linac. The beam power in the downstream rapid-cycling Booster synchrotron will be doubled by raising the machine cycle frequency from 15 to 20 Hz and by increasing the injected beam intensity by a factor 1.5. This has to be accomplished without raising uncontrolled losses beyond the administrative limit of 1 W/m. In addition, slip-stacking efficiency in the Recycler — the next machine in the accelerator chain- sets an upper limit on the longitudinal emittance of the beam delivered by the Booster. As part of an effort to better understand potential losses and emittance blow-up in the Booster, we have been conducting full cycle 6D simulations using the code pyORBIT. The simulations include space charge, wall impedance effects and transition crossing. In this paper, we discuss our experience with the code and present representative results for possible operational scenarios.
Paper: THPC69
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC69
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPC82
Design of the low-emittance complex bend lattice
3233
The demands of a higher brightness photon beam push the electron beam emittance of storage rings towards a diffraction-limited level. The concept of multi-bend achromat (MBA) structure and its variations, containing multiple dipoles in a cell, has been widely employed in the fourth-generation storage ring light sources. Recently, a novel concept of lattice structure, called complex bend lattice, extends the option for low emittance ring lattice design. This paper presents the developed low-emittance complex bend lattices. The benefits of using complex bends include low natural emittance, long straights for IDs, more free space for accelerator equipment, and reduced power consumption for magnets.
Paper: THPC82
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC82
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
THPC83
Test of parallel beam-based alignment at NSLS-II
3237
Misalignment of magnets in the storage rings causes trajectory deviation when the beam traverses through magnets, resulting in the degraded performance of linear optics and nonlinear dynamics. The beam-based alignment (BBA) technique is commonly used to steer the beam passing through the centers of magnets. Recently, a new method has been developed to determine the centers of multiple magnets simultaneously [1]. In this paper, the test of this fast BBA method at NSLS-II is presented.
Paper: THPC83
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC83
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPG06
Tune feedback system in the Taiwan photon source
3258
The paper outlines the successful implementation of a global tune feedback system at the Taiwan Photon Source (TPS) to compensate the tune variation resulting from adjustments in the gap and phase of the insertion devices. The global tune feedback system deployed in the TPS employs two families of quadrupole magnets to sustain betatron tunes at the desired working point. The adjustment currents (feedback quantities) are crucial for this process, which are calculated from a tune response matrix derived from the lattice model, with tune shift quantities provided by the bunch-by-bunch feedback system, and the algorithm of singular value decomposition (SVD).
Paper: THPG06
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG06
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPG07
TPS booster power supply performance experiment and monitoring program
3261
The TPS is a latest generation high-brightness synchro-tron light source scheduled to be commissioned in 2014. Its booster is designed to ramp electron beams from 150 MeV to 3 GeV at a frequency of 3 Hz. There are 54 dipole magnets, powered by one power supply unit, and 84 quadrupole magnets, powered by 4 power supply units according to their respective functions. During routine user time, a top-up injection occurs every 4 minutes. At this time, the stability of the booster's power supply units greatly affects the smoothness of the injection process. This paper will discuss how variations in the booster power output waveform affect injection and the monitor-ing program developed for this purpose.
Paper: THPG07
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG07
About: Received: 09 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPG36
Continuous position estimation for the full remote alignment system of the High Luminosity LHC upgrade
3337
The Full Remote Alignment System (FRAS) is an alignment system remotely controlled and monitored that comprises almost one thousand permanent sensors distributed along the 200 meters of equipment that will be installed in the frame of the High Luminosity LHC (HL-LHC) project on either side of the ATLAS and CMS detectors. The sensors, along with their electronics and a system of motorized actuators, will be used to adjust the relative positions of the components remotely, in real time, with no human intervention needed in the irradiated environment of the tunnel. In this contribution we describe the design and the implementation of the position estimation algorithm which is a core-component of the FRAS. This algorithm will process the data provided by all the sensors to determine exact positions and orientations of the associated components in real-time. The position estimation module is designed as a reusable C++ library and builds on the existing CERN LGC, a modular least-square software. It will be fully integrated into the FRAS software stack and is entirely file-less during operation. In this paper we will demonstrate its performance in a realistic case study and showcase its ability to provide position updates on a much higher frequency than the required 1 Hz.
Paper: THPG36
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG36
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPG37
Parallel quadrupole modulation for fast beam-based determination of magnet centers
3341
A method to simultaneously determine the magnetic centers of multiple magnets with beam-based measurements is proposed. Similar to the quadrupole modulation system (QMS) method that is widely used for beam-based alignment measurement, the strengths of the group of selected magnets are modulated. The orbit shifts induced by the modulation are used to deduce the kicks applied at the magnet locations with the help of orbit response matrix calculated with the lattice model. By varying the beam orbit at the magnets, with a pair of corrector of magnets or local orbit bumps, and repeating the modulation measurement at each orbit, the magnet centers can be determined through fitting the calculated kicks versus the beam orbit. Demonstration of the method on a storage ring is presented. The method can also been applied to nonlinear magnets.
Paper: THPG37
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG37
About: Received: 10 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPG40
Time-of-flight beam loss monitor for the Advanced Photon Source Upgrade booster-to-storage-ring transport line
3348
We present initial results from the booster-to-storage-ring beam-loss monitor (BTSBLM) employing time-of-fight analysis to localize and minimize losses along the BTS line. The BTSBLM utilizes a pair of high-purity, fused silica fiber optic cables running in parallel along the 65-m BTS transport line. Photomultipliers located at both upstream and downsteam ends of each fiber monitor Cherenkov radiation generated by lost electrons. The downstream detectors receive temporally-compressed, higher-intensity, spatially-inverted signals, while the upstream waveforms are temporally expanded with lower intensity allowing finer time resolution; both upstream and downstream effects owing to the refractive index in the fiber glass. Each radiation-hard optical fiber is composed of 600, 660, and 710-micron-diameter core, cladding, and buffer and is similar to those used in the newly commissioned LCLS-II superconducting linac BLM system. Realtime waveforms are recorded on a fast oscilloscope and available for diagnostic observation through EPICS waveform records. Remote controlled high-voltage power supplies provide gain adjustment. Data from booster and storage-ring commissioning are presented.
Paper: THPG40
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG40
About: Received: 16 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPG65
Equipment protection system against unexpected abnormalities during high-intensity proton beam operation at J-PARC MR
3420
The J-PARC MR synchrotron began high repetition operation with shortened accelerator cycles in 2022. So far, FX has been supplying a 2x10e+14 proton per pulse (ppp) beam to the Neutrino Experimental Facility with a repetition rate of 1.36 seconds, and SX has been supplying a 0.6x10e+14 ppp beam to the Hadron Experimental Facility with a 5.20 seconds repetition. The amount of heat per accelerated proton beam pulse exceeds 1 MJ, and it is an important issue to avoid damage to the equipment caused by high-intense beam due to abnormalities during beam acceleration. Since the MR is operated in different extraction modes, i.e. FX and SX, the countermeasures are also different, and the adequate protection system also needs to be considered, respectively. Therefore, the countermeasures have been put in place, including a high-speed beam abort system and/or a fast sequential interlock between devices. This report summarizes the systems to protect equipment from abnormalities that unexpectedly occur during high-intensity proton beam acceleration.
Paper: THPG65
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG65
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPG78
AGS Booster model calibration and digital-twin development
3449
An accurate physics simulation model is key to accelerator operation because all beam control and optimization algorithms require good understanding of the accelerator and its elements. For the AGS Booster, discrepancies between the real physical system and online simulation model have been a long-standing issue. Due to the lack of a reliable model, the current practice of beam control relies mainly on empirical tuning by experienced operators, which may be inefficient or sub-optimal. In this work, we investigate two main factors that can cause discrepancies between simulation and reality in the AGS Booster: magnet misalignments and magnet transfer functions. We developed a orbit response measurement script that collects real machine data in the Booster for model calibration. By matching simulated data with real data, we can develop a more accurate simulation model for future polarization optimizations, and build the foundation for a fully functional digital-twin.
Paper: THPG78
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG78
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPG79
An automated quad scan based emittance measurement software
3453
Beam emittance plays the crucial role in a Beam transportation system. At a fixed-target beamline off the AGS Booster Synchrotron, beam emittance is determined through measuring the beam width via a segmented multi-wire ion chamber (SWIC) and varying quadrupole strength. The width of the beam signal (as Full Width Half Max) on the SWIC passes through a minimum value and the resulting dataset of FWHM per magnet current is used to fit a function. Using this technique, new controls software has been developed to set up measurements, acquire data, and perform analysis through a python-based scripts to calculate the emittance along the NASA Space Radiation Laboratory (NSRL) beamline. Initial results of the program are presented to for various points along the beamline in a variety of conditions.
Paper: THPG79
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG79
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPG85
Updates to Xopt for online accelerator optimization and control
3469
The recent development of advanced black box optimization algorithms has promised order of magnitude improvements in optimization speed when solving accelerator physics problems. These algorithms have been implemented in the python package Xopt, which has been used to solve online and offline accelerator optimization problems at a wide number of facilities, including at SLAC, Argonne, BNL, DESY, ESRF, and others. In this work, we describe updates to the Xopt framework that expand its capabilities and improves optimization performance in solving online optimization problems. We also discuss how Xopt has been incorporated into the Badger graphical user interface that allows easy access to these advanced control algorithms in the accelerator control room. Finally, we describe how to integrate machine learning based surrogate models provided by the LUME-model package into online optimization via Xopt.
Paper: THPG85
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG85
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPR02
Revised error sensitivity study for the ESS proton linac
3481
The normal-conducting injector of the superconducting proton linac of the European Spallation Source (ESS) was commissioned in 2023. Commissioning of the superconducting linac is planned by end of 2024, followed by first beam on the spallation target in 2025. One of the prominent challenges in commissioning and operation of high power accelerators, such as the linac of the ESS, is to minimize beam loss to protect its components from excessive activation and potential damage. Sensitivity studies looking at various types of errors were conducted in the past during the design phase for defining requirements and tolerances. With the commissioning of the full linac approaching, a revised error sensitivity study was carried out, and the result is presented in this paper. The aim of the revised study is to better understand the relation between potential error sources and loss patterns.
Paper: THPR02
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR02
About: Received: 20 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPR51
A large momentum acceptance gantry for light-weight proton therapy facility: its beam lattice, magnets design and clinical advantages
3632
As one of the state-of-the-art radiotherapy approaches, proton therapy possesses conformal dose profiles yet expensive cost. Designing a facility with a small footprint and a high treatment efficiency is the main goal for researchers to fulfill the potential of proton therapy and make it more affordable both for vendors and patients. In this contribution, the design of a light-weight proton therapy gantry based on the alternating-gradient canted-cosine-theta (AG-CCT) super-conducting (SC) magnet is presented. The AG-CCT magnets adopt large bores and combined function design. With fine field harmonic control and fringe field shape optimization of the magnets, the multi-particle tracking results prove that the gantry achieves a momentum acceptance of ±8%. So that the full energy range from 70 to 230 MeV can be covered with merely 3 field switch points. Combined with a fast degrader component, whose switch time is below 50 ms, the energy modulation speed can be greatly fastened. To fully utilize the advantages of the large momentum acceptance gantry, the energy spread of the proton beam is expanded and a reduced treatment plan is proposed. Compared with the standard treatment plan, the energy layers number of a prostate case is reduced by 61.3% with comparable plan quality. In summary, the proposed gantry has significant superiority both in manufacture and clinical aspects.
Paper: THPR51
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR51
About: Received: 14 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
THPR58
Fabrication and tuning of a 325 MHz ion-injector prototype for particle therapy facility
3650
In order to miniaturize ion injectors for particle therapy, a design of ion injectors based on a 325 MHz operating frequency was completed. The LINAC was consist of a 2.0 m length RFQ and a 3.8 m length IH-DTL, which was designed to accelerate 12C4+, 3H+, 3He+ and 18O6+ beams to 7 MeV/u. The RFQ cavity and the first DTL tank was been manufactured using aluminum. This paper gives an overview of the fabrication and tuning procedure of the prototype. The quadrupole electric field of the RFQ is adjusted flat by the tuner while reducing the dipole field components in both directions. The measured DTL electric field distribution after tuning is in good agreement with the simulation results.
Paper: THPR58
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR58
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPR59
Using octupoles to create uniform electron beam produced by irradiation accelerators
3653
In contemporary radiotherapy, most accelerators employ the scatter technique to achieve a relatively uniform dose distribution of electron beams. However, this method often results in the loss of a substantial number of particles, leading to suboptimal efficiency. This paper proposes a method utilizing permanent magnet components to homogenize the beam, achieving both beam spreading and uniformity within a short distance without particle loss. The proposed homogenization beamline comprises two quadrupole magnets and two octupole magnets, ultimately yielding a square field with a side length of approximately 20 cm. The manuscript includes theoretical derivations and simulation validations, with the physical prototype currently under fabrication. Experimental results will be provided in future work.
Paper: THPR59
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR59
About: Received: 11 May 2024 — Revised: 19 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPR62
Current status of MINIBEE: minibeam beamline for preclinical experiments on spatial fractionation in the FLASH regime
3663
In vivo studies support that the combination of protons and spatial fractionation, the so-called proton minibeam radiotherapy (pMBT), enhances the protection of normal tissue for a given tumor dose. A preclinical pMBT facility for small animal irradiation at the 68 MeV cyclotron of Helmholtz-Zentrum Berlin (HZB) will improve the understanding of this method. A two-step energy-degrading system will first define the maximum energy of the beam and further degrading will occur before the target forming a spread-out Bragg peak (SOBP), if necessary. Beam size and divergence will be adjusted by slit systems before a 90-degree magnet bending the beam into the experimental room. At the current stage, a magnetic quadrupole triplet placed close to the target demagnifies the beam by a factor of ~5. The goal is to generate a magnetically focused minibeam of 50 micrometer sigma. Scanning magnets will enable a raster-scan application in the tumor. Conventional dose rate delivery will be allowed while FLASH applications can be achieved with the possible use of a ridge filter. The results of beamline simulations by TRACE-3D and BDSIM will be presented.
Paper: THPR62
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR62
About: Received: 14 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPS11
Cold plate upgrade at the SNS
3748
The Spallation Neutron Source (SNS) employed over 200 cold plates in its Injection Kicker and quadrupole power supplies for semiconductor cooling. Each cold plate consisted of an aluminum base with interconnected copper tubes that were brazed together. Unfortunately, the durability of these plates was compromised over time due to corrosion of the copper tubes by de-ionized water. This corrosion led to the formation of small pinhole leaks, which became increasingly problematic in recent years, causing more frequent leaks and subsequent operational downtime for the SNS system. To tackle this issue, a novel solution was pursued involving the incorporation of stainless-steel tubes in the redesign. Two types of cold plates underwent rigorous simulations and extensive testing. One of the redesigned cold plates demonstrated competitive performance and was identified as a feasible replacement option. Consequently, a comprehensive initiative was executed to replace all cold plates.
Paper: THPS11
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS11
About: Received: 30 Apr 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024
THPS18
Impact of Delta undulator on SIRIUS beam dynamics
3769
SIRIUS is the Brazilian 4th generation synchrotron light source. Currently, SIRIUS is in its Phase 1 stage of the project, with 14 beamlines proposed, some of which are already used by external users. Recently, the SABIÁ beamline underwent a transition where its commissioning insertion device (ID) was replaced by the beamline’s titular ID, an in-house developed DELTA undulator. This device offers versatility in generating various polarizations of light depending on the relative positions of the ID cassettes. However, each permissible configuration engenders distinct perturbations in beam dynamics, particularly affecting beam orbit, optics, and equilibrium parameters. This paper reports the impacts of the DELTA on beam dynamics and outlines the correction strategies implemented to mitigate these effects
Paper: THPS18
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS18
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPS54
Magnetic measurements for Halbach-type permanent quadrupoles using a single-stretched wire system
3864
In the framework of the acceleration techniques, the Plasma Wake Field Acceleration (PWFA) is one of the most promising in terms of high machine compactness. For this purpose, a crucial role is played by the particle beam focusing upward and downward the plasma-beam interaction, performed by high gradient Permanent Magnet Quadrupoles (PMQs). In the framework of the INFN-LNF SPARC_LAB (Sources for Plasma Accelerators and Radiation Compton with Laser And Beam) six Halbach-type PMQs have been tested before installing them into the machine. This paper presents the outcomes of magnetic measurements conducted using a Single-Stretched Wire (SSW) system. The results include comprehensive details on integrated gradients, magnetic multipole components, and roll angles of the magnets. By considering the operational parameters of the machine, the results show that the tested magnets can be feasibly installed only within limited triplets configurations.
Paper: THPS54
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS54
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPS56
Field characterization of axially and radially magnetized neodymium rings
3868
Permanent magnets are attractive options for nano focusing and $q$-magnification in MeV ultrafast electron diffraction (MeV-UED) due to their high field strengths and compact footprints. In this work, we present field characterization of axially and radially magnetized neodymium rings. Such rings can produce strong axisymmetric focusing and naturally fulfill the requirement of stigmatic imaging for post-sample optical systems. Field qualities of the rings and their application in MeV-UED are studied and presented.
Paper: THPS56
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS56
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPS71
Multi-physics and multi-objective design optimization of quadrupole resonators under geometric uncertainties
3912
Exploring the fundamental properties of materials such as niobium, NbTiN, multilayers or Nb3Sn, in high-precision surface resistance measurements is highly relevant to superconducting radio-frequency (RF) technology. Typically, for a precise determination of the RF properties of superconducting samples, the calorimetric measurement is carried out with a quadrupole resonator (QPR). Still, one of the main challenges in the QPR design and operations is to mitigate the impact of microphonics and Lorentz force (LF) detuning, on the one hand, and the RF losses on the adapter flange with the fabrication tolerances, on the other hand, into QPR functioning. For this reason, we address the electro-stress-heat coupled problem under geometric uncertainties to study a significant measurement bias of the surface resistance, observed mainly for the third operating mode of the given QPR. We then use a multi-objective and multi-physics shape optimization method to compensate for its influence and find the optimal QPR design in the Pareto sense. Finally, the optimization results and their implications for QPR operating conditions are discussed to demonstrate the proposed approach.
Paper: THPS71
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS71
About: Received: 15 May 2024 — Revised: 05 Jun 2024 — Accepted: 05 Jun 2024 — Issue date: 01 Jul 2024