IPAC2021 - List of Keywords (proton)

Paper	Title	Other Keywords	Page
MOPAB001	Power Deposition in Superconducting Dispersion Suppressor Magnets Downstream of the Betatron Cleaning Insertion for HL-LHC	collimation, dipole, simulation, operation	37
	A. Waets, C. Bahamonde Castro, E. Belli, R. Bruce, N. Fuster-Martínez, A. Lechner, A. Mereghetti, S. Redaelli, M. Sabaté-Gilarte, E. Skordis CERN, Meyrin, Switzerland
	Funding: Research supported by the HL-LHC project The power deposited in dispersion suppressor magnets downstream of the Large Hadron Collider (LHC) betatron cleaning insertion is governed by off-momentum particles scattered out of the primary collimators. In order to mitigate the risk of magnet quenches during periods of short beam lifetime in future High-Luminosity (HL-LHC) operation, new dispersion suppressor (DS) collimators are considered for installation (one per beam). In this paper, we present FLUKA simulations for both protons and Pb ions at 7 TeV, predicting the power deposition in the DS magnets, including the new higher-field dipoles 11T which are needed to integrate the collimator in the cold region next to the cleaning insertion. The simulated power deposition levels for the adopted HL-LHC collimator configuration and settings are used to assess the quench margin by comparison with the present estimated quench levels.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB001
About •	paper received ※ 19 May 2021 paper accepted ※ 07 July 2021 issue date ※ 16 August 2021
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MOPAB002	Risk of Halo-Induced Magnet Quenches in the HL-LHC Beam Dump Insertion	insertion, collimation, betatron, operation	41
	J.B. Potoine, A. Apollonio, E. Belli, C. Bracco, R. Bruce, M. D’Andrea, R. García Alía, A. Lechner, G. Lerner, S. Morales Vigo, S. Redaelli, V. Rizzoglio, E. Skordis, A. Waets CERN, Meyrin, Switzerland F. Wrobel IES, Montpellier, France
	Funding: Research supported by the HL-LHC project After the High Luminosity (HL-LHC) upgrade, the LHC will be exposed to a higher risk of magnet quenches during periods of short beam lifetime. Collimators in the extraction region (IR6) assure the protection of magnets against asynchronous beam dumps, but they also intercept a fraction of the beam halo leaking from the betatron cleaning insertion. In this paper, we assess the risk of quenching nearby quadrupoles during beam lifetime drops. In particular, we present an empirical analysis of halo losses in IR6 using LHC Run 2 (2015-2018) beam loss monitor measurements. Based on these results, the halo-induced power density in magnet coils expected in HL-LHC is estimated using FLUKA Monte Carlo shower simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB002
About •	paper received ※ 19 May 2021 paper accepted ※ 13 July 2021 issue date ※ 22 August 2021
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MOPAB005	Studies for an LHC Pilot Run with Oxygen Beams	target, luminosity, MMI, operation	53
	R. Bruce, R. Alemany-Fernández, H. Bartosik, M.A. Jebramcik, J.M. Jowett, M. Schaumann CERN, Geneva, Switzerland
	Motivated by the study of collective effects in small systems with oxygen-oxygen (O-O) collisions, and improvements to the understanding of high-energy cosmic ray interactions from proton-oxygen (p-O) collisions, a short LHC oxygen run during Run 3 has been proposed. This article presents estimates for the obtainable luminosity performance in these two running modes based on simulations of a typical fill. The requested integrated luminosity, projected beam conditions, data-taking and commissioning times are considered and a running scenario is proposed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB005
About •	paper received ※ 17 May 2021 paper accepted ※ 25 May 2021 issue date ※ 19 August 2021
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MOPAB012	Energy Deposition Study of the CERN HL-LHC Optics v1.5 in the ATLAS and CMS Insertions	luminosity, insertion, optics, radiation	76
	M. Sabaté-Gilarte, F. Cerutti CERN, Meyrin, Switzerland
	Funding: Research supported by the HL-LHC project The High Luminosity Large Hadron Collider (HL-LHC) is the approved CERN project aiming at further increasing the integrated luminosity of the LHC by a factor 10. As such, it implies a complete redesign of the experimental high-luminosity insertions of ATLAS and CMS. The progressive evolution of the new layout and optics requires a continuous analysis of the radiation environment, to which magnets and other equipment are exposed to. This is assured by means of Monte Carlo simulations of the collision debris on the evolving machine model. The latter featured several developments, such as the explicit inclusion of the cold protection diodes of the final focusing circuits as well as the crab cavities cryomodule. This work presents the most updated characterization of the radiation field with FLUKA and its impact in the insertion region and the dispersion suppressor of Point 1 and 5, for the HL-LHC optics v1.5 released in 2019. Various optimization and mitigation studies are highlighted, providing key information for maximizing the lifetime of new and present magnets.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB012
About •	paper received ※ 18 May 2021 paper accepted ※ 25 May 2021 issue date ※ 21 August 2021
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MOPAB014	First High Spin-Flip Efficiency for High Energy Polarized Protons	polarization, resonance, dipole, experiment	84
	H. Huang, J. Kewisch, C. Liu, A. Marusic, W. Meng, F. Méot, P. Oddo, V. Ptitsyn, V.H. Ranjbar, T. Roser BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. In order to minimize the systematic errors for the Relativistic Heavy Ion Collider (RHIC) spin physics experiments, flipping the spin of each bunch of protons during the stores is needed. Experiments done with single RF magnet at energies less than 2 GeV have demonstrated a spin-flip efficiency over 99%. At high energy colliders with Siberian snakes, a single magnet spin flipper does not work because of the large spin tune spread and the generation of multiple, overlapping resonances. Over past decade, RHIC spin flipper design has evolved and a sophisticated spin flipper, constructed of nine-dipole magnets, was developed to flip the spin in RHIC. A special optics choice was also used to make the spin tune spread very small. In recent experiment, 97% spin-flip efficiency was measured at both 24 and 255 GeV for the first time. The results show that efficient spin flipping can be achieved at high energies.
	Poster MOPAB014 [0.984 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB014
About •	paper received ※ 16 May 2021 paper accepted ※ 08 June 2021 issue date ※ 20 August 2021
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MOPAB015	Feasibility of Polarized Deuteron Beam in the EIC	resonance, polarization, solenoid, detector	87
	H. Huang, F. Méot, V. Ptitsyn, V.H. Ranjbar, T. Roser BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The physics program in the EIC calls for polarized neutron beam at high energies. The best neutron carriers are 3He nuclei and deuterons. Both neutron carries are expected to be used by spin physics program in the EIC. Due to the small magnetic moment anomaly of deuteron particles, much higher magnetic fields are required for spin rotation, so full Siberian snake is not feasible. However, the resonance strength is in general weak and the number of resonances is also small. It is possible to deal with individual resonances with conventional methods, such as betatron tune jump for intrinsic depolarizing resonances; and a weak partial snakes for imperfection resonances. The study shows that accelerating polarized deuteron beyond 100GeV/n is possible in the EIC.
	Poster MOPAB015 [0.977 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB015
About •	paper received ※ 16 May 2021 paper accepted ※ 28 May 2021 issue date ※ 13 August 2021
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MOPAB024	Efficient Coupling of Hydrodynamic and Energy-Deposition Codes for Hydrodynamic-Tunnelling Studies on High-Energy Particle Accelerators	simulation, target, coupling, experiment	119
	C. Wiesner, F. Carra, J. Kruse-Hansen, M. Masci, D. Wollmann CERN, Meyrin, Switzerland Y. Nie KIT, Karlsruhe, Germany
	The machine-protection evaluation of high-energy accelerators comprises the study of beyond-design failures, including the direct beam impact onto machine elements. In case of a direct impact, the nominal beam of the Large Hadron Collider (LHC) would penetrate more than 30 meters into a solid copper target. The penetration depth due to the time structure of the particle beam is, thus, significantly longer than predicted from purely static energy-deposition simulations with 7 TeV protons. This effect, known as hydrodynamic tunnelling, is caused by the beam-induced density depletion of the material at the target axis, which allows subsequent bunches to penetrate deeper into the target. Its proper simulation requires, therefore, to sequentially couple an energy-deposition code and a hydrodynamic code for the different target densities. This paper describes a method to efficiently couple the simulations codes Autodyn and FLUKA based on automatic density assignment and input file generation, and presents the results achieved for a sample case.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB024
About •	paper received ※ 19 May 2021 paper accepted ※ 05 July 2021 issue date ※ 28 August 2021
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MOPAB027	Improving the Luminosity Burn-Off Estimate by Considering Single-Diffractive Effects	scattering, luminosity, collider, simulation	130
	F.F. Van der Veken, H. Burkhardt, M. Giovannozzi, V.K.B. Olsen CERN, Geneva, Switzerland
	Collisions in a high-luminosity collider result in a continuous burn-off of the circulating beams that is the dominant effect that reduces the instantaneous luminosity over time. In order to obtain a good estimate of the luminosity evolution, it is imperative to have an accurate understanding of the burn-off. Typically, this is calculated based on the inelastic cross-section, as it provides a direct estimate of the number of protons that participate in inelastic collisions, and are hence removed. Likewise, protons that participate in elastic collisions will remain in the machine acceptance, still contributing to luminosity. In between these two regimes lie diffractive collisions, for which the protons have a certain probability to remain in the machine acceptance. Recent developments of the SixTrack code allow it to interface with Pythia, thus allowing for more precise simulations to obtain a better estimate of the diffractive part of the cross-section. In this paper, we will mainly concentrate on slowly-drifting protons that are close to the acceptance limit, resulting from single-diffractive scattering.
	Poster MOPAB027 [1.193 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB027
About •	paper received ※ 18 May 2021 paper accepted ※ 31 May 2021 issue date ※ 11 August 2021
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MOPAB031	Development and Operation of Vacuum System for Rapid Cycling Synchrotron to Target Beam Transfer Line of China Spallation Neutron Source	vacuum, target, neutron, operation	145
	J.M. Liu, Y.H. Guan, S.M. Liu, B. Tan, P.C. Wang DNSC, Dongguan, People’s Republic of China H. Dong IHEP, Beijing, People’s Republic of China H.Y. He, T. Huang IHEP CSNS, Guangdong Province, People’s Republic of China
	China Spallation Neutron Source (CSNS) is a major scientific project during the National Eleventh Five-Year Plan. It consists of a negative hydrogen ion linear accelerator, a rapid cycling synchrotron ( RCS), a linac to RCS beam transfer line (LRBT), an RCS to target beam transfer line (RTBT), and a target station. As an important part of CSNS, the RTBT connects the rapid cycling synchrotron and the target window. This paper described the design requirements, technical solutions, and operating conditions of the vacuum system for the CSNS RCS to target beam transfer line. In addition, the fast valve protection system and its verification results were also expounded. The CSNS has been in operation for over three years, during this period, the beam power has been gradually improved from 10KW to 100KW, and the vacuum system for RTBT has been operating stably.
	Poster MOPAB031 [0.581 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB031
About •	paper received ※ 19 May 2021 paper accepted ※ 24 May 2021 issue date ※ 25 August 2021
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MOPAB132	The Multi-Mega-Watt Target Station for the European Spallation Source Neutrino Super Beam	target, experiment, hadron, ion-source	466
	E. Baussan, E. Bouquerel, L. D’Alessi, M. Dracos, P. Poussot, J. Thomas, J. Wurtz, V. Zeter IPHC, Strasbourg Cedex 2, France P. Cupial, M. Koziol, L.J. Lacny, J. Snamina AGH University of Science and Technology, Kraków, Poland I. Efthymiopoulos CERN, Meyrin, Switzerland T. Tolba University of Hamburg, Hamburg, Germany
	Funding: This project has received funding from the European Union Horizon 2020 research and innovation program under grant agreement No 777419 and also by the Deutsche Forschungsgemeinschaft No 423761110. One of the next challenges in fundamental physics is to understand the origin of matter/antimatter asymmetry in the Universe. In particular, intense neutrinos could play an important role to elucidate this mystery and better understand the expansion of the Universe. The ESSnuSB collaboration proposes to use the proton linac of the European Spallation Source currently under construction in Lund (Sweden) to produce a very intense neutrino super beam, in parallel with the spallation neutron production. A very challenging part of the proposed facility is the Target Station which will have to afford 5 MW proton beam power. This poster will present the hadronic collector and the whole facility to produce the next generation of neutrino superbeam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB132
About •	paper received ※ 20 May 2021 paper accepted ※ 27 May 2021 issue date ※ 18 August 2021
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MOPAB160	Tools for the Development and Applications of the IsoDAR Cyclotron	cyclotron, rfq, target, injection	550
	L.H. Waites, J.R. Alonso, J.M. Conrad, D. Koser, D. Winklehner MIT, Cambridge, Massachusetts, USA
	Funding: NSF provided funding for the RFQDIP project, Draper laboratory provided a fellowship for the graduate student The IsoDAR cyclotron is a 60 MeV cyclotron designed to output 10mA of protons in order to be a driver for a neutrino experiment. However, this high power can be used in other useful and important applications outside of particle physics. The IsoDAR cyclotron accelerates H²⁺, which allows the beam to be highly versatile and important for the development of high-power targets. This could help alleviate a huge bottleneck in the medical isotope community. IsoDAR could also be used for the development of materials. The accelerator system uses many new tools, including novel methods of applying machine learning, as well as several of the uses of this new technology. With these applications and tools, the IsoDAR cyclotron can have an important impact on the accelerator, medical, and physics communities.
	Poster MOPAB160 [0.424 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB160
About •	paper received ※ 15 May 2021 paper accepted ※ 24 June 2021 issue date ※ 13 August 2021
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MOPAB173	Physics Program and Experimental for AWAKE Run 2	plasma, electron, wakefield, experiment	586
	P. Muggli MPI, Muenchen, Germany
	Run 1 experimental results demonstrate many characteristics of the self-modulation (SM) in plasma of a long, 400GeV SPS proton bunch. Externally injected, 19MeV electrons were accelerated to 2GeV. Based on these results, we are assembling a physics and experiment program aiming at producing a multi-GeV electron bunch with emittance and energy spread sufficiently low for possible early applications to high-energy physics experiments. Plans include two plasmas, the first for SM, the second for acceleration, and of scalable length, separated by an injection region. The first plasma includes a density step to maintain large-amplitude wakefields after saturation of the SM process. Seeding of the SM process may be obtained from an electron bunch. The 150MeV witness electron bunch from an S-band gun, X-band linac has parameters that produce plasma electron blow out and loading of the wakefields in order to minimize final energy spread and emittance*. We are studying the possibility of using a helicon plasma source for the accelerator, a source that can in principle be very long (100s of m). AWAKE, PRL 122, 054802 (2019), Turner, PRL 122, 054801 (2019), Turner, PRAB 23, 081302, (2020), Braunmueller PRL 125, 264801 (2020) AWAKE, Nature 561, 363 (2018) *Olsen, PRAB 21, 011301 (2018)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB173
About •	paper received ※ 18 May 2021 paper accepted ※ 28 May 2021 issue date ※ 02 September 2021
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MOPAB174	Foil Hits Reduction by Minimizing Injection Beam Size at the Foil in J-PARC RCS	injection, scattering, beam-losses, operation	590
	P.K. Saha, H. Harada, K. Okabe, F. Tamura, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan H. Hotchi KEK, Tokai, Ibaraki, Japan
	Funding: Pranab Kumar Saha The uncontrolled beam loss caused by the foil scattering of the circulating beam during multi-turn charge-exchange injection is one of the main sources for high residual radiation at the injection area of J-PARC 3-GeV rapid cycling synchrotron. We studied to reduce foil hits of the circulating beam by minimizing the vertical injection beam size at the foil and using a smaller vertical foil size. The vertical foil size was reduced according to the injection beam size by maintaining the stripping efficiency. As a result, the number of circulating beam passing through foil was significantly reduced due to smaller foil size. The simulation and measurement results of the foil hits reduction are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB174
About •	paper received ※ 20 May 2021 paper accepted ※ 31 May 2021 issue date ※ 28 August 2021
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MOPAB177	ELENA Commissioning and Status	antiproton, experiment, MMI, electron	598
	C. Carli, M.E. Angoletta, W. Bartmann, L. Bojtár, F. Butin, B. Dupuy, Y. Dutheil, M.A. Fraser, P. Freyermuth, D. Gamba, L.V. Jørgensen, B. Lefort, O. Marqversen, M. McLean, S. Ogur, S. Pasinelli, L. Ponce, G. Tranquille CERN, Geneva, Switzerland
	The Extra Low ENergy Antiproton ring ELENA is a small synchrotron recently constructed and commissioned to decelerate antiprotons injected from the Antiproton Decelerator AD with a kinetic energy of 5.3 MeV down to 100 keV. Controlled deceleration in the synchrotron, equipped with an electron cooler to reduce losses and generate dense bunches, allows the experiments, typically capturing the antiprotons in traps and manipulating them further, to improve the trapping efficiency by one to two orders of magnitude. During 2018, bunches with an energy of 100 keV with parameters close to nominal have been demonstrated, and first beams have been provided to an experiment in a new experimental zone. The magnetic transfer lines from the AD to the experiments have been replaced by electrostatic lines from ELENA. Commissioning of the new transfer lines and, in parallel, studies to better understand the ring with H⁻ beams from a dedicated source, have started in autumn 2020. The first 100 keV antiproton physics run using ELENA will start in late summer 2021.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB177
About •	paper received ※ 18 May 2021 paper accepted ※ 14 June 2021 issue date ※ 23 August 2021
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MOPAB178	Systematic Effects Limiting the Sensitivity of "Magic Energy" Proton EDM Rings	dipole, betatron, pick-up, focusing	602
	C. Carli, M. Haj Tahar CERN, Geneva, Switzerland
	Proposals to measure a possible Electric Dipole Moment (EDM) of protons in an electro-static storage ring are studied by a world-wide community. The machine is operated at the so-called "magic energy" to satisfy the "frozen spin" condition such that, without imperfections and with the well known magnetic moment of the particle, the spin is always oriented parallel to the direction of movement. The effect of a finite EDM is a build-up of a vertical spin component. Any effect, other than a finite EDM, leading as well to a build-up of a vertical spin limits the sensitivity of the experiment. Such "systematic effects" are caused by machine imperfections, such as magnetic fields inside the magnetic shield surrounding the ring, and misalignments of electro-static elements or of the RF cavity. Operation of the machine with counter-rotating beams helps mitigating some of the effects. The most dangerous effects are those, which cannot be disentangled from an EDM by combining measurements from both counter-rotating beams, such as an average residual radial magnetic field penetrating the magnetic shield or a combination of magnetic fields and misalignments of electric elements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB178
About •	paper received ※ 18 May 2021 paper accepted ※ 17 June 2021 issue date ※ 20 August 2021
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MOPAB179	Simulations of AGS Boosters Imperfection Resonances for Protons and Helions	resonance, simulation, experiment, quadrupole	606
	K. Hock, H. Huang, F. Méot, N. Tsoupas BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. As part of the effort to increase the polarization of the proton beam for the physics experiments at RHIC, a scan of orbit harmonic corrector strengths is performed in the Booster to ensure polarization transmission through the \|G gamma\|=3 and 4 imperfection resonances is optimized. These harmonic scans have been simulated using quadrupole alignment data and accurately match experimental data. The method used to simulate polarized protons is extended to polarized helions for crossing the \|G gamma\|=5 through \|G gamma\|=10 imperfection resonances and used to determine the corrector strength required to cross each resonance.
	Poster MOPAB179 [0.437 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB179
About •	paper received ※ 17 May 2021 paper accepted ※ 31 May 2021 issue date ※ 02 September 2021
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MOPAB180	AGS Dynamic Aperture at Injection of Polarized Protons and Helions	dynamic-aperture, coupling, injection, extraction	610
	K. Hock, H. Huang, F. Méot, N. Tsoupas BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. Polarized helions are part of the physics program for the future EIC. An AC dipole has been installed in the AGS Booster to preserve polarization as helions are accelerated to \|Ggamma\|=10.5. Extraction from the AGS Booster at \|Ggamma\|=7.5 is possible but: would involve crossing an intrinsic resonance in the AGS, and would be the lowest rigidity beam injected into the AGS, and therefore experiences strong distortions of the optical functions because of the AGS two partial snakes. This lower rigidity would exacerbate the optical distortions from the snake, reducing the dynamic aperture. A comparison of the dynamic aperture of protons at Ggamma=4.5 to that of helions at \|Ggamma\|=7.5 and \|Ggamma\|=10.5 show that extraction at \|Ggamma\|=10.5 provides a larger dynamic aperture. This larger aperture would allow helions to be placed inside the spin tune gap generated by the two partial helices in AGS earlier in the cycle.
	Poster MOPAB180 [0.453 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB180
About •	paper received ※ 17 May 2021 paper accepted ※ 31 May 2021 issue date ※ 20 August 2021
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MOPAB181	Non-Delivery Time Reduction at MedAustron	extraction, dipole, synchrotron, MMI	613
	L. Adler, S. Danzinger, F. Farinon, F. Feichtinger, G. Guidoboni, N. Kahn, C. Kurfürst, D.A. Prokopovich, A. Wastl EBG MedAustron, Wr. Neustadt, Austria L.C. Penescu Abstract Landscapes, Montpellier, France
	Funding: Funding by the NÖ WIRTSCHAFTS- UND TOURISMUSFONDS under grant number WST3-F-5033232/001-2020. MedAustron is a cancer treatment center in Austria providing proton and carbon ion beams to three clinical and one non-clinical research beam lines. The slow extraction of particles from the synchrotron follows a third order resonance extraction scheme. Currently, for every change of extraction energy a new spill needs to be generated. Besides the beam-on time of the particle delivery, every spill is also comprised of non-delivery time components e.g. the multiturn injection, acceleration or magnet conditioning. For small tumor target volumes, this non-delivery time is the major contribution to the overall treatment time. A dedicated performance improvement project (supported with a grant from the state of lower Austria) was executed with the goal to reduce these non-delivery times without affecting important clinical beam parameters such as the beam size or penetration depth. The implemented reduction of the non-delivery time >50% could be achieved, resulting in beam-on time reductions for reference treatment plans between 25% (largest proton PTV) and 58% (smallest carbon PTV). Results of commissioning efforts, technical details and the achieved optimizations will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB181
About •	paper received ※ 14 May 2021 paper accepted ※ 28 May 2021 issue date ※ 25 August 2021
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MOPAB192	LILac Energy Upgrade to 13 MeV	cavity, linac, controls, LLRF	651
	B. Koubek, S. Altürk, M. Busch, H. Höltermann, J.D. Kaiser, H. Podlech, U. Ratzinger, M. Schuett, M. Schwarz, W. Schweizer, D. Strehl, R. Tiede, C. Trageser BEVATECH, Frankfurt, Germany A. Brunzel, P. Nonn, H. Schlarb DESY, Hamburg, Germany A.V. Butenko, D.E. Donets, B.V. Golovenskiy, A. Govorov, K.A. Levterov, D.A. Lyuosev, A.A. Martynov, V.A. Monchinsky, D.O. Ponkin, K.V. Shevchenko, I.V. Shirikov, E. Syresin JINR, Dubna, Moscow Region, Russia
	In the frame of the NICA (Nuclotron-based Ion Collider fAcility) ion collider upgrade a new light ion LINAC for protons and ions will be built in collaboration between JINR and BEVATECH GmbH. While ions with a mass-to-charge ratio up to 3 will be fed into the NUCLOTRON ring with an energy of 7 MeV/u, protons are supposed to be accelerated up to an energy of 13 MeV using a third IH structure. This energy upgrade comprises a third IH structure, a dual-use Debuncher cavity as well as an extension of the LLRF control system built on MicroTCA technology.
	Poster MOPAB192 [4.914 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB192
About •	paper received ※ 11 May 2021 paper accepted ※ 31 May 2021 issue date ※ 20 August 2021
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MOPAB207	Design Guideline for Minimizing Space-Charge-Induced Emittance Growth	emittance, rfq, space-charge, linac	682
	C. Zhang GSI, Darmstadt, Germany
	Space-charge-induced emittance growth is a big concern for designing low-energy and high-intensity linacs. The Equipartitioning Principle was introduced to minimize space-charge-induced emittance growth by removing free energy between the transverse and longitudinal degrees of freedom. In this study, a different design guideline is being proposed. It suggests holding the ratio of longitudinal emittance to transverse emittance around one and take advantage of low emittance transfer for minimizing emittance growth. Using a high-intensity RFQ accelerator as an example, a comparison between the two design methods has been made.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB207
About •	paper received ※ 17 May 2021 paper accepted ※ 21 May 2021 issue date ※ 01 September 2021
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MOPAB209	Commissioning of SANAEM RFQ Accelerator	rfq, cavity, vacuum, plasma	690
	B. Yasatekin, A. Alacakir, A.S. Bolukdemir, I. Kilic, Y. Olgac TENMAK-NUKEN, Ankara, Turkey E. Cicek KEK, Ibaraki, Japan E. Cosgun UNIST, Ulsan, Republic of Korea
	The former SANAEM RFQ is upgraded with a newly manufactured cavity, made of oxygen-free copper (OFC), having the capability of accelerating protons from 20 keV to 1.3 MeV. In the assembling of cavity vanes, flanges, etc., indium wire is preferred over the brazing process providing a more flexible and easy method for vacuum sealing. After assembling the cavity, argon plasma cleaning is performed for the final cleaning and RF pre-conditioning. Vacuum tests revealed that levels of 2·10^-7 mbar could be achieved quite easily. RF power conditioning of the RFQ cavity is successfully completed with the observation of quite few sparks. In the commissioning tests with the proton beam, a magnetic analyzer is used to measure the energy of the particles. This paper presents the strategy and the results concerning the commissioning of the proton beam with special emphasis on the RFQ cavity.
	Poster MOPAB209 [5.076 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB209
About •	paper received ※ 19 May 2021 paper accepted ※ 14 June 2021 issue date ※ 22 August 2021
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MOPAB210	High-Gradient Booster for Enhanced Proton Radiography at LANSCE	linac, booster, cavity, focusing	693
	S.S. Kurennoy, Y.K. Batygin LANL, Los Alamos, New Mexico, USA
	Increasing energy of proton beam at LANSCE from 800 MeV to 3 GeV improves radiography resolution ~10 times. We propose accomplishing this energy boost with a compact cost-effective linac based on cryo-cooled normal conducting high-gradient RF accelerating structures. High-gradient structures exceeding 100 MV/m have been developed for electron acceleration and operate with short RF pulse lengths below 1 us. Though such parameters are unusual for typical proton linacs, they fit perfectly for proton radiography (pRad) applications. The pRad limits contiguous trains of beam micro-pulses to less than 80 ns to prevent blur in images. For a compact pRad booster at LANSCE, we develop a staged design: a short section to capture and compress the 800-MeV proton beam followed by the main high-gradient linac. Our beam dynamics study addresses the beam magnetic focusing and minimizing its energy spread, which are challenging in high-gradient structures but very important for successful pRad operation.
	Poster MOPAB210 [0.809 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB210
About •	paper received ※ 10 May 2021 paper accepted ※ 17 August 2021 issue date ※ 11 August 2021
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MOPAB241	Design of the Proton and Electron Transfer Lines for AWAKE Run 2c	plasma, electron, acceleration, experiment	778
	R.L. Ramjiawan JAI, Oxford, United Kingdom S. Döbert, E. Gschwendtner, P. Muggli, F.M. Velotti, L. Verra CERN, Meyrin, Switzerland J.P. Farmer MPI-P, München, Germany P. Muggli MPI, Muenchen, Germany
	The AWAKE Run 1 experiment achieved electron acceleration to 2 GeV using plasma wakefield acceleration driven by 400 GeV, self-modulated proton bunches from the CERN SPS. The Run 2c phase of the experiment aims to build on these results by demonstrating acceleration to ~10 GeV while preserving the quality of the accelerated electron beam. To realize this, there will be an additional plasma cell, to separate the proton bunch self-modulation and the electron acceleration. A new 150 MeV beamline is required to transport and focus the witness electron beam to a beam size of several microns at the injection point. This specification is designed to preserve the beam emittance during acceleration, also requiring micron-level stability between the driver and witness beams. To facilitate these changes, the Run 1 proton transfer line will be reconfigured to shift the first plasma cell 40 m downstream. The Run 1 electron beamline will be adapted and used to inject electron bunches into the first plasma cell to seed the proton bunch self-modulation. Proposed adjustments to the proton transfer line and studies for the designs of the two electron transfer lines are detailed in this contribution.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB241
About •	paper received ※ 18 May 2021 paper accepted ※ 02 June 2021 issue date ※ 17 August 2021
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MOPAB263	Preliminary Beam Dynamics Studies for 200 MeV Superconducting Linac Planned at KOMAC	linac, DTL, radiation, lattice	837
	S. Lee, J.J. Dang, H.S. Kim, H.-J. Kwon Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea Y.-S. Cho KAERI, Daejon, Republic of Korea
	Funding: This work has been supported through KOMAC operation fund of KAERI by the Korea government (MSIT). Korea Multi-purpose Accelerator Complex (KOMAC) is planning an energy upgrade of the existing 100 MeV proton linac to 200 MeV using a superconducting Half Wave Resonator (HWR) operating at 350 MHz. A cryomodule is planned to house four HWR cavities with a warm doublet focusing lattice structure. Matching between the already existing DTL section and HWR section is designed and studied. We report the preliminary study of the beam dynamics of the 200 MeV superconducting linac carried out at KOMAC.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB263
About •	paper received ※ 20 May 2021 paper accepted ※ 01 July 2021 issue date ※ 24 August 2021
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MOPAB267	End to End Simulations of Antiproton Transport and Degradation	simulation, antiproton, experiment, electron	847
	S. Padden, E. Kukstas, P. Pusa, V. Rodin, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom K. Nordlund HIP, University of Helsinki, Finland V. Rodin, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The ELENA ring decelerates anti-protons to 100 keV down from 5.3 MeV with transport to experiments handled by electrostatic transfer lines. Even at 100 keV antiprotons are still too high in energy for direct injection into an ion trap, and this is why degrader foils are used to further lower the energy. This contribution presents full end-to-end simulations from the point of extraction until passing through the foil using realistic beam transport simulations coupled with accurate simulations of degrader foils via the use of density functional theory and molecular dynamics. Particles are tracked from the point of extraction until their injection into the trap with full physical modeling at all time steps. The results of this study provide a versatile platform for the optimization of low energy ion experiments towards specific targets.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB267
About •	paper received ※ 19 May 2021 paper accepted ※ 09 June 2021 issue date ※ 24 August 2021
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MOPAB279	Non-Invasive Beam Profile Monitoring for the HL-LHC Hollow Electron Lens	photon, electron, background, luminosity	884
	A. Salehilashkajani, N. Kumar, O. Sedláček, C.P. Welsch, H.D. Zhang The University of Liverpool, Liverpool, United Kingdom M. Ady, N.S. Chritin, N. Jens, O.R. Jones, R. Kersevan, T. Lefèvre, S. Mazzoni, G. Papazoglou, A. Rossi, G. Schneider, R. Veness CERN, Geneva, Switzerland P. Forck, S. Udrea GSI, Darmstadt, Germany N. Kumar, O. Sedláček, C.P. Welsch, H.D. Zhang Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: This work was supported by the HL-LHC-UK phase II project funded by STFC under Grant Ref: ST/T001925/1 and the STFC Cockcroft core grant No. ST/G008248/1. A Hollow Electron Lens (HEL) is currently under development for the High-Luminosity upgrade of the Large Hadron Collider (HL-LHC). In this device, a hollow electron beam co-propagates with a central proton beam and provides active halo control in the LHC. To ensure the concentricity of the two beams, a non-invasive diagnostic instrument is currently being commissioned. This instrument is a compact version of an existing prototype that leverages beam induced fluorescence with supersonic gas curtain technology. This contribution includes the design features of this version of the monitor, recent progress, and future plans for tests at the Cockcroft Institute and the electron lens test stand at CERN.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB279
About •	paper received ※ 18 May 2021 paper accepted ※ 15 June 2021 issue date ※ 02 September 2021
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MOPAB299	STRUCTURAL OPTIMIZATION DESIGN OF FARADAY CUP FOR BEAM COMMISSIONING OF CSNS	target, MMI, neutron, linac	943
	A.X. Wang, L. Kang, M. Meng, J.L. Sun IHEP, Beijing, People’s Republic of China J.X. Chen, H.Y. He, L. Liu, R.H. Liu, X.J. Nie, C.J. Ning, R.Y. Qiu, G.Y. Wang, T. Yang, J.B. Yu, Y.J. Yu, J.S. Zhang, D.H. Zhu IHEP CSNS, Guangdong Province, People’s Republic of China
	Faraday cup is used to absorb and stop the beam during the two phases of beam commissioning, such as the front end (FE) system and the temporary line after the drift tube linac (DTL) at the Chinese Spallation Neutron Source (CSNS). According to the beam physical parameters, graphite is selected to stop the beam directly, and oxygen-free copper which is just behind the graphite as the thermal conductive material. By the analysis and comparison of the target type and cooling efficiency, the single slant target is adopted. The incident angle between the target surface and the beam is set as 10°, meanwhile a new waterfall type water-cooling structure with parallel tunnels is designed to improve the cooling efficiency. The finite element software ANSYS is used for thermal analysis of the model, by which the diameter and interval of water cooling tunnels are optimized. The faraday cup discussed in this paper is finally successfully installed in the beam commissioning line and went well.
	Poster MOPAB299 [1.113 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB299
About •	paper received ※ 13 May 2021 paper accepted ※ 08 July 2021 issue date ※ 19 August 2021
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MOPAB315	Beam Diagnostics for Commissioning and Operation of the FAIR Proton Linac	linac, diagnostics, rfq, MMI	972
	T. Sieber, P. Forck, S. Udrea GSI, Darmstadt, Germany J. Herranz, A. Vizcaino-de-Julian Proactive Research and Development, Sabadell, Spain
	For the planned antiproton experiments at FAIR a dedicated proton injector Linac is currently under construction. It will be connected via the old UNILAC transfer beamline to SIS18 and has a length of ~30 m. The Linac will accelerate protons up to a final energy of 68 MeV, at a pulse length of 35 µs and a maximum repetition rate of 4 Hz. It will operate at 325 MHz and consists of a new so called "Ladder" RFQ type, followed by a chain of CH-cavities, partially coupled by rf-coupling cells. We have worked out a diagnostics system, which allows detailed measurement and study of all beam parameters during commissioning and later during regular operation. The diagnostics devices will - in a first step - be installed on a diagnostics testbench for stepwise commissioning. We present the concepts for Linac and testbench with some special emphasis on energy measurements with spectrometer and SEM Grid profile measurements.
	Poster MOPAB315 [3.149 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB315
About •	paper received ※ 14 May 2021 paper accepted ※ 24 June 2021 issue date ※ 30 August 2021
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MOPAB335	SNS Warm Linac Circulator Breakdown Considerations for the PPU Project	operation, linac, simulation, DTL	1041
	G.D. Toby, Y.W. Kang, S.-H. Kim, S.W. Lee, J.S. Moss ORNL, Oak Ridge, Tennessee, USA
	Funding: * This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract number DE-AC05-00OR22725. Multipacting in accelerating structures is a complex phenomenon about which there is much to be understood. While multipacting research efforts have primarily been focused on superconducting radio frequency (SRF) systems, normal conducting accelerating structures which have a higher thermal capacity, and a greater vacuum pressure tolerance could benefit from additional investigation. This research details multipacting simulation methods and the results of 3-D electromagnetic simulations of RF vacuum windows used on normal conducting linac (NCL) cavities. Benchmarking of the peak electric fields in these structures, benefits of material processing and possible techniques for reducing or eliminating multipacting activities are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB335
About •	paper received ※ 17 May 2021 paper accepted ※ 28 May 2021 issue date ※ 23 August 2021
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MOPAB341	First C-Band High Gradient Cavity Testing Results at LANL	cavity, GUI, operation, klystron	1057
	E.I. Simakov, R.L. Fleming, D. Gorelov, T.A. Jankowski, M.F. Kirshner, J.W. Lewellen, J.D. Pizzolatto, M.E. Schneider, T. Tajima LANL, Los Alamos, New Mexico, USA X. Lu, E.A. Nanni, S.G. Tantawi SLAC, Menlo Park, California, USA M.E. Middendorf ANL, Lemont, Illinois, USA
	Funding: Los Alamos National Laboratory LDRD Program. This poster will report the results of high gradient testing of the two proton β=0.5 C-band accelerating cavities. The cavities for proton acceleration were fabricated at SLAC and tested at high gradient C-band accelerator test stand at LANL. One cavity was made of copper, and the second was made of a copper-silver alloy. LANL test stand was constructed around a 50 MW, 5.712 GHz Canon klystron and is capable to provide power for conditioning single cell accelerating cavities for operation at surface electric fields up to 300 MV/m. These β=0.5 C-band cavities were the first two cavities tested on LANL C-band test stand. The presentation will report achieved gradients, breakdown probabilities, and other characteristics measured during the high power operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB341
About •	paper received ※ 19 May 2021 paper accepted ※ 25 May 2021 issue date ※ 30 August 2021
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MOPAB400	Development of Helium Vessel Welding Process for SNS PPU Cavities	cavity, cryomodule, neutron, accelerating-gradient	1212
	P. Dhakal, E. Daly, G.K. Davis, J.F. Fischer, N.A. Huque, K. Macha, P.D. Owen, K.M. Wilson, M. Wiseman JLab, Newport News, Virginia, USA
	Funding: This manuscript has been authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The Spallation Neutron Source Proton Power Upgrade cavities are produced by Research Instrument with all the cavity processing done at vendor sites with final chemistry applied to the cavity to be electropolishing. Cavities are delivered to Jefferson Lab, ready to be tested. One of the tasks to be completed before the arrival of production-ready PPU cavities is to develop a robust helium vessel welding protocol. We have successfully developed the process and applied it to three six-cell high beta cavities. Here, we present the summary of RF results, welding process development, and post helium vessel RF results.
	Poster MOPAB400 [1.313 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB400
About •	paper received ※ 18 May 2021 paper accepted ※ 26 May 2021 issue date ※ 01 September 2021
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MOPAB404	A Low Emittance Compact Proton Injector for a Proton Therapy Facility	ion-source, emittance, LEBT, rfq	1218
	S.X. Peng, J.E. Chen, B.J. Cui, Z.Y. Guo, Y.X. Jiang, K. Li, T.H. Ma, J. Sun, W.B. Wu, A.L. Zhang, J.F. Zhang PKU, Beijing, People’s Republic of China Y.H. Pu Shanghai APACTRON Particle Equipment Company Limited, Shanghai, People’s Republic of China
	To meet the requirements of a Proton Therapy Facility funded by the National Key Research and Development Program of China, a new compact ion source-LEBT integrated proton injector was developed at Peking University (PKU). It consists of a typical PKU permanent magnet compact 2.45 GHz ECR ion source (PMECRIS) and an electrostatic LEBT with an electrostatic lens, a beam chopper, a set of beam steers, an ACCT, a bellow, an e-trap, and a valve. A 1000 L/s molecular pump is adopted to maintain the vacuum for this integrated injector. The length from RF matching plane to RFQ front flange is about 450 mm. Chopper is used to shorten the pulse length from ms to µs with sharp edges. Test results of this PMECR source prove that it has the ability to deliver a proton beam with a current from 10 mA to 90 mA with a duty factor of 3%(100Hz/0.3ms) and its RMS emittance less than 0.1 mm·mrad at 30 keV. The acceptance tests of this integrated injector have been performed with a 30 keV hydrogen beam. A required proton current of 18 mA with ripple wave less than 0.1 mA successfully passed through a 20 mm aperture diaphragm at RFQ entrance flange. Its rms emittance is about 0.06 mm·mrad.
	Poster MOPAB404 [1.946 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB404
About •	paper received ※ 19 May 2021 paper accepted ※ 17 August 2021 issue date ※ 18 August 2021
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MOPAB411	Quantifying DNA Damage in Comet Assay Images Using Neural Networks	network, software, experiment, radiation	1233
	S.J.K. Dhinsey, T. Greenshaw, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom J.L. Parsons Cancer Research Centre, University of Liverpool, Liverpool, United Kingdom C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: This work was supported by the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1. Proton therapy for cancer treatment is a rapidly growing field and increasing evidence suggests it induces more complex DNA damage than photon therapy. Accurate comparison between the two treatments requires quantification of the DNA damage the cause, which can be assessed using the Comet Assay. The program outlined here is based on neural network architecture and aims to speed up analysis of Comet Assay images and provide accurate, quantifiable assessment of the DNA damage levels apparent in individual cells. The Comet Assay is an established technique in which DNA fragments are spread out under the influence of an electric field, producing a comet-like object. The elongation and intensity of the comet tail (consisting of DNA fragments) indicate the level of damage incurred. Many methods to measure this damage exist, using a variety of algorithms. However, these can be time consuming, so often only a small fraction of the comets available in an image are analysed. The automatic analysis presented in this contribution aims to improve this. To supplement the training and testing of the network, a Monte Carlo model will also be presented to create simulated comet assay images.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB411
About •	paper received ※ 19 May 2021 paper accepted ※ 09 June 2021 issue date ※ 16 August 2021
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MOPAB413	The Next Ion Medical Machine Study at CERN: Towards a Next Generation Cancer Research and Therapy Facility with Ion Beams	synchrotron, linac, superconducting-magnet, operation	1240
	M. Vretenar, V. Bencini, E. Benedetto, M.R. Khalvati, A.M. Lombardi, M. Sapinski, D. Tommasini CERN, Meyrin, Switzerland E. Benedetto, M. Sapinski TERA, Novara, Italy P. Foka GSI, Darmstadt, Germany
	Cancer therapy with ions has several advantages over X-ray and proton therapy, but its diffusion remains limited primarily because of the size and cost of the accelerator. To develop technologies that might improve performance and reduce accelerator cost with respect to present facilities, CERN has recently launched the Next Ion Medical Machine Study (NIMMS), leveraging CERN expertise in accelerator fields to disseminate technologies developed for basic science. A perspective user and key partner of NIMMS is the SEEIIST (South East European International Institute for Sustainable Technologies), established to build in the region an innovative facility for combined cancer therapy and biomedical research with ion beams. For SEEIIST and other potential users, three options are being considered. Conceptual designs of a warm-magnet synchrotron at high beam intensity, of a compact superconducting synchrotron, and of a high-frequency linear accelerator have been compared in terms of cost, risk and development time. The development of curved superconducting magnets, of compact synchrotrons and ion gantries, and of linacs is being pursued within EU-funded projects or specific collaborations
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB413
About •	paper received ※ 18 May 2021 paper accepted ※ 20 July 2021 issue date ※ 13 August 2021
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MOPAB416	BDSIM Developments for Hadron Therapy Centre Applications	simulation, radiation, shielding, neutron	1252
	E. Ramoisiaux, E. Gnacadja, C. Hernalsteens, N. Pauly, R. Tesse, M. Vanwelde ULB, Bruxelles, Belgium S.T. Boogert, L.J. Nevay Royal Holloway, University of London, Surrey, United Kingdom C. Hernalsteens CERN, Geneva, Switzerland W. Shields JAI, Egham, Surrey, United Kingdom
	Hadron therapy centres are evolving towards reduced-footprint layouts, often featuring a single treatment room. The evaluation of beam properties, radiation protection quantities, and concrete shielding activation via numerical simulations poses new challenges that can be tackled using the numerical beam transport and Monte-Carlo code Beam Delivery Simulation (BDSIM), allowing a seamless simulation of the dynamics as a whole. Specific developments have been carried out in BDSIM to advance its efficiency toward such applications, and a detailed 4D Monte-Carlo scoring mechanism has been implemented. It produces tallies such as the spatial-energy differential fluence in arbitrary scoring meshes. The feature makes use of the generic boost::histogram library and allows an event-by-event serialisation and storage in the ROOT data format. The pyg4ometry library is extended to improve the visualisation of critical features such as the complex geometries of BDSIM models, the beam tracks, and the scored quantities. Data are converted from Geant4 and ROOT to a 3D visualisation using the VTK framework. These features are applied to a complete IBA Proteus One model.
	Poster MOPAB416 [1.575 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB416
About •	paper received ※ 19 May 2021 paper accepted ※ 12 July 2021 issue date ※ 15 August 2021
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MOPAB417	Preliminary Study of a Large Energy Acceptance FFA Beam Delivery System for Particle Therapy	optics, focusing, superconducting-magnet, radiation	1256
	J.S.L. Yap, E.R. Higgins, S.L. Sheehy The University of Melbourne, Melbourne, Victoria, Australia
	The availability and use of ion beams for radiotherapy has grown significantly, led by technological developments to exploit the dosimetric advantages offered by charged particles. The benefits of particle therapy (PT) are well identified however its utilisation is still limited by high facility costs and technological challenges. A possibility to address both of these can be considered by improvements to the beam delivery system (BDS). Existing beamlines and gantries transport beams with a momentum range of ±1% and consequently, adjustments in depth or beam energy require all the magnetic fields to be changed. The speed to switch energies is a limiting constraint of the BDS and a determinant of the overall treatment time. A novel concept using fixed field alternating gradient (FFA) optics enables a large energy acceptance (LEA) as beams of varying energies can traverse the beamline at multiple physical positions given the same magnetic field. This presents the potential to provide faster, higher quality treatments at lower costs, with the capability to deliver advanced PT techniques such as multi-ion therapy. We explore the applicability and benefits of a LEA BDS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB417
About •	paper received ※ 18 May 2021 paper accepted ※ 27 July 2021 issue date ※ 15 August 2021
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MOPAB418	Tracking and LET Measurements with the MiniPIX-TimePIX Detector for 60 MeV Clinical Protons	detector, radiation, instrumentation, experiment	1260
	J.S.L. Yap, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom N.J.S. Bal NIKHEF, Amsterdam, The Netherlands M.D. Brooke University of Oxford, Oxford, United Kingdom C. Granja, C. Oancea ADVACAM s.r.o, Prague, Czech Republic A. Kacperek The Douglas Cyclotron, The Clatterbridge Cancer Centre NHS Foundation Trust, Wirral, United Kingdom C.P. Welsch, J.S.L. Yap The University of Liverpool, Liverpool, United Kingdom
	Funding: EU FP7 grant agreement 215080, H₂020 Marie Sklodowska-Curie grant agreement No 675265, OMA - Optimization of Medical Accelerators and the Cockcroft Institute core grant STGA00076-01. Recent advancements in accelerator technology have led the rapid emergence of particle therapy facilities worldwide, affirming the need for enhanced characterisation methods of radiation fields and radiobiological effects. The Clatterbridge Cancer Centre, UK operates a 60 MeV proton beam to treat ocular cancers and facilitates studies into proton induced radiobiological responses. Accordingly, an indicator of radiation quality is the linear energy transfer (LET), a challenging physical quantity to measure. The MiniPIX-Timepix is a miniaturised, hybrid semiconductor pixel detector with a Timepix ASIC, enabling wide-range measurements of the deposited energy, position and direction of individual charged particles. High resolution spectrometric tracking and simultaneous energy measurements of single particles enable the beam profile, time, spatial dose mapping and LET (0.1 to >100 keV/µm) to be resolved. Measurements were performed to determine the LET spectra in silicon, at different positions along the Bragg Peak (BP). We discuss the experimental setup, preliminary results and applicability of the MiniPIX for clinical environments.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB418
About •	paper received ※ 18 May 2021 paper accepted ※ 23 July 2021 issue date ※ 25 August 2021
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MOPAB419	Acceleration and Measurement of Alpha Particles and Hydrogen Molecular Ions with the HZB Cyclotron	cyclotron, radiation, vacuum, scattering	1264
	G. Kourkafas, J. Bundesmann, A. Denker, T. Fanselow, J. Röhrich HZB, Berlin, Germany J. Heufelder, A. Weber Charite, Berlin, Germany
	The HZB cyclotron has treated more than 4000 patients with eye tumors using protons. The accelerator can also provide heavier ions which could be suitable for ocular radiation therapy. Helium ions exhibit less lateral spread, increased relative biological effectiveness and a sharper Bragg-Peak compared to protons of the same range, while minimizing nuclear fragmentation and thus excessive dose downstream the irradiated volume compared to more heavy ions. When accelerating fully stripped helium ions (alpha particles), hydrogen molecular ions can also be accelerated to the same energy with a small tuning of the machine due to having almost the same mass-to-charge ratio, yielding a proton beam of double current after the beam exits the vacuum window towards the target. The acceleration and characterization of these two ion species are described in this paper, suggesting the feasibility of a corresponding clinical cyclotron for ocular or even deep-seated tumors.
	Poster MOPAB419 [0.806 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB419
About •	paper received ※ 19 May 2021 paper accepted ※ 09 June 2021 issue date ※ 13 August 2021
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TUXA04	Coherent Excitations and Circular Attractors in Cooled Ion Bunches	electron, collider, operation, experiment	1279
	S. Seletskiy, A.V. Fedotov, D. Kayran BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy In electron coolers, under certain conditions, a mismatch in either gamma-factors or trajectory angles between an electron and an ion beam can cause the formation of a circular attractor in the ion beam phase space. This leads to coherent excitations of the ions with a small synchrotron or betatron amplitude and results in unusual beam dynamics, including bifurcations. In this paper, we consider the effect of coherent excitations and discuss its implications both for Low Energy RHIC Electron Cooler (LEReC) and for high energy electron coolers proposed for the Electron-Ion Collider (EIC).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUXA04
About •	paper received ※ 19 May 2021 paper accepted ※ 20 July 2021 issue date ※ 11 August 2021
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TUPAB030	Superb Fixed Field Permanent Magnet Proton Therapy Gantry	permanent-magnet, radiation, hadron, MMI	1405
	D. Trbojevic, S.J. Brooks, T. Roser, N. Tsoupas BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. We present the top notch design of the proton therapy gantry made of permanent magnets with very strong focusing. This represents a superb solution fulfilling all cancer treatment requirements for all energies without changing any parameters. The proton energy range is between 60-250 MeV. The beam arrives to the patient focused at each required treatment energy. The scanning system is place between the end of the gantry and the patient. There are multiple advantages of this design: easy operation, no significant electrical power - just for the correction system, low weight, low cost. The design is based on the recent very successful commissioning of the permanent magnet ERL ’CBETA’ at Cornell University.
	Poster TUPAB030 [7.816 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB030
About •	paper received ※ 17 May 2021 paper accepted ※ 07 June 2021 issue date ※ 21 August 2021
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TUPAB031	Construction and Installation of the New CERN Proton Synchrotron Internal Beam Dumps	vacuum, MMI, shielding, interface	1409
	K.G. Andersen, M. Calviani, A. Cherif, T. Coiffet, A. De Macedo, S. Devidal, J.-M. Geisser, S.S. Gilardoni, M.M.J. Gillet, E. Grenier-Boley, J.M. Heredia, A. Majbour, F. Monnet, M.R. Monteserin, F.-X. Nuiry, D. Pugnat, G. Romagnoli, Y.D.R. Seraphin, J.A.F. Somoza, N. Thaus CERN, Geneva 23, Switzerland
	In the framework of the CERN Large Hadron Collider Injectors Upgrade (LIU) Project, the Proton Synchrotron (PS) has been equipped with two new movable Internal Dumps (PSID), each of them capable of absorbing particle beams of an energy of up to 100 kJ. These dumps replace the old Internal Dumps, which have been operated in the accelerator complex since their installation in 1975 until their decommissioning and removal from the machine during the second LHC Long Shut down (LS2). This contribution will address the construction and testing phases of the new PSIDs, including the assembly of the dump core, its actuation system and the respective shielding, mechanical running-in tests, metrology adjustments, Ultra-High Vacuum (UHV) and impedance acceptance tests. The described installation work was completed successfully, and the new generation Dumps are currently operational in the PS machine.
	Poster TUPAB031 [3.146 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB031
About •	paper received ※ 18 May 2021 paper accepted ※ 27 May 2021 issue date ※ 26 August 2021
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TUPAB036	The Accelerator Design Progress for EIC Strong Hadron Cooling	electron, hadron, linac, emittance	1424
	E. Wang, S. Peggs, V. Ptitsyn, F.J. Willeke, W. Xu BNL, Upton, New York, USA S.V. Benson JLab, Newport News, Virginia, USA D. Douglas Douglas Consulting, York, Virginia, USA C.M. Gulliford, G.H. Hoffstaetter Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA C.E. Mayes Xelera Research LLC, Ithaca, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy, The Electron-Ion Collider will achieve a luminosity of 10³⁴ cm^-2 s⁻¹ by incorporating strong hadron cooling to counteract hadron Intra-Beam Scattering, using a coherent electron cooling scheme. An accelerator will deliver the beams with key parameters, such as 1 nC bunch charge, and 1e-4 energy spread. The paper presents the design and beam dynamics simulation results. Methods to minimize beam noise, the challenges of the accelerator design, and the R&D topics being pursued are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB036
About •	paper received ※ 16 May 2021 paper accepted ※ 11 June 2021 issue date ※ 01 September 2021
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TUPAB040	Design Concept for the Second Interaction Region for Electron-Ion Collider	electron, detector, dipole, optics	1435
	B.R. Gamage, V. Burkert, R. Ent, Y. Furletova, D.W. Higinbotham, A. Hutton, F. Lin, T.J. Michalski, V.S. Morozov, R. Rajput-Ghoshal, D. Romanov, T. Satogata, A. Seryi, A.V. Sy, C. Weiss, M. Wiseman, W. Wittmer, Y. Zhang JLab, Newport News, Virginia, USA E.C. Aschenauer, J.S. Berg, A. Jentsch, A. Kiselev, C. Montag, R.B. Palmer, B. Parker, V. Ptitsyn, F.J. Willeke, H. Witte BNL, Upton, New York, USA C. Hyde ODU, Norfolk, Virginia, USA P. Nadel-Turonski SBU, Stony Brook, New York, USA
	Funding: Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177 and Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. The possibility of two interaction regions (IRs) is a design requirement for Electron-Ion Collider (EIC). There is also a significant interest from the nuclear physics community to have a 2nd IR with measurement capabilities complementary to those of the 1st IR. While the 2nd IR will be in operation over the entire energy range of ~20GeV to ~140GeV center of mass (CM). The 2nd IR can also provide an acceptance coverage complementary to that of the 1st. In this paper, we present a brief overview and the current progress of the 2nd IR design in terms of the parameters, magnet layout, and beam dynamics.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB040
About •	paper received ※ 24 May 2021 paper accepted ※ 31 August 2021 issue date ※ 30 August 2021
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TUPAB138	Determination of the Phase of Wakefield Driven by a Self-Modulated Proton Bunch in Plasma	plasma, wakefield, electron, emittance	1710
	K. Moon, M. Chung UNIST, Ulsan, Republic of Korea P. Muggli MPI-P, München, Germany
	Funding: This work was partly supported by the National Research Foundation of Korea (Nos. NRF-2016R1A5A1013277 and NRF-2020R1A2C1010835) The phase of wakefield driven by a self-modulated proton bunch depends on the type of seeding method and by the beam-plasma parameters.* Particularly when a preceding electron bunch generates seed wakefield, the proton bunch modulation is strongly affected by the seed bunch dynamics along with the plasma. Intrinsic wakefield dephasing from self-modulation of proton bunch can lead to complex evolution of the bunch and wakefield, making it difficult to design an experimental setup for witness beam injection. Using the particle-in-cell code FBPIC,** we investigate in detail the trends of seed electron and driver proton bunch parameter sensitivity to the phase of wakefield in time in the proton bunch frame. We focus on the parameters affecting the phase of the wakefield through the beam’s radial dynamics, such as beam emittance, radial size, energy, and beam to plasma density ratio. Parameter variations are compared to those in the case of the phase of wakefield driven by a non-evolving seed bunch. F. Batsch, arXiv:2012.09676 [physics.plasm-ph] *R. Lehe, M. Kirchen, I.A. Andriyash, B.B. Godfrey, and J.-L. Vay, Comput. Phys. Comm. 203, 66-82 (2016)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB138
About •	paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 30 August 2021
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TUPAB159	Awake Run 2 at CERN	plasma, electron, experiment, acceleration	1757
	E. Gschwendtner CERN, Meyrin, Switzerland
	The AWAKE Run 2 experiment, starting in 2021 at CERN, aims to achieve high-charge bunches of electrons accelerated to high energy (~10 GeV) while maintaining beam quality. AWAKE Run 2 also aims to show that the process is scalable so that, by the end of the run, the AWAKE-scheme technology could be used for first particle physics applications. The first two phases of Run 2 include the investigation of the seeding of the proton bunch self-modulation with the current electron beam in the existing AWAKE facility and the test of a second new plasma source with a density step allowing to maintain strong accelerating fields. In the third phase of Run 2, electrons with an energy of 150 MeV, produced in a newly installed electron source, will be injected into a second plasma source and accelerated to high energies (several GeVs) while keeping good emittance. In the fourth phase, it is planned to replace the second plasma source with a scalable one, which eventually could be used for long-distance acceleration and first applications. In this paper, we present the program of the four phases of AWAKE Run 2, the technical challenges and the proposed schedule.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB159
About •	paper received ※ 17 May 2021 paper accepted ※ 11 June 2021 issue date ※ 19 August 2021
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TUPAB160	Preparation for Electron-Seeding of Proton Bunch Self-Modulation in AWAKE	electron, plasma, experiment, simulation	1761
	G. Zevi Della Porta, E. Gschwendtner, L. Verra CERN, Meyrin, Switzerland K. Moon UNIST, Ulsan, Republic of Korea P. Muggli, L. Verra MPI, Muenchen, Germany
	The next milestone of the Advanced Wakefield Experiment (AWAKE) at CERN will be to demonstrate that the self-modulation of a long proton bunch can be seeded by a short electron bunch preceding it. This seeding method will lead to phase-reproducible self-modulation of the entire proton bunch, as required for the future AWAKE program. In the Spring of 2021, before receiving proton beams from the CERN SPS, AWAKE plans to hold a dry run of the electron seeding experiments, to commission the system and to determine the parameter scans that will be used in experiments with protons. Electron bunches of 10-20 MeV with varying charge, radius, emittance and energy will be sent in 10 m of low-density plasma. The effects of beam-plasma interactions on the amplitude of the wakefields driven by the different bunches will be studied by observing the energy spectra at the end of the plasma. This paper presents preliminary experimental results from the first two days of measurements as well as the beginning of a simulation-based study of electron propagation in plasma.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB160
About •	paper received ※ 18 May 2021 paper accepted ※ 15 June 2021 issue date ※ 27 August 2021
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TUPAB168	Beam Commissioning of a 325 MHz Proton IH-DTL at XiPAF	DTL, cavity, emittance, linac	1777
	P.F. Ma, X. Guan, R. Tang, M.W. Wang, X.W. Wang, Q.Z. Xing, W.B. Ye, S.X. Zheng TUB, Beijing, People’s Republic of China W. Chen, W.L. Liu, W. Lv, M.T. Qiu, B.C. Wang, D. Wang, M.C. Wang, Z.M. Wang, Y.H. Yan, Y. Yang, M.T. Zhao NINT, Xi’an, People’s Republic of China
	The Inter-Digital H-mode Drift Tube Linac (IH-DTL) is widely used as the main component of injectors for medical synchrotrons. This paper describes the beam commissioning of a compact 325 MHz IH-DTL with modified KONUS beam dynamics at Tsinghua University (THU). This IH-DTL accelerates the proton beam from 3 MeV to 7 MeV in 1m. The average energy of the beam is 7.0 MeV with the energy spread range of -0.6 MeV to 0.3 MeV. The output transverse normalized RMS emittance of the beam is 0.58 (x)/0.58 (y) pi mm mrad with the input emittance of 0.43 (x)/0.37 (y) pi mm mrad. The beam test results show good agreement with the beam dynamics design.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB168
About •	paper received ※ 08 May 2021 paper accepted ※ 16 June 2021 issue date ※ 14 August 2021
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TUPAB172	Quadrupole Magnet Design for a Heavy-Ion IH-DTL	quadrupole, heavy-ion, DTL, linac	1793
	P.F. Ma, C.T. Du, X. Guan, M.W. Wang, X.W. Wang, Y.L. Wang, Q.Z. Xing, X.D. Yu, S.X. Zheng TUB, Beijing, People’s Republic of China W. Chen, W.L. Liu, W. Lv, M.T. Qiu, B.C. Wang, D. Wang, M.C. Wang, Z.M. Wang, Y.H. Yan, M.T. Zhao NINT, Xi’an, People’s Republic of China
	Xi’an Proton Application Facility (XiPAF) will be upgraded to provide heavy-ion beams with a heavy-ion injector. The injector consists of an ECR heavy-ion source, a Low Energy Beam Transport line (LEBT), a Radio Frequency Quadrupole (RFQ), an Interdigital H-mode Drift Tube Linac (IH-DTL), and a Linac to Ring Beam Transport line (LRBT). The IH-DTL can accelerate the ions with mass to charge up to 6.5 from 0.4 MeV/u to 2 MeV/u. To provide transverse focusing, the electro-magnetic quadrupoles are installed inside the drift tubes of IH-DTL, thus the magnet needs to be high-gradient and compact. This paper gives the quadrupole magnet design for the heavy-ion IH-DTL. The results show that the quadrupole magnet design can meet the requirements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB172
About •	paper received ※ 08 May 2021 paper accepted ※ 21 June 2021 issue date ※ 23 August 2021
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TUPAB175	ESSnuSB Linac and Transfer Line: Lattice Design and Error Studies	linac, lattice, dipole, DTL	1805
	N. Blaskovic Kraljevic, M. Eshraqi, B.T. Folsom ESS, Lund, Sweden
	Funding: ESSnuSB has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 777419. The ESS neutrino superbeam (ESSnuSB) project is being studied as an upgrade to the European Spallation Source (ESS). This proposed upgrade consists of adding an H⁻ source to the existing beamline in order to send H⁻ pulses in between proton pulses, effectively doubling the beam power from 5 MW to 10 MW. In this contribution, we present the 2.5 GeV linear accelerator (linac) lattice and the design of the transfer line from the linac to the accumulator ring, where pulses would be stacked to achieve short proton pulses of high intensity. The results of error studies, quantifying the effect of accelerator imperfections and H⁻ ion stripping losses on the beam transport through the linac and transfer line, are also presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB175
About •	paper received ※ 19 May 2021 paper accepted ※ 14 June 2021 issue date ※ 31 August 2021
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TUPAB179	Design of an MBEC Cooler for the EIC	electron, kicker, hadron, simulation	1819
	W.F. Bergan, P. Baxevanis, M. Blaskiewicz, E. Wang BNL, Upton, New York, USA G. Stupakov SLAC, Menlo Park, California, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. Reaching maximal luminosity for the planned electron-ion collider (EIC) calls for some form of strong hadron cooling to counteract beam emittance increase from IBS. We discuss plans to use microbunched electron cooling (MBEC) to achieve this. The principle of this method is that the hadron beam will copropogate with a beam of electrons, imprinting its own density modulation on the electron beam. These electron phase space perturbations are amplified before copropogating with the hadrons again in a kicker section. By making the hadron transit time between modulator and kicker dependent on hadron energy and transverse offset, the energy kicks which they receive from the electrons will tend to reduce their longitudinal and transverse emittances. We discuss details of the analytic theory and searches for optimal realistic parameter settings to achieve a maximal cooling rate while limiting the effects of diffusion and electron beam saturation. We also place limits on the necessary electron beam quality. These results are corroborated by simulations.
	Poster TUPAB179 [4.006 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB179
About •	paper received ※ 19 May 2021 paper accepted ※ 18 June 2021 issue date ※ 24 August 2021
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TUPAB180	Plasma Simulations for an MBEC Cooler for the EIC	electron, hadron, simulation, kicker	1823
	W.F. Bergan BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. In order to reach its maximum luminosity, the electron-ion collider (EIC) is being designed to use microbunched electron cooling (MBEC) to cool the hadron beam. This involves having the hadron beam imprint on a beam of electrons, enhancing the perturbations in the electron beam using the microbunching instability, and feeding back on the original hadron beam to correct deviations in hadron energy, and, through the use of dispersion, the transverse emittances. This process has been modelled analytically in the linear regime. However, in order to maximize the cooling rate, we wish to know how much saturation in the electron beam is acceptable before the effects of nonlinearity cause significant deviations from the analytic results. To understand this, we have developed a code to do fast one-dimensional plasma simulations of hadrons and electrons as they move through the MBEC section of the EIC. In addition to permitting us to understand the effects of saturation, other effects are included which do not fit easily in the analytic formalism. G. Stupakov and P. Baxevanis, PRAB 22, 034401 (2019).
	Poster TUPAB180 [1.955 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB180
About •	paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 18 August 2021
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TUPAB188	InnovaTron: An Innovative High-Intensity Industrial Cyclotron for Production of Tc-99m and Other Frontier Medical Radioisotopes*	cyclotron, extraction, ion-source, acceleration	1841
	G. D’Agostino, Q. Flandroy, E. Forton, W.J.G.M. Kleeven, J. Mandrillon, V. Nuttens, E. van der Kraaij IBA, Louvain-la-Neuve, Belgium
	Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 886190. Tc-99m is the most used radioisotope in nuclear medicine. It is almost exclusively produced with a few ageing research reactors worldwide. In response to growing concerns about Tc-99m availability and its increasing demand, alternative production routes are being explored. The EU-funded InnovaTron project aims at designing an innovative compact high-intensity self-extracting cyclotron able to deliver proton beams with currents up to 5 mA or more for the direct production of Tc-99m. It could be also used for production of high quantities of other frontier medical radioisotopes. The proton beams exit without using an electrostatic deflector to overcome its current limitations. A prototype cyclotron was built by IBA in 2001. Currents up to 2 mA were extracted from it. However, at higher intensities, the extraction efficiency was not higher than 70-75% and the extracted emittance was rather large. The InnovaTron project will implement new technological solutions in the self-extracting cyclotron to be used for large-scale industrial applications. An overview on the InnovaTron project is here presented together with the first simulation results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB188
About •	paper received ※ 18 May 2021 paper accepted ※ 01 June 2021 issue date ※ 25 August 2021
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TUPAB198	ESS DTL Tuning Using Machine Learning Methods	network, cavity, DTL, linac	1872
	J.S. Lundquist, N. Milas, E. Nilsson ESS, Lund, Sweden S. Werin Lund University, Lund, Sweden
	The European Spallation Source, currently under construction in Lund, Sweden, will be the world’s most powerful neutron source. It is driven by a proton linac with a current of 62.5 mA, 2.86 ms long pulses at 14 Hz. The final section of its normal-conducting front-end consists of a 39 m long drift tube linac (DTL) divided into five tanks, designed to accelerate the proton beam from 3.6 MeV to 90 MeV. The high beam current and power impose challenges to the design and tuning of the machine and the RF amplitude and phase have to be set within 1% and 1 degree of the design values. The usual method used to define the RF set-point is signature matching, which can be a time consuming and challenging process, and new techniques to meet the growing complexity of accelerator facilities are highly desirable. In this paper we study the usage of Machine Learning to determine the RF optimum amplitude and phase. The data from a simulated phase scan is fed into an artificial neural network in order to identify the needed changes to achieve the best tuning. Our test for the ESS DTL1 shows promising results, and further development of the method will be outlined.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB198
About •	paper received ※ 17 May 2021 paper accepted ※ 21 June 2021 issue date ※ 13 August 2021
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TUPAB199	Progress on the Proton Power Upgrade at the Spallation Neutron Source	target, klystron, linac, cryomodule	1876
	M.S. Champion, C.N. Barbier, M.S. Connell, J. Galambos, M.P. Howell, S.-H. Kim, J.S. Moss, B.W. Riemer, K.S. White ORNL, Oak Ridge, Tennessee, USA E. Daly JLab, Newport News, Virginia, USA N.J. Evans, G.D. Johns ORNL RAD, Oak Ridge, Tennessee, USA
	Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. This research was supported by the DOE Office of Science, Basic Energy Science. The Proton Power Upgrade Project at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory will double the proton power capability from 1.4 to 2.8 MW. This will be accomplished through an energy increase from 1.0 to 1.3 GeV and a beam current increase from 26 to 38 mA. The energy increase will be accomplished through the addition of 7 cryomodules to the linear accelerator (Linac). The beam current increase will be supported by upgrading several radio-frequency systems in the normal-conducting section of the Linac. Upgrades to the accumulator ring injection and extraction regions will accommodate the increase in beam energy. A new 2-MW-capable target and supporting systems will be developed and installed. Conventional facility upgrades include build-out of the existing klystron gallery and construction of a tunnel stub to facilitate future beam transport to the second target station. The project received approval to proceed with construction in October 2020. Procurements are in progress, and some installation activities have already occurred. Most of the installation will take place during three outages in 2022-2023. The project early finish is planned for 2025.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB199
About •	paper received ※ 10 May 2021 paper accepted ※ 28 May 2021 issue date ※ 21 August 2021
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TUPAB204	Upgrade of Los Alamos Accelerator Facility as a Fusion Prototypic Neutron Source	target, neutron, radiation, linac	1890
	Y.K. Batygin, E.J. Pitcher LANL, Los Alamos, New Mexico, USA
	Funding: Work supported by US DOE under contract 89233218CNA000001 The Fusion Prototypic Neutron Source (FPNS) is considered to be a testbed for scientific understanding of material degradation in future nuclear fusion reactors. The primary mission of FPNS is to provide a damage rate in samples of 8-11 dpa/calendar year with He/dpa ratio of 10 appm in irradiation volume of 50 cubic cm or larger with irradiation temperature 300-1000 deg C and flux gradient less than 20%/cm in the plane of the sample. Los Alamos Neutron Science Center (LANSCE) is an attractive candidate for FPNS project. Accelerator Facility was designed and operated for an extended period as a 0.8-MW Meson Factory. Existing setup of the LANSCE accelerator complex can nearly fulfill requirements of the fusion neutron source station. The primary function of the upgraded accelerator systems is the safe and reliable delivery of a 1.25-mA continuous proton beam current at 800-MeV beam energy from the switchyard to the target assembly to create 1 MW power of proton beam interacting with a solid tungsten target. The present study describes existing accelerator setup and further development required to meet the needs of FPNS project.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB204
About •	paper received ※ 14 May 2021 paper accepted ※ 02 June 2021 issue date ※ 21 August 2021
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TUPAB205	Advancement of LANSCE Front End Accelerator Facility	rfq, DTL, neutron, linac	1894
	Y.K. Batygin, D. Gorelov, S.S. Kurennoy, J.W. Lewellen, N.A. Moody, L. Rybarcyk LANL, Los Alamos, New Mexico, USA
	Funding: Work supported by US DOE under contract 89233218CNA000001 The LANSCE accelerator started routine operation in 1972 as a high-power facility for fundamental research and national security applications. To reduce long-term operational risk, we propose to develop a new Front End of accelerator facility. It contains 100-keV injector with 3-MeV RFQ, and 6-tanks Drift Tube Linac to accelerate particles up to energy of 100 MeV. The low-energy injector concept includes two independent transports merging H⁺ and H⁻ beams at the entrance of RFQ. Beamlines are aimed to perform preliminary beam bunching in front of accelerator section with subsequent simultaneous acceleration of two different beams in a single RFQ. The paper discusses design topics of new Front End of accelerator facility.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB205
About •	paper received ※ 12 May 2021 paper accepted ※ 28 May 2021 issue date ※ 14 August 2021
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TUPAB208	FETS-FFA Ring Study	lattice, injection, optics, closed-orbit	1901
	J.-B. Lagrange, D.J. Kelliher, A.P. Letchford, S. Machida, C.R. Prior, C.T. Rogers STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom S.J. Brooks BNL, Upton, New York, USA C. Brown Brunel University, Middlesex, United Kingdom J. Pasternak STFC/RAL, Chilton, Didcot, Oxon, United Kingdom J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom E. Yamakawa JAI, Egham, Surrey, United Kingdom
	ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK, providing a proton beam with a power of 0.2~MW. Detailed studies are under way for a major upgrade, including the use of Fixed Field alternating gradient Accelerator (FFA). A proof-of-principle FFA ring, called FETS-FFA is planned to investigate the feasibility of this kind of machine for the required MW beam power. This paper discusses the study of the FETS-FFA ring case.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB208
About •	paper received ※ 19 May 2021 paper accepted ※ 08 July 2021 issue date ※ 14 August 2021
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TUPAB210	Construction Status of the COMET Experimental Facility	target, experiment, solenoid, radiation	1907
	Y. Fukao, K. Agari, H. Akiyama, E. Hirose, M. Ieiri, Y. Igarashi, M.I. Iio, N. Kamei, Y. Katoh, Y. Komatsu, R. Kurasaki, M. Maki, S. Makimura, S. Mihara, M. Minakawa, Y. Morino, F. Muto, H. Nishiguchi, T. Okamura, K. Sasaki, Y. Sato, S. Sawada, N. Sumi, H. Takahashi, K.H. Tanaka, A. Toyoda, K. Ueno, H. Watanabe, Y. Yamanoi, M.Y. Yoshida KEK, Tsukuba, Japan
	COMET (COherent Muon to Electron Transition) is an experimental project that hunts for a phenomenon of the conversion from the muon to the electron (mu-e conversion). The mu-e conversion violates the lepton flavor universality and its discovery indicates a proof of the physics beyond the standard model of the particle physics. The experiment utilizes a high-intensity primary proton-beam of J-PARC (Japan Proton Accelerator Research Complex). The proton beam is injected to a target about 700mm long to generate a high intensity muon beam so as to accumulate huge statistics and achieve the final goal of a sensitivity of 10^-16. Construction of the experimental facility is underway at a high pace towards an engineering run in 2022 and the first physics run in 2023. In this presentation, we would like to present a current status of the COMET facility construction.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB210
About •	paper received ※ 17 June 2021 paper accepted ※ 21 June 2021 issue date ※ 13 August 2021
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TUPAB231	Cooling of an Annular Beam by Using Nonlinear Effects	resonance, dipole, emittance, extraction	1968
	F. Capoani, M. Giovannozzi, R. Tomás García CERN, Geneva, Switzerland A. Bazzani, F. Capoani Bologna University, Bologna, Italy
	In recent years, nonlinear effects have been used to modify the transverse beam distribution by crossing nonlinear resonances adiabatically. This allows generating transversally split beams, in which the initial single Gaussian is divided into several ones depending on the order and stability type of the resonance used. Nonlinear effects could be used to try and cool a beam by acting on its transverse beam distribution. In this paper, we present and discuss the special case of a beam with an annular distribution, showing how the resulting emittance could be reduced by means of nonlinear effects.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB231
About •	paper received ※ 10 May 2021 paper accepted ※ 16 June 2021 issue date ※ 21 August 2021
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TUPAB232	Linear Coupling and Adiabaticity of Emittance Exchange	resonance, coupling, emittance, extraction	1972
	F. Capoani, M. Giovannozzi CERN, Geneva, Switzerland A. Bazzani, F. Capoani Bologna University, Bologna, Italy A.I. Neishtadt IKI, Moscow, Russia A.I. Neishtadt Loughborough University, Leicestershre, United Kingdom
	In circular accelerators, crossing the coupling resonance induces the exchange of the transverse emittances, provided the process is adiabatic. In this paper, we introduce a theoretical framework to analyze the resonance-crossing process, based on Hamiltonian mechanics, which is capable of explaining all the features of the emittance exchange process.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB232
About •	paper received ※ 11 May 2021 paper accepted ※ 16 June 2021 issue date ※ 27 August 2021
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TUPAB240	The Impact of Trajectory-Shaped Coil on the Beam Dynamics in the SC230 Superconducting Cyclotron	cyclotron, betatron, extraction, induction	2002
	I.D. Lyapin, O. Karamyshev, V. Malinin, D. Popov JINR/DLNP, Dubna, Moscow region, Russia G.A. Karamysheva JINR, Dubna, Moscow Region, Russia
	In this paper, we compared the effect of the cyclotron coil shape on the beam dynamics. Two models were created. The first has a conventional round coil, the second has a coil that follows the trajectory of the protons. Parameters of extracted beams are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB240
About •	paper received ※ 19 May 2021 paper accepted ※ 27 May 2021 issue date ※ 21 August 2021
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TUPAB258	Impact of Coherent Beam-Beam Interaction on the Landau Damping of the Transverse Coupled-Bunch Instability	dipole, electron, damping, coupling	2062
	R. Li JLab, Newport News, Virginia, USA M. Blaskiewicz BNL, Upton, New York, USA
	Funding: This work is supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177. In the EIC design, at high average-current operation, the transverse coupled-bunch instability (TCBI) induced by the long-range transverse resistive-wall wakefield in the electron storage ring (eSR) has a fast growth rate and requires efficient mitigation. A natural mitigation mechanism is provided by the beam-beam interaction at the interaction point (IP), which gives a strong Landau damping for the TCBI in the eSR. In this study, using a simplified simulation model, we investigate how this Landau damping from the beam-beam interaction behaves when the coherent beam-beam interaction at IP is considered. Our method and results will be presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB258
About •	paper received ※ 21 June 2021 paper accepted ※ 01 July 2021 issue date ※ 25 August 2021
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TUPAB262	The Characteristic of the Beam Position Growth in CSNS/RCS	neutron, MMI, impedance, synchrotron	2073
	L. Huang, S. Wang IHEP, Beijing, People’s Republic of China S.Y. Xu DNSC, Dongguan, People’s Republic of China
	Funding: Work supported by NNSF of China: N0. U1832210 An instability of the beam position growth is observed in the beam commissioning of the Rapid Cycling Synchrotron of the China Spallation Neutron Source. To simplify the study, a series of measurements have been performed to characterize the instability in the DC mode with consistent energy of 80 MeV. The measurement campaign is introduced in the paper and it conforms to the characteristics of the coupled bunch instability.
	Poster TUPAB262 [3.748 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB262
About •	paper received ※ 13 May 2021 paper accepted ※ 02 June 2021 issue date ※ 22 August 2021
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TUPAB263	The Phase Loop Status of the RF System in CSNS/RCS	feedback, cavity, space-charge, MMI	2076
	L. Huang, X. Li, S. Wang IHEP, Beijing, People’s Republic of China M.T. Li, H.Y. Liu IHEP CSNS, Guangdong Province, People’s Republic of China Y. Liu DNSC, Dongguan, People’s Republic of China
	The Rapid Cycling Synchrotron (RCS) of the China Spallation Neutron Source (CSNS) is a high intensity proton accelerator. The acceleration system consists of eight ferrite loaded cavities. The RCS is the space charge dominant machine and it is mitigated through the bunch factor optimization in the beam commissioning, so the injected beam will occupy a larger bucket size and unavoidable mismatch with the bucket, thus the dipole oscillation is excited. The phase loop scheme is designed to restrict the oscillation in the RF system, but the transmission efficiency is reduced by the phase loop and the bunch factor also increases, so the phase loop scheme is studied. To keep the phase loop but also maintain the transmission efficiency, we optimized the original phase loop scheme, but the beam loss still increases small when the loop on.
	Poster TUPAB263 [1.548 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB263
About •	paper received ※ 13 May 2021 paper accepted ※ 02 June 2021 issue date ※ 21 August 2021
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TUPAB283	Feasibility Study of ChDR Diagnostic Device in the LHC	radiation, diagnostics, flattop, electron	2139
	K. Łasocha Jagiellonian University, Kraków, Poland M. Bergamaschi, M. Krupa, K. Łasocha, T. Lefèvre, S. Mazzoni, N. Mounet, E. Senes CERN, Geneva, Switzerland D.M. Harryman JAI, Egham, Surrey, United Kingdom P. Karataev Royal Holloway, University of London, Surrey, United Kingdom A. Potylitsyn TPU, Tomsk, Russia A. Schloegelhofer TU Vienna, Wien, Austria
	In recent years Cherenkov Diffraction Radiation (ChDR) has been reported as a phenomenon suitable for various types of particle accelerator diagnostics. As it would typically work best for highly relativistic beam, past studies and experiments have been mostly focusing on the lepton machines. This contribution investigates the prospects on the utilization of ChDR as a diagnostic tool for the Large Hadron Collider (LHC). Based on theoretical considerations and simulation results we estimate the properties of the expected radiation, both in the incoherent and coherent domain, and we compare them with the requirements of the existing diagnostic systems. We also address the potential problem of the use of dielectric radiators in circular machines, where secondary electrons could potentially lead to the creation of electron clouds inside the beam pipe that may affect the radiator.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB283
About •	paper received ※ 14 May 2021 paper accepted ※ 18 June 2021 issue date ※ 02 September 2021
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TUPAB284	BPM for the High Energy Beam Transport Line of MINERVA Project at SCK•CEN	linac, instrumentation, experiment, electron	2143
	H. Kraft, L. Perrot Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
	This paper presents the status of developments concerning button type BPM. Results of our analytical model BPMOK will compare the measurements done at IPHI facility at CEA-Saclay and GANIL/SPIRAL2 in Caen. The measurements aims to compare the response of the analytical model depending on beam positions, sizes, intensities and energies. BPMOK is validated to predict BPM responses in order to make parametric studies. Starting from already existing BPM built for the MINERVA LINAC, the analytical model is used to design the BPM for the HEBT.
	Poster TUPAB284 [1.475 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB284
About •	paper received ※ 10 May 2021 paper accepted ※ 02 June 2021 issue date ※ 28 August 2021
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TUPAB311	Nonlinear Correctors Tuning for the Collector Ring Isochronous Mode	sextupole, betatron, optics, controls	2218
	M.A. Lyalin, I. Koop, D.B. Shwartz BINP SB RAS, Novosibirsk, Russia I. Koop, M.A. Lyalin, D.B. Shwartz NSU, Novosibirsk, Russia
	One of the operating modes for the Collector Ring (CR) under construction in Darmstadt is the isochronous mode, in which the captured ions circulate with an equal period regardless of their momentum. The measurement of the orbital period T by the time-of-flight sensors makes it possible to precisely determine the mass to the charge ratio of the ion under study. For this, the change of the circulation period dT should not exceed 1·10^-6 for dT/T in the entire momentum acceptance of the 0.62%. Modeling in the Strategic Accelerator Design code showed that without nonlinear effects compensation, the orbital period variation is 1·10^-5. In this work, the parameters of nonlinear correctors, which are sextupoles and octupoles in CR, are determined, necessary for the isochronous mode implementation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB311
About •	paper received ※ 29 May 2021 paper accepted ※ 16 June 2021 issue date ※ 14 August 2021
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TUPAB325	Data-Driven Risk Matrices for CERN’s Accelerators	operation, linac, synchrotron, machine-protect	2260
	T. Cartier-Michaud, A. Apollonio, G.B. Blarasin, B. Todd, J.A. Uythoven CERN, Geneva, Switzerland
	Funding: Research supported by the HL-LHC project. A risk matrix is a common tool used in risk assessment, defining risk levels with respect to the severity and probability of the occurrence of an undesired event. Risk levels can then be used for different purposes, e.g. defining subsystem reliability or personnel safety requirements. Over the history of the Large Hadron Collider (LHC), several risk matrices have been defined to guide system design. Initially, these were focused on machine protection systems, more recently these have also been used to prioritize consolidation activities. A new data-driven development of risk matrices for CERN’s accelerators is presented in this paper, based on data collected in the CERN Accelerator Fault Tracker (AFT). The data-driven approach improves the granularity of the assessment, and limits uncertainty in the risk estimation, as it is based on operational experience. In this paper the authors introduce the mathematical framework, based on operational failure data, and present the resulting risk matrix for LHC.
	Poster TUPAB325 [0.499 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB325
About •	paper received ※ 19 May 2021 paper accepted ※ 24 June 2021 issue date ※ 17 August 2021
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Paper

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Other Keywords

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Power Deposition in Superconducting Dispersion Suppressor Magnets Downstream of the Betatron Cleaning Insertion for HL-LHC

collimation, dipole, simulation, operation

37

A. Waets, C. Bahamonde Castro, E. Belli, R. Bruce, N. Fuster-Martínez, A. Lechner, A. Mereghetti, S. Redaelli, M. Sabaté-Gilarte, E. Skordis
CERN, Meyrin, Switzerland

Funding: Research supported by the HL-LHC project
The power deposited in dispersion suppressor magnets downstream of the Large Hadron Collider (LHC) betatron cleaning insertion is governed by off-momentum particles scattered out of the primary collimators. In order to mitigate the risk of magnet quenches during periods of short beam lifetime in future High-Luminosity (HL-LHC) operation, new dispersion suppressor (DS) collimators are considered for installation (one per beam). In this paper, we present FLUKA simulations for both protons and Pb ions at 7 TeV, predicting the power deposition in the DS magnets, including the new higher-field dipoles 11T which are needed to integrate the collimator in the cold region next to the cleaning insertion. The simulated power deposition levels for the adopted HL-LHC collimator configuration and settings are used to assess the quench margin by comparison with the present estimated quench levels.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB001

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paper received ※ 19 May 2021 paper accepted ※ 07 July 2021 issue date ※ 16 August 2021

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MOPAB002

Risk of Halo-Induced Magnet Quenches in the HL-LHC Beam Dump Insertion

insertion, collimation, betatron, operation

41

J.B. Potoine, A. Apollonio, E. Belli, C. Bracco, R. Bruce, M. D’Andrea, R. García Alía, A. Lechner, G. Lerner, S. Morales Vigo, S. Redaelli, V. Rizzoglio, E. Skordis, A. Waets
CERN, Meyrin, Switzerland
F. Wrobel
IES, Montpellier, France

Funding: Research supported by the HL-LHC project
After the High Luminosity (HL-LHC) upgrade, the LHC will be exposed to a higher risk of magnet quenches during periods of short beam lifetime. Collimators in the extraction region (IR6) assure the protection of magnets against asynchronous beam dumps, but they also intercept a fraction of the beam halo leaking from the betatron cleaning insertion. In this paper, we assess the risk of quenching nearby quadrupoles during beam lifetime drops. In particular, we present an empirical analysis of halo losses in IR6 using LHC Run 2 (2015-2018) beam loss monitor measurements. Based on these results, the halo-induced power density in magnet coils expected in HL-LHC is estimated using FLUKA Monte Carlo shower simulations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB002

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paper received ※ 19 May 2021 paper accepted ※ 13 July 2021 issue date ※ 22 August 2021

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MOPAB005

Studies for an LHC Pilot Run with Oxygen Beams

target, luminosity, MMI, operation

53

R. Bruce, R. Alemany-Fernández, H. Bartosik, M.A. Jebramcik, J.M. Jowett, M. Schaumann
CERN, Geneva, Switzerland

Motivated by the study of collective effects in small systems with oxygen-oxygen (O-O) collisions, and improvements to the understanding of high-energy cosmic ray interactions from proton-oxygen (p-O) collisions, a short LHC oxygen run during Run 3 has been proposed. This article presents estimates for the obtainable luminosity performance in these two running modes based on simulations of a typical fill. The requested integrated luminosity, projected beam conditions, data-taking and commissioning times are considered and a running scenario is proposed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB005

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paper received ※ 17 May 2021 paper accepted ※ 25 May 2021 issue date ※ 19 August 2021

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MOPAB012

Energy Deposition Study of the CERN HL-LHC Optics v1.5 in the ATLAS and CMS Insertions

luminosity, insertion, optics, radiation

76

M. Sabaté-Gilarte, F. Cerutti
CERN, Meyrin, Switzerland

Funding: Research supported by the HL-LHC project
The High Luminosity Large Hadron Collider (HL-LHC) is the approved CERN project aiming at further increasing the integrated luminosity of the LHC by a factor 10. As such, it implies a complete redesign of the experimental high-luminosity insertions of ATLAS and CMS. The progressive evolution of the new layout and optics requires a continuous analysis of the radiation environment, to which magnets and other equipment are exposed to. This is assured by means of Monte Carlo simulations of the collision debris on the evolving machine model. The latter featured several developments, such as the explicit inclusion of the cold protection diodes of the final focusing circuits as well as the crab cavities cryomodule. This work presents the most updated characterization of the radiation field with FLUKA and its impact in the insertion region and the dispersion suppressor of Point 1 and 5, for the HL-LHC optics v1.5 released in 2019. Various optimization and mitigation studies are highlighted, providing key information for maximizing the lifetime of new and present magnets.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB012

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paper received ※ 18 May 2021 paper accepted ※ 25 May 2021 issue date ※ 21 August 2021

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MOPAB014

First High Spin-Flip Efficiency for High Energy Polarized Protons

polarization, resonance, dipole, experiment

84

H. Huang, J. Kewisch, C. Liu, A. Marusic, W. Meng, F. Méot, P. Oddo, V. Ptitsyn, V.H. Ranjbar, T. Roser
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
In order to minimize the systematic errors for the Relativistic Heavy Ion Collider (RHIC) spin physics experiments, flipping the spin of each bunch of protons during the stores is needed. Experiments done with single RF magnet at energies less than 2 GeV have demonstrated a spin-flip efficiency over 99%. At high energy colliders with Siberian snakes, a single magnet spin flipper does not work because of the large spin tune spread and the generation of multiple, overlapping resonances. Over past decade, RHIC spin flipper design has evolved and a sophisticated spin flipper, constructed of nine-dipole magnets, was developed to flip the spin in RHIC. A special optics choice was also used to make the spin tune spread very small. In recent experiment, 97% spin-flip efficiency was measured at both 24 and 255 GeV for the first time. The results show that efficient spin flipping can be achieved at high energies.

Poster MOPAB014 [0.984 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB014

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paper received ※ 16 May 2021 paper accepted ※ 08 June 2021 issue date ※ 20 August 2021

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MOPAB015

Feasibility of Polarized Deuteron Beam in the EIC

resonance, polarization, solenoid, detector

87

H. Huang, F. Méot, V. Ptitsyn, V.H. Ranjbar, T. Roser
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The physics program in the EIC calls for polarized neutron beam at high energies. The best neutron carriers are 3He nuclei and deuterons. Both neutron carries are expected to be used by spin physics program in the EIC. Due to the small magnetic moment anomaly of deuteron particles, much higher magnetic fields are required for spin rotation, so full Siberian snake is not feasible. However, the resonance strength is in general weak and the number of resonances is also small. It is possible to deal with individual resonances with conventional methods, such as betatron tune jump for intrinsic depolarizing resonances; and a weak partial snakes for imperfection resonances. The study shows that accelerating polarized deuteron beyond 100GeV/n is possible in the EIC.

Poster MOPAB015 [0.977 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB015

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paper received ※ 16 May 2021 paper accepted ※ 28 May 2021 issue date ※ 13 August 2021

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MOPAB024

Efficient Coupling of Hydrodynamic and Energy-Deposition Codes for Hydrodynamic-Tunnelling Studies on High-Energy Particle Accelerators

simulation, target, coupling, experiment

119

C. Wiesner, F. Carra, J. Kruse-Hansen, M. Masci, D. Wollmann
CERN, Meyrin, Switzerland
Y. Nie
KIT, Karlsruhe, Germany

The machine-protection evaluation of high-energy accelerators comprises the study of beyond-design failures, including the direct beam impact onto machine elements. In case of a direct impact, the nominal beam of the Large Hadron Collider (LHC) would penetrate more than 30 meters into a solid copper target. The penetration depth due to the time structure of the particle beam is, thus, significantly longer than predicted from purely static energy-deposition simulations with 7 TeV protons. This effect, known as hydrodynamic tunnelling, is caused by the beam-induced density depletion of the material at the target axis, which allows subsequent bunches to penetrate deeper into the target. Its proper simulation requires, therefore, to sequentially couple an energy-deposition code and a hydrodynamic code for the different target densities. This paper describes a method to efficiently couple the simulations codes Autodyn and FLUKA based on automatic density assignment and input file generation, and presents the results achieved for a sample case.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB024

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paper received ※ 19 May 2021 paper accepted ※ 05 July 2021 issue date ※ 28 August 2021

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MOPAB027

Improving the Luminosity Burn-Off Estimate by Considering Single-Diffractive Effects

scattering, luminosity, collider, simulation

130

F.F. Van der Veken, H. Burkhardt, M. Giovannozzi, V.K.B. Olsen
CERN, Geneva, Switzerland

Collisions in a high-luminosity collider result in a continuous burn-off of the circulating beams that is the dominant effect that reduces the instantaneous luminosity over time. In order to obtain a good estimate of the luminosity evolution, it is imperative to have an accurate understanding of the burn-off. Typically, this is calculated based on the inelastic cross-section, as it provides a direct estimate of the number of protons that participate in inelastic collisions, and are hence removed. Likewise, protons that participate in elastic collisions will remain in the machine acceptance, still contributing to luminosity. In between these two regimes lie diffractive collisions, for which the protons have a certain probability to remain in the machine acceptance. Recent developments of the SixTrack code allow it to interface with Pythia, thus allowing for more precise simulations to obtain a better estimate of the diffractive part of the cross-section. In this paper, we will mainly concentrate on slowly-drifting protons that are close to the acceptance limit, resulting from single-diffractive scattering.

Poster MOPAB027 [1.193 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB027

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paper received ※ 18 May 2021 paper accepted ※ 31 May 2021 issue date ※ 11 August 2021

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MOPAB031

Development and Operation of Vacuum System for Rapid Cycling Synchrotron to Target Beam Transfer Line of China Spallation Neutron Source

vacuum, target, neutron, operation

145

J.M. Liu, Y.H. Guan, S.M. Liu, B. Tan, P.C. Wang
DNSC, Dongguan, People’s Republic of China
H. Dong
IHEP, Beijing, People’s Republic of China
H.Y. He, T. Huang
IHEP CSNS, Guangdong Province, People’s Republic of China

China Spallation Neutron Source (CSNS) is a major scientific project during the National Eleventh Five-Year Plan. It consists of a negative hydrogen ion linear accelerator, a rapid cycling synchrotron ( RCS), a linac to RCS beam transfer line (LRBT), an RCS to target beam transfer line (RTBT), and a target station. As an important part of CSNS, the RTBT connects the rapid cycling synchrotron and the target window. This paper described the design requirements, technical solutions, and operating conditions of the vacuum system for the CSNS RCS to target beam transfer line. In addition, the fast valve protection system and its verification results were also expounded. The CSNS has been in operation for over three years, during this period, the beam power has been gradually improved from 10KW to 100KW, and the vacuum system for RTBT has been operating stably.

Poster MOPAB031 [0.581 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB031

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paper received ※ 19 May 2021 paper accepted ※ 24 May 2021 issue date ※ 25 August 2021

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MOPAB132

The Multi-Mega-Watt Target Station for the European Spallation Source Neutrino Super Beam

target, experiment, hadron, ion-source

466

E. Baussan, E. Bouquerel, L. D’Alessi, M. Dracos, P. Poussot, J. Thomas, J. Wurtz, V. Zeter
IPHC, Strasbourg Cedex 2, France
P. Cupial, M. Koziol, L.J. Lacny, J. Snamina
AGH University of Science and Technology, Kraków, Poland
I. Efthymiopoulos
CERN, Meyrin, Switzerland
T. Tolba
University of Hamburg, Hamburg, Germany

Funding: This project has received funding from the European Union Horizon 2020 research and innovation program under grant agreement No 777419 and also by the Deutsche Forschungsgemeinschaft No 423761110.
One of the next challenges in fundamental physics is to understand the origin of matter/antimatter asymmetry in the Universe. In particular, intense neutrinos could play an important role to elucidate this mystery and better understand the expansion of the Universe. The ESSnuSB collaboration proposes to use the proton linac of the European Spallation Source currently under construction in Lund (Sweden) to produce a very intense neutrino super beam, in parallel with the spallation neutron production. A very challenging part of the proposed facility is the Target Station which will have to afford 5 MW proton beam power. This poster will present the hadronic collector and the whole facility to produce the next generation of neutrino superbeam.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB132

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paper received ※ 20 May 2021 paper accepted ※ 27 May 2021 issue date ※ 18 August 2021

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MOPAB160

Tools for the Development and Applications of the IsoDAR Cyclotron

cyclotron, rfq, target, injection

550

L.H. Waites, J.R. Alonso, J.M. Conrad, D. Koser, D. Winklehner
MIT, Cambridge, Massachusetts, USA

Funding: NSF provided funding for the RFQDIP project, Draper laboratory provided a fellowship for the graduate student
The IsoDAR cyclotron is a 60 MeV cyclotron designed to output 10mA of protons in order to be a driver for a neutrino experiment. However, this high power can be used in other useful and important applications outside of particle physics. The IsoDAR cyclotron accelerates H²⁺, which allows the beam to be highly versatile and important for the development of high-power targets. This could help alleviate a huge bottleneck in the medical isotope community. IsoDAR could also be used for the development of materials. The accelerator system uses many new tools, including novel methods of applying machine learning, as well as several of the uses of this new technology. With these applications and tools, the IsoDAR cyclotron can have an important impact on the accelerator, medical, and physics communities.

Poster MOPAB160 [0.424 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB160

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paper received ※ 15 May 2021 paper accepted ※ 24 June 2021 issue date ※ 13 August 2021

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MOPAB173

Physics Program and Experimental for AWAKE Run 2

plasma, electron, wakefield, experiment

586

P. Muggli
MPI, Muenchen, Germany

Run 1 experimental results demonstrate many characteristics of the self-modulation (SM) in plasma of a long, 400GeV SPS proton bunch*. Externally injected, 19MeV electrons were accelerated to 2GeV**. Based on these results, we are assembling a physics and experiment program aiming at producing a multi-GeV electron bunch with emittance and energy spread sufficiently low for possible early applications to high-energy physics experiments. Plans include two plasmas, the first for SM, the second for acceleration, and of scalable length, separated by an injection region. The first plasma includes a density step to maintain large-amplitude wakefields after saturation of the SM process. Seeding of the SM process may be obtained from an electron bunch. The 150MeV witness electron bunch from an S-band gun, X-band linac has parameters that produce plasma electron blow out and loading of the wakefields in order to minimize final energy spread and emittance***. We are studying the possibility of using a helicon plasma source for the accelerator, a source that can in principle be very long (100s of m).
*AWAKE, PRL 122, 054802 (2019), Turner, PRL 122, 054801 (2019), Turner, PRAB 23, 081302, (2020), Braunmueller PRL 125, 264801 (2020)
**AWAKE, Nature 561, 363 (2018)
***Olsen, PRAB 21, 011301 (2018)

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB173

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paper received ※ 18 May 2021 paper accepted ※ 28 May 2021 issue date ※ 02 September 2021

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MOPAB174

Foil Hits Reduction by Minimizing Injection Beam Size at the Foil in J-PARC RCS

injection, scattering, beam-losses, operation

590

P.K. Saha, H. Harada, K. Okabe, F. Tamura, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
H. Hotchi
KEK, Tokai, Ibaraki, Japan

Funding: Pranab Kumar Saha
The uncontrolled beam loss caused by the foil scattering of the circulating beam during multi-turn charge-exchange injection is one of the main sources for high residual radiation at the injection area of J-PARC 3-GeV rapid cycling synchrotron. We studied to reduce foil hits of the circulating beam by minimizing the vertical injection beam size at the foil and using a smaller vertical foil size. The vertical foil size was reduced according to the injection beam size by maintaining the stripping efficiency. As a result, the number of circulating beam passing through foil was significantly reduced due to smaller foil size. The simulation and measurement results of the foil hits reduction are presented in this paper.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB174

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paper received ※ 20 May 2021 paper accepted ※ 31 May 2021 issue date ※ 28 August 2021

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MOPAB177

ELENA Commissioning and Status

antiproton, experiment, MMI, electron

598

C. Carli, M.E. Angoletta, W. Bartmann, L. Bojtár, F. Butin, B. Dupuy, Y. Dutheil, M.A. Fraser, P. Freyermuth, D. Gamba, L.V. Jørgensen, B. Lefort, O. Marqversen, M. McLean, S. Ogur, S. Pasinelli, L. Ponce, G. Tranquille
CERN, Geneva, Switzerland

The Extra Low ENergy Antiproton ring ELENA is a small synchrotron recently constructed and commissioned to decelerate antiprotons injected from the Antiproton Decelerator AD with a kinetic energy of 5.3 MeV down to 100 keV. Controlled deceleration in the synchrotron, equipped with an electron cooler to reduce losses and generate dense bunches, allows the experiments, typically capturing the antiprotons in traps and manipulating them further, to improve the trapping efficiency by one to two orders of magnitude. During 2018, bunches with an energy of 100 keV with parameters close to nominal have been demonstrated, and first beams have been provided to an experiment in a new experimental zone. The magnetic transfer lines from the AD to the experiments have been replaced by electrostatic lines from ELENA. Commissioning of the new transfer lines and, in parallel, studies to better understand the ring with H⁻ beams from a dedicated source, have started in autumn 2020. The first 100 keV antiproton physics run using ELENA will start in late summer 2021.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB177

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paper received ※ 18 May 2021 paper accepted ※ 14 June 2021 issue date ※ 23 August 2021

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MOPAB178

Systematic Effects Limiting the Sensitivity of "Magic Energy" Proton EDM Rings

dipole, betatron, pick-up, focusing

602

C. Carli, M. Haj Tahar
CERN, Geneva, Switzerland

Proposals to measure a possible Electric Dipole Moment (EDM) of protons in an electro-static storage ring are studied by a world-wide community. The machine is operated at the so-called "magic energy" to satisfy the "frozen spin" condition such that, without imperfections and with the well known magnetic moment of the particle, the spin is always oriented parallel to the direction of movement. The effect of a finite EDM is a build-up of a vertical spin component. Any effect, other than a finite EDM, leading as well to a build-up of a vertical spin limits the sensitivity of the experiment. Such "systematic effects" are caused by machine imperfections, such as magnetic fields inside the magnetic shield surrounding the ring, and misalignments of electro-static elements or of the RF cavity. Operation of the machine with counter-rotating beams helps mitigating some of the effects. The most dangerous effects are those, which cannot be disentangled from an EDM by combining measurements from both counter-rotating beams, such as an average residual radial magnetic field penetrating the magnetic shield or a combination of magnetic fields and misalignments of electric elements.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB178

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paper received ※ 18 May 2021 paper accepted ※ 17 June 2021 issue date ※ 20 August 2021

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MOPAB179

Simulations of AGS Boosters Imperfection Resonances for Protons and Helions

resonance, simulation, experiment, quadrupole

606

K. Hock, H. Huang, F. Méot, N. Tsoupas
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
As part of the effort to increase the polarization of the proton beam for the physics experiments at RHIC, a scan of orbit harmonic corrector strengths is performed in the Booster to ensure polarization transmission through the |G gamma|=3 and 4 imperfection resonances is optimized. These harmonic scans have been simulated using quadrupole alignment data and accurately match experimental data. The method used to simulate polarized protons is extended to polarized helions for crossing the |G gamma|=5 through |G gamma|=10 imperfection resonances and used to determine the corrector strength required to cross each resonance.

Poster MOPAB179 [0.437 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB179

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paper received ※ 17 May 2021 paper accepted ※ 31 May 2021 issue date ※ 02 September 2021

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MOPAB180

AGS Dynamic Aperture at Injection of Polarized Protons and Helions

dynamic-aperture, coupling, injection, extraction

610

K. Hock, H. Huang, F. Méot, N. Tsoupas
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
Polarized helions are part of the physics program for the future EIC. An AC dipole has been installed in the AGS Booster to preserve polarization as helions are accelerated to |Ggamma|=10.5. Extraction from the AGS Booster at |Ggamma|=7.5 is possible but: would involve crossing an intrinsic resonance in the AGS, and would be the lowest rigidity beam injected into the AGS, and therefore experiences strong distortions of the optical functions because of the AGS two partial snakes. This lower rigidity would exacerbate the optical distortions from the snake, reducing the dynamic aperture. A comparison of the dynamic aperture of protons at Ggamma=4.5 to that of helions at |Ggamma|=7.5 and |Ggamma|=10.5 show that extraction at |Ggamma|=10.5 provides a larger dynamic aperture. This larger aperture would allow helions to be placed inside the spin tune gap generated by the two partial helices in AGS earlier in the cycle.

Poster MOPAB180 [0.453 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB180

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paper received ※ 17 May 2021 paper accepted ※ 31 May 2021 issue date ※ 20 August 2021

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MOPAB181

Non-Delivery Time Reduction at MedAustron

extraction, dipole, synchrotron, MMI

613

L. Adler, S. Danzinger, F. Farinon, F. Feichtinger, G. Guidoboni, N. Kahn, C. Kurfürst, D.A. Prokopovich, A. Wastl
EBG MedAustron, Wr. Neustadt, Austria
L.C. Penescu
Abstract Landscapes, Montpellier, France

Funding: Funding by the NÖ WIRTSCHAFTS- UND TOURISMUSFONDS under grant number WST3-F-5033232/001-2020.
MedAustron is a cancer treatment center in Austria providing proton and carbon ion beams to three clinical and one non-clinical research beam lines. The slow extraction of particles from the synchrotron follows a third order resonance extraction scheme. Currently, for every change of extraction energy a new spill needs to be generated. Besides the beam-on time of the particle delivery, every spill is also comprised of non-delivery time components e.g. the multiturn injection, acceleration or magnet conditioning. For small tumor target volumes, this non-delivery time is the major contribution to the overall treatment time. A dedicated performance improvement project (supported with a grant from the state of lower Austria) was executed with the goal to reduce these non-delivery times without affecting important clinical beam parameters such as the beam size or penetration depth. The implemented reduction of the non-delivery time >50% could be achieved, resulting in beam-on time reductions for reference treatment plans between 25% (largest proton PTV) and 58% (smallest carbon PTV). Results of commissioning efforts, technical details and the achieved optimizations will be presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB181

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paper received ※ 14 May 2021 paper accepted ※ 28 May 2021 issue date ※ 25 August 2021

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MOPAB192

LILac Energy Upgrade to 13 MeV

cavity, linac, controls, LLRF

651

B. Koubek, S. Altürk, M. Busch, H. Höltermann, J.D. Kaiser, H. Podlech, U. Ratzinger, M. Schuett, M. Schwarz, W. Schweizer, D. Strehl, R. Tiede, C. Trageser
BEVATECH, Frankfurt, Germany
A. Brunzel, P. Nonn, H. Schlarb
DESY, Hamburg, Germany
A.V. Butenko, D.E. Donets, B.V. Golovenskiy, A. Govorov, K.A. Levterov, D.A. Lyuosev, A.A. Martynov, V.A. Monchinsky, D.O. Ponkin, K.V. Shevchenko, I.V. Shirikov, E. Syresin
JINR, Dubna, Moscow Region, Russia

In the frame of the NICA (Nuclotron-based Ion Collider fAcility) ion collider upgrade a new light ion LINAC for protons and ions will be built in collaboration between JINR and BEVATECH GmbH. While ions with a mass-to-charge ratio up to 3 will be fed into the NUCLOTRON ring with an energy of 7 MeV/u, protons are supposed to be accelerated up to an energy of 13 MeV using a third IH structure. This energy upgrade comprises a third IH structure, a dual-use Debuncher cavity as well as an extension of the LLRF control system built on MicroTCA technology.

Poster MOPAB192 [4.914 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB192

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paper received ※ 11 May 2021 paper accepted ※ 31 May 2021 issue date ※ 20 August 2021

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MOPAB207

Design Guideline for Minimizing Space-Charge-Induced Emittance Growth

emittance, rfq, space-charge, linac

682

C. Zhang
GSI, Darmstadt, Germany

Space-charge-induced emittance growth is a big concern for designing low-energy and high-intensity linacs. The Equipartitioning Principle was introduced to minimize space-charge-induced emittance growth by removing free energy between the transverse and longitudinal degrees of freedom. In this study, a different design guideline is being proposed. It suggests holding the ratio of longitudinal emittance to transverse emittance around one and take advantage of low emittance transfer for minimizing emittance growth. Using a high-intensity RFQ accelerator as an example, a comparison between the two design methods has been made.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB207

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paper received ※ 17 May 2021 paper accepted ※ 21 May 2021 issue date ※ 01 September 2021

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MOPAB209

Commissioning of SANAEM RFQ Accelerator

rfq, cavity, vacuum, plasma

690

B. Yasatekin, A. Alacakir, A.S. Bolukdemir, I. Kilic, Y. Olgac
TENMAK-NUKEN, Ankara, Turkey
E. Cicek
KEK, Ibaraki, Japan
E. Cosgun
UNIST, Ulsan, Republic of Korea

The former SANAEM RFQ is upgraded with a newly manufactured cavity, made of oxygen-free copper (OFC), having the capability of accelerating protons from 20 keV to 1.3 MeV. In the assembling of cavity vanes, flanges, etc., indium wire is preferred over the brazing process providing a more flexible and easy method for vacuum sealing. After assembling the cavity, argon plasma cleaning is performed for the final cleaning and RF pre-conditioning. Vacuum tests revealed that levels of 2·10^-7 mbar could be achieved quite easily. RF power conditioning of the RFQ cavity is successfully completed with the observation of quite few sparks. In the commissioning tests with the proton beam, a magnetic analyzer is used to measure the energy of the particles. This paper presents the strategy and the results concerning the commissioning of the proton beam with special emphasis on the RFQ cavity.

Poster MOPAB209 [5.076 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB209

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paper received ※ 19 May 2021 paper accepted ※ 14 June 2021 issue date ※ 22 August 2021

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MOPAB210

High-Gradient Booster for Enhanced Proton Radiography at LANSCE

linac, booster, cavity, focusing

693

S.S. Kurennoy, Y.K. Batygin
LANL, Los Alamos, New Mexico, USA

Increasing energy of proton beam at LANSCE from 800 MeV to 3 GeV improves radiography resolution ~10 times. We propose accomplishing this energy boost with a compact cost-effective linac based on cryo-cooled normal conducting high-gradient RF accelerating structures. High-gradient structures exceeding 100 MV/m have been developed for electron acceleration and operate with short RF pulse lengths below 1 us. Though such parameters are unusual for typical proton linacs, they fit perfectly for proton radiography (pRad) applications. The pRad limits contiguous trains of beam micro-pulses to less than 80 ns to prevent blur in images. For a compact pRad booster at LANSCE, we develop a staged design: a short section to capture and compress the 800-MeV proton beam followed by the main high-gradient linac. Our beam dynamics study addresses the beam magnetic focusing and minimizing its energy spread, which are challenging in high-gradient structures but very important for successful pRad operation.

Poster MOPAB210 [0.809 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB210

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paper received ※ 10 May 2021 paper accepted ※ 17 August 2021 issue date ※ 11 August 2021

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MOPAB241

Design of the Proton and Electron Transfer Lines for AWAKE Run 2c

plasma, electron, acceleration, experiment

778

R.L. Ramjiawan
JAI, Oxford, United Kingdom
S. Döbert, E. Gschwendtner, P. Muggli, F.M. Velotti, L. Verra
CERN, Meyrin, Switzerland
J.P. Farmer
MPI-P, München, Germany
P. Muggli
MPI, Muenchen, Germany

The AWAKE Run 1 experiment achieved electron acceleration to 2 GeV using plasma wakefield acceleration driven by 400 GeV, self-modulated proton bunches from the CERN SPS. The Run 2c phase of the experiment aims to build on these results by demonstrating acceleration to ~10 GeV while preserving the quality of the accelerated electron beam. To realize this, there will be an additional plasma cell, to separate the proton bunch self-modulation and the electron acceleration. A new 150 MeV beamline is required to transport and focus the witness electron beam to a beam size of several microns at the injection point. This specification is designed to preserve the beam emittance during acceleration, also requiring micron-level stability between the driver and witness beams. To facilitate these changes, the Run 1 proton transfer line will be reconfigured to shift the first plasma cell 40 m downstream. The Run 1 electron beamline will be adapted and used to inject electron bunches into the first plasma cell to seed the proton bunch self-modulation. Proposed adjustments to the proton transfer line and studies for the designs of the two electron transfer lines are detailed in this contribution.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB241

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paper received ※ 18 May 2021 paper accepted ※ 02 June 2021 issue date ※ 17 August 2021

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MOPAB263

Preliminary Beam Dynamics Studies for 200 MeV Superconducting Linac Planned at KOMAC

linac, DTL, radiation, lattice

837

S. Lee, J.J. Dang, H.S. Kim, H.-J. Kwon
Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea
Y.-S. Cho
KAERI, Daejon, Republic of Korea

Funding: This work has been supported through KOMAC operation fund of KAERI by the Korea government (MSIT).
Korea Multi-purpose Accelerator Complex (KOMAC) is planning an energy upgrade of the existing 100 MeV proton linac to 200 MeV using a superconducting Half Wave Resonator (HWR) operating at 350 MHz. A cryomodule is planned to house four HWR cavities with a warm doublet focusing lattice structure. Matching between the already existing DTL section and HWR section is designed and studied. We report the preliminary study of the beam dynamics of the 200 MeV superconducting linac carried out at KOMAC.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB263

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paper received ※ 20 May 2021 paper accepted ※ 01 July 2021 issue date ※ 24 August 2021

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MOPAB267

End to End Simulations of Antiproton Transport and Degradation

simulation, antiproton, experiment, electron

847

S. Padden, E. Kukstas, P. Pusa, V. Rodin, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
K. Nordlund
HIP, University of Helsinki, Finland
V. Rodin, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The ELENA ring decelerates anti-protons to 100 keV down from 5.3 MeV with transport to experiments handled by electrostatic transfer lines. Even at 100 keV antiprotons are still too high in energy for direct injection into an ion trap, and this is why degrader foils are used to further lower the energy. This contribution presents full end-to-end simulations from the point of extraction until passing through the foil using realistic beam transport simulations coupled with accurate simulations of degrader foils via the use of density functional theory and molecular dynamics. Particles are tracked from the point of extraction until their injection into the trap with full physical modeling at all time steps. The results of this study provide a versatile platform for the optimization of low energy ion experiments towards specific targets.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB267

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paper received ※ 19 May 2021 paper accepted ※ 09 June 2021 issue date ※ 24 August 2021

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MOPAB279

Non-Invasive Beam Profile Monitoring for the HL-LHC Hollow Electron Lens

photon, electron, background, luminosity

884

A. Salehilashkajani, N. Kumar, O. Sedláček, C.P. Welsch, H.D. Zhang
The University of Liverpool, Liverpool, United Kingdom
M. Ady, N.S. Chritin, N. Jens, O.R. Jones, R. Kersevan, T. Lefèvre, S. Mazzoni, G. Papazoglou, A. Rossi, G. Schneider, R. Veness
CERN, Geneva, Switzerland
P. Forck, S. Udrea
GSI, Darmstadt, Germany
N. Kumar, O. Sedláček, C.P. Welsch, H.D. Zhang
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: This work was supported by the HL-LHC-UK phase II project funded by STFC under Grant Ref: ST/T001925/1 and the STFC Cockcroft core grant No. ST/G008248/1.
A Hollow Electron Lens (HEL) is currently under development for the High-Luminosity upgrade of the Large Hadron Collider (HL-LHC). In this device, a hollow electron beam co-propagates with a central proton beam and provides active halo control in the LHC. To ensure the concentricity of the two beams, a non-invasive diagnostic instrument is currently being commissioned. This instrument is a compact version of an existing prototype that leverages beam induced fluorescence with supersonic gas curtain technology. This contribution includes the design features of this version of the monitor, recent progress, and future plans for tests at the Cockcroft Institute and the electron lens test stand at CERN.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB279

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paper received ※ 18 May 2021 paper accepted ※ 15 June 2021 issue date ※ 02 September 2021

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MOPAB299

STRUCTURAL OPTIMIZATION DESIGN OF FARADAY CUP FOR BEAM COMMISSIONING OF CSNS

target, MMI, neutron, linac

943

A.X. Wang, L. Kang, M. Meng, J.L. Sun
IHEP, Beijing, People’s Republic of China
J.X. Chen, H.Y. He, L. Liu, R.H. Liu, X.J. Nie, C.J. Ning, R.Y. Qiu, G.Y. Wang, T. Yang, J.B. Yu, Y.J. Yu, J.S. Zhang, D.H. Zhu
IHEP CSNS, Guangdong Province, People’s Republic of China

Faraday cup is used to absorb and stop the beam during the two phases of beam commissioning, such as the front end (FE) system and the temporary line after the drift tube linac (DTL) at the Chinese Spallation Neutron Source (CSNS). According to the beam physical parameters, graphite is selected to stop the beam directly, and oxygen-free copper which is just behind the graphite as the thermal conductive material. By the analysis and comparison of the target type and cooling efficiency, the single slant target is adopted. The incident angle between the target surface and the beam is set as 10°, meanwhile a new waterfall type water-cooling structure with parallel tunnels is designed to improve the cooling efficiency. The finite element software ANSYS is used for thermal analysis of the model, by which the diameter and interval of water cooling tunnels are optimized. The faraday cup discussed in this paper is finally successfully installed in the beam commissioning line and went well.

Poster MOPAB299 [1.113 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB299

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paper received ※ 13 May 2021 paper accepted ※ 08 July 2021 issue date ※ 19 August 2021

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MOPAB315

Beam Diagnostics for Commissioning and Operation of the FAIR Proton Linac

linac, diagnostics, rfq, MMI

972

T. Sieber, P. Forck, S. Udrea
GSI, Darmstadt, Germany
J. Herranz, A. Vizcaino-de-Julian
Proactive Research and Development, Sabadell, Spain

For the planned antiproton experiments at FAIR a dedicated proton injector Linac is currently under construction. It will be connected via the old UNILAC transfer beamline to SIS18 and has a length of ~30 m. The Linac will accelerate protons up to a final energy of 68 MeV, at a pulse length of 35 µs and a maximum repetition rate of 4 Hz. It will operate at 325 MHz and consists of a new so called "Ladder" RFQ type, followed by a chain of CH-cavities, partially coupled by rf-coupling cells. We have worked out a diagnostics system, which allows detailed measurement and study of all beam parameters during commissioning and later during regular operation. The diagnostics devices will - in a first step - be installed on a diagnostics testbench for stepwise commissioning. We present the concepts for Linac and testbench with some special emphasis on energy measurements with spectrometer and SEM Grid profile measurements.

Poster MOPAB315 [3.149 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB315

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paper received ※ 14 May 2021 paper accepted ※ 24 June 2021 issue date ※ 30 August 2021

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MOPAB335

SNS Warm Linac Circulator Breakdown Considerations for the PPU Project

operation, linac, simulation, DTL

1041

G.D. Toby, Y.W. Kang, S.-H. Kim, S.W. Lee, J.S. Moss
ORNL, Oak Ridge, Tennessee, USA

Funding: * This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract number DE-AC05-00OR22725.
Multipacting in accelerating structures is a complex phenomenon about which there is much to be understood. While multipacting research efforts have primarily been focused on superconducting radio frequency (SRF) systems, normal conducting accelerating structures which have a higher thermal capacity, and a greater vacuum pressure tolerance could benefit from additional investigation. This research details multipacting simulation methods and the results of 3-D electromagnetic simulations of RF vacuum windows used on normal conducting linac (NCL) cavities. Benchmarking of the peak electric fields in these structures, benefits of material processing and possible techniques for reducing or eliminating multipacting activities are discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB335

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paper received ※ 17 May 2021 paper accepted ※ 28 May 2021 issue date ※ 23 August 2021

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MOPAB341

First C-Band High Gradient Cavity Testing Results at LANL

cavity, GUI, operation, klystron

1057

E.I. Simakov, R.L. Fleming, D. Gorelov, T.A. Jankowski, M.F. Kirshner, J.W. Lewellen, J.D. Pizzolatto, M.E. Schneider, T. Tajima
LANL, Los Alamos, New Mexico, USA
X. Lu, E.A. Nanni, S.G. Tantawi
SLAC, Menlo Park, California, USA
M.E. Middendorf
ANL, Lemont, Illinois, USA

Funding: Los Alamos National Laboratory LDRD Program.
This poster will report the results of high gradient testing of the two proton β=0.5 C-band accelerating cavities. The cavities for proton acceleration were fabricated at SLAC and tested at high gradient C-band accelerator test stand at LANL. One cavity was made of copper, and the second was made of a copper-silver alloy. LANL test stand was constructed around a 50 MW, 5.712 GHz Canon klystron and is capable to provide power for conditioning single cell accelerating cavities for operation at surface electric fields up to 300 MV/m. These β=0.5 C-band cavities were the first two cavities tested on LANL C-band test stand. The presentation will report achieved gradients, breakdown probabilities, and other characteristics measured during the high power operation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB341

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paper received ※ 19 May 2021 paper accepted ※ 25 May 2021 issue date ※ 30 August 2021

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MOPAB400

Development of Helium Vessel Welding Process for SNS PPU Cavities

cavity, cryomodule, neutron, accelerating-gradient

1212

P. Dhakal, E. Daly, G.K. Davis, J.F. Fischer, N.A. Huque, K. Macha, P.D. Owen, K.M. Wilson, M. Wiseman
JLab, Newport News, Virginia, USA

Funding: This manuscript has been authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
The Spallation Neutron Source Proton Power Upgrade cavities are produced by Research Instrument with all the cavity processing done at vendor sites with final chemistry applied to the cavity to be electropolishing. Cavities are delivered to Jefferson Lab, ready to be tested. One of the tasks to be completed before the arrival of production-ready PPU cavities is to develop a robust helium vessel welding protocol. We have successfully developed the process and applied it to three six-cell high beta cavities. Here, we present the summary of RF results, welding process development, and post helium vessel RF results.

Poster MOPAB400 [1.313 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB400

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paper received ※ 18 May 2021 paper accepted ※ 26 May 2021 issue date ※ 01 September 2021

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MOPAB404

A Low Emittance Compact Proton Injector for a Proton Therapy Facility

ion-source, emittance, LEBT, rfq

1218

S.X. Peng, J.E. Chen, B.J. Cui, Z.Y. Guo, Y.X. Jiang, K. Li, T.H. Ma, J. Sun, W.B. Wu, A.L. Zhang, J.F. Zhang
PKU, Beijing, People’s Republic of China
Y.H. Pu
Shanghai APACTRON Particle Equipment Company Limited, Shanghai, People’s Republic of China

To meet the requirements of a Proton Therapy Facility funded by the National Key Research and Development Program of China, a new compact ion source-LEBT integrated proton injector was developed at Peking University (PKU). It consists of a typical PKU permanent magnet compact 2.45 GHz ECR ion source (PMECRIS) and an electrostatic LEBT with an electrostatic lens, a beam chopper, a set of beam steers, an ACCT, a bellow, an e-trap, and a valve. A 1000 L/s molecular pump is adopted to maintain the vacuum for this integrated injector. The length from RF matching plane to RFQ front flange is about 450 mm. Chopper is used to shorten the pulse length from ms to µs with sharp edges. Test results of this PMECR source prove that it has the ability to deliver a proton beam with a current from 10 mA to 90 mA with a duty factor of 3%(100Hz/0.3ms) and its RMS emittance less than 0.1 mm·mrad at 30 keV. The acceptance tests of this integrated injector have been performed with a 30 keV hydrogen beam. A required proton current of 18 mA with ripple wave less than 0.1 mA successfully passed through a 20 mm aperture diaphragm at RFQ entrance flange. Its rms emittance is about 0.06 mm·mrad.

Poster MOPAB404 [1.946 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB404

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paper received ※ 19 May 2021 paper accepted ※ 17 August 2021 issue date ※ 18 August 2021

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MOPAB411

Quantifying DNA Damage in Comet Assay Images Using Neural Networks

network, software, experiment, radiation

1233

S.J.K. Dhinsey, T. Greenshaw, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
J.L. Parsons
Cancer Research Centre, University of Liverpool, Liverpool, United Kingdom
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: This work was supported by the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1.
Proton therapy for cancer treatment is a rapidly growing field and increasing evidence suggests it induces more complex DNA damage than photon therapy. Accurate comparison between the two treatments requires quantification of the DNA damage the cause, which can be assessed using the Comet Assay. The program outlined here is based on neural network architecture and aims to speed up analysis of Comet Assay images and provide accurate, quantifiable assessment of the DNA damage levels apparent in individual cells. The Comet Assay is an established technique in which DNA fragments are spread out under the influence of an electric field, producing a comet-like object. The elongation and intensity of the comet tail (consisting of DNA fragments) indicate the level of damage incurred. Many methods to measure this damage exist, using a variety of algorithms. However, these can be time consuming, so often only a small fraction of the comets available in an image are analysed. The automatic analysis presented in this contribution aims to improve this. To supplement the training and testing of the network, a Monte Carlo model will also be presented to create simulated comet assay images.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB411

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paper received ※ 19 May 2021 paper accepted ※ 09 June 2021 issue date ※ 16 August 2021

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MOPAB413

The Next Ion Medical Machine Study at CERN: Towards a Next Generation Cancer Research and Therapy Facility with Ion Beams

synchrotron, linac, superconducting-magnet, operation

1240

M. Vretenar, V. Bencini, E. Benedetto, M.R. Khalvati, A.M. Lombardi, M. Sapinski, D. Tommasini
CERN, Meyrin, Switzerland
E. Benedetto, M. Sapinski
TERA, Novara, Italy
P. Foka
GSI, Darmstadt, Germany

Cancer therapy with ions has several advantages over X-ray and proton therapy, but its diffusion remains limited primarily because of the size and cost of the accelerator. To develop technologies that might improve performance and reduce accelerator cost with respect to present facilities, CERN has recently launched the Next Ion Medical Machine Study (NIMMS), leveraging CERN expertise in accelerator fields to disseminate technologies developed for basic science. A perspective user and key partner of NIMMS is the SEEIIST (South East European International Institute for Sustainable Technologies), established to build in the region an innovative facility for combined cancer therapy and biomedical research with ion beams. For SEEIIST and other potential users, three options are being considered. Conceptual designs of a warm-magnet synchrotron at high beam intensity, of a compact superconducting synchrotron, and of a high-frequency linear accelerator have been compared in terms of cost, risk and development time. The development of curved superconducting magnets, of compact synchrotrons and ion gantries, and of linacs is being pursued within EU-funded projects or specific collaborations

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB413

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paper received ※ 18 May 2021 paper accepted ※ 20 July 2021 issue date ※ 13 August 2021

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MOPAB416

BDSIM Developments for Hadron Therapy Centre Applications

simulation, radiation, shielding, neutron

1252

E. Ramoisiaux, E. Gnacadja, C. Hernalsteens, N. Pauly, R. Tesse, M. Vanwelde
ULB, Bruxelles, Belgium
S.T. Boogert, L.J. Nevay
Royal Holloway, University of London, Surrey, United Kingdom
C. Hernalsteens
CERN, Geneva, Switzerland
W. Shields
JAI, Egham, Surrey, United Kingdom

Hadron therapy centres are evolving towards reduced-footprint layouts, often featuring a single treatment room. The evaluation of beam properties, radiation protection quantities, and concrete shielding activation via numerical simulations poses new challenges that can be tackled using the numerical beam transport and Monte-Carlo code Beam Delivery Simulation (BDSIM), allowing a seamless simulation of the dynamics as a whole. Specific developments have been carried out in BDSIM to advance its efficiency toward such applications, and a detailed 4D Monte-Carlo scoring mechanism has been implemented. It produces tallies such as the spatial-energy differential fluence in arbitrary scoring meshes. The feature makes use of the generic boost::histogram library and allows an event-by-event serialisation and storage in the ROOT data format. The pyg4ometry library is extended to improve the visualisation of critical features such as the complex geometries of BDSIM models, the beam tracks, and the scored quantities. Data are converted from Geant4 and ROOT to a 3D visualisation using the VTK framework. These features are applied to a complete IBA Proteus One model.

Poster MOPAB416 [1.575 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB416

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paper received ※ 19 May 2021 paper accepted ※ 12 July 2021 issue date ※ 15 August 2021

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MOPAB417

Preliminary Study of a Large Energy Acceptance FFA Beam Delivery System for Particle Therapy

optics, focusing, superconducting-magnet, radiation

1256

J.S.L. Yap, E.R. Higgins, S.L. Sheehy
The University of Melbourne, Melbourne, Victoria, Australia

The availability and use of ion beams for radiotherapy has grown significantly, led by technological developments to exploit the dosimetric advantages offered by charged particles. The benefits of particle therapy (PT) are well identified however its utilisation is still limited by high facility costs and technological challenges. A possibility to address both of these can be considered by improvements to the beam delivery system (BDS). Existing beamlines and gantries transport beams with a momentum range of ±1% and consequently, adjustments in depth or beam energy require all the magnetic fields to be changed. The speed to switch energies is a limiting constraint of the BDS and a determinant of the overall treatment time. A novel concept using fixed field alternating gradient (FFA) optics enables a large energy acceptance (LEA) as beams of varying energies can traverse the beamline at multiple physical positions given the same magnetic field. This presents the potential to provide faster, higher quality treatments at lower costs, with the capability to deliver advanced PT techniques such as multi-ion therapy. We explore the applicability and benefits of a LEA BDS.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB417

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paper received ※ 18 May 2021 paper accepted ※ 27 July 2021 issue date ※ 15 August 2021

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MOPAB418

Tracking and LET Measurements with the MiniPIX-TimePIX Detector for 60 MeV Clinical Protons

detector, radiation, instrumentation, experiment

1260

J.S.L. Yap, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
N.J.S. Bal
NIKHEF, Amsterdam, The Netherlands
M.D. Brooke
University of Oxford, Oxford, United Kingdom
C. Granja, C. Oancea
ADVACAM s.r.o, Prague, Czech Republic
A. Kacperek
The Douglas Cyclotron, The Clatterbridge Cancer Centre NHS Foundation Trust, Wirral, United Kingdom
C.P. Welsch, J.S.L. Yap
The University of Liverpool, Liverpool, United Kingdom

Funding: EU FP7 grant agreement 215080, H₂020 Marie Sklodowska-Curie grant agreement No 675265, OMA - Optimization of Medical Accelerators and the Cockcroft Institute core grant STGA00076-01.
Recent advancements in accelerator technology have led the rapid emergence of particle therapy facilities worldwide, affirming the need for enhanced characterisation methods of radiation fields and radiobiological effects. The Clatterbridge Cancer Centre, UK operates a 60 MeV proton beam to treat ocular cancers and facilitates studies into proton induced radiobiological responses. Accordingly, an indicator of radiation quality is the linear energy transfer (LET), a challenging physical quantity to measure. The MiniPIX-Timepix is a miniaturised, hybrid semiconductor pixel detector with a Timepix ASIC, enabling wide-range measurements of the deposited energy, position and direction of individual charged particles. High resolution spectrometric tracking and simultaneous energy measurements of single particles enable the beam profile, time, spatial dose mapping and LET (0.1 to >100 keV/µm) to be resolved. Measurements were performed to determine the LET spectra in silicon, at different positions along the Bragg Peak (BP). We discuss the experimental setup, preliminary results and applicability of the MiniPIX for clinical environments.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB418

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paper received ※ 18 May 2021 paper accepted ※ 23 July 2021 issue date ※ 25 August 2021

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MOPAB419

Acceleration and Measurement of Alpha Particles and Hydrogen Molecular Ions with the HZB Cyclotron

cyclotron, radiation, vacuum, scattering

1264

G. Kourkafas, J. Bundesmann, A. Denker, T. Fanselow, J. Röhrich
HZB, Berlin, Germany
J. Heufelder, A. Weber
Charite, Berlin, Germany

The HZB cyclotron has treated more than 4000 patients with eye tumors using protons. The accelerator can also provide heavier ions which could be suitable for ocular radiation therapy. Helium ions exhibit less lateral spread, increased relative biological effectiveness and a sharper Bragg-Peak compared to protons of the same range, while minimizing nuclear fragmentation and thus excessive dose downstream the irradiated volume compared to more heavy ions. When accelerating fully stripped helium ions (alpha particles), hydrogen molecular ions can also be accelerated to the same energy with a small tuning of the machine due to having almost the same mass-to-charge ratio, yielding a proton beam of double current after the beam exits the vacuum window towards the target. The acceleration and characterization of these two ion species are described in this paper, suggesting the feasibility of a corresponding clinical cyclotron for ocular or even deep-seated tumors.

Poster MOPAB419 [0.806 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB419

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paper received ※ 19 May 2021 paper accepted ※ 09 June 2021 issue date ※ 13 August 2021

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TUXA04

Coherent Excitations and Circular Attractors in Cooled Ion Bunches

electron, collider, operation, experiment

1279

S. Seletskiy, A.V. Fedotov, D. Kayran
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy
In electron coolers, under certain conditions, a mismatch in either gamma-factors or trajectory angles between an electron and an ion beam can cause the formation of a circular attractor in the ion beam phase space. This leads to coherent excitations of the ions with a small synchrotron or betatron amplitude and results in unusual beam dynamics, including bifurcations. In this paper, we consider the effect of coherent excitations and discuss its implications both for Low Energy RHIC Electron Cooler (LEReC) and for high energy electron coolers proposed for the Electron-Ion Collider (EIC).

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUXA04

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paper received ※ 19 May 2021 paper accepted ※ 20 July 2021 issue date ※ 11 August 2021

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TUPAB030

Superb Fixed Field Permanent Magnet Proton Therapy Gantry

permanent-magnet, radiation, hadron, MMI

1405

D. Trbojevic, S.J. Brooks, T. Roser, N. Tsoupas
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
We present the top notch design of the proton therapy gantry made of permanent magnets with very strong focusing. This represents a superb solution fulfilling all cancer treatment requirements for all energies without changing any parameters. The proton energy range is between 60-250 MeV. The beam arrives to the patient focused at each required treatment energy. The scanning system is place between the end of the gantry and the patient. There are multiple advantages of this design: easy operation, no significant electrical power - just for the correction system, low weight, low cost. The design is based on the recent very successful commissioning of the permanent magnet ERL ’CBETA’ at Cornell University.

Poster TUPAB030 [7.816 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB030

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paper received ※ 17 May 2021 paper accepted ※ 07 June 2021 issue date ※ 21 August 2021

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TUPAB031

Construction and Installation of the New CERN Proton Synchrotron Internal Beam Dumps

vacuum, MMI, shielding, interface

1409

K.G. Andersen, M. Calviani, A. Cherif, T. Coiffet, A. De Macedo, S. Devidal, J.-M. Geisser, S.S. Gilardoni, M.M.J. Gillet, E. Grenier-Boley, J.M. Heredia, A. Majbour, F. Monnet, M.R. Monteserin, F.-X. Nuiry, D. Pugnat, G. Romagnoli, Y.D.R. Seraphin, J.A.F. Somoza, N. Thaus
CERN, Geneva 23, Switzerland

In the framework of the CERN Large Hadron Collider Injectors Upgrade (LIU) Project, the Proton Synchrotron (PS) has been equipped with two new movable Internal Dumps (PSID), each of them capable of absorbing particle beams of an energy of up to 100 kJ. These dumps replace the old Internal Dumps, which have been operated in the accelerator complex since their installation in 1975 until their decommissioning and removal from the machine during the second LHC Long Shut down (LS2). This contribution will address the construction and testing phases of the new PSIDs, including the assembly of the dump core, its actuation system and the respective shielding, mechanical running-in tests, metrology adjustments, Ultra-High Vacuum (UHV) and impedance acceptance tests. The described installation work was completed successfully, and the new generation Dumps are currently operational in the PS machine.

Poster TUPAB031 [3.146 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB031

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paper received ※ 18 May 2021 paper accepted ※ 27 May 2021 issue date ※ 26 August 2021

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TUPAB036

The Accelerator Design Progress for EIC Strong Hadron Cooling

electron, hadron, linac, emittance

1424

E. Wang, S. Peggs, V. Ptitsyn, F.J. Willeke, W. Xu
BNL, Upton, New York, USA
S.V. Benson
JLab, Newport News, Virginia, USA
D. Douglas
Douglas Consulting, York, Virginia, USA
C.M. Gulliford, G.H. Hoffstaetter
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
C.E. Mayes
Xelera Research LLC, Ithaca, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy,
The Electron-Ion Collider will achieve a luminosity of 10³⁴ cm^-2 s⁻¹ by incorporating strong hadron cooling to counteract hadron Intra-Beam Scattering, using a coherent electron cooling scheme. An accelerator will deliver the beams with key parameters, such as 1 nC bunch charge, and 1e-4 energy spread. The paper presents the design and beam dynamics simulation results. Methods to minimize beam noise, the challenges of the accelerator design, and the R&D topics being pursued are discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB036

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paper received ※ 16 May 2021 paper accepted ※ 11 June 2021 issue date ※ 01 September 2021

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TUPAB040

Design Concept for the Second Interaction Region for Electron-Ion Collider

electron, detector, dipole, optics

1435

B.R. Gamage, V. Burkert, R. Ent, Y. Furletova, D.W. Higinbotham, A. Hutton, F. Lin, T.J. Michalski, V.S. Morozov, R. Rajput-Ghoshal, D. Romanov, T. Satogata, A. Seryi, A.V. Sy, C. Weiss, M. Wiseman, W. Wittmer, Y. Zhang
JLab, Newport News, Virginia, USA
E.C. Aschenauer, J.S. Berg, A. Jentsch, A. Kiselev, C. Montag, R.B. Palmer, B. Parker, V. Ptitsyn, F.J. Willeke, H. Witte
BNL, Upton, New York, USA
C. Hyde
ODU, Norfolk, Virginia, USA
P. Nadel-Turonski
SBU, Stony Brook, New York, USA

Funding: Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177 and Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
The possibility of two interaction regions (IRs) is a design requirement for Electron-Ion Collider (EIC). There is also a significant interest from the nuclear physics community to have a 2nd IR with measurement capabilities complementary to those of the 1st IR. While the 2nd IR will be in operation over the entire energy range of ~20GeV to ~140GeV center of mass (CM). The 2nd IR can also provide an acceptance coverage complementary to that of the 1st. In this paper, we present a brief overview and the current progress of the 2nd IR design in terms of the parameters, magnet layout, and beam dynamics.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB040

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paper received ※ 24 May 2021 paper accepted ※ 31 August 2021 issue date ※ 30 August 2021

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TUPAB138

Determination of the Phase of Wakefield Driven by a Self-Modulated Proton Bunch in Plasma

plasma, wakefield, electron, emittance

1710

K. Moon, M. Chung
UNIST, Ulsan, Republic of Korea
P. Muggli
MPI-P, München, Germany

Funding: This work was partly supported by the National Research Foundation of Korea (Nos. NRF-2016R1A5A1013277 and NRF-2020R1A2C1010835)
The phase of wakefield driven by a self-modulated proton bunch depends on the type of seeding method and by the beam-plasma parameters.* Particularly when a preceding electron bunch generates seed wakefield, the proton bunch modulation is strongly affected by the seed bunch dynamics along with the plasma. Intrinsic wakefield dephasing from self-modulation of proton bunch can lead to complex evolution of the bunch and wakefield, making it difficult to design an experimental setup for witness beam injection. Using the particle-in-cell code FBPIC,** we investigate in detail the trends of seed electron and driver proton bunch parameter sensitivity to the phase of wakefield in time in the proton bunch frame. We focus on the parameters affecting the phase of the wakefield through the beam’s radial dynamics, such as beam emittance, radial size, energy, and beam to plasma density ratio. Parameter variations are compared to those in the case of the phase of wakefield driven by a non-evolving seed bunch.
*F. Batsch, arXiv:2012.09676 [physics.plasm-ph]
**R. Lehe, M. Kirchen, I.A. Andriyash, B.B. Godfrey, and J.-L. Vay, Comput. Phys. Comm. 203, 66-82 (2016)

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB138

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paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 30 August 2021

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TUPAB159

Awake Run 2 at CERN

plasma, electron, experiment, acceleration

1757

E. Gschwendtner
CERN, Meyrin, Switzerland

The AWAKE Run 2 experiment, starting in 2021 at CERN, aims to achieve high-charge bunches of electrons accelerated to high energy (~10 GeV) while maintaining beam quality. AWAKE Run 2 also aims to show that the process is scalable so that, by the end of the run, the AWAKE-scheme technology could be used for first particle physics applications. The first two phases of Run 2 include the investigation of the seeding of the proton bunch self-modulation with the current electron beam in the existing AWAKE facility and the test of a second new plasma source with a density step allowing to maintain strong accelerating fields. In the third phase of Run 2, electrons with an energy of 150 MeV, produced in a newly installed electron source, will be injected into a second plasma source and accelerated to high energies (several GeVs) while keeping good emittance. In the fourth phase, it is planned to replace the second plasma source with a scalable one, which eventually could be used for long-distance acceleration and first applications. In this paper, we present the program of the four phases of AWAKE Run 2, the technical challenges and the proposed schedule.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB159

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paper received ※ 17 May 2021 paper accepted ※ 11 June 2021 issue date ※ 19 August 2021

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TUPAB160

Preparation for Electron-Seeding of Proton Bunch Self-Modulation in AWAKE

electron, plasma, experiment, simulation

1761

G. Zevi Della Porta, E. Gschwendtner, L. Verra
CERN, Meyrin, Switzerland
K. Moon
UNIST, Ulsan, Republic of Korea
P. Muggli, L. Verra
MPI, Muenchen, Germany

The next milestone of the Advanced Wakefield Experiment (AWAKE) at CERN will be to demonstrate that the self-modulation of a long proton bunch can be seeded by a short electron bunch preceding it. This seeding method will lead to phase-reproducible self-modulation of the entire proton bunch, as required for the future AWAKE program. In the Spring of 2021, before receiving proton beams from the CERN SPS, AWAKE plans to hold a dry run of the electron seeding experiments, to commission the system and to determine the parameter scans that will be used in experiments with protons. Electron bunches of 10-20 MeV with varying charge, radius, emittance and energy will be sent in 10 m of low-density plasma. The effects of beam-plasma interactions on the amplitude of the wakefields driven by the different bunches will be studied by observing the energy spectra at the end of the plasma. This paper presents preliminary experimental results from the first two days of measurements as well as the beginning of a simulation-based study of electron propagation in plasma.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB160

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paper received ※ 18 May 2021 paper accepted ※ 15 June 2021 issue date ※ 27 August 2021

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TUPAB168

Beam Commissioning of a 325 MHz Proton IH-DTL at XiPAF

DTL, cavity, emittance, linac

1777

P.F. Ma, X. Guan, R. Tang, M.W. Wang, X.W. Wang, Q.Z. Xing, W.B. Ye, S.X. Zheng
TUB, Beijing, People’s Republic of China
W. Chen, W.L. Liu, W. Lv, M.T. Qiu, B.C. Wang, D. Wang, M.C. Wang, Z.M. Wang, Y.H. Yan, Y. Yang, M.T. Zhao
NINT, Xi’an, People’s Republic of China

The Inter-Digital H-mode Drift Tube Linac (IH-DTL) is widely used as the main component of injectors for medical synchrotrons. This paper describes the beam commissioning of a compact 325 MHz IH-DTL with modified KONUS beam dynamics at Tsinghua University (THU). This IH-DTL accelerates the proton beam from 3 MeV to 7 MeV in 1m. The average energy of the beam is 7.0 MeV with the energy spread range of -0.6 MeV to 0.3 MeV. The output transverse normalized RMS emittance of the beam is 0.58 (x)/0.58 (y) pi mm mrad with the input emittance of 0.43 (x)/0.37 (y) pi mm mrad. The beam test results show good agreement with the beam dynamics design.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB168

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paper received ※ 08 May 2021 paper accepted ※ 16 June 2021 issue date ※ 14 August 2021

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TUPAB172

Quadrupole Magnet Design for a Heavy-Ion IH-DTL

quadrupole, heavy-ion, DTL, linac

1793

P.F. Ma, C.T. Du, X. Guan, M.W. Wang, X.W. Wang, Y.L. Wang, Q.Z. Xing, X.D. Yu, S.X. Zheng
TUB, Beijing, People’s Republic of China
W. Chen, W.L. Liu, W. Lv, M.T. Qiu, B.C. Wang, D. Wang, M.C. Wang, Z.M. Wang, Y.H. Yan, M.T. Zhao
NINT, Xi’an, People’s Republic of China

Xi’an Proton Application Facility (XiPAF) will be upgraded to provide heavy-ion beams with a heavy-ion injector. The injector consists of an ECR heavy-ion source, a Low Energy Beam Transport line (LEBT), a Radio Frequency Quadrupole (RFQ), an Interdigital H-mode Drift Tube Linac (IH-DTL), and a Linac to Ring Beam Transport line (LRBT). The IH-DTL can accelerate the ions with mass to charge up to 6.5 from 0.4 MeV/u to 2 MeV/u. To provide transverse focusing, the electro-magnetic quadrupoles are installed inside the drift tubes of IH-DTL, thus the magnet needs to be high-gradient and compact. This paper gives the quadrupole magnet design for the heavy-ion IH-DTL. The results show that the quadrupole magnet design can meet the requirements.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB172

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paper received ※ 08 May 2021 paper accepted ※ 21 June 2021 issue date ※ 23 August 2021

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TUPAB175

ESSnuSB Linac and Transfer Line: Lattice Design and Error Studies

linac, lattice, dipole, DTL

1805

N. Blaskovic Kraljevic, M. Eshraqi, B.T. Folsom
ESS, Lund, Sweden

Funding: ESSnuSB has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 777419.
The ESS neutrino superbeam (ESSnuSB) project is being studied as an upgrade to the European Spallation Source (ESS). This proposed upgrade consists of adding an H⁻ source to the existing beamline in order to send H⁻ pulses in between proton pulses, effectively doubling the beam power from 5 MW to 10 MW. In this contribution, we present the 2.5 GeV linear accelerator (linac) lattice and the design of the transfer line from the linac to the accumulator ring, where pulses would be stacked to achieve short proton pulses of high intensity. The results of error studies, quantifying the effect of accelerator imperfections and H⁻ ion stripping losses on the beam transport through the linac and transfer line, are also presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB175

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paper received ※ 19 May 2021 paper accepted ※ 14 June 2021 issue date ※ 31 August 2021

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TUPAB179

Design of an MBEC Cooler for the EIC

electron, kicker, hadron, simulation

1819

W.F. Bergan, P. Baxevanis, M. Blaskiewicz, E. Wang
BNL, Upton, New York, USA
G. Stupakov
SLAC, Menlo Park, California, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
Reaching maximal luminosity for the planned electron-ion collider (EIC) calls for some form of strong hadron cooling to counteract beam emittance increase from IBS. We discuss plans to use microbunched electron cooling (MBEC) to achieve this. The principle of this method is that the hadron beam will copropogate with a beam of electrons, imprinting its own density modulation on the electron beam. These electron phase space perturbations are amplified before copropogating with the hadrons again in a kicker section. By making the hadron transit time between modulator and kicker dependent on hadron energy and transverse offset, the energy kicks which they receive from the electrons will tend to reduce their longitudinal and transverse emittances. We discuss details of the analytic theory and searches for optimal realistic parameter settings to achieve a maximal cooling rate while limiting the effects of diffusion and electron beam saturation. We also place limits on the necessary electron beam quality. These results are corroborated by simulations.

Poster TUPAB179 [4.006 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB179

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paper received ※ 19 May 2021 paper accepted ※ 18 June 2021 issue date ※ 24 August 2021

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TUPAB180

Plasma Simulations for an MBEC Cooler for the EIC

electron, hadron, simulation, kicker

1823

W.F. Bergan
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
In order to reach its maximum luminosity, the electron-ion collider (EIC) is being designed to use microbunched electron cooling (MBEC) to cool the hadron beam. This involves having the hadron beam imprint on a beam of electrons, enhancing the perturbations in the electron beam using the microbunching instability, and feeding back on the original hadron beam to correct deviations in hadron energy, and, through the use of dispersion, the transverse emittances. This process has been modelled analytically in the linear regime*. However, in order to maximize the cooling rate, we wish to know how much saturation in the electron beam is acceptable before the effects of nonlinearity cause significant deviations from the analytic results. To understand this, we have developed a code to do fast one-dimensional plasma simulations of hadrons and electrons as they move through the MBEC section of the EIC. In addition to permitting us to understand the effects of saturation, other effects are included which do not fit easily in the analytic formalism.
* G. Stupakov and P. Baxevanis, PRAB 22, 034401 (2019).

Poster TUPAB180 [1.955 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB180

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paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 18 August 2021

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TUPAB188

InnovaTron: An Innovative High-Intensity Industrial Cyclotron for Production of Tc-99m and Other Frontier Medical Radioisotopes*

cyclotron, extraction, ion-source, acceleration

1841

G. D’Agostino, Q. Flandroy, E. Forton, W.J.G.M. Kleeven, J. Mandrillon, V. Nuttens, E. van der Kraaij
IBA, Louvain-la-Neuve, Belgium

Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 886190.
Tc-99m is the most used radioisotope in nuclear medicine. It is almost exclusively produced with a few ageing research reactors worldwide. In response to growing concerns about Tc-99m availability and its increasing demand, alternative production routes are being explored. The EU-funded InnovaTron project aims at designing an innovative compact high-intensity self-extracting cyclotron able to deliver proton beams with currents up to 5 mA or more for the direct production of Tc-99m. It could be also used for production of high quantities of other frontier medical radioisotopes. The proton beams exit without using an electrostatic deflector to overcome its current limitations. A prototype cyclotron was built by IBA in 2001. Currents up to 2 mA were extracted from it. However, at higher intensities, the extraction efficiency was not higher than 70-75% and the extracted emittance was rather large. The InnovaTron project will implement new technological solutions in the self-extracting cyclotron to be used for large-scale industrial applications. An overview on the InnovaTron project is here presented together with the first simulation results.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB188

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paper received ※ 18 May 2021 paper accepted ※ 01 June 2021 issue date ※ 25 August 2021

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TUPAB198

ESS DTL Tuning Using Machine Learning Methods

network, cavity, DTL, linac

1872

J.S. Lundquist, N. Milas, E. Nilsson
ESS, Lund, Sweden
S. Werin
Lund University, Lund, Sweden

The European Spallation Source, currently under construction in Lund, Sweden, will be the world’s most powerful neutron source. It is driven by a proton linac with a current of 62.5 mA, 2.86 ms long pulses at 14 Hz. The final section of its normal-conducting front-end consists of a 39 m long drift tube linac (DTL) divided into five tanks, designed to accelerate the proton beam from 3.6 MeV to 90 MeV. The high beam current and power impose challenges to the design and tuning of the machine and the RF amplitude and phase have to be set within 1% and 1 degree of the design values. The usual method used to define the RF set-point is signature matching, which can be a time consuming and challenging process, and new techniques to meet the growing complexity of accelerator facilities are highly desirable. In this paper we study the usage of Machine Learning to determine the RF optimum amplitude and phase. The data from a simulated phase scan is fed into an artificial neural network in order to identify the needed changes to achieve the best tuning. Our test for the ESS DTL1 shows promising results, and further development of the method will be outlined.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB198

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paper received ※ 17 May 2021 paper accepted ※ 21 June 2021 issue date ※ 13 August 2021

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TUPAB199

Progress on the Proton Power Upgrade at the Spallation Neutron Source

target, klystron, linac, cryomodule

1876

M.S. Champion, C.N. Barbier, M.S. Connell, J. Galambos, M.P. Howell, S.-H. Kim, J.S. Moss, B.W. Riemer, K.S. White
ORNL, Oak Ridge, Tennessee, USA
E. Daly
JLab, Newport News, Virginia, USA
N.J. Evans, G.D. Johns
ORNL RAD, Oak Ridge, Tennessee, USA

Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. This research was supported by the DOE Office of Science, Basic Energy Science.
The Proton Power Upgrade Project at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory will double the proton power capability from 1.4 to 2.8 MW. This will be accomplished through an energy increase from 1.0 to 1.3 GeV and a beam current increase from 26 to 38 mA. The energy increase will be accomplished through the addition of 7 cryomodules to the linear accelerator (Linac). The beam current increase will be supported by upgrading several radio-frequency systems in the normal-conducting section of the Linac. Upgrades to the accumulator ring injection and extraction regions will accommodate the increase in beam energy. A new 2-MW-capable target and supporting systems will be developed and installed. Conventional facility upgrades include build-out of the existing klystron gallery and construction of a tunnel stub to facilitate future beam transport to the second target station. The project received approval to proceed with construction in October 2020. Procurements are in progress, and some installation activities have already occurred. Most of the installation will take place during three outages in 2022-2023. The project early finish is planned for 2025.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB199

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paper received ※ 10 May 2021 paper accepted ※ 28 May 2021 issue date ※ 21 August 2021

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TUPAB204

Upgrade of Los Alamos Accelerator Facility as a Fusion Prototypic Neutron Source

target, neutron, radiation, linac

1890

Y.K. Batygin, E.J. Pitcher
LANL, Los Alamos, New Mexico, USA

Funding: Work supported by US DOE under contract 89233218CNA000001
The Fusion Prototypic Neutron Source (FPNS) is considered to be a testbed for scientific understanding of material degradation in future nuclear fusion reactors. The primary mission of FPNS is to provide a damage rate in samples of 8-11 dpa/calendar year with He/dpa ratio of 10 appm in irradiation volume of 50 cubic cm or larger with irradiation temperature 300-1000 deg C and flux gradient less than 20%/cm in the plane of the sample. Los Alamos Neutron Science Center (LANSCE) is an attractive candidate for FPNS project. Accelerator Facility was designed and operated for an extended period as a 0.8-MW Meson Factory. Existing setup of the LANSCE accelerator complex can nearly fulfill requirements of the fusion neutron source station. The primary function of the upgraded accelerator systems is the safe and reliable delivery of a 1.25-mA continuous proton beam current at 800-MeV beam energy from the switchyard to the target assembly to create 1 MW power of proton beam interacting with a solid tungsten target. The present study describes existing accelerator setup and further development required to meet the needs of FPNS project.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB204

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paper received ※ 14 May 2021 paper accepted ※ 02 June 2021 issue date ※ 21 August 2021

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TUPAB205

Advancement of LANSCE Front End Accelerator Facility

rfq, DTL, neutron, linac

1894

Y.K. Batygin, D. Gorelov, S.S. Kurennoy, J.W. Lewellen, N.A. Moody, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA

Funding: Work supported by US DOE under contract 89233218CNA000001
The LANSCE accelerator started routine operation in 1972 as a high-power facility for fundamental research and national security applications. To reduce long-term operational risk, we propose to develop a new Front End of accelerator facility. It contains 100-keV injector with 3-MeV RFQ, and 6-tanks Drift Tube Linac to accelerate particles up to energy of 100 MeV. The low-energy injector concept includes two independent transports merging H⁺ and H⁻ beams at the entrance of RFQ. Beamlines are aimed to perform preliminary beam bunching in front of accelerator section with subsequent simultaneous acceleration of two different beams in a single RFQ. The paper discusses design topics of new Front End of accelerator facility.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB205

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paper received ※ 12 May 2021 paper accepted ※ 28 May 2021 issue date ※ 14 August 2021

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TUPAB208

FETS-FFA Ring Study

lattice, injection, optics, closed-orbit

1901

J.-B. Lagrange, D.J. Kelliher, A.P. Letchford, S. Machida, C.R. Prior, C.T. Rogers
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
S.J. Brooks
BNL, Upton, New York, USA
C. Brown
Brunel University, Middlesex, United Kingdom
J. Pasternak
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
E. Yamakawa
JAI, Egham, Surrey, United Kingdom

ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK, providing a proton beam with a power of 0.2~MW. Detailed studies are under way for a major upgrade, including the use of Fixed Field alternating gradient Accelerator (FFA). A proof-of-principle FFA ring, called FETS-FFA is planned to investigate the feasibility of this kind of machine for the required MW beam power. This paper discusses the study of the FETS-FFA ring case.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB208

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paper received ※ 19 May 2021 paper accepted ※ 08 July 2021 issue date ※ 14 August 2021

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TUPAB210

Construction Status of the COMET Experimental Facility

target, experiment, solenoid, radiation

1907

Y. Fukao, K. Agari, H. Akiyama, E. Hirose, M. Ieiri, Y. Igarashi, M.I. Iio, N. Kamei, Y. Katoh, Y. Komatsu, R. Kurasaki, M. Maki, S. Makimura, S. Mihara, M. Minakawa, Y. Morino, F. Muto, H. Nishiguchi, T. Okamura, K. Sasaki, Y. Sato, S. Sawada, N. Sumi, H. Takahashi, K.H. Tanaka, A. Toyoda, K. Ueno, H. Watanabe, Y. Yamanoi, M.Y. Yoshida
KEK, Tsukuba, Japan

COMET (COherent Muon to Electron Transition) is an experimental project that hunts for a phenomenon of the conversion from the muon to the electron (mu-e conversion). The mu-e conversion violates the lepton flavor universality and its discovery indicates a proof of the physics beyond the standard model of the particle physics. The experiment utilizes a high-intensity primary proton-beam of J-PARC (Japan Proton Accelerator Research Complex). The proton beam is injected to a target about 700mm long to generate a high intensity muon beam so as to accumulate huge statistics and achieve the final goal of a sensitivity of 10^-16. Construction of the experimental facility is underway at a high pace towards an engineering run in 2022 and the first physics run in 2023. In this presentation, we would like to present a current status of the COMET facility construction.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB210

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paper received ※ 17 June 2021 paper accepted ※ 21 June 2021 issue date ※ 13 August 2021

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TUPAB231

Cooling of an Annular Beam by Using Nonlinear Effects

resonance, dipole, emittance, extraction

1968

F. Capoani, M. Giovannozzi, R. Tomás García
CERN, Geneva, Switzerland
A. Bazzani, F. Capoani
Bologna University, Bologna, Italy

In recent years, nonlinear effects have been used to modify the transverse beam distribution by crossing nonlinear resonances adiabatically. This allows generating transversally split beams, in which the initial single Gaussian is divided into several ones depending on the order and stability type of the resonance used. Nonlinear effects could be used to try and cool a beam by acting on its transverse beam distribution. In this paper, we present and discuss the special case of a beam with an annular distribution, showing how the resulting emittance could be reduced by means of nonlinear effects.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB231

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paper received ※ 10 May 2021 paper accepted ※ 16 June 2021 issue date ※ 21 August 2021

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TUPAB232

Linear Coupling and Adiabaticity of Emittance Exchange

resonance, coupling, emittance, extraction

1972

F. Capoani, M. Giovannozzi
CERN, Geneva, Switzerland
A. Bazzani, F. Capoani
Bologna University, Bologna, Italy
A.I. Neishtadt
IKI, Moscow, Russia
A.I. Neishtadt
Loughborough University, Leicestershre, United Kingdom

In circular accelerators, crossing the coupling resonance induces the exchange of the transverse emittances, provided the process is adiabatic. In this paper, we introduce a theoretical framework to analyze the resonance-crossing process, based on Hamiltonian mechanics, which is capable of explaining all the features of the emittance exchange process.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB232

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paper received ※ 11 May 2021 paper accepted ※ 16 June 2021 issue date ※ 27 August 2021

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TUPAB240

The Impact of Trajectory-Shaped Coil on the Beam Dynamics in the SC230 Superconducting Cyclotron

cyclotron, betatron, extraction, induction

2002

I.D. Lyapin, O. Karamyshev, V. Malinin, D. Popov
JINR/DLNP, Dubna, Moscow region, Russia
G.A. Karamysheva
JINR, Dubna, Moscow Region, Russia

In this paper, we compared the effect of the cyclotron coil shape on the beam dynamics. Two models were created. The first has a conventional round coil, the second has a coil that follows the trajectory of the protons. Parameters of extracted beams are discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB240

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paper received ※ 19 May 2021 paper accepted ※ 27 May 2021 issue date ※ 21 August 2021

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TUPAB258

Impact of Coherent Beam-Beam Interaction on the Landau Damping of the Transverse Coupled-Bunch Instability

dipole, electron, damping, coupling

2062

R. Li
JLab, Newport News, Virginia, USA
M. Blaskiewicz
BNL, Upton, New York, USA

Funding: This work is supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.
In the EIC design, at high average-current operation, the transverse coupled-bunch instability (TCBI) induced by the long-range transverse resistive-wall wakefield in the electron storage ring (eSR) has a fast growth rate and requires efficient mitigation. A natural mitigation mechanism is provided by the beam-beam interaction at the interaction point (IP), which gives a strong Landau damping for the TCBI in the eSR. In this study, using a simplified simulation model, we investigate how this Landau damping from the beam-beam interaction behaves when the coherent beam-beam interaction at IP is considered. Our method and results will be presented in this paper.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB258

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paper received ※ 21 June 2021 paper accepted ※ 01 July 2021 issue date ※ 25 August 2021

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TUPAB262

The Characteristic of the Beam Position Growth in CSNS/RCS

neutron, MMI, impedance, synchrotron

2073

L. Huang, S. Wang
IHEP, Beijing, People’s Republic of China
S.Y. Xu
DNSC, Dongguan, People’s Republic of China

Funding: Work supported by NNSF of China: N0. U1832210
An instability of the beam position growth is observed in the beam commissioning of the Rapid Cycling Synchrotron of the China Spallation Neutron Source. To simplify the study, a series of measurements have been performed to characterize the instability in the DC mode with consistent energy of 80 MeV. The measurement campaign is introduced in the paper and it conforms to the characteristics of the coupled bunch instability.

Poster TUPAB262 [3.748 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB262

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paper received ※ 13 May 2021 paper accepted ※ 02 June 2021 issue date ※ 22 August 2021

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TUPAB263

The Phase Loop Status of the RF System in CSNS/RCS

feedback, cavity, space-charge, MMI

2076

L. Huang, X. Li, S. Wang
IHEP, Beijing, People’s Republic of China
M.T. Li, H.Y. Liu
IHEP CSNS, Guangdong Province, People’s Republic of China
Y. Liu
DNSC, Dongguan, People’s Republic of China

The Rapid Cycling Synchrotron (RCS) of the China Spallation Neutron Source (CSNS) is a high intensity proton accelerator. The acceleration system consists of eight ferrite loaded cavities. The RCS is the space charge dominant machine and it is mitigated through the bunch factor optimization in the beam commissioning, so the injected beam will occupy a larger bucket size and unavoidable mismatch with the bucket, thus the dipole oscillation is excited. The phase loop scheme is designed to restrict the oscillation in the RF system, but the transmission efficiency is reduced by the phase loop and the bunch factor also increases, so the phase loop scheme is studied. To keep the phase loop but also maintain the transmission efficiency, we optimized the original phase loop scheme, but the beam loss still increases small when the loop on.

Poster TUPAB263 [1.548 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB263

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paper received ※ 13 May 2021 paper accepted ※ 02 June 2021 issue date ※ 21 August 2021

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TUPAB283

Feasibility Study of ChDR Diagnostic Device in the LHC

radiation, diagnostics, flattop, electron

2139

K. Łasocha
Jagiellonian University, Kraków, Poland
M. Bergamaschi, M. Krupa, K. Łasocha, T. Lefèvre, S. Mazzoni, N. Mounet, E. Senes
CERN, Geneva, Switzerland
D.M. Harryman
JAI, Egham, Surrey, United Kingdom
P. Karataev
Royal Holloway, University of London, Surrey, United Kingdom
A. Potylitsyn
TPU, Tomsk, Russia
A. Schloegelhofer
TU Vienna, Wien, Austria

In recent years Cherenkov Diffraction Radiation (ChDR) has been reported as a phenomenon suitable for various types of particle accelerator diagnostics. As it would typically work best for highly relativistic beam, past studies and experiments have been mostly focusing on the lepton machines. This contribution investigates the prospects on the utilization of ChDR as a diagnostic tool for the Large Hadron Collider (LHC). Based on theoretical considerations and simulation results we estimate the properties of the expected radiation, both in the incoherent and coherent domain, and we compare them with the requirements of the existing diagnostic systems. We also address the potential problem of the use of dielectric radiators in circular machines, where secondary electrons could potentially lead to the creation of electron clouds inside the beam pipe that may affect the radiator.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB283

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paper received ※ 14 May 2021 paper accepted ※ 18 June 2021 issue date ※ 02 September 2021

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TUPAB284

BPM for the High Energy Beam Transport Line of MINERVA Project at SCK•CEN

linac, instrumentation, experiment, electron

2143

H. Kraft, L. Perrot
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France

This paper presents the status of developments concerning button type BPM. Results of our analytical model BPMOK will compare the measurements done at IPHI facility at CEA-Saclay and GANIL/SPIRAL2 in Caen. The measurements aims to compare the response of the analytical model depending on beam positions, sizes, intensities and energies. BPMOK is validated to predict BPM responses in order to make parametric studies. Starting from already existing BPM built for the MINERVA LINAC, the analytical model is used to design the BPM for the HEBT.

Poster TUPAB284 [1.475 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB284

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paper received ※ 10 May 2021 paper accepted ※ 02 June 2021 issue date ※ 28 August 2021

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TUPAB311

Nonlinear Correctors Tuning for the Collector Ring Isochronous Mode

sextupole, betatron, optics, controls

2218

M.A. Lyalin, I. Koop, D.B. Shwartz
BINP SB RAS, Novosibirsk, Russia
I. Koop, M.A. Lyalin, D.B. Shwartz
NSU, Novosibirsk, Russia

One of the operating modes for the Collector Ring (CR) under construction in Darmstadt is the isochronous mode, in which the captured ions circulate with an equal period regardless of their momentum. The measurement of the orbital period T by the time-of-flight sensors makes it possible to precisely determine the mass to the charge ratio of the ion under study. For this, the change of the circulation period dT should not exceed 1·10^-6 for dT/T in the entire momentum acceptance of the 0.62%. Modeling in the Strategic Accelerator Design code showed that without nonlinear effects compensation, the orbital period variation is 1·10^-5. In this work, the parameters of nonlinear correctors, which are sextupoles and octupoles in CR, are determined, necessary for the isochronous mode implementation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB311

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paper received ※ 29 May 2021 paper accepted ※ 16 June 2021 issue date ※ 14 August 2021

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TUPAB325

Data-Driven Risk Matrices for CERN’s Accelerators

operation, linac, synchrotron, machine-protect

2260

T. Cartier-Michaud, A. Apollonio, G.B. Blarasin, B. Todd, J.A. Uythoven
CERN, Geneva, Switzerland

Funding: Research supported by the HL-LHC project.
A risk matrix is a common tool used in risk assessment, defining risk levels with respect to the severity and probability of the occurrence of an undesired event. Risk levels can then be used for different purposes, e.g. defining subsystem reliability or personnel safety requirements. Over the history of the Large Hadron Collider (LHC), several risk matrices have been defined to guide system design. Initially, these were focused on machine protection systems, more recently these have also been used to prioritize consolidation activities. A new data-driven development of risk matrices for CERN’s accelerators is presented in this paper, based on data collected in the CERN Accelerator Fault Tracker (AFT). The data-driven approach improves the granularity of the assessment, and limits uncertainty in the risk estimation, as it is based on operational experience. In this paper the authors introduce the mathematical framework, based on operational failure data, and present the resulting risk matrix for LHC.

Poster TUPAB325 [0.499 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB325

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paper received ※ 19 May 2021 paper accepted ※ 24 June 2021 issue date ※ 17 August 2021

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TUPAB326

Injection Optimization and Study of XiPAF Synchrotron

injection, simulation, synchrotron, experiment

2264

X.Y. Liu, X. Guan, Y. Li, M.W. Wang, X.W. Wang, H.J. Yao, W.B. Ye, H.J. Zeng, S.X. Zheng
TUB, Beijing, People’s Republic of China
W.L. Liu, D. Wang, M.C. Wang, Z.M. Wang, Y. Yang, M.T. Zhao
NINT, Shannxi, People’s Republic of China

The synchrotron of XiPAF (Xi’an 200MeV proton application Facility) is a compact proton synchrotron, which using H^- stripping injection and phase space painting scheme. Now XiPAF is under commissioning with some achievements, the current intensity after injection reach 43mA, the corresponding particle number is 2.3·10¹¹, and the injection efficiency is 57%. The simulation results by PyOrbit show that the injection efficiency is 77%. In this paper, we report how the injection intensity and efficiency were optimized. We analyzed the difference between simulation and experiments, and quantitatively investigate the factors affecting injection efficiency through experiments.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB326

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paper received ※ 14 May 2021 paper accepted ※ 22 June 2021 issue date ※ 22 August 2021

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TUPAB361

Study and Design of a Fast Switching Magnet for the MYRRHA Project

dipole, linac, optics, beam-transport

2356

E. Froidefond, F. Bouly, P.-O. Dumont
LPSC, Grenoble Cedex, France
D. Vandeplassche
SCK•CEN, Mol, Belgium

Funding: Work supported by SCK•CEN, CNRS/IN2P3, Univ. Grenoble Alpes.
The MYRRHA project aims at building an Accelerator Driven System demonstrator, which consists of two injectors and a superconducting linac. The proton beam from the first injector accelerated up to 17 MeV goes to the linac (600 MeV) through a Medium Energy Beam Transfer line (MEBT). Whereas in the meantime, the beam from the second injector is sent to a beam dump. In case of failure in the first injector, the beam of the awaiting injector is sent to the linac. A switching magnet located at the junction of the two injection lines performs this beam switch in less than 1.5 seconds. A magnetic design and a mechanical structure of this magnet proposed to the MYRRHA project are presented.
*emmanuel.froidefond@lpsc.in2p3.fr

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB361

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paper received ※ 19 May 2021 paper accepted ※ 19 July 2021 issue date ※ 23 August 2021

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TUPAB402

Review of Technologies for Ion Therapy Accelerators

synchrotron, extraction, linac, heavy-ion

2465

H.X.Q. Norman, R.B. Appleby, A.F. Steinberg
UMAN, Manchester, United Kingdom
E. Benedetto
TERA, Novara, Italy
E. Benedetto, M. Sapinski
CERN, Meyrin, Switzerland
H.L. Owen
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
H.L. Owen
Cockcroft Institute, Warrington, Cheshire, United Kingdom
M. Sapinski
GSI, Darmstadt, Germany
S.L. Sheehy
The University of Melbourne, Melbourne, Victoria, Australia

Cancer therapy using protons and heavier ions such as carbon has demonstrated advantages over other radiotherapy treatments. To bring about the next generation of clinical facilities, the requirements are likely to reduce the footprint, obtain beam intensities above 1E10 particles per spill, and achieve faster extraction for more rapid, flexible treatment. This review follows the technical development of ion therapy, discussing how machine parameters have evolved, as well as trends emerging in technologies for novel treatments such as FLASH. To conclude, the future prospects of ion therapy accelerators are evaluated.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB402

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paper received ※ 19 May 2021 paper accepted ※ 28 July 2021 issue date ※ 24 August 2021

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TUPAB407

A Novel Beam Optics Concept to Maximize the Transmission Through Cyclotron-based Proton Therapy Gantries

optics, emittance, quadrupole, simulation

2477

V. Maradia, A.C. Giovannelli, A.L. Lomax, D. Meer, S. Psoroulas, J.M. Schippers, D.C. Weber
PSI, Villigen PSI, Switzerland
V. Maradia
ETH, Zurich, Switzerland
D.C. Weber
University of Zurich, University Hospital, Zurich, Switzerland
D.C. Weber
KRO, Bern, Switzerland

Funding: This work is funded by a PSI inter-departmental funding initiative (CROSS).
Most of the conventional beam optics of cyclotron-based proton gantries were designed to provide point-to-point focus in both planes with an imaging factor between 1 and 2 from the entrance of the gantry to the patient. This means that a small beam size at the gantry entrance is required to achieve the required small beam size at the patient. Due to the typically used beam emittance, this in turn results in large beam divergence at the gantry entrance, increasing the possibility of beam losses along the gantry as the beam envelope gets close to the apertures. To maximize transmission through the gantry, we propose a novel beam optics concept using 3:1 imaging. It reduces the beam divergence at the gantry entrance by factor 3 while still achieving a small beam size at the patient. The beam envelope is better controlled and keeps clear of the apertures compared to the 1:1 or 1:2 imaging beam envelope. For PSI Gantry 2, the novel 3:1 imaging beam optics increase the proton beam transmission for lower energies by 40% compare to 1:1 imaging beam optics. The usage of small imaging factors can help to maximize transmission for different gantry lattices, thus reducing treatment times.

Poster TUPAB407 [1.347 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB407

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paper received ※ 10 May 2021 paper accepted ※ 02 June 2021 issue date ※ 29 August 2021

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WEXA06

Study of Pb-Pb and Pb-p Collision Debris in the CERN LHC in View of HL-LHC Operation

operation, luminosity, hadron, heavy-ion

2528

M. Sabaté-Gilarte, R. Bruce, F. Cerutti, A. Lechner
CERN, Meyrin, Switzerland

Funding: Research supported by the HL-LHC project
For the first time, a full characterization of the Pb-Pb and Pb-p collision debris as well as its impact in terms of energy deposition in the long straight section (LSS) of CERN’s Large Hadron Collider has been carried out. By means of Monte Carlo simulations with FLUKA, both inelastic nuclear interaction and electromagnetic dissociation were taken into account as source term for lead ion operation, while for Pb-p operation only nuclear interaction is of importance. The radiation exposure of detectors exclusively destined for ion beam runs is assessed, allowing drawing implications of their use. This work gave the opportunity for an unprecedented validation of simulation results against measurement of beam loss monitors (BLM) in the experimental LSS during ion operation. Pb-Pb operation refers to the 2018 ion run at 6.37 TeV per charge with a +160 microrad half crossing angle in the vertical plane at the ATLAS interaction point. Instead, Pb-p operation was benchmarked for the 2016 ion run at 6.5 TeV per charge with -140 microrad half crossing angle in the vertical plane at the same location.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXA06

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paper received ※ 18 May 2021 paper accepted ※ 05 July 2021 issue date ※ 22 August 2021

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WEXB05

Beam Commissioning SPIRAL2

linac, MEBT, rfq, MMI

2540

A.K. Orduz, M. Di Giacomo, R. Ferdinand, B. Jacquot, O. Kamalou, J.-M. Lagniel, G. Normand, A. Savalle
GANIL, Caen, France
D. Uriot
CEA-IRFU, Gif-sur-Yvette, France

The SPIRAL2 injector includes a 5 mA proton-deuteron ECR source, a 1 mA ECR heavy ion source (up to A/Q =3) and a CW 0.73 MeV/u RFQ. It has been successfully commissioned using a diagnostic-plate in parallel with the superconducting linac installation. The green light has been obtained for the LINAC commissioning in July of 2019, starting with the Medium Energy Beam Transport (MEBT) commissioning with protons then with helium in 2020. The MEBT line and tuning process are described. The main experimental results are given, including the emittance and profile measurements which are compared with TraceWin simulations. RFQ output energy variation has been found due to an input energy error, its correction optimizing the source platform voltage is presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXB05

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paper received ※ 19 May 2021 paper accepted ※ 25 June 2021 issue date ※ 13 August 2021

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WEXB07

Transverse Beam Profile Measurements from Extraction Losses in the PS

extraction, septum, kicker, emittance

2548

J.R. Hunt, F. Cerutti, L.S. Esposito, M. Giovannozzi, A. Huschauer, G. Russo
CERN, Geneva, Switzerland
G. Russo
Goethe Universität Frankfurt, Frankfurt am Main, Germany

During Multi-Turn Extraction (MTE) of continuous beams in the Proton Synchrotron (PS) at CERN, losses are generated on the blade of both the active and non-active septum during the rise time of the extraction kickers. Utilising pCVD Diamond detectors, secondary signal generated from these losses is measured. The high time resolution of these devices allows for insight into the detail of the horizontal beam distribution during extraction, and hence useful information such as the horizontal beam emittance may be computed. In this contribution, FLUKA simulations to relate the detector response to the beam impact conditions on the blades of the two septa are presented. The dependence on the beam angle, magnetic fringe field, and positioning of the detector is explored. Finally, realistic beam distributions are used to determine expected signal profiles at each septum.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXB07

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paper received ※ 18 May 2021 paper accepted ※ 20 July 2021 issue date ※ 27 August 2021

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WEXB08

Beam Losses and Emittance Growth Studies at the Record High Space-Charge in the Booster

booster, emittance, space-charge, operation

2552

V.D. Shiltsev, J.S. Eldred, V.A. Lebedev, K. Seiya
Fermilab, Batavia, Illinois, USA

Comprehensive studies of high intensity proton beams in the 0.4-8 GeV FNAL Booster synchrotron have revealed interesting nonlinear dynamics of the beam losses and emittance growth at the record high dQ_SC=0.6. We report the results of the studies and directions of further improvements to prepare the Booster to the era of even higher intensity operation with new 0.8 GeV PIP-II linac.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXB08

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paper received ※ 24 May 2021 paper accepted ※ 02 July 2021 issue date ※ 17 August 2021

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WEPAB001

Accelerator Challenges of the LHeC Project

electron, emittance, optics, linac

2570

B.J. Holzer, K.D.J. André, O.S. Brüning
CERN, Geneva, Switzerland
S.A. Bogacz
JLab, Newport News, Virginia, USA
M. Klein
The University of Liverpool, Liverpool, United Kingdom

The LHeC project studies the design of a future electron-proton collider at CERN that will run in parallel to the standard LHC operation. For this purpose, the existing LHC storage ring will be combined with an Energy Recovery Linac (ERL), to accelerate electrons up to kinetic energy of 50 GeV. This concept - also applicable to the FCC-eh collider and studied at the PERLE project as prototype version - allows a peak luminosity of 10³⁴ cm^-2 s^-1. A sophisticated design of the RF structures, linacs, arcs, and interaction region is required. The electrons are accelerated and, after the interaction point, their energy is recovered through the same RF structures. While this energy recovery concept is a very promising approach, severe challenges are set by the layout of the interaction region, the beam separation concept and the design of the linac and arc lattice for the highest possible momentum acceptance. Emittance control and beam-beam effect of both, electron and proton beams, have been studied in front-to-end simulations and will be presented. We summarise the design principles of the ERL, the optimization of the arc lattice, and the main parameters of the project.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB001

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paper received ※ 17 May 2021 paper accepted ※ 21 June 2021 issue date ※ 21 August 2021

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WEPAB008

Numerical Noise Study in EIC Beam-Beam Simulations

simulation, electron, emittance, resonance

2592

D. Xu, Y. Hao
FRIB, East Lansing, Michigan, USA
Y. Luo, C. Montag
BNL, Upton, New York, USA
J. Qiang
LBNL, Berkeley, California, USA

In the Electron-Ion Collider (EIC) design, a flat beam collision scheme is adopted to achieve 1e34 luminosity. We found that the vertical growth of the proton beam is much larger than of the round beam. In this article we present the numerical noise study about the number of macroparticles, the electron slice number, and the electron bunch length. Both weak-strong and strong-strong simulation methods are used. It turns out the proton emittance growth in the strong-strong simulation mainly comes from the numberical noise. This study helps us to perform beam-beam simulation correctly for EIC.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB008

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paper received ※ 17 May 2021 paper accepted ※ 31 August 2021 issue date ※ 31 August 2021

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WEPAB012

Preliminary Investigation into Accelerators for In-Situ Cultural Heritage Research

rfq, linac, radiation, detector

2605

T.K. Charles
The University of Liverpool, Liverpool, United Kingdom
A. Castilla
CERN, Meyrin, Switzerland
A. Castilla
Lancaster University, Lancaster, United Kingdom

Ion Beam Analysis (IBA) centres have provided researchers with powerful techniques to analyse objects of cultural significance in a non-destructive and non-invasive manner. However, in some cases it is not be feasible to remove an object from the field or museum and transport it to the laboratory. In this conference proceedings, we report the initial results of an investigation into the feasibility of a compact accelerator that can be taken to sites of cultural significance, for PIXE analysis. In particular, we consider the application of a compact, robust accelerator that is capable to producing 2 MeV protons that can be taken into the field to perform PIXE measurements on rock art. We detail the main challenges and considerations for such a device, as well as highlighting the potential benefits of this new accelerator application.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB012

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paper received ※ 18 May 2021 paper accepted ※ 25 June 2021 issue date ※ 10 August 2021

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WEPAB018

Space-Charge Effects in Ionization Beam Profile Monitors

booster, space-charge, electron, synchrotron

2628

V.D. Shiltsev
Fermilab, Batavia, Illinois, USA

Ionization profile monitors (IPMs) are widely used in accelerators for non-destructive and fast diagnostics of high energy particle beams. At high beam intensities, the space-charge forces make the measured IPM profiles significantly different from those of the beams. We analyze dynamics of the secondaries in IPMs and develop an effective algorithm to reconstruct the beam sizes from the measured IPM profiles. Efficiency of the developed theory is illustrated in application to the Fermilab 8 GeV proton Booster IPMs.

Poster WEPAB018 [0.731 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB018

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paper received ※ 19 May 2021 paper accepted ※ 24 June 2021 issue date ※ 20 August 2021

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WEPAB024

Release of Crystal Routine for Multi-Turn Proton Simulations within SixTrack v5

simulation, collimation, collider, hadron

2648

M. D’Andrea, A. Mereghetti, D. Mirarchi, V.K.B. Olsen, S. Redaelli
CERN, Geneva, Switzerland

Crystal collimation is studied as a possible scheme to further improve the efficiency of ion collimation at the High Luminosity Large Hadron Collider (HL-LHC), as well as for possible applications in the CERN program of Physics Beyond Colliders. This concept relies on the use of bent crystals that can deflect high-energy halo particles at large angles, of the order of tens of urad. In order to reproduce key experimental results of crystal collimation tests and predict the performance of this system when applied to present and future machines, a dedicated simulation routine was developed. This routine is capable of modeling both coherent and incoherent interactions of beam particles with crystal collimators, and is fully integrated into the magnetic tracking and collimator modeling provided by the single-particle tracking code SixTrack. This paper describes the implementation of the routine in the latest version of SixTrack and its most recent improvements, in particular regarding the treatment of the crystal miscut angle.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB024

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paper received ※ 19 May 2021 paper accepted ※ 23 June 2021 issue date ※ 14 August 2021

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WEPAB064

Front-to-End Simulations of the Energy Recovery Linac for the LHeC Project

emittance, electron, radiation, linac

2740

K.D.J. André, B.J. Holzer
CERN, Geneva, Switzerland

The LHeC project aims to study the electron-proton deep inelastic scattering at the TeV energy scale with an innovative accelerator program. It exploits the promising energy recovery technology in order to collide an intense 50 GeV lepton beam with one hadron beam from the High Luminosity Large Hadron Collider (HL-LHC) in parallel to the hadron-hadron operation. The paper presents the studies that have been performed to assess the performance of the machine and the efficiency of the energy recovery process for different scalings of the ERL. The studies include emittance blow-up due to synchrotron radiation emission and beam-disruption created by the strong beam-beam force at the interaction point. The design principles of the ERL structure are discussed, including the particle detector bypass and the interaction region, and the results of the tracking simulations are presented, considering the complete multi-turn ERL process. Special attention is turned to the lepton beam emittance budget and the resulting energy recovery performance.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB064

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paper received ※ 18 May 2021 paper accepted ※ 24 June 2021 issue date ※ 28 August 2021

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WEPAB139

Beam Tracking Simulations for Stage 1 of the Laser-Hybrid Accelerator for Radiobiological Applications (LhARA)

laser, simulation, target, plasma

2939

H.T. Lau
Imperial College London, London, United Kingdom

The Laser-hybrid Accelerator for Radiobiological Applications (LhARA) is a unique and flexible facility proposed for radiobiological studies. The first stage of LhARA consists of an intense laser source interacting with a thin foil target producing a large flux of protons with energies up to 15 MeV. Particles will propagate through a combination of plasma (Gabor) lenses and magnetic elements to an achromat arc delivering the beam vertically to an in-vitro end station. An end-to-end simulation from the laser source to the end station is required to verify the conceptual design of the beamline. The laser-plasma interaction is simulated with Smilei (a particle-in-cell code) to produce a two-dimensional (2D) distribution of particles. Whilst it is possible to simulate the laser-plasma interaction in three dimensions (3D), access to the computing resources needed to run highly resolved simulations was not available. A sampling routine will be described which samples the 2D distribution to generate a 3D beam. The Monte Carlo simulation programs BDSIM and GPT were used to track the beam. Results of the simulations will be shown and compared to the results of an idealized Gaussian beam.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB139

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paper received ※ 18 May 2021 paper accepted ※ 01 July 2021 issue date ※ 10 August 2021

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WEPAB140

Second Beam Test and Numerical Investigation of the Imperial College Plasma (Gabor) Lens Prototype

plasma, focusing, electron, laser

2943

T.S. Dascalu
Imperial College London, London, United Kingdom
R. Bingham, C.G. Whyte
USTRAT/SUPA, Glasgow, United Kingdom
C.L. Cheung, H.T. Lau, K.R. Long, T. Nonnenmacher, J.K. Pozimski
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

Funding: STFC through the Imperial Impact Acceleration Account
The design of the Laser-hybrid Accelerator for Radiobiological Applications (LhARA) is based on a series of plasma lenses to capture, focus, and select the energy of the ions produced in the laser-target interaction. A second beam test of the first plasma lens prototype, built at the Imperial College London, took place in October 2017 at the Ion Beam Centre of the University of Surrey. 1.4 MeV proton pencil beams were imaged 0.67m downstream of the lens on a scintillator screen over a wide range of settings. On top of the focusing effect, the electron plasma converted pencil beams into rings. The intensity of each ring shows a different degree of modulation along its circumference. Analysis of the results indicates non-uniformity and an off-axis rotation of the electron plasma. The effect on the beam is presented and compared to the results of a simulation of the plasma dynamics and proton beam transport through the lens. A particle-tracking code was used to study the impact of plasma instabilities on the focusing forces produced by the lens. The m = 1 diocotron instability was associated with the formation of rings from the pencil beams.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB140

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paper received ※ 19 May 2021 paper accepted ※ 29 August 2021 issue date ※ 18 August 2021

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WEPAB152

Carbon Nanotubes as Cold Electron Field Emitters for Electron Cooling in the CERN Extra Low Energy Antiproton (ELENA) Ring

electron, vacuum, experiment, antiproton

2975

B. Galante, G. Tranquille
CERN, Meyrin, Switzerland
O. Apsimon, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
J. Resta-López
IFIC, Valencia, Spain

In ELENA electron cooling reduces the emittance of the antiproton beam allowing to deliver a high-quality beam to the experiments at the unprecedented low energy of 100 keV. To cool the antiproton beam at this low energy, the electron gun must emit electrons with as monoenergetic a distribution as possible. The currently used thermionic gun limits the cooling performance due to the relatively high transverse energy spread of the emitted electrons. Optimization is therefore being studied, aiming at developing a cold-cathode electron gun. This has led to the investigation of carbon nanotubes (CNTs) as cold electron field emitters. CNTs are considered the most promising field emitter material due to their high aspect ratio, chemical stability, and capability to deliver high current densities. To assess the feasibility of using such material operationally a full characterization is required, focussing on key parameters such as emitted current, emission stability, and lifetime. This contribution will present the status of ongoing experiments reporting on the conditioning process necessary to reach good stability over time and the emitting performance of different CNT arrays.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB152

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paper received ※ 18 May 2021 paper accepted ※ 25 June 2021 issue date ※ 16 August 2021

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WEPAB166

Concept of an Accelerator-Driven Neutron Source for the Production of Atmospheric Radiations

neutron, target, shielding, radiation

2998

P. Lee, N.-W. Kang
Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea
M. Moon
KAERI, Daejon, Republic of Korea

Funding: This work has been supported through KOMAC operation fund of KAERI and the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2021R1C1C1007100).
At the Korea Multi-purpose Accelerator Complex (KOMAC) of Korea Atomic Energy Research Institute (KAERI), we are studying an accelerator-driven neutron source for the production of white neutron beams that resemble the atmospheric radiations on the earth. In the concept of the neutron source, high-energy neutrons are generated by using a 200-MeV proton beam on a heavy-metal target in a target station, which is consisted of a target, moderator, reflector, and biological shields, and a part of the high-energy neutrons are guided in a forward direction to make neutron beams with the atmospheric-like energy spectrum. The conceptual design has 6 more thermal-neutron beamlines at the separation of 30 degrees for the fundamental research on neutron science. Here, we present the concepts of the target station and basic parameters regarding the neutron source.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB166

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paper received ※ 18 May 2021 paper accepted ※ 01 July 2021 issue date ※ 28 August 2021

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WEPAB174

Study of the Electron Seeded Proton Self-Modulation Using FBPIC

plasma, wakefield, electron, simulation

3008

L. Liang, G.X. Xia
The University of Manchester, Manchester, United Kingdom
A. Bonatto
Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Brazil
L. Liang, G.X. Xia
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: This work is supported by the Cockcroft Institute Core Grant and the STFC AWAKE Run 2 grant ST/T001917/1
In order to make a full use of the whole proton bunch to drive large amplitude plasma wakefields and suppress the uncontrolled growth of any possible instabilities at the head of the proton bunch, the AWAKE Run 2 experiment plans to use an electron bunch to seed the formation of the proton bunch self-modulation. Additionally, a density step in the plasma channel will be used to freeze the selfmodulation process to keep the wakefield amplitude. In this work, numerical simulations performed with FBPIC are used to investigate the electron seeded proton self-modulation and the effect of the plasma density step as well.

Poster WEPAB174 [1.751 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB174

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paper received ※ 10 May 2021 paper accepted ※ 28 June 2021 issue date ※ 24 August 2021

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WEPAB179

Recent Status of J-PARC Rapid Cycling Synchrotron

operation, shielding, synchrotron, injection

3027

K. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

The 3 GeV rapid cycling synchrotron (RCS) at the Ja-pan Proton Accelerator Research Complex (J-PARC) provides more than 500 kW beams to the Material and Life Science Facility (MLF) and Main Ring (MR). In such a high-intensity hadron accelerator, even losing less than 0.1% of the beam can cause many problems. Such lost protons can cause serious radio-activation and accelerator component malfunctions. Therefore, we have been continuing a beam study to achieve high-power operation. In addition, we have also improved and maintained the accelerator components to enable stable operation. This paper reports the status of the J-PARC RCS over the last two years.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB179

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paper received ※ 13 May 2021 paper accepted ※ 25 June 2021 issue date ※ 22 August 2021

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WEPAB181

New Opportunities in Low Energy Antiproton Research

electron, antiproton, experiment, FEL

3035

C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 721559.
Experiments with low-energy antiprotons are at the cutting edge of science and offer unique opportunities to test some of the fundamental laws of physics. The experiments are, however, very difficult to realize. They critically depend on high-performance numerical tools that can model realistic beam transport and storage and also require advanced beam monitors and detectors that can fully characterize the beam. Finally, novel experiments need to be designed that exploit the enhanced beam quality that the new ELENA ring at CERN provides. This paper presents some selected findings from the pan-European AVA network’s three scientific work packages. It shows results from studies into electron cooling at the new ELENA storage ring, research into carbon nanotubes as cold electron field emitters for electron cooling, and how antiproton-atom collision experiments can be optimized using GEANT4. Finally, the paper gives an overview of the network’s interdisciplinary training program.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB181

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paper received ※ 16 May 2021 paper accepted ※ 11 June 2021 issue date ※ 11 August 2021

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WEPAB184

Optimization of Medical Accelerators

network, medical-accelerators, FEL, detector

3042

C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sk’odowska-Curie grant agreement No 675265.
Between 2016 and 2020, 15 Fellows have carried out collaborative research within the 4 MEUR Optimization of Medical Accelerators (OMA) EU-funded innovative training network. Based at universities, research and clinical facilities, as well as industry partners in several European countries, the Fellows have successfully developed a range of beam and patient imaging techniques, improved biological and physical models in Monte Carlo codes, and also help improve the design of existing and future clinical facilities. This paper gives an overview of the research outcomes of this network. It presents results from tracking and LET measurements with the MiniPIX-TimePIX detector for 60 MeV clinical protons, a new treatment planning approach accounting for prompt gamma range verification and interfractional anatomical changes, and summarizes findings from high-gradient testing of an S-band, normal-conducting low phase velocity accelerating structure. Finally, it gives a brief over-view of the scientific and training events organized by the OMA consortium.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB184

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paper received ※ 16 May 2021 paper accepted ※ 14 July 2021 issue date ※ 21 August 2021

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WEPAB185

Target Bypass Beam Optics for Future High Intensity Fixed Target Experiments in the CERN North Area

target, experiment, quadrupole, optics

3046

G.L. D’Alessandro, D. Banerjee, J. Bernhard, M. Brugger, N. Doble, L. Gatignon, A. Gerbershagen, B. Rae, F.M. Velotti
CERN, Meyrin, Switzerland
S.M. Gibson
JAI, Egham, Surrey, United Kingdom

Several of the proposed experiments for operation at the K12 beam line would profit from significant beam intensity increase. Among those, there is the KLEVER experiment that would require an intensity of 2x10¹³ protons per 4.8 s long spill. The main goal of the experiment is to measure BR(KL->pi0 nu nu) to test the Standard Model structure by itself, and in combination with results from NA62 for BR(K±>pi+ nu nu). NA62 could also profit from higher intensities, and could be run in a new configuration called NA62HI(gher intensity). In the current configuration the beam is transported from the SPS to the TT24 beamline. This beamline leads to the T4 target that attenuates the beam for P42. After T4 the beam is directed into the P42 beamline before impinging on the T10 target and creating the particles necessary for the experiment. Those are finally transported to the detector via K12. This paper presents the idea of partially bypassing T4 and changing the P42 beamline configuration in order to have a sufficiently small beam size at the T10 target for both KLEVER and NA62-HI. Optics studies are developed in MADX and the AppLE.py, software developed at CERN.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB185

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paper received ※ 17 May 2021 paper accepted ※ 01 July 2021 issue date ※ 27 August 2021

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WEPAB187

The ENUBET Multi Momentum Secondary Beamline Design

target, kaon, electron, experiment

3053

E.G. Parozzi, N. Charitonidis
CERN, Geneva, Switzerland
G. Brunetti, E.G. Parozzi, F. Terranova
Universita Milano Bicocca, MILANO, Italy
A. Longhin, M. Pari, F. Pupilli
INFN- Sez. di Padova, Padova, Italy
A. Longhin, M. Pari
Univ. degli Studi di Padova, Padova, Italy
E.G. Parozzi, F. Terranova
INFN MIB, MILANO, Italy

The aim of neutrino physics for the next decades is to detect effects due to CP violation, mass hierarchy, and search for effects beyond the Standard Model predictions. Future experiments need precise measurements of the neutrino interaction cross-sections at the ~GeV/c regime, currently limited by the exact knowledge of the initial neutrino flux on a ~10-20% uncertainty level. The ENUBET project is proposing a novel facility, capable of constraining the neutrino flux normalization through the precise monitoring of the Ke3 (K±>e+pi0nu) decay products in an instrumented decay tunnel. ENUBET can also monitor muons from the two body kaon and pion decays (nu flux) and measure the neutrino energy with a 10% precision without relying on the event reconstruction at the neutrino detector. We present here a novel design based on a broad (4-8.5 GeV/c) momentum range secondary beamline, that widen the cross-section energy range that can be explored by ENUBET. In this poster, we discuss the target optimization studies and we show the early results on the new line’s optics and the layout design. We discuss the expected performance of this line and the forthcoming activities.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB187

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paper received ※ 13 May 2021 paper accepted ※ 29 July 2021 issue date ※ 14 August 2021

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WEPAB192

Simulation Study on Double Diffuser for Loss Reduction in Slow Extraction at J-PARC Main Ring

simulation, extraction, operation, scattering

3069

R. Muto, Y. Arakaki, T. Kimura, S. Murasugi, K. Okamura, Y. Shirakabe, M. Tomizawa, E. Yanaoka
KEK, Tokai, Ibaraki, Japan
A. Matsumura
Nihon Advanced Technology Co., Ltd, Ibaraki, Nakagun, Tokaimura, Japan

J-PARC (Japan Proton Accelerator Research Complex) Main Ring delivers slow-extracted 30~GeV proton beam to various nuclear and particle physics experiments. In the slow extraction the beam loss at the electrostatic septum (ESS) is inevitable, and the beam loss reduction is a key issue to realize the high-intensity beam delivery. We carried out simulation studies on the effectiveness of the beam diffusers at the upstream of the ESS for the beam loss reduction with various materials and dimensions of the diffusers. We found out that putting two diffusers simultaneously on the beam was effective for the beam loss reduction, and the expected beam loss was 0.35 times as high as the operation without diffusers. According to the simulation results we installed the diffusers in the J-PARC Main Ring. We performed beam test with one diffuser and beam loss reduction of 60% was observed, which was in good agreement with the simulation results.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB192

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paper received ※ 19 May 2021 paper accepted ※ 28 June 2021 issue date ※ 21 August 2021

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WEPAB205

XiPAF Synchrotron Slow Extraction Commissioning

extraction, experiment, synchrotron, sextupole

3106

W.B. Ye, X. Guan, Y. Li, X.Y. Liu, M.W. Wang, X.W. Wang, Y. Yang, H.J. Yao, H.J. Zeng, S.X. Zheng
TUB, Beijing, People’s Republic of China
W.L. Liu, D. Wang, M.C. Wang, Z.M. Wang, Y. Yang, M.T. Zhao
NINT, Shannxi, People’s Republic of China

Xi’an 200 MeV Proton Application Facility (XiPAF) is a project to fulfill the need for the experimental simulation of the space radiation environment. It comprises a 7 MeV H⁻ linac, a 60~230 MeV proton synchrotron, and experimental stations. Slow extraction commissioning for 60 MeV proton beam in XiPAF synchrotron has been finished. After commissioning, the maximal experiment extraction efficiency with the RF-knockout (RF-KO) method can up to 85%. The reason for beam loss has been analyzed and presented in this paper. Besides, an experiment of multiple energy extraction has been conducted in XiPAF synchrotron. The proton beams of 3 different energies were successfully extracted in 1.54 s.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB205

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paper received ※ 18 May 2021 paper accepted ※ 07 July 2021 issue date ※ 31 August 2021

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WEPAB212

Physics Studies for the LBNF Graphite Target Design

target, focusing, detector, simulation

3123

J.J. Back
University of Warwick, Coventry, United Kingdom

We present the simulated physics performance of the Long-Baseline Neutrino Facility (LBNF) graphite target that is being designed by the RAL High Power Targets Group for the Deep Underground Neutrino Experiment (DUNE). We first compare three conceptual cylindrical target design options as a function of target length (up to 2.2 m): downstream supported, two individual targets and an upstream-supported cantilever. Choosing the cantilever design as the baseline, we show the effect of widening the upstream inner conductor of the first focusing horn to provide extra space for supporting the target. We also give estimates of the expected performance of the 1.5 m prototype and 1.8 m production cantilevered targets. Furthermore, we show the effects of the main engineering updates made to the other two focusing horns since the DUNE TDR.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB212

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paper received ※ 17 May 2021 paper accepted ※ 05 July 2021 issue date ※ 26 August 2021

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WEPAB213

Optimization of Antiproton-Atom Collision Studies Using GEANT4

antiproton, experiment, simulation, bunching

3126

V. Rodin, A. Farricker, N. Kumar, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
N. Kumar, V. Rodin, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 721559.
The interaction between antiprotons and hydrogen or helium atoms is a fundamental problem in many-particle atomic physics, attracting strong interest from both theory and experiments. Atomic collisions are ideal to study the three and four-body Coulomb problem as the number of possible reaction channels is limited. Currently, only the total cross-sections of such interactions have been measured in an energy range between keV and a few MeV. This contribution investigates the discrepancies between different theories and available experimental data. It also describes a pathway for obtaining differential cross-sections. A purpose-designed experimental setup is presented and detailed Geant4 simulations provide an insight into the interaction between short (ns) antiproton bunches and a dense gas-jet target.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB213

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paper received ※ 23 May 2021 paper accepted ※ 30 June 2021 issue date ※ 24 August 2021

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WEPAB214

Realistic Simulations of Stray Field Impact on Low Energy Transfer Lines

solenoid, experiment, simulation, antiproton

3130

V. Rodin, S. Padden, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
A. Farricker, S. Padden, V. Rodin, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
J. Resta-López
UVEG, Burjasot (Valencia), Spain

Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 721559.
Low energy (~100 keV) facilities working with antiprotons, heavy ions, or charged molecules may experience severe beam transport instabilities caused by field imperfections. For example, long (~10 m), unshielded beamlines will not be able to transfer particles due to the natural Earth magnetic field or stray fields from closely located experiments. Currently, only a limited number of simulation codes allow a simplified representation of such field errors, limiting capabilities for beam delivery optimization. In this contribution, a new simulation approach is presented that can provide detailed insight into 4D beam transport. It illustrates the impact of imperfections and stray fields on beam stability and quality through simulations of two antiproton experiments located in the Antimatter Factory (AD) at CERN in Geneva, Switzerland. Magnetic field imperfections are examined in two different ways, providing greater flexibility and an opportunity to benchmark all outcomes. Simulation performance is analyzed as a function of the level of detail and efficiency.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB214

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paper received ※ 19 May 2021 paper accepted ※ 12 July 2021 issue date ※ 18 August 2021

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WEPAB215

Simulation of Intra-Beam Scattering in PyHEADTAIL

scattering, emittance, simulation, space-charge

3134

V. Rodin, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
A. Oeftiger
GSI, Darmstadt, Germany
V. Rodin, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 721559
High-intensity beams in low-energy synchrotrons are subject to space charge as well as intra-beam scattering (IBS). Accurate modelling of both effects becomes essential when the transverse emittances and minimum bunch length are determined through heating processes and resonances induced by machine errors. To date, only very few tools available to the general public allow to simultaneously study space charge and IBS in self-consistent simulations. In this contribution, we present our recent development of an IBS module for PyHEADTAIL, an open-source 6D multi-particle tracking tool, which already includes various 2.5D and 3D space-charge models based on the self-consistent particle-in-cell algorithm. A simulation example of high-intensity bunch rotation demonstrates the joint impact of applied heating effects. Our model is based on the Martini and Bjorken-Mitingwa theories. Benchmarks of our implementation against IBS modules provided in the MAD-X and JSPEC codes are shown.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB215

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paper received ※ 23 May 2021 paper accepted ※ 14 July 2021 issue date ※ 13 August 2021

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WEPAB221

H⁰ Stark Stripping and Component Irradiation in Fermilab Booster

site, booster, radiation, kicker

3142

J.A. Johnstone, D.E. Johnson
Fermilab, Batavia, Illinois, USA

Funding: Work supported by Fermi Research Alliance, LLC under contract no. DE-AC02-07CH11359
In foil stripping of H⁻ some fraction of the emerging neutral H⁰ will be in excited states, which can then strip through the Stark effect in the magnetic field of the downstream orbit bump magnet. The resultant H⁺ will experience a depleted net kick compared to protons emerging from the foil and will track on trajectories different from the nominal circulating beam. This will lead to irradiation of downstream machine components. An analysis of these processes is of particular importance looking forward to the much higher beam power of the Fermilab PIP-II era. This study investigates where these errant protons will be lost, how much power is deposited, and whether this will be a shielding concern.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB221

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paper received ※ 11 May 2021 paper accepted ※ 09 June 2021 issue date ※ 20 August 2021

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WEPAB243

Longitudinal Microwave Instability Study at Transition Crossing with Ion Beams in the CERN PS

impedance, emittance, simulation, controls

3197

A. Lasheen, H. Damerau, A. Huschauer, B.K. Popovic
CERN, Meyrin, Switzerland

The luminosity of lead ion collisions in the Large Hadron Collider (LHC) was significantly increased during the 2018 ion run by reducing the bunch spacing from 100 ns to 75 ns, allowing to increase the total number of bunches. With the new 75 ns variant, three instead of four bunches are generated each cycle in the Low Energy Ion Ring (LEIR) and the Proton Synchrotron (PS) with up to 30% larger intensity per bunch. The beam was produced with satisfactory quality but at the limit of stability in the injectors. In particular, the minimum longitudinal emittance in the PS is limited by a strong longitudinal microwave instability occurring just after transition crossing. The uncontrolled blow-up generates tails, which translate into an unacceptably large satellite population following the RF manipulations prior to extraction from the PS. In this paper, instability measurements are compared to particle simulations using the latest PS impedance model to identify the driving impedance sources. Moreover, means to mitigate the instability are discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB243

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paper received ※ 19 May 2021 paper accepted ※ 06 July 2021 issue date ※ 29 August 2021

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WEPAB245

A Possible Modification of Ceramic Chambers in the Injection Area at the RCS in J-PARC

impedance, simulation, injection, dipole

3205

Y. Shobuda, K. Horino, J. Kamiya, K. Kotoku, T. Takayanagi, T. Ueno, T. Yanagibashi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

The J-PARC RCS is composed of ceramic chambers covered over copper stripes to suppress the eddy current on the chamber. The inductance, comprising the copper stripes and flanges, in combination with the capacitors makes an LCR electric circuit with the chamber and can cause field modulation in the chamber. Though most chambers are not harmful at the RCS, the chambers at the injection area excite beam losses, because a trapezoid field pattern is excited to accumulate LINAC beam during the injection period. In this report, we consider several types of ceramic chambers to suppress the field modulation. One type is a ceramic chamber covered over copper stripes in parallel with damping resistors. Another is that covered over spiral copper stripes with only capacitors.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB245

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paper received ※ 19 May 2021 paper accepted ※ 01 July 2021 issue date ※ 18 August 2021

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WEPAB248

Kurth Vlasov-Poisson Solution for a Beam in the Presence of Time-Dependent Isotropic Focusing

focusing, emittance, space-charge, simulation

3213

C.E. Mitchell, K. Hwang, R.D. Ryne
LBNL, Berkeley, California, USA

Funding: This work was supported by the Director, Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The well-known K-V distribution provides an exact solution of the self-consistent Vlasov-Poisson system describing an unbunched charged particle beam with nonzero temperature in the presence of time-dependent linear transverse focusing. We describe a lesser-known exact solution of the Vlasov-Poisson system that is based on the work of Kurth in stellar dynamics. Unlike the K-V distribution, the Kurth distribution is a true function of the phase space variables, and the solution may be constructed on either the 4D or 6D phase space, for the special case of isotropic linear focusing. Numerical studies are performed for benchmarking simulation codes, and the stability properties of a 4D Kurth distribution are compared with those of a K-V distribution.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB248

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paper received ※ 19 May 2021 paper accepted ※ 14 July 2021 issue date ※ 02 September 2021

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WEPAB252

Transient Beam-Beam Effect During Electron Bunch Replacement in the EIC

electron, emittance, injection, simulation

3228

J. Qiang
LBNL, Berkeley, California, USA
M. Blaskiewicz, Y. Luo, C. Montag, F.J. Willeke, D. Xu
BNL, Upton, New York, USA
Y. Hao
FRIB, East Lansing, Michigan, USA

The high luminosity, high polarization electron-ion collider (EIC) will provide great opportunities in nuclear physics study. In order to maintain high polarization, the electron beam will be replaced every few minutes during the collider operation. This frequent replacement of electron beams can affect proton beam quality during the collision. In this paper, we report on the study of the transient effect of electron beam replacement on proton beam emittance growth through strong-strong beam-beam simulation. The effect of electron beam injection imperfection will be included in the study.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB252

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paper received ※ 17 May 2021 paper accepted ※ 21 June 2021 issue date ※ 02 September 2021

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WEPAB273

Cooling and Diffusion Rates in Coherent Electron Cooling Concepts

electron, kicker, plasma, hadron

3281

S. Nagaitsev, V.A. Lebedev
Fermilab, Batavia, Illinois, USA
W.F. Bergan, E. Wang
BNL, Upton, New York, USA
G. Stupakov
SLAC, Menlo Park, California, USA

Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics.
We present analytic cooling and diffusion rates for a simplified model of coherent electron cooling (CEC), based on a proton energy kick at each turn. This model also allows to estimate analytically the rms value of electron beam density fluctuations in the "kicker" section. Having such analytic expressions should allow for better understanding of the CEC mechanism, and for a quicker analysis and optimization of main system parameters. Our analysis is applicable to any CEC amplification mechanism, as long as the wake (kick) function is available.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB273

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paper received ※ 10 May 2021 paper accepted ※ 28 July 2021 issue date ※ 29 August 2021

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WEPAB292

Application of Machine Learning to Predict the Response of the Liquid Mercury Target at the Spallation Neutron Source

target, neutron, simulation, experiment

3340

L. Lin, S. Gorti, J.C. Mach, H. Tran, D.E. Winder
ORNL, Oak Ridge, Tennessee, USA

Funding: Basic Energy Sciences U.S. Department of Energy SC-22/Germantown Building 1000 Independence Avenue., SW Washington, DC 20585 P: (301) 903 - 3081 F: (301) 903 - 6594
The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is currently the most powerful accelerator-driven neutron source in the world. The intense proton pulses strike on SNS’s mercury target to provide bright neutron beams, which also leads to severe fluid-structure interactions inside the target. Prediction of resultant loading on the target is difficult particularly when helium gas is intentionally injected into mercury to reduce the loading and mitigate the pitting damage on the target’s internal walls. Leveraging the power of machine learning and the measured target strain, we have developed machine learning surrogates for modeling the discrepancy between simulations and experimental strain data. We then employ these surrogates to guide the refinement of the high-fidelity mercury/helium mixture model to predict a better match of target strain response.

Poster WEPAB292 [0.930 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB292

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paper received ※ 19 May 2021 paper accepted ※ 02 July 2021 issue date ※ 10 August 2021

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WEPAB327

Sheet Electron Probe for Beam Tomography

electron, diagnostics, cathode, simulation

3437

V.G. Dudnikov, M.A. Cummings, G. Dudnikova
Muons, Inc, Illinois, USA

Funding: Work is funded by DOE SBIR grant DE-SC0021581
An electron beam probe has been successfully used for the determination of accelerated particle density distributions. However, the apparatus used for this diagnostic had a large size and complex design which limit the broad use of this diagnostic for tomography of accelerated bunches. We propose a new approach to electron beam tomography: we will generate a continuous sheet of electrons. As the ion beam bunches pass through the sheet, they cause distortions in the distribution of sheet electrons arriving at CCD device on the other side of the beam that is interpreted to give a continuous measurement of the beam profile. The apparatus to generate the sheet beam is a strip cathode, which, compared to the scanning electron beam probe, is smaller, has a simpler design and less expensive manufacturing, has better magnetic shielding, has higher sensitivity, higher resolution, has better accuracy of measurement and better time resolution. With this device, it is possible to develop almost ideal tomography diagnostics of bunches in linear accelerators and in circular accelerators and storage rings.

Poster WEPAB327 [0.640 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB327

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paper received ※ 19 May 2021 paper accepted ※ 15 July 2021 issue date ※ 20 August 2021

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WEPAB363

Dynamic Response of Spallation Volume to Beam Raster on the European Spallation Source Target

target, resonance, operation, simulation

3552

Y. Lee
ESS, Lund, Sweden

To achieve a desirably low beam intensity on the target, the European Spallation Source (ESS) adopted a beam raster system at the high beta beam transport part of the linac. The raster system paints the beam on the target with frequencies up to 40 kHz within the 2.86 ms beam pulse, to form a uniformly expanded beam footprint. While the beam raster reduces the time-averaged beam current density to a level that the 5 years of design lifetime of the target system can be achieved with a high operational reliability, it could potentially induce deleterious dynamic excitations in the spallation volume made of tungsten. The stress wavelets created by raster sweeps can be amplified if the sweep frequency is in tune with a resonance mode of the tungsten volume. This coherent interference of the wavelets could lead to a high dynamic stress in tungsten, posing a risk of premature failure of the target. In this paper, the dynamic response of the spallation volume of the ESS target to different beam raster frequencies has been analysed, using multi-physics simulations based on measured material data. Finally, a safe operational range of the beam raster frequency band is proposed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB363

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paper received ※ 12 May 2021 paper accepted ※ 02 July 2021 issue date ※ 01 September 2021

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WEPAB364

Third-Generation CERN n_TOF Spallation Target: Final Design and Examinations of Irradiated Prototype

target, neutron, radiation, experiment

3555

R. Esposito, O. Aberle, M. Calviani, T. Coiffet, M.D. Crouvizier, R. Franqueira Ximenes, V. Maire, A.T. Perez Fontenla, M.A. Timmins
CERN, Geneva, Switzerland

The new neutron spallation target for the CERN neutron Time-Of-Flight (n_TOF) facility is based on a nitrogen-cooled Pb core impacted by short high-intensity proton beam pulses. An extensive material characterization campaign has been carried out to define the constitutive behavior of lead and assess its response under pulsed proton beam irradiation. The activities carried out include a beam irradiation test in the CERN HiRadMat facility. The tests and inspections performed show a robust behavior of the core material during operation and prominent static hardening recovery already at room temperature.

Poster WEPAB364 [1.011 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB364

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paper received ※ 18 May 2021 paper accepted ※ 11 June 2021 issue date ※ 20 August 2021

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WEPAB366

Towards the Last Stages of the CERN’s AD-Target Area Consolidation Project and Recommissioning Plans to Resume Operation

target, antiproton, operation, MMI

3563

C. Torregrosa, C. Ahdida, A. Bouvard, A. Broche, S. Burger, M.E.J. Butcher, M. Calviani, V. Clerc, A. De Macedo, S. De Man, F.A. Deslande, M. Di Castro, T. Dobers, T. Feniet, R. Ferriere, E. Fornasiere, R. Franqueira Ximenes, T.J. Giles, J.L. Grenard, E. Grenier-Boley, G. Gräwer, M. Guinchard, M.D. Jedrychowski, K. Kershaw, B. Lefort, E. Lopez Sola, J.M. Martin Ruiz, A. Martínez Sellés, G. Matulenaite, C.Y. Mucher, A. Newborough, M. Perez Ornedo, E. Perez-Duenas, A. Perillo-Marcone, L. Ponce, N. Solieri, M.B. Szewczyk, P.A. Thonet, M.A. Timmins, A. Tursun, W. Van den Broucke, F.M. Velotti, C. Vendeuvre, V. Vlachoudis
CERN, Meyrin, Switzerland
J.C. Espadanal
LIP, Lisboa, Portugal

Antiprotons are produced at CERN at the Antiproton Decelerator (AD) Target Area by impacting 26 GeV/c proton beams onto a fixed target. Further collection, momentum selection, and transport of the secondary particles - including antiprotons - towards the AD ring is realised by a 400 kA pulsed magnetic horn and a set of magnetic dipoles and quadrupoles. A major consolidation of the area - in operation since the 80s - has taken place during the CERN Long Shutdown 2 (2019-2021). Among other activities, such upgrade included: (i) Installation of a new air-cooled target design and manufacturing of a new batch of magnetic horns, including a surface pulsing test-bench for their validation and fine-tuning (ii) Installation of a new positioning and maintenance system for the target and horn (iii) Refurbishment and decontamination of the Target Area and its equipment, (iv) Construction of a new surface service building to house new nuclear ventilation systems. This contribution presents an overview of such activities and lesson learnt. In addition, it provides the latest results from refractory metals R&D for the antiproton target and a summary of the recommissioning and optimization plans.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB366

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paper received ※ 18 May 2021 paper accepted ※ 21 June 2021 issue date ※ 01 September 2021

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WEPAB367

Bubble Generation in the SNS 2 MW Mercury Target

target, injection, experiment, operation

3567

C.N. Barbier, M.P. Costa, K.C. Johns, D. Ottinger, F. Rasheed, B.W. Riemer, R.L. Sangrey, J.R. Weinmeister, D.E. Winder
ORNL, Oak Ridge, Tennessee, USA

The accelerator at the Spallation Neutron Source is currently being upgraded to increase the proton beam power from 1.4 MW to 2.8 MW. About 2 MW will go to the first target station, while the rest will go to the future second target station. The first target station uses a mercury target. When the short proton beam pulse hits it, strong pressure waves are developed inside the mercury and the vessel itself, causing weld failures and cavitation erosion. The pressure wave can be significantly mitigated by injecting small helium bubbles into the mercury. SNS has been injecting helium since 2017 using small orifices but has met challenges in fabrication and operations with them. Thus, for the 2 MW target, swirl bubblers will be used to increase gas injection and improve reliability. A 2 MW prototypical target was built and tested in a mercury process loop available at Oak Ridge National Laboratory. Acrylic viewports on the top of the target were used to determine the bubble size distribution (BSD) generated by the swirl bubblers. It was found that the bubblers were not only capable of generating small bubbles but that the BSD was independent of gas injection rate.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB367

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paper received ※ 10 May 2021 paper accepted ※ 22 June 2021 issue date ※ 20 August 2021

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WEPAB401

Study for Alternative Cavity Wall and Inductive Insert Material

storage-ring, impedance, simulation, experiment

3650

C.E. Taylor, C.-F. Chen, T.W. Hall, E. Henestroza, J.T.M. Lyles, J. Upadhyay
LANL, Los Alamos, New Mexico, USA
S. Biedron, M.A. Fazio, S.I. Salvador, T.J. Schaub
UNM-ECE, Albuquerque, USA

Funding: Contract No. 89233218CNA000001, supported by the U.S. Department of Energy’s National Nuclear Security Administration (NNSA), for the management and operation of Los Alamos National Laboratory (LANL).
The goal of this work was to develop a solution to the problem of longitudinal beam instability. Beam instability has been a significant problem with storage rings’ performance for many decades. The proton storage ring (PSR) at the Los Alamos Neutron Science Center (LANCE) is no exception. To mitigate the instability, it was found that ferrite inductive inserts can be used to bunch the protons that are diverging due to the electron background. The PSR was the first storage ring to successfully use inductive inserts to mitigate the longitudinal instability with normal production beams. However, years later new machine upgrades facilitate shorter, more intense beams to meet the needs of researchers. The ferrite inserts used to reduce the transverse instabilities induce a microwave instability with the shorter more intense proton beam. This study investigates alternative magnetic materials for inductive inserts in particle beam storage rings, including the necessary engineering for maintaining the ideal temperature during operation.
’ tjschaub@unm.edu

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB401

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paper received ※ 29 May 2021 paper accepted ※ 02 July 2021 issue date ※ 15 August 2021

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THXA06

The Effect of Beam Velocity Distribution on Electron-Cooling at Elena

electron, emittance, antiproton, simulation

3700

B. Veglia, A. Farricker, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
A. Farricker
UMAN, Manchester, United Kingdom
B. Veglia, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: Work supported by EU Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 721559.
ELENA is a novel storage ring at CERN, designed to deliver low energy, high-quality antiprotons to antimatter experiments. The electron cooler is a key component of this decelerator, which counters the beam blow-up as the antiproton energy is reduced from 5.3 MeV to 100 keV. Typical numerical approximations on electron cooling processes assume that the density distribution of electrons in analytical form and the velocity distribution space to be Maxwellian. However, it is useful to have an accurate description of the cooling process based on a realistic electron distribution. In this contribution, BETACOOL simulations of the ELENA antiproton beam phase space evolution were performed using uniform, Gaussian, and "hollow beam" electron velocity distributions. The results are compared with simulations considering a custom electron beam distribution obtained with G4beamline. The program was used to simulate the interaction of an initially Gaussian electron beam with the magnetic field measured inside the electron cooler interaction chamber. The resulting beam lifetime and equilibrium parameters are then compared with measurements.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THXA06

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paper received ※ 18 May 2021 paper accepted ※ 01 July 2021 issue date ※ 14 August 2021

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THXC03

Evolution of the High-Power Spallation Neutron Mercury Target at the SNS

target, operation, neutron, injection

3735

D.E. Winder
ORNL, Oak Ridge, Tennessee, USA

Funding: UT-Battelle, LLC, under Grant DE-AC05-00OR22725 with the US Department of Energy (DOE).
The Spallation Neutron Source (SNS) began operation in 2006 and first operated at its full 1.4 MW power in 2013. Targets, which receive the pulsed proton beam, were a limiting factor for reliable full power operation for several years. Reaching reliable target operation at 1.4 MW required not only changes to the target design but also support and coordination across the entire SNS enterprise. The history and some key lessons learned are presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THXC03

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paper received ※ 19 May 2021 paper accepted ※ 01 July 2021 issue date ※ 01 September 2021

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THPAB015

Studies of the Imperfection in Crab Crossing Scheme for Electron-Ion Collider

cavity, electron, solenoid, luminosity

3784

Y. Hao, J.S. Berg, D. Holmes, Y. Luo, C. Montag
BNL, Upton, New York, USA
V.S. Morozov
JLab, Newport News, Virginia, USA
J. Qiang
LBNL, Berkeley, California, USA
D. Xu
FRIB, East Lansing, Michigan, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
Crab crossing scheme is the essential scheme that accommodates large crossing angle without loss of luminosity in the design of Electron-Ion collider (EIC). The ideal optics and phase advances of the crab cavity pair are set to create a local crabbing bump in the interaction region (IR). However, there are always small errors in the actual lattice of IR. In this article, we will present the simulation and analytical studies on the imperfections in the crab crossing scheme in the EIC design. The tolerance of the imperfection and the possible remedies can be concluded from these studies.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB015

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paper received ※ 17 May 2021 paper accepted ※ 16 July 2021 issue date ※ 12 August 2021

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THPAB028

Beam-Beam Related Design Parameter Optimization for the Electron-Ion Collider

electron, simulation, betatron, luminosity

3808

Y. Luo, J.S. Berg, M. Blaskiewicz, W. Fischer, X. Gu, H. Lovelace III, C. Montag, R.B. Palmer, S. Peggs, V. Ptitsyn, F.J. Willeke
BNL, Upton, New York, USA
Y. Hao, D. Xu
FRIB, East Lansing, Michigan, USA
H. Huang
ODU, Norfolk, Virginia, USA
E.A. Nissen, T. Satogata
JLab, Newport News, Virginia, USA
J. Qiang
LBNL, Berkeley, California, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The design luminosity goal for the Electron-Ion Collider (EIC) is 1e34 cm^-2s⁻¹. To achieve such a high luminosity, the EIC design adopts high bunch intensities, flat beams at the interaction point (IP) with a small vertical β^*-function, and a high collision frequency, together with crab cavities to compensate the geometrical luminosity loss due to the large crossing angle of 25mrad. In this article, we present our strategies and approaches to obtain the design luminosity by optimizing some key beam-beam related design parameters. Through our extensive strong-strong and weak-strong beam-beam simulations, we found that beam flatness, electron and proton beam size matching at the IP, electron and proton working points, and synchro-betatron resonances arising from the crossing angle collision play a crucial role in proton beam size growth and luminosity degradation. After optimizing those parameters, we found a set of beam-beam related design parameters to reach the design luminosity with an acceptable beam-beam performance.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB028

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paper received ※ 17 May 2021 paper accepted ※ 28 July 2021 issue date ※ 25 August 2021

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THPAB029

Dynamic Aperture Evaluation for the Hadron Storage Ring in the Electron-Ion Collider

dynamic-aperture, cavity, electron, dipole

3812

Y. Luo, J.S. Berg, M. Blaskiewicz, W. Fischer, X. Gu, H. Lovelace III, C. Montag, R.B. Palmer, S. Peggs, V. Ptitsyn, F.J. Willeke, H. Witte
BNL, Upton, New York, USA
Y. Hao, D. Xu
FRIB, East Lansing, Michigan, USA
H. Huang
ODU, Norfolk, Virginia, USA
V.S. Morozov, E.A. Nissen, T. Satogata
JLab, Newport News, Virginia, USA
J. Qiang
LBNL, Berkeley, California, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The Electron-Ion Collider (EIC) is aiming at a design luminosity of 1e34 cm^-2s⁻¹. To maintain such a high luminosity, both beams in the EIC need an acceptable beam lifetime in the presence of the beam-beam interaction. For this purpose, we carried out weak-strong element-by-element particle tracking to evaluate the long-term dynamic aperture for the hadron ring lattice design. We improved our simulation code SimTrack to treat some new lattice design features, such as radially offset on-momentum orbits, coordinate transformations in the interaction region, etc. In this article, we will present the preliminary dynamic aperture calculation results with β^*- function scan, radial orbit shift, crossing angle collision, and magnetic field errors.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB029

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paper received ※ 17 May 2021 paper accepted ※ 01 September 2021 issue date ※ 28 August 2021

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THPAB140

Modelling Seeded Self Modulation of Long Elliptical Bunches in Plasma

plasma, wakefield, simulation, emittance

4030

A. Perera, O. Apsimon, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
O. Apsimon, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
J. Resta-López
IFIC, Valencia, Spain

Funding: This work was supported by STFC Centre for Doctoral Training in Data-Intensive Science (LIV. DAT) under grant ST/P006752/1 and the STFC Scientific Computing Department’s SCARF cluster.
The stability of particle bunches undergoing seeded self-modulation (SSM) over tens or hundreds of meters is crucial to the generation of GV/m wakefields that can accelerate electron beams as proposed for use in several high energy plasma-based linear colliders. Here, 3D particle-in-cell simulations using QuickPIC are compared to an analytical model of seeded self-modulation (SSM) of elliptical beam envelopes using linear wakefield theory. It is found that there is quantitative agreement between simulations and analytical predictions for the envelope in the early growth of the SSM. A scaling law is derived for the reduction of the maximum overall modulation growth rate with aspect ratio and is found to match well with simulation.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB140

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paper received ※ 19 May 2021 paper accepted ※ 22 July 2021 issue date ※ 31 August 2021

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THPAB158

BEAM COLLIMATION IN THE PIP-II LINAC TO BOOSTER TRANSFER LINE

injection, booster, collimation, linac

4068

D.E. Johnson, V.V. Kapin, J.-F. Ostiguy, V.I. Sidorov, M. Xiao
Fermilab, Batavia, Illinois, USA
D.G. Georgobiani
FRIB, East Lansing, Michigan, USA

Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics.
The new PIP-II superconducting linac will deliver a 2 mA average H^- beam to the existing Booster synchrotron. The injected beam is accumulated by charge exchange over approximately 300 turns; phase space painting is used to mitigate space charge effects. To limit the power load on the internal waste beam absorber from the transverse tails of the H⁻ distribution missing the foil, the beam will be collimated in both planes in the linac to Booster transfer line using compact collimators of a novel design. Both the number of parasitic hits and the fraction of the beam missing the foil are sensitive functions of the H⁻ beam centroid position with respect to the edge of the foil. The positioning of the collimation is constrained by the availability of suitable space in the transfer line lattice, by specifics of the collimator design, by the phase space orientation at the collimator, and by the betatron phase advance to the foil needed to achieve proper orientation of the spatial distribution at the injection point. In this contribution, we describe the procedure by which collimator positions were optimized. We then discuss the expected performance of the overall system.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB158

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paper received ※ 04 June 2021 paper accepted ※ 02 July 2021 issue date ※ 26 August 2021

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THPAB165

5 MW Beam Power in the ESSnuSB Accumulator: A Way to Manage Foil Stripping Injection at 14 Hz Linac Pulse Rate

emittance, linac, injection, space-charge

4072

H. Schönauer
CERN, Geneva, Switzerland
Y. Zou
Uppsala University, Uppsala, Sweden

Funding: This work is supported by the European Union’s Horizon 2020 research and innovation program under grant agreement No 777419.
In the past, the scenario for foil stripping consisted of splitting a linac pulse into 4 rings, or 3 or 4 intermediate pulses, and one ring. At present, the scenario, in view of laser stripping, consists of one ring, one pulse, split into four batches. Conventional stripping geometry would lead to foil evaporation under this beam load. One way out appears to be replacing the standard corner foil by a single-edge foil rotated to about 45deg. The tilted foil allows moving the injection point together with the painting bumps along the foil edge, distributing the deposited beam power over a larger foil area. Simulation results obtained with the same tools as in the past scenarios are presented. They show peak foil temperatures, which compare with the best results obtained from the past scenarios.

Poster THPAB165 [2.205 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB165

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paper received ※ 11 May 2021 paper accepted ※ 21 June 2021 issue date ※ 18 August 2021

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THPAB170

RF Deflector Design for Rapid Proton Therapy

cavity, simulation, polarization, quadrupole

4086

E.J.C. Snively, G.B. Bowden, V.A. Dolgashev, Z. Li, E.A. Nanni, D.T. Palmer, S.G. Tantawi
SLAC, Menlo Park, California, USA

Funding: This work is supported by US Department of Energy Contract No. DE-AC02-76SF00515.
Pencil beam scanning of charged particle beams is a key technology enabling high dose rate cancer therapy. The potential benefits of high-speed dose delivery include not only a reduction in total treatment time and improvements to motion management during treatment but also the possibility of enhanced healthy tissue sparing through the FLASH effect, a promising new treatment modality. We present here the design of an RF deflector operating at 2.856 GHz for the rapid steering of 150 MeV proton beams. The design utilizes a TE11-like mode supported by two posts protruding into a pillbox geometry to form an RF dipole. This configuration provides a significant enhancement to the efficiency of the structure, characterized by a transverse shunt impedance of 68 MOhm/m, as compared to a conventional TM11 deflector. We discuss simulations of the structure performance for several operating configurations including the addition of a permanent magnet quadrupole to amplify the RF-driven deflection. In addition to simulation studies, we will present preliminary results from a 3-cell prototype fabricated using four copper slabs to accommodate the non-axially symmetric cell geometry.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB170

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paper received ※ 19 May 2021 paper accepted ※ 14 July 2021 issue date ※ 27 August 2021

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THPAB173

Fundamental Study on Electromagnetic Characteristics of Half-Wave Resonator for 200 MeV Energy Upgrade of KOMAC Proton Linac

cavity, simulation, linac, SRF

4098

J.J. Dang, Y.-S. Cho, H.S. Kim, H.-J. Kwon, S. Lee
Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea

Funding: This work has been supported through KOMAC operation fund of KAERI by the Korea government (MSIT).
A superconducting linac has been developed at KOrea Multi-purpose Accelerator Complex (KOMAC). A goal of the SRF linac is to increase proton beam energy from 100 MeV to 200 MeV. 350 MHz medium beta half-wave resonator (HWR) should provide 3.6 MV accelerating voltage to achieve the energy upgrade. An electromagnetic (EM) analysis on the parametrically designed HWR cavity was conducted. The cavity design was optimized to reduce a peak electric field and a peak magnetic field while satisfying the required acerating voltage. In addition, a mechanical-EM coupled simulation was conducted to estimate a helium pressure sensitivity. Also, Lorentz force detuning was simulated. The design is being optimized to minimize the frequency detuning due to the helium pressure and Lorentz force.

Poster THPAB173 [0.800 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB173

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paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 23 August 2021

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THPAB176

Studies on Beam Collimation System for the ESSnuSB Accumulator

collimation, scattering, linac, simulation

4107

Y. Zou, M. Olvegård
Uppsala University, Uppsala, Sweden

Funding: This work is supported by the European Union Horizon 2020 research and innovation program under grant agreement No 777419.
The ESSnuSB, a neutrino facility based on the European Spallation Source, aims at measuring, with precision, the charge-parity (CP) violating lepton phase at the 2nd oscillation maximum. The ESS linac will have to be upgraded to provide an additional 5 MW beam for the ESSnuSB to produce an unprecedented high-intensity neutrino beam. An accumulator ring is employed to compress the 2.86 ms long pulse from the linac to around 1.5 µs in order to satisfy the target requirements and improve the physics performance. In the operation of a high-intensity proton accumulator, the most important issue is to minimize the uncontrolled beam loss to reduce component activation to make hands-on maintenance possible. For this purpose, a two-stage collimation system is designed, which consists of a thin scraper to scatter halo particles and secondary collimators to absorb those scattered particles. Phase advances between scraper and secondary collimators, together with the material, the thickness of collimators, have been detailed studied and numerical simulations have been performed to evaluate the performance of the collimation system. This paper presents the design of the collimation system.

Poster THPAB176 [5.022 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB176

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paper received ※ 11 May 2021 paper accepted ※ 21 June 2021 issue date ※ 01 September 2021

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THPAB183

New Longitudinal Beam Production Methods in the CERN Proton Synchrotron Booster

space-charge, emittance, resonance, cavity

4130

S.C.P. Albright, F. Antoniou, F. Asvesta, H. Bartosik, C. Bracco, E. Renner
CERN, Meyrin, Switzerland
E. Renner
TU Vienna, Wien, Austria

As part of the LHC Injectors Upgrade (LIU) project, significant improvements were made to the CERN Proton Synchrotron Booster (PSB) during the 2019/2020 long shutdown, including a new Finemet-based wideband RF system, renovated longitudinal beam control, and a new magnetic cycle. To meet the requirements of the diverse experimental program, the PSB provides beams with intensities spanning three orders of magnitude and a large range of longitudinal emittances. To maximize the brightness, in particular for the LHC beams, the voltages at low energy are designed to reduce the impact of transverse space charge using a second RF harmonic in bunch lengthening mode. At high energies, the risk of longitudinal microwave instability is avoided by optimizing the longitudinal distribution to raise the instability threshold. RF phase noise is applied to provide controlled longitudinal emittance blow-up and to shape the longitudinal distribution. This paper discusses the design of the RF functions used to meet the beam specifications, whilst ensuring longitudinal stability.

Poster THPAB183 [6.692 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB183

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paper received ※ 18 May 2021 paper accepted ※ 22 July 2021 issue date ※ 20 August 2021

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THPAB186

Review of Proton Linac Beam Dynamic Simulation Code

linac, simulation, space-charge, software

4137

X.Y. Feng, J. Peng
IHEP CSNS, Guangdong Province, People’s Republic of China

CSNS-II project design a linac accelerates 40 mA H⁻ beam from 3.8 MeV to 300 MeV, which should not only overcome the space-charge effect at low energy but also have high efficiency at high energy. Therefore, lots of simulation studies should be done on a variety of codes. Each of them has its own characteristics. For example, MAD can easily match quadrupole fast while it couldn’t do the multiparticle calculation. This paper will introduce some common and efficient code used to design linac and study beam dynamic performance.

Poster THPAB186 [0.880 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB186

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paper received ※ 17 May 2021 paper accepted ※ 08 July 2021 issue date ※ 11 August 2021

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THPAB206

Validating pyORBIT for Modeling Beam Dynamics in the IOTA Ring

space-charge, octupole, emittance, dynamic-aperture

4190

R. Li
UW-Madison/PD, Madison, Wisconsin, USA
J.-F. Ostiguy, T. Sen
Fermilab, Batavia, Illinois, USA

Funding: Supported by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics.
The Integrable Optics Test Accelerator (IOTA) ring is a new Fermilab facility dedicated to beam physics experiments, currently operating with 150 MeV electrons. Space charge effects are expected to be significant when it operates with 2.5 MeV protons. In this contribution, we present results of a suite of validation tests of PyORBIT, a PICstyle space charge code. Single particle dynamics of quasiintegrable optics using an octupole string in IOTA is compared with MADX, and shown to be in good agreement. Requirements for the convergence of space charge computations are systematically established and when possible, tests involving space charge are compared with theoretical predictions.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB206

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paper received ※ 19 May 2021 paper accepted ※ 08 July 2021 issue date ※ 12 August 2021

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THPAB284

Analytical and Numerical Characterization of Cherenkov Diffraction Radiation as a Longitudinal Electron Bunch Profile Monitor for AWAKE Run 2

radiation, electron, plasma, wakefield

4355

C. Davut, G.X. Xia
UMAN, Manchester, United Kingdom
O. Apsimon
The University of Liverpool, Liverpool, United Kingdom
O. Apsimon
Cockcroft Institute, Warrington, Cheshire, United Kingdom
P. Karataev
Royal Holloway, University of London, Surrey, United Kingdom
P. Karataev
JAI, Egham, Surrey, United Kingdom
T. Lefèvre, S. Mazzoni
CERN, Geneva, Switzerland

In this paper, CST simulations of the coherent Cherenkov Diffraction Radiation with a range of parameters for different dielectric target materials and geometries are discussed and compared with the theoretical investigation of the Polarization Current Approach to design a prototype of a radiator for the bunch length/profile monitor for AWAKE Run 2. It was found that the result of PCA theory and CST simulation are consistent with each other regarding the shape of the emitted ChDR cone.
* Karlovets, D. V. (2011). JETP, 113(1), 27-45.
** Shevelev, M. V., & Konkov, A. S. (2014). JETP, 118(4), 501-511.
*** Curcio, A., et al.(2020). PRAB, 23(2), 022802.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB284

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paper received ※ 16 May 2021 paper accepted ※ 14 July 2021 issue date ※ 10 August 2021

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THPAB291

DYVACS (DYnamic VACuum Simulation) Code: Gas Density Profiles in Presence of Electron Cloud in the LHC

electron, vacuum, injection, photon

4373

S. Bilgen, B. Mercier, G. Sattonnay
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
V. Baglin
CERN, Meyrin, Switzerland

The computation of residual gas density profiles in particle accelerators is an essential task to optimize beam pipes and vacuum system design. In a hadron collider such as the LHC, the beam induces dynamic effects due to ion, electron, and photon-stimulated gas desorption. The well-known VASCO* code developed at CERN in 2004 is already used to estimate vacuum stability and density profiles in steady-state conditions. Nevertheless, some phenomena are not taken into account such as the ionization of residual gas by the electron clouds and the evolution of the electronic density related to the electron cloud build-up. Therefore, we propose an upgrade of this code by introducing electron cloud maps** to estimate the electron density and the ionization of gas by electrons leading to an increase of induced desorption. The pressure evolution computed with DYVACS reproduces with good accuracy the experimental pressure recorded in the VPS beam pipes sector*** of the LHC from the proton beam injection to the stable beam period. Additionally, DYVACS can also be used as a predictive tool to compute the pressure evolution in the beam pipes for Future Circular Colliders (FCC-hh or -ee).
* A. Rossi, Tech. Report, LHC Project Note 341
** T. Demma et al Phys. Rev. Acceler. and Beams 10, 114401 (2007)
*** B. Henrist et al, Proc. IPAC2014, Dresden

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB291

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paper received ※ 19 May 2021 paper accepted ※ 02 August 2021 issue date ※ 31 August 2021

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THPAB292

Dynamic Pressure in the LHC: Detection of Ions Induced by Ionization of Residual Gas by the Proton Beam and by the Electron-Cloud

electron, experiment, vacuum, ECR

4377

S. Bilgen, B. Mercier, G. Sattonnay
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
V. Baglin
CERN, Meyrin, Switzerland

Ultra-High Vacuum is an essential requirement to achieve design performances and high luminosities in high-energy particle colliders. Consequently, the understanding of the dynamic pressure evolution during accelerator operation is fundamental to provide solutions to mitigate pressure rises induced by multiple effects leading to beam instabilities. For the LHC, the appearance of instabilities may be due to the succession of several phenomena: (i) the induced desorption of gases adsorbed on the surfaces leading to pressure rises; (ii) the creation of secondary particles (ions, electrons); (iii) the production of the so-called Electron Cloud build-up by multipacting effect. This work aims to investigate some fundamental phenomena which drive the dynamic pressure in the LHC, namely the effects induced by electrons and ions interacting with the copper surface of the beam screens. Electron and ion currents, as well as pressure, were recorded in situ in the Vacuum Pilot Sector (VPS*) located on the LHC ring during the RUN II. By analyzing the results, more ions than expected were detected and the interplay between electrons, ions, and pressure changes was investigated.
* The LHC Vacuum Pilot-Sector Project, B. Henrist, V. Baglin, G. Bregliozzi, and P. Chiggiato, CERN, Geneva, Switzerland, Proceedings of IPAC2014, Dresden, Germany

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB292

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paper received ※ 19 May 2021 paper accepted ※ 01 July 2021 issue date ※ 27 August 2021

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THPAB317

Experiment and Simulation Study on the Capture and Acceleration Process of XiPAF Synchrotron

acceleration, synchrotron, experiment, cavity

4409

Y. Li, X. Guan, X.Y. Liu, M.W. Wang, X.W. Wang, Q.Z. Xing, Y. Yang, H.J. Yao, W.B. Ye, S.X. Zheng
TUB, Beijing, People’s Republic of China
W.L. Liu, D. Wang, Z.M. Wang, Y. Yang, M.T. Zhao
NINT, Shannxi, People’s Republic of China

The beam commissioning of the capture and acceleration process on the XiPAF (Xi’an 200MeV Proton Application Facility) synchrotron has been carried out. The efficiency of the experiment results has been compared with the simulation results. At present, the efficiency of the capture process with single-harmonic is about 73%, and the acceleration efficiency is about 82%, and the simulation results are 77% and 96% without space charge effect, respectively. In order to improve efficiency, dual-harmonic was used during the capture and acceleration process. During the experiment, the capture efficiency was increased by 5%, and the acceleration efficiency was increased by 4%. The capture efficiency decreases with the increase of the maximum RF voltages. We analyzed the reasons for the decrease in capture efficiency. In the next step, further verification will be carried out through experiments under different conditions.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB317

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paper received ※ 19 May 2021 paper accepted ※ 08 July 2021 issue date ※ 23 August 2021

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THPAB364

Mu*STAR: A System to Consume Spent Nuclear Fuel While Economically Generating Nuclear Power

site, target, neutron, operation

4499

R.P. Johnson, R.J. Abrams, M.A. Cummings, S.A. Kahn, J.D. Lobo, T.J. Roberts
Muons, Inc, Illinois, USA

Mu*STAR is a superconducting-accelerator driven, subcritical, molten-salt reactor designed to consume the spent nuclear fuel (SNF) from today’s commercial fleet of light water reactors. In the process of doing so it will: 1. generate electricity in a cost-competitive manner, 2. significantly reduce the waste-stream volume per Gigawatt-hour generated, 3. greatly reduce the radio-toxic lifetime of the waste stream. As many states and countries now prohibit licensing of new nuclear plants until a national strategy has been established for the long-term disposal of their nuclear waste, Mu*STAR can be an important enabler for new nuclear facilities. This is especially important in the light of climate change, as nuclear energy is the only carbon-free technology for a base-load generation that is readily expandable.

Poster THPAB364 [0.497 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB364

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paper received ※ 20 May 2021 paper accepted ※ 12 July 2021 issue date ※ 02 September 2021

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FRXB05

Muon Ionization Cooling Experiment: Results & Prospects

emittance, experiment, solenoid, collider

4528

C.T. Rogers
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

A high-energy muon collider could be the most powerful and cost-effective collider approach in the multi-TeV regime, and a neutrino source based on decay of an intense muon beam would be ideal for measurement of neutrino oscillation parameters. Muon beams may be created through the decay of pions produced in the interaction of a proton beam with a target. The muons are subsequently accelerated and injected into a storage ring where they decay producing a beam of neutrinos, or collide with counter-rotating antimuons. Cooling of the muon beam would enable more muons to be accelerated resulting in a more intense neutrino source and higher collider luminosity. Ionization cooling is the novel technique by which it is proposed to cool the beam. The Muon Ionization Cooling Experiment collaboration constructed a section of an ionization cooling channel and used it to provide the first demonstration of ionization cooling. Here the observation of ionization cooling is described. The cooling performance is studied for a variety of beam and magnetic field configurations. The outlook for muon ionization cooling demonstrations is discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-FRXB05

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paper received ※ 19 May 2021 paper accepted ※ 19 July 2021 issue date ※ 23 August 2021

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FRXC05

Gas Jet In-Vivo Dosimetry for Particle Beam Therapy

operation, diagnostics, cyclotron, GUI

4548

J. Wolfenden, N. Kumar, A. Salehilashkajani, C.P. Welsch, H.D. Zhang
The University of Liverpool, Liverpool, United Kingdom
N. Kumar, A. Salehilashkajani, C.P. Welsch, J. Wolfenden, H.D. Zhang
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: This work is supported by the HL-LHC-UK project funded by STFC and CERN and the STFC Cockcroft core grant No. ST/G008248/1.
Medical applications of charged particle beams require a full online characterisation of the beam to ensure patient safety, treatment efficacy, and facility efficiency. In-vivo dosimetry, measurement of delivered dose during treatment, is a significant part of this characterisation. Current methods offer limited information or are invasive to the beam, meaning measurements must be done offline. This contribution presents the development of a non-invasive gas jet in-vivo dosimeter for treatment facilities. The technique is based on the interaction between a particle beam and a supersonic gas jet curtain, which was originally developed for the high luminosity upgrade of the large hadron collider (HL-LHC). To demonstrate the medical application of this technique, an existing HL-LHC test system with minor modifications will be installed at the University of Birmingham’s 35 MeV proton cyclotron, which has properties comparable to that of a treatment beam. This contribution presents the design and development of this test setup, plans for initial benchmarking measurements, and plans for a future optimised medical accelerator gas jet in-vivo dosimeter.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-FRXC05

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paper received ※ 18 May 2021 paper accepted ※ 23 July 2021 issue date ※ 11 August 2021

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