HB2023 - List of Keywords (emittance)

Paper	Title	Other Keywords	Page
MOA1I1	Beam Performance with the LHC Injectors Upgrade	brightness, injection, operation, target	1
	G. Rumolo, S.C.P. Albright, R. Alemany-Fernández, M.E. Angoletta, C. Antuono, T. Argyropoulos, F. Asvesta, M.J. Barnes, H. Bartosik, P. Baudrenghien, G. Bellodi, N. Biancacci, C. Bracco, N. Bruchon, E. Carlier, J. Coupard, H. Damerau, G.P. Di Giovanni, A. Findlay, M.A. Fraser, A. Funken, R. Garoby, S.S. Gilardoni, B. Goddard, G. Hagmann, K. Hanke, A. Huschauer, G. Iadarola, V. Kain, I. Karpov, J.-B. Lallement, A. Lasheen, T.E. Levens, K.S.B. Li, A.M. Lombardi, E.H. Maclean, D. Manglunki, I. Mases Solé, M. Meddahi, L. Mether, B. Mikulec, E. Montesinos, Y. Papaphilippou, G. Papotti, K. Paraschou, C. Pasquino, F. Pedrosa, T. Prebibaj, S. Prodon, D. Quartullo, F. Roncarolo, B. Salvant, M. Schenk, R. Scrivens, E.N. Shaposhnikova, L. Sito, P.K. Skowroński, A. Spierer, R. Steerenberg, M. Sullivan, F.M. Velotti, R. Veness, C. Vollinger, R. Wegner, C. Zannini, E. de la Fuente CERN, Meyrin, Switzerland T. Prebibaj IAP, Frankfurt am Main, Germany
	The LHC Injectors Upgrade (LIU) project was put in place between 2010 and 2021 to increase the intensity and brightness in the LHC injectors to match the challenging requirements of the High-Luminosity LHC (HL-LHC) project, while ensuring reliable operation of the injectors complex up to the end of the HL-LHC era (ca. 2040). During the 2019-2020 CERN accelerators shutdown, extensive hardware modifications were implemented in the entire LHC proton and ion injection chains, involving the new Linac4, the Proton Synchrotron Booster (PSB), the Proton Synchrotron (PS), the Super Proton Synchrotron (SPS) and the ion PS injectors, i.e. the Linac3 and the Low Energy Ion Ring (LEIR). Since 2021, beams have been recommissioned throughout the injectors’ chain and the beam parameters are being gradually ramped up to meet the LIU specifications using new beam dynamics solutions adapted to the upgraded accelerators. This paper focuses on the proton beams and describes the current state of the art.
	Slides MOA1I1 [10.002 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-MOA1I1
About •	Received ※ 29 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 18 October 2023
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MOA1I2	FRIB from Commissioning to Operation	linac, target, operation, experiment	9
	P.N. Ostroumov, K. Fukushima, A.J. Gonzalez, K. Hwang, T. Kanemura, T. Maruta, A.S. Plastun, J. Wei, T. Zhang, Q. Zhao FRIB, East Lansing, Michigan, USA
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan, and Michigan State University. The Facility for Rare Isotope Beams (FRIB) was fully commissioned in early 2022, and the operation for physics experiments started shortly thereafter. Various ion beam species have been accelerated up to 240 MeV/u and delivered to the target. During the first year of user operations, the FRIB provided 4252 beam hours with 91% availability for nuclear science. In addition, FRIB delivered about 1000 hours of various ion beam species at beam energies up to 40 MeV/u for single-event experiments. Typically, the experiments with a specific species rare isotope beam last a week or two. Each experiment requires a different primary beam species with specific energies. The primary beam power has been gradually increased from 1 kW to 10 kW over the past 1.5 years. The Accelerator Physics (AP) group develops high-level physics applications to minimize machine set-up time. Focuses include identifying beam halo sources, controlling emittances of multiple-charge-state beams, and studying the beam loss mechanisms to prepare for the ultimate 400 kW operation. This paper discusses the experience and challenges of operating a high-power CW heavy ion accelerator.
	Slides MOA1I2 [6.556 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-MOA1I2
About •	Received ※ 22 September 2023 — Accepted ※ 10 October 2023 — Issued ※ 17 October 2023
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MOA3I1	Beam Dynamics Challenges in the Design of the Electron-Ion Collider	electron, polarization, hadron, proton	23
	Y. Luo, M. Blaskiewicz, D. Marx, E. Wang, F.J. Willeke BNL, Upton, New York, USA A. Blednykh, C. Montag, V. Ptitsyn, V.H. Ranjbar, S. Verdú-Andrés Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA S. Nagaitsev JLab, Newport News, Virginia, 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 (EIC), presently under construction at Brookhaven National Laboratory, will collide polarized high-energy electron beams with hadron beams, achieving luminosities up to 1 × 10³⁴ cm^¿2 s^¿1 in the center-of-mass energy range of 20-140 GeV. To achieve such high luminosity, we adopt high bunch intensities for both beams, small and flat transverse beam sizes at the interaction point (IP), a large crossing angle of 25 mrad, and a novel strong hadron cooling in the Hadron Storage Ring (HSR) to counteract intra-beam scattering (IBS) at the collision energy. In this talk, we will review the beam dynamics challenges in the design of the EIC, particularly the single-particle dynamic aperture, polarization maintenance, beam-beam interaction, impedance budget and instabilities. We will also briefly mention some technical challenges associated with beam dynamics, such as strong hadron cooling, multipoles and noises of crab cavities, power supply current ripples, and the vacuum upgrade to existing beam pipes of the Hadron Storage Ring of the EIC.
	Slides MOA3I1 [3.437 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-MOA3I1
About •	Received ※ 02 October 2023 — Revised ※ 06 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 18 October 2023
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TUC1I1	Multi-beam Operation of LANSCE Accelerator Facility	proton, linac, operation, alignment	58
	Y.K. Batygin LANL, Los Alamos, New Mexico, USA
	The unique feature of the LANSCE accelerator facility is the simultaneous delivering of beams to five experimental targets. Proton beam with energy of 100-MeV is delivered to Isotope Production Facility (IPF), while 800-MeV H⁻ beams are distributed to four experimental areas: the Lujan Neutron Scattering Center, the Weapons Neutron Research facility (WNR), the Proton Radiography facility (pRad), and the Ultra-Cold Neutron facility (UCN). Multi-beam operation of accelerator facility requires careful optimization of beam losses, which is achieved by precise tuning of the beam, imposing restriction on amplitudes and phases of RF sections, application of beam-based alignment, control of H⁻ beam stripping, optimization of ion sources performance and low-energy beam transport operation under space-charge neutralization. The near - term plans are to replace obsolete systems of the LANSCE linear accelerator with modern Front End, which is the part of Los Alamos Modernization Project (LAMP). This paper summarizes experimental results obtained during operation of LANSCE accelerator facility and considers plans to expand performance of the accelerator for near-and long-term operations.
	Slides TUC1I1 [10.013 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC1I1
About •	Received ※ 30 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 31 October 2023
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TUC3I1	Ultra-low Emittance Bunches from Laser Cooled Ion Traps for Intense Focal Points	laser, luminosity, space-charge, ECR	128
	S.J. Brooks BNL, Upton, New York, USA
	Laser-cooled ion traps are used to prepare groups of ions in very low temperature states, exhibiting such phenomena as Coulomb crystallization. This corresponds to very small normalized RMS emittances of 10^-13–10^-12 m, compared to typical accelerator ion sources in the 10^-7–10^-6 m range. Such bunches could potentially be focused a million times smaller, compensating for the lower number of ions per bunch. Such an ultra-low emittance source could enable high-specific-luminosity colliders where reduced beam current and apertures are needed to produce a given luminosity. Further advances needed to enable such colliders include linear, helical or ring cooling channel designs for increased bunch number or current throughput. Novel high density focal points using only a single bunch also appear possible, where the high density particles collide with themselves. At collider energies ~100 GeV, these approach the nuclear density and offer a way of studying larger quantities of neutron star matter and other custom nuclear matter in the lab.
	Slides TUC3I1 [167.328 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC3I1
About •	Received ※ 26 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 24 October 2023
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TUC3I2	Shaping High Brightness and Fixed Target Beams with the CERN PSB Charge Exchange Injection	injection, operation, target, brightness	135
	C. Bracco, S.C.P. Albright, F. Asvesta, G.P. Di Giovanni, F. Roncarolo CERN, Meyrin, Switzerland
	CERN adopted the charge exchange injection technique for the first time in the PS Booster after Long Shutdown 2. This allowed to overcome space charge limitations, tailor high brightness beams for the LHC and deliver high intensity flux of protons to the fixed target experiments. Details on the concept, physics, hardware and diagnostic tools are presented while retracing the exciting steps of the successful commissioning period and the first years of operation with this system. A look to the future is taken by explaining the next stages to achieve the ambitious Luminosity targets foreseen for the HL-LHC era.
	Slides TUC3I2 [19.053 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC3I2
About •	Received ※ 01 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 24 October 2023
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TUC4I1	A Kicker Impedance Reduction Scheme with Diode Stack and Resistor at the RCS in J-PARC	kicker, impedance, simulation, extraction	162
	Y. Shobuda, H. Harada, P.K. Saha, T. Takayanagi, F. Tamura, T. Togashi, Y. Watanabe, K. Yamamoto, M. Yamamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	At the 3-GeV Rapid Cycling Synchrotron (RCS) within the Japan Proton Accelerator Research Complex (J-PARC), kicker impedance causes beam instability. A 1-MW beam with a large emittance can be delivered to the Material and Life Science Experimental Facility (MLF) by suppressing beam instabilities without the need for a transverse feedback system¿simply by turning off the sextuple magnets. However, we require other high-intensity and high-quality beams with smaller emittances for the Main Ring (MR). To address this, we proposed a scheme for suppressing the kicker impedance using a diode stack and resistors, which effectively reduces beam instability. Importantly, these devices have a negligible effect on the extracted beam from the RCS.
	Slides TUC4I1 [2.713 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC4I1
About •	Received ※ 26 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 10 October 2023
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WEA1I2	Analytical and Numerical Studies on Kicked Beams in the Context of Half-Integer Studies	resonance, space-charge, coupling, damping	188
	G. Franchetti GSI, Darmstadt, Germany F. Asvesta, H. Bartosik, T. Prebibaj CERN, Meyrin, Switzerland
	In the context of the half-integer studies an investigation of the dynamics of the kicked beam has revealed surprising properties. The coupling of space charge with chromatic- ity in addition to usual damping/non-damping dynamics, exhibits new properties typical of a linear coupling. This proceeding covers the status of these studies carried out with analytical and numerical approaches and the prelimi- nary results of experimental investigations in the CERN PS Booster.
	Slides WEA1I2 [24.966 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA1I2
About •	Received ※ 02 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 13 October 2023 — Issued ※ 24 October 2023
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WEA3C2	Benchmarking of PATH and RF-Track in the Simulation of Linac4	space-charge, linac, DTL, simulation	249
	G. Bellodi, J.-B. Lallement, A. Latina, A.M. Lombardi CERN, Meyrin, Switzerland
	A benchmarking campaign has been initiated to compare PATH and RF-Track in modelling high-intensity, low-energy hadron beams. The development of extra functionalities in RF-Track was required to handle an unbunched beam from the source and to ease the user interface. The Linac4 RFQ and downstream accelerating structures were adopted as test case scenarios. This paper will give an overview of the results obtained so far and plans for future code development.
	Slides WEA3C2 [4.809 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA3C2
About •	Received ※ 27 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 18 October 2023
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WEC3I1	Self-Consistent Injection Painting for Space Charge Mitigation	space-charge, injection, solenoid, experiment	258
	N.J. Evans, V.S. Morozov ORNL RAD, Oak Ridge, Tennessee, USA T.V. Gorlov, A.M. Hoover ORNL, Oak Ridge, Tennessee, USA
	Funding: This work was conducted at UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy, with partial funding provided by Field Work Proposal ORNL-ERKCS41. I will present results of experiments at the Spallation Neutron Source to implement a method of phase space painting we refer to as ¿eigenpainting¿, in which beam is injected along one eigenvector of the transfer matrix of a ring with full coupling. The method and resultant distribution were initially proposed by Danilov almost to linearize the space charge force, minimizing space charge tune spread. In the theoretically ideal case this so-called Danilov distribution has uniform charge distribution, elliptical envelope in real-space, and a vanishing 4D transverse emittance. Such a beam can be maintained throughout injection. The Danilov distribution has implications for increasing beam intensity beyond the conventional space charge limit through a reduction of both tune spread and shift, and increasing collider performance. This talk will present current limits on beam quality, and details of the preparation of the optics in the SNS accumulator ring, including the installation of new solenoid magnets. The status of experiments to improve beam quality and characterize the interesting dynamical implications of the defining features of the Danilov distribution will also be discussed.
	Slides WEC3I1 [2.687 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEC3I1
About •	Received ※ 28 September 2023 — Revised ※ 10 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 23 October 2023
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WEC3I2	Mitigation of Space Charge Effects in RHIC and Its Injectors	booster, space-charge, injection, polarization	264
	V. Schoefer, C.J. Gardner, K. Hock, H. Huang, K. Zeno 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 RHIC collider physics program, in particular its polarized proton and low energy heavy ion components, present unique challenges for maintaining collider performance in the presence of space charge effects. Polarized beam performance is especially sensitive to emittance increases, since they decrease both the luminosity and polarization. Operation of the collider with gold beams at sub-injection energies (down to 3.85 GeV/n Au) with space charge tune shifts up to 0.1 required special care to optimize both the ion lifetime and its interaction with the electron-beam cooler. We describe the operational experience in these modes and some of the mitigation efforts.
	Slides WEC3I2 [10.503 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEC3I2
About •	Received ※ 29 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 14 October 2023
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WEC3C2	High Energy Cooling	electron, proton, undulator, linac	274
	V.A. Lebedev Fermilab, Batavia, Illinois, USA
	The paper considers methods of particle cooling applicable to beam cooling in high energy hadron colliders at the collision energy. Presently, there are two major methods of the cooling the electron cooling and stochastic cooling. The later, in application to colliders, requires exceptionally large frequency band of cooling system. Presently two methods are considered. They are the optical stochastic cooling (OSC) and the coherent electron cooling (CEC). OSC and CEC are essentially extensions of microwave stochastic cooling, operating in 1-10 GHz frequency range, to the optical frequencies enabling bands up to 30-300 THz. The OSC uses undulators as a pickup and a kicker, and an optical amplifier for signal amplification, while the CEC uses an electron beam for all these functions. We discuss major limitations, advantages and disadvantages of electron and stochastic cooling systems.
	Slides WEC3C2 [1.054 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEC3C2
About •	Received ※ 26 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 30 October 2023
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WEA4I1	Development of Non-Destructive Beam Envelope Measurements Using BPMs for Low Beta Heavy Ion Beams in SRF Cavities	simulation, cavity, quadrupole, heavy-ion	284
	T. Nishi, O. Kamigaito, N. Sakamoto, T. Watanabe, K. Yamada RIKEN Nishina Center, Wako, Japan T. Adachi RIKEN, Saitama, Japan
	Accurate measurement and control of the beam envelope are crucial issues, particularly in high-power accelerator facilities. However, the use of destructive monitors is limited to low-intensity beams. Furthermore, in the case of beam transport between superconducting cavities, these destructive monitors are avoided to prevent the generation of dust particles and outgassing. In the Superconducting RIKEN LINAC, or SRILAC [1], we utilize 8 non-destructive Beam Energy Position Monitors (BEPMs)[2] to measure beam positions and energies. Recently we are developing a method for estimating the beam envelope by combining the quadrupole moments from BEPMs, which consist of four cosine-shape electrodes, with transfer matrix[3]. While this method has been applied to electron and proton beams, it has not been practically demonstrated for heavy ion beams in beta ¿0.1 regions. By combining BEPM simulations, we are making progress toward the reproduction of experimental results, overcoming specific issues associated with low beta. This development will present the possibility of a new method for beam envelope measurement in LEBT and MEBT, especially for hadron beam facilities. [1] K. Yamada et al., in Proc. SRF2021, paper MOOFAV01(2021). [2] T. Watanabe et al., in Proc. IBIC2020, paper FRAO04 (2020). [3] R. H. Miller et al., in Proc. HEAC¿83, pp. 603¿605 (1983).
	Slides WEA4I1 [10.867 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA4I1
About •	Received ※ 12 October 2023 — Revised ※ 13 October 2023 — Accepted ※ 18 October 2023 — Issued ※ 01 November 2023
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WEA4I2	Linac4 Source and Low Energy Experience and Challenges	rfq, linac, solenoid, simulation	290
	E. Sargsyan, G. Bellodi, F.D.L. Di Lorenzo, J. Etxebarria, J.-B. Lallement, A.M. Lombardi, M. O’Neil CERN, Meyrin, Switzerland
	At the end of Long Shutdown 2 (LS2), in 2020 Linac4 became the new injector of CERN’s proton accelerator complex. The previous version of the Linac4 H⁻ ion source (IS03), produced an operational pulsed peak beam current of 35 mA, resulting in 27 mA after the Radio-Frequency Quadrupole (RFQ). This limited transmission was mainly due to the extracted beam emittance exceeding the acceptance of the RFQ. A new geometry of the Linac4 source extraction electrodes has been developed with the aim of decreasing the extracted beam emittance and increasing the transmission through the RFQ. The new source (IS04) has been studied and thoroughly tested at the Linac4 source test stand. At the start of the 2023 run, the IS04 was installed as operational source in the Linac4 tunnel and is being successfully used for operation with 27 mA peak current after the RFQ. During high-intensity tests, the source, the linac, and the transfer-line to the Proton Synchrotron Booster (PSB) were also tested with a peak beam current of up to 50 mA from the source resulting in 35 mA at the PSB injection. This paper discusses the recent developments, tests, and future plans for the Linac4 H⁻ ion source.
	Slides WEA4I2 [2.217 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA4I2
About •	Received ※ 27 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 29 October 2023
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WEA4C1	Beam Loss Studies in the CSNS Linac	linac, DTL, operation, lattice	297
	J. Peng, X.Y. Feng, Y. Han, H.C. Liu, X.B. Luo IHEP CSNS, Guangdong Province, People’s Republic of China S. Fu, M.Y. Huang, Y. Li, Z.P. Li, X. Liu, S. Wang, Y. Yuan IHEP, Beijing, People’s Republic of China S.Y. Xu DNSC, Dongguan, People’s Republic of China
	The China Spallation Neutron Source¿CSNS¿accelerator comprises an 80MeV linac and a 1.6GeV rapid cycling synchrotron. It started operation in 2018, and the beam power delivered to the target has increased from 20kW to 140kW, step by step. Various beam loss studies have been performed through the accelerator to improve the beam power and availability. For the CSNS linac, the primary source of the beam loss is the halo generated by beam mismatches. In the upgrade plan of the CSNS, the beam current will increase five times, which requires more strict beam loss control. Much work is done during the design phase to keep the loss down to 1W/m of loss limit. This paper will report results obtained from beam experiments and optimization methods applied to the CSNS linac upgrade design.
	Slides WEA4C1 [3.736 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA4C1
About •	Received ※ 01 October 2023 — Revised ※ 06 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 13 October 2023
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THC1C1	Transverse Emittance Reconstruction Along the Cycle of the CERN Antiproton Decelerator	electron, operation, antiproton, proton	358
	G. Russo, B. Dupuy, D. Gamba, L. Ponce CERN, Meyrin, Switzerland
	The precise knowledge of the transverse beam emittances on the different energy plateaus of the CERN Antiproton Decelerator (AD) ring is important for assessing the machine performance and beam quality. This paper presents a methodology for reconstructing transverse beam profiles from scraper measurements employing the Abel transform. The proposed methodology provides a precise, reproducible and user independent way of computing the beam emittance, as well as a useful tool to qualitatively track machine performance in routine operation. As discussed in this paper, its application has already been proven crucial for the operational setting-up of the stochastic cooling and for determining the proper functioning of the electron cooling in AD. It also opens up the possibility for detailed benchmarking studies of the cooling performance in different machine and beam conditions.
	Slides THC1C1 [2.426 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THC1C1
About •	Received ※ 30 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 18 October 2023
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THA2C1	Measurement of Transverse Beam Emittance for a High-Intensity Proton Injector	solenoid, space-charge, simulation, beam-transport	363
	D.-H. Kim, H.S. Kim, H.-J. Kwon, S. Lee KOMAC, KAERI, Gyeongju, Republic of Korea
	Funding: This work was supported through "KOMAC operation fund" of KAERI by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (KAERI-524320-23) We propose a simple and fast diagnostics method for the transverse beam emittance using a solenoid magnet. The solenoid scan data is analyzed employing the hard edge solenoid model and thick lens approximation. The analytical method is validated by beam dynamics simulations with varying input beam parameters. To address the space charge effect in a simplified manner, the space charge force is linearized and incorporated between segments of the drift-solenoid transfer matrix. For intense hadron injectors with higher beam current accounting for space charge prove to be more effective for correction. Building upon the method validated through beam simulation, experiments are conducted on space charge compensation at the beam test stand in the Korea Multipurpose Accelerator Complex (KOMAC). In a constant ion source operating condition, beam emittance is measured from solenoid scans while varying the flow rate of krypton gas injection. Notable shifts are observed in transverse beam emittance attributable to krypton gas injection, implying some optimal gas flow rate for mitigating emittance growth.
	Slides THA2C1 [3.438 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THA2C1
About •	Received ※ 23 October 2023 — Revised ※ 28 October 2023 — Accepted ※ 30 October 2023 — Issued ※ 20 November 2023
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THA2C2	Comparison of Longitudinal Emittance of Various RFQs	rfq, simulation, focusing, linac	368
	M. Comunian, L. Bellan, A. Pisent INFN/LNL, Legnaro (PD), Italy
	In various projects a large variety of RFQs has been developed, for different application, with different average current, frequency, and energy range. On this article a comparison, in a scaled way, will be done, using the build RFQs of IFMIF, ESS, SPES, ANTHEM, PIAVE. On particular the beam dynamics characteristics will be analyzed, like transmission, output longitudinal emittance and real performance versus simulation.
	Slides THA2C2 [6.261 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THA2C2
About •	Received ※ 30 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 16 October 2023
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THAFP04	Investigation of Tail-dominated Instability in the Fermilab Recycler Ring	space-charge, operation, diagnostics, coupling	403
	O. Mohsen, R. Ainsworth, A.V. Burov Fermilab, Batavia, Illinois, USA
	In our recent operational run, a single bunch, tail-dominated instability was observed in the Fermilab Recycler ring. This instability exclusively occurs in the vertical plane when the chromaticity is close to zero. In this study, we conduct a detailed analysis of this instability under different operational parameters. We investigate the impact of space charge on the head-tail motion and propose potential interpretations of the underlying mechanism of the instability. Moreover, we explore methods to mitigate this instability in the future.
	Slides THAFP04 [1.429 MB]
	Poster THAFP04 [0.892 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP04
About •	Received ※ 25 September 2023 — Revised ※ 09 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 29 October 2023
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THAFP07	Preliminary Results on Transverse Phase Space Tomography at KOMAC	linac, proton, quadrupole, diagnostics	415
	S. Lee, J.J. Dang, D.-H. Kim, H.S. Kim, H.-J. Kwon, S.P. Yun KOMAC, KAERI, Gyeongju, Republic of Korea
	Funding: This work has been supported through KOMAC operation fund of KAERI by Ministry of Science and ICT, the Korean government (KAERI ID no. : 524320-23) Beam loss is a critical issue to be avoid in high power proton accelerators due to machine protection from radiation. Nonlinear processes add higher order moments and cause halo and tail structures to a beam, resulting in beam losses. Hence it becomes more important to characterize beams for high power accelerators. Conventional beam diagnostic methods can measure only approximate elliptical features of a beam and are not suitable for high power beams. Tomography method reconstructs a multidimensional distribution from its lower-dimensional projections. We used this method to reconstruct the 4D transverse (x, x’, y, y’) phase space distribution of the beam from the accelerator at KOMAC (Korea Multipurpose Accelerator Complex). RFQ BTS (Radio Frequency Quadrupole Beam Test System) was constructed and commissioned in 2022. In the BTS, we performed tomography experiements and obtained preliminary results on 4D transverse phase space beam distribution. We also have applied the tomography measurement techniques to the 100 MeV proton linac. In this paper, we describe the tomography measurement system and present the preliminary results obtained from the BTS and the 100 MeV proton linac.
	Slides THAFP07 [2.018 MB]
	Poster THAFP07 [1.035 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP07
About •	Received ※ 01 October 2023 — Revised ※ 05 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 13 October 2023
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THAFP08	Performance of the Ion Chain at the CERN Injector Complex and Transmission Studies During the 2023 Slip Stacking Commissioning	injection, linac, MMI, extraction	418
	M. Slupecki, S.C.P. Albright, R. Alemany-Fernández, M.E. Angoletta, T. Argyropoulos, H. Bartosik, P. Baudrenghien, G. Bellodi, M. Bozzolan, R. Bruce, C. Carli, J. Cenede, H. Damerau, A. Frassier, D. Gamba, G. Hagmann, A. Huschauer, V. Kain, G. Khatri, D. Küchler, A. Lasheen, K.S.B. Li, E. Mahner, G. Papotti, G. Piccinini, A. Rey, M. Schenk, R. Scrivens, A. Spierer, G. Tranquille, D. Valuch, F.M. Velotti, R. Wegner CERN, Meyrin, Switzerland E. Waagaard EPFL, Lausanne, Switzerland
	The 2023 run has been decisive for the LHC Ion Injector Complex. It demonstrated the capability of producing full trains of momentum slip stacked lead ions in the SPS. Slip stacking is a technique of interleaving particle trains, reducing the bunch spacing in SPS from 100 ns to 50 ns. It is needed to reach the total ion intensity requested by the HL-LHC project, as defined by updated common LIU/HL-LHC target beam parameters. This paper reviews the lead beam characteristics across the Ion Injector Complex, including transmission efficiencies up to the SPS extraction. It also documents the difficulties found during the commissioning and the solutions put in place.
	Slides THAFP08 [1.114 MB]
	Poster THAFP08 [1.995 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP08
About •	Received ※ 01 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 21 October 2023
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THBP06	RFQ Upgrades for IFMIF-DONES	rfq, simulation, neutron, toolkit	451
	M. Comunian, L. Bellan, A. Palmieri, A. Pisent INFN/LNL, Legnaro (PD), Italy
	In the framework of IFMIF-DONES (International Fusion Materials Irradiation Facility- DEMO-Oriented Neutron Early Source) ¿ a powerful neutron irradiation facility for studies and certification of materials to be used in fusion reactors is planned as part of the European roadmap to fusion electricity. A possible RFQ upgrade has been designed. In this article the beam dynamics of an RFQ able to handle CW 200 mA of Deuterium, based on experience of IFMIF RFQ, will be presented.
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP06
About •	Received ※ 24 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 15 October 2023
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THBP09	Pushing High Intensity and High Brightness Limits in the CERN PSB after the LIU Upgrades	resonance, brightness, space-charge, injection	458
	F. Asvesta, S.C.P. Albright, H. Bartosik, C. Bracco, G.P. Di Giovanni, T. Prebibaj CERN, Meyrin, Switzerland
	After the successful completion of the LHC Injectors Upgrade (LIU) project, the CERN Proton Synchrotron Booster (PSB) has produced beams with up to two times higher brightness. However, the efforts to continuously improve the beam quality for the CERN physics experiments are ongoing. In particular, the high brightness LHC beams show non-Gaussian tails in the transverse profiles that can cause losses in the downstream machines, and even at LHC injection. As a result, alternative production schemes based on triple harmonic capture are being investigated in order to preserve brightness and reduce transverse tails at the same time. In addition, in view of a possible upgrade to the ISOLDE facility that would require approximately twice the number of protons per ring, the ultimate intensity reach of the PSB is explored. In this context, injection schemes using painting both transversely and longitudinally in order to mitigate the strong space charge effects are developed.
	Poster THBP09 [0.751 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP09
About •	Received ※ 28 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 20 October 2023
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THBP12	Slow vs Fast Landau Damping Threshold Measurement at the LHC and Implications for the HL-LHC	octupole, damping, experiment, simulation	470
	X. Buffat, L. Giacomel, N. Mounet CERN, Meyrin, Switzerland
	The mechanism of Loss of Landau Damping by Diffusion (L2D2) was observed in dedicated experiments at the LHC using a controlled external source of noise. Nevertheless, the predictions of stability threshold by L2D2 models are plagued by the poor knowledge of the natural noise floor affecting the LHC beams. Experimental measurements of the stability threshold on slow and fast time scales are used to better constrain the model. The improved model is then used to quantify requirements in terms of Landau damping for the HL-LHC.
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP12
About •	Received ※ 29 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 30 October 2023
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THBP15	Optimizing Resonance Driving Terms Using MAD-NG Parametric Maps	optics, resonance, injection, octupole	483
	L. Deniau, S. Kostoglou, E.H. Maclean, K. Paraschou, T.H.B. Persson, R. Tomás García CERN, Meyrin, Switzerland
	In 2023, a review of the LHC octupolar resonance driving terms at injection was carried out, motivated by two observations: (i) unwanted losses during the injection process with strongly powered octupoles and (ii) an expected reduction in emittance growth from e-cloud effects in simulations with weaker octupolar resonances. The MAD-NG code was used to simultaneously optimise the main octupolar resonances: 4Qx, 4Qy, and 2Qx-2Qy by adjusting 16 quadrupole families and 16 octupole families, for a total of 32 parameters. These knobs were introduced as parameters in the transfer map, allowing the Jacobian required by the optimiser to be calculated in a single pass, saving 32 additional optics evaluations and avoiding finite difference approximations. Constraints on tunes, amplitude detuning and optics around the machine were also considered as part of the optimisation process. This paper reviews the parametric optimisation with MAD-NG and compares the results with MADX-PTC.
	Poster THBP15 [0.938 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP15
About •	Received ※ 02 October 2023 — Revised ※ 06 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 17 October 2023
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THBP16	Emittance Growth From Electron Clouds Forming in the LHC Arc Quadrupoles	simulation, resonance, optics, electron	487
	K. Paraschou, H. Bartosik, L. Deniau, G. Iadarola, E.H. Maclean, L. Mether, Y. Papaphilippou, G. Rumolo, R. Tomás García CERN, Meyrin, Switzerland T. Pieloni, J.M.B. Potdevin EPFL, Lausanne, Switzerland
	Operation of the Large Hadron Collider with proton bunches spaced 25 ns apart favours the formation of electron clouds. In fact, a slow emittance growth is observed in proton bunches at injection energy (450 GeV), showing a bunch-by-bunch signature that is compatible with electron cloud effects. The study of these effects is particularly relevant in view of the planned HL-LHC upgrade, which relies on significantly increased beam intensity and brightness. Particle tracking simulations that take into account both electron cloud effects and the non-linear magnetic fields of the lattice suggest that the electron clouds forming in the arc quadrupoles are responsible for the observed degradation. In this work, the simulation results are studied to gain insight into the mechanism which drives the slow emittance growth. Finally, it is discussed how optimising the optics of the lattice can allow the mitigation of such effects.
	Poster THBP16 [3.432 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP16
About •	Received ※ 29 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 11 October 2023
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THBP19	Experimental Investigations on the High-Intensity Effects Near the Half-Integer Resonance in the PSB	resonance, space-charge, experiment, brightness	499
	T. Prebibaj, F. Antoniou, F. Asvesta, H. Bartosik CERN, Meyrin, Switzerland G. Franchetti GSI, Darmstadt, Germany
	Space charge effects are the main limitation for the brightness performance of the Proton Synchrotron Booster (PSB) at CERN. Following the upgrades of the LHC Injectors Upgrade (LIU) project, the PSB delivered unprecedented brightness even exceeding the projected target parameters. A possibility for further increasing the brightness is to operate above the half-integer resonance 2Q_y=9 in order to avoid emittance blow-up from resonances at Q_x,y=4 due to the strong space charge detuning. The half-integer resonance can be compensated to a great extent using the available quadrupole correctors in the PSB, and also deliberately excited in a controlled way. The control of the half-integer resonance and the flexibility of the PSB to create a variety of different beam and machine conditions allowed the experimental characterization of space charge effects near this resonance. This contribution reports the experimental observations of the particle trapping during the dynamic crossing of the half-integer, as well as systematic studies of the beam degradation from space charge induced resonance crossing.
	Poster THBP19 [3.077 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP19
About •	Received ※ 30 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 23 October 2023
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THBP22	On Liouvillian High Power Beam Accumulation	injection, closed-orbit, accumulation, linac	511
	J.-M. Lagniel GANIL, Caen, France M.E. Eshraqi, N. Milas ESS, Lund, Sweden
	Funding: This work is co-funded by the European Union It is acknowledged that the injection of high power proton beams into synchrotrons must be done using stripping injection of H⁻ beams which are accelerated by an injector, as done in many facilities worldwide such as ISIS, JPARC, SNS and CERN. However, this technique is not necessarily the only way of accumulation and in some cases might not represent the best choice. For example in the case of the ESSnuSB Accumulator Ring, accelerating the protons injecting them to the ring could represent savings in capital cost, reduced risk of losses in the linac and transfer lines and simplification to the overall project. This work presents the development of a method allowing to optimize the 4D Liouvillian accumulation of high-power proton and heavy ion beams and finishes with a discussion on the pros and cons of proton injection compared to more traditional H⁻ stripping injection method.
	Poster THBP22 [2.126 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP22
About •	Received ※ 01 October 2023 — Revised ※ 05 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 28 October 2023
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THBP23	Exploring Space Charge and Intra-beam Scattering Effects in the CERN Ion Injector Chain	space-charge, scattering, injection, operation	515
	E. Waagaard EPFL, Lausanne, Switzerland H. Bartosik CERN, Meyrin, Switzerland
	As of today, the LHC ion physics programme is mostly based on Pb ion collisions. The ALICE3 detector proposal requests significantly higher nucleon-nucleon luminosities, as compared to today¿s operation. This improved performance could be potentially achieved with lighter ion species than Pb. In this respect, the CERN Ion Injector chain (consisting of Linac3, LEIR, PS and SPS) will need to provide significantly higher beam intensities with light ion beams as compared to the present ones, whereas operational experience with such beams is limited. We present space charge and intra-beam scattering studies across the Ion Injector chain and strategies to build benchmarked simulation models for optimised ion performance. This is the first step for identifying the ideal ion isotopes and charge states for maximised LHC luminosity production.
	Poster THBP23 [2.744 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP23
About •	Received ※ 29 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 24 October 2023
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THBP24	RCS and Accumulator Rings Designs for ISIS II	injection, space-charge, proton, lattice	519
	D.J. Adams STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom H.V. Cavanagh, I.S.K. Gardner, B.S. Kyle, H. Rafique, C.M. Warsop, R.E. Williamson STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK, which provides 0.2 MW of beam power via a 50 Hz, 800 MeV proton RCS. Detailed studies are now underway to find the optimal configuration for a next generation, short-pulsed neutron source that will define a major ISIS upgrade, with construction beginning ~2031. Determining the optimal specification for such a facility is the subject of an ongoing study involving neutron users, target and instrument experts. The accelerator designs being considered for the MW beam powers required, include proposals exploiting FFA rings as well as conventional accumulator and RCS rings. This paper summarises work on physics designs for the conventional rings. Details of lattice designs, injection and extraction systems, correction systems as well as detailed 3D PIC simulations used to ensure 0.1% losses and low foil hits are presented. Designs for a 0.4 to 1.2 GeV RCS and 1.2 GeV AR are outlined. Work on the next stages of the study are also summarised to benchmark and minimise predicted losses, and thus maximise the high intensity limit of designs.
	Poster THBP24 [3.231 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP24
About •	Received ※ 28 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 22 October 2023
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THBP34	PSI Injector II and the 72 MeV Transfer Line: MinT-Simulation vs. Measurements	cyclotron, space-charge, simulation, extraction	547
	C. Baumgarten, H. Zhang PSI, Villigen PSI, Switzerland
	PSI’s Injector II cyclotron is the only cyclotron worldwide that makes use of the so-called "Vortex effect", in which strong space charge forces generate the counter-intuitive effect to "roll up" bunches thus keeping them longitudinally compact. The effect has been verified by bunch shape measurements and the PIC-code OPAL. However, PSI’s new fast matrix code MinT allows to reproduce the Vortex effect by a linear matrix model which is computational much cheaper than PIC simulations, and is suitable for "online use" in Control rooms. Furthermore it provides the second moments of matched distributions.
	Poster THBP34 [0.840 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP34
About •	Received ※ 30 September 2023 — Revised ※ 03 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 31 October 2023
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THBP38	Two-Dimensional Longitudinal Painting at Injection into the CERN PS Booster	injection, linac, target, synchrotron	563
	S.C.P. Albright, F. Asvesta, B. Bielawski, C. Bracco, P.K. Skowroński, R. Wegner CERN, Meyrin, Switzerland
	To inject highest beam intensities at the transfer from Linac4 into the four rings of the PS Booster (PSB) at CERN, protons must be accumulated during up to 148 turns in total. With the conventional, fixed chopping pattern this process results in an approximately rectangular distribution in the longitudinal phase space. As the bucket shape in the PSB does not correspond to this distribution, the process leads to longitudinal mismatch, contributing to emittance growth and reduced transmission. The field in the last accelerating cavity of Linac4 can be modulated, which leads to fine corrections of the extracted beam energy. At the same time, the chopping pattern can be varied. Combining both allows injecting a near uniform longitudinal distribution whose boundary corresponds to an iso-Hamiltonian contour of the RF bucket, hence significantly reducing mismatch. In an operational context, the longitudinal painting must be controlled in a way that allows easy intensity variation, and can even require different painting configurations for each of the four PSB rings. This contribution presents the first demonstration of longitudinal painting in the PSB, and its impact on beam performance.
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP38
About •	Received ※ 30 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 24 October 2023
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THBP44	ImpactX Modeling of Benchmark Tests for Space Charge Validation	space-charge, focusing, cavity, proton	583
	C.E. Mitchell, M. Garten, A. Huebl, R. Lehé, J. Qiang, R.T. Sandberg, J.-L. Vay LBNL, Berkeley, California, USA
	The code ImpactX represents the next generation of the particle-in-cell code IMPACT-Z, featuring s-based symplectic tracking with 3D space charge, parallelism with GPU acceleration, adaptive mesh-refinement, and modernized language features. With such a code comes a renewed need for space charge validation using well-defined benchmarks. For this purpose, the code is continuously checked against a test suite of exactly-solvable problems. The suite includes field calculation tests, dynamical tests involving coasting or stationary beams, and beams matched to periodic focusing channels. To study the long-time multi-turn performance of the code in a more complex setting, we investigate problems involving high-intensity storage rings, such as the GSI benchmark problem for space charge induced trapping. Comparisons against existing codes are made where possible.
	Poster THBP44 [1.020 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP44
About •	Received ※ 01 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 26 October 2023
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THBP53	Commissioning and Operation of the Collimation System at the RCS of CSNS	collimation, controls, proton, MMI	615
	S.Y. Xu, J. Chen, S. Wang IHEP, Beijing, People’s Republic of China K. Zhou IHEP CSNS, Guangdong Province, People’s Republic of China
	For high-intensity proton synchrotrons, minimizing particle losses during machine operation is essential to avoid radiation damage. Uncontrolled beam loss posed a significant challenge to achieving higher beam intensity and power for high-intensity proton synchrotrons. The beam collimation system can remove halo particles and to localize the beam loss. The use of collimation system is an important means of controlling uncontrolled beam loss in high-power proton accelerators. To reduce the uncontrolled beam loss, a transverse collimation system was designed for the RCS of CSNS. The design transverse collimator is a two-stage collimator. During the beam commissioning of CSNS, the designed two-stage collimator has been changed to one-stage collimator to overcome the problem of low collimation efficiency caused by insufficient phase shift between the primary and secondary collimators. By optimizing the collimation system, the beam loss is well localized in the collimator area, effectively reducing uncontrolled beam loss. The beam power of CSNS achieved the design value of 100 kW with small uncontrolled beam loss.
	Poster THBP53 [0.780 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP53
About •	Received ※ 30 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 10 October 2023
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FRC1I2	High Beam Current Operation with Beam Diagnostics at LIPAc	operation, diagnostics, neutron, beam-diagnostic	649
	S. Kwon, T. Akagi, A. De Franco, K. Hirosawa, K. Kondo, K. Masuda, M. Ohta QST Rokkasho, Aomori, Japan F. Bénédetti, Y. Carin, F. Cismondi, D. Gex IFMIF/EVEDA, Rokkasho, Japan B. Bolzon, N. Chauvin CEA-IRFU, Gif-sur-Yvette, France D. Jimenez-Rey, I. Podadera, A. Rodríguez Páramo, V. Villamayor CIEMAT, Madrid, Spain L. Maindive UGR, Granada, Spain J. Marroncle CEA-DRF-IRFU, France J.C. Morales Vega, I. Podadera Consorcio IFMIF-DONES España, Granada, Spain M. Poggi INFN/LNL, Legnaro (PD), Italy
	The Linear IFMIF Prototype Accelerator (LIPAc) is under commissioning in Rokkasho Fusion Institute in Japan and aims to accelerate 125 mA D⁺ at 9 MeV in CW mode for validating the IFMIF accelerator design. To insure a fine characterization and tuning of the machine many beam diagnostics are installed such as CTs, profile/position/loss/bunch length monitors spanning from Injector to the beam dump (BD). The beam operations in 1.0 ms pulsed D⁺ at 5 MeV was successfully completed with a low power BD (Phase B) in 2019. Despite the challenges posed by the pandemic, the crucial transition to a new linac configuration was also finalized to enable operation in 1.0 ms to CW D⁺ at 5 MeV with the high-power BD (Phase B+). Thanks to the efforts of the entire team, the 1st beam operation of Phase B+ was carried out in 2021. We present the experiences and challenges encountered during the beam operations, particularly the findings from the interceptive devices to measure the beam profile and emittance using tungsten wires rackets, SEMGrid. We also discuss the quick results on other beam diagnostics from the beam operation of Phase B+ toward HDC, which are currently conducting in this Summer.
	Slides FRC1I2 [9.323 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-FRC1I2
About •	Received ※ 02 October 2023 — Revised ※ 06 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 23 October 2023
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Paper

Title

Other Keywords

Page

MOA1I1

Beam Performance with the LHC Injectors Upgrade

brightness, injection, operation, target

1

G. Rumolo, S.C.P. Albright, R. Alemany-Fernández, M.E. Angoletta, C. Antuono, T. Argyropoulos, F. Asvesta, M.J. Barnes, H. Bartosik, P. Baudrenghien, G. Bellodi, N. Biancacci, C. Bracco, N. Bruchon, E. Carlier, J. Coupard, H. Damerau, G.P. Di Giovanni, A. Findlay, M.A. Fraser, A. Funken, R. Garoby, S.S. Gilardoni, B. Goddard, G. Hagmann, K. Hanke, A. Huschauer, G. Iadarola, V. Kain, I. Karpov, J.-B. Lallement, A. Lasheen, T.E. Levens, K.S.B. Li, A.M. Lombardi, E.H. Maclean, D. Manglunki, I. Mases Solé, M. Meddahi, L. Mether, B. Mikulec, E. Montesinos, Y. Papaphilippou, G. Papotti, K. Paraschou, C. Pasquino, F. Pedrosa, T. Prebibaj, S. Prodon, D. Quartullo, F. Roncarolo, B. Salvant, M. Schenk, R. Scrivens, E.N. Shaposhnikova, L. Sito, P.K. Skowroński, A. Spierer, R. Steerenberg, M. Sullivan, F.M. Velotti, R. Veness, C. Vollinger, R. Wegner, C. Zannini, E. de la Fuente
CERN, Meyrin, Switzerland
T. Prebibaj
IAP, Frankfurt am Main, Germany

The LHC Injectors Upgrade (LIU) project was put in place between 2010 and 2021 to increase the intensity and brightness in the LHC injectors to match the challenging requirements of the High-Luminosity LHC (HL-LHC) project, while ensuring reliable operation of the injectors complex up to the end of the HL-LHC era (ca. 2040). During the 2019-2020 CERN accelerators shutdown, extensive hardware modifications were implemented in the entire LHC proton and ion injection chains, involving the new Linac4, the Proton Synchrotron Booster (PSB), the Proton Synchrotron (PS), the Super Proton Synchrotron (SPS) and the ion PS injectors, i.e. the Linac3 and the Low Energy Ion Ring (LEIR). Since 2021, beams have been recommissioned throughout the injectors’ chain and the beam parameters are being gradually ramped up to meet the LIU specifications using new beam dynamics solutions adapted to the upgraded accelerators. This paper focuses on the proton beams and describes the current state of the art.

Slides MOA1I1 [10.002 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-MOA1I1

About •

Received ※ 29 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 18 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOA1I2

FRIB from Commissioning to Operation

linac, target, operation, experiment

9

P.N. Ostroumov, K. Fukushima, A.J. Gonzalez, K. Hwang, T. Kanemura, T. Maruta, A.S. Plastun, J. Wei, T. Zhang, Q. Zhao
FRIB, East Lansing, Michigan, USA

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan, and Michigan State University.
The Facility for Rare Isotope Beams (FRIB) was fully commissioned in early 2022, and the operation for physics experiments started shortly thereafter. Various ion beam species have been accelerated up to 240 MeV/u and delivered to the target. During the first year of user operations, the FRIB provided 4252 beam hours with 91% availability for nuclear science. In addition, FRIB delivered about 1000 hours of various ion beam species at beam energies up to 40 MeV/u for single-event experiments. Typically, the experiments with a specific species rare isotope beam last a week or two. Each experiment requires a different primary beam species with specific energies. The primary beam power has been gradually increased from 1 kW to 10 kW over the past 1.5 years. The Accelerator Physics (AP) group develops high-level physics applications to minimize machine set-up time. Focuses include identifying beam halo sources, controlling emittances of multiple-charge-state beams, and studying the beam loss mechanisms to prepare for the ultimate 400 kW operation. This paper discusses the experience and challenges of operating a high-power CW heavy ion accelerator.

Slides MOA1I2 [6.556 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-MOA1I2

About •

Received ※ 22 September 2023 — Accepted ※ 10 October 2023 — Issued ※ 17 October 2023

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MOA3I1

Beam Dynamics Challenges in the Design of the Electron-Ion Collider

electron, polarization, hadron, proton

23

Y. Luo, M. Blaskiewicz, D. Marx, E. Wang, F.J. Willeke
BNL, Upton, New York, USA
A. Blednykh, C. Montag, V. Ptitsyn, V.H. Ranjbar, S. Verdú-Andrés
Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA
S. Nagaitsev
JLab, Newport News, Virginia, 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 (EIC), presently under construction at Brookhaven National Laboratory, will collide polarized high-energy electron beams with hadron beams, achieving luminosities up to 1 × 10³⁴ cm^¿2 s^¿1 in the center-of-mass energy range of 20-140 GeV. To achieve such high luminosity, we adopt high bunch intensities for both beams, small and flat transverse beam sizes at the interaction point (IP), a large crossing angle of 25 mrad, and a novel strong hadron cooling in the Hadron Storage Ring (HSR) to counteract intra-beam scattering (IBS) at the collision energy. In this talk, we will review the beam dynamics challenges in the design of the EIC, particularly the single-particle dynamic aperture, polarization maintenance, beam-beam interaction, impedance budget and instabilities. We will also briefly mention some technical challenges associated with beam dynamics, such as strong hadron cooling, multipoles and noises of crab cavities, power supply current ripples, and the vacuum upgrade to existing beam pipes of the Hadron Storage Ring of the EIC.

Slides MOA3I1 [3.437 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-MOA3I1

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Received ※ 02 October 2023 — Revised ※ 06 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 18 October 2023

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TUC1I1

Multi-beam Operation of LANSCE Accelerator Facility

proton, linac, operation, alignment

58

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

The unique feature of the LANSCE accelerator facility is the simultaneous delivering of beams to five experimental targets. Proton beam with energy of 100-MeV is delivered to Isotope Production Facility (IPF), while 800-MeV H⁻ beams are distributed to four experimental areas: the Lujan Neutron Scattering Center, the Weapons Neutron Research facility (WNR), the Proton Radiography facility (pRad), and the Ultra-Cold Neutron facility (UCN). Multi-beam operation of accelerator facility requires careful optimization of beam losses, which is achieved by precise tuning of the beam, imposing restriction on amplitudes and phases of RF sections, application of beam-based alignment, control of H⁻ beam stripping, optimization of ion sources performance and low-energy beam transport operation under space-charge neutralization. The near - term plans are to replace obsolete systems of the LANSCE linear accelerator with modern Front End, which is the part of Los Alamos Modernization Project (LAMP). This paper summarizes experimental results obtained during operation of LANSCE accelerator facility and considers plans to expand performance of the accelerator for near-and long-term operations.

Slides TUC1I1 [10.013 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC1I1

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Received ※ 30 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 31 October 2023

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TUC3I1

Ultra-low Emittance Bunches from Laser Cooled Ion Traps for Intense Focal Points

laser, luminosity, space-charge, ECR

128

S.J. Brooks
BNL, Upton, New York, USA

Laser-cooled ion traps are used to prepare groups of ions in very low temperature states, exhibiting such phenomena as Coulomb crystallization. This corresponds to very small normalized RMS emittances of 10^-13–10^-12 m, compared to typical accelerator ion sources in the 10^-7–10^-6 m range. Such bunches could potentially be focused a million times smaller, compensating for the lower number of ions per bunch. Such an ultra-low emittance source could enable high-specific-luminosity colliders where reduced beam current and apertures are needed to produce a given luminosity. Further advances needed to enable such colliders include linear, helical or ring cooling channel designs for increased bunch number or current throughput. Novel high density focal points using only a single bunch also appear possible, where the high density particles collide with themselves. At collider energies ~100 GeV, these approach the nuclear density and offer a way of studying larger quantities of neutron star matter and other custom nuclear matter in the lab.

Slides TUC3I1 [167.328 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC3I1

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Received ※ 26 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 24 October 2023

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TUC3I2

Shaping High Brightness and Fixed Target Beams with the CERN PSB Charge Exchange Injection

injection, operation, target, brightness

135

C. Bracco, S.C.P. Albright, F. Asvesta, G.P. Di Giovanni, F. Roncarolo
CERN, Meyrin, Switzerland

CERN adopted the charge exchange injection technique for the first time in the PS Booster after Long Shutdown 2. This allowed to overcome space charge limitations, tailor high brightness beams for the LHC and deliver high intensity flux of protons to the fixed target experiments. Details on the concept, physics, hardware and diagnostic tools are presented while retracing the exciting steps of the successful commissioning period and the first years of operation with this system. A look to the future is taken by explaining the next stages to achieve the ambitious Luminosity targets foreseen for the HL-LHC era.

Slides TUC3I2 [19.053 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC3I2

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Received ※ 01 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 24 October 2023

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TUC4I1

A Kicker Impedance Reduction Scheme with Diode Stack and Resistor at the RCS in J-PARC

kicker, impedance, simulation, extraction

162

Y. Shobuda, H. Harada, P.K. Saha, T. Takayanagi, F. Tamura, T. Togashi, Y. Watanabe, K. Yamamoto, M. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

At the 3-GeV Rapid Cycling Synchrotron (RCS) within the Japan Proton Accelerator Research Complex (J-PARC), kicker impedance causes beam instability. A 1-MW beam with a large emittance can be delivered to the Material and Life Science Experimental Facility (MLF) by suppressing beam instabilities without the need for a transverse feedback system¿simply by turning off the sextuple magnets. However, we require other high-intensity and high-quality beams with smaller emittances for the Main Ring (MR). To address this, we proposed a scheme for suppressing the kicker impedance using a diode stack and resistors, which effectively reduces beam instability. Importantly, these devices have a negligible effect on the extracted beam from the RCS.

Slides TUC4I1 [2.713 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC4I1

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Received ※ 26 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 10 October 2023

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WEA1I2

Analytical and Numerical Studies on Kicked Beams in the Context of Half-Integer Studies

resonance, space-charge, coupling, damping

188

G. Franchetti
GSI, Darmstadt, Germany
F. Asvesta, H. Bartosik, T. Prebibaj
CERN, Meyrin, Switzerland

In the context of the half-integer studies an investigation of the dynamics of the kicked beam has revealed surprising properties. The coupling of space charge with chromatic- ity in addition to usual damping/non-damping dynamics, exhibits new properties typical of a linear coupling. This proceeding covers the status of these studies carried out with analytical and numerical approaches and the prelimi- nary results of experimental investigations in the CERN PS Booster.

Slides WEA1I2 [24.966 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA1I2

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Received ※ 02 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 13 October 2023 — Issued ※ 24 October 2023

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WEA3C2

Benchmarking of PATH and RF-Track in the Simulation of Linac4

space-charge, linac, DTL, simulation

249

G. Bellodi, J.-B. Lallement, A. Latina, A.M. Lombardi
CERN, Meyrin, Switzerland

A benchmarking campaign has been initiated to compare PATH and RF-Track in modelling high-intensity, low-energy hadron beams. The development of extra functionalities in RF-Track was required to handle an unbunched beam from the source and to ease the user interface. The Linac4 RFQ and downstream accelerating structures were adopted as test case scenarios. This paper will give an overview of the results obtained so far and plans for future code development.

Slides WEA3C2 [4.809 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA3C2

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Received ※ 27 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 18 October 2023

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WEC3I1

Self-Consistent Injection Painting for Space Charge Mitigation

space-charge, injection, solenoid, experiment

258

N.J. Evans, V.S. Morozov
ORNL RAD, Oak Ridge, Tennessee, USA
T.V. Gorlov, A.M. Hoover
ORNL, Oak Ridge, Tennessee, USA

Funding: This work was conducted at UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy, with partial funding provided by Field Work Proposal ORNL-ERKCS41.
I will present results of experiments at the Spallation Neutron Source to implement a method of phase space painting we refer to as ¿eigenpainting¿, in which beam is injected along one eigenvector of the transfer matrix of a ring with full coupling. The method and resultant distribution were initially proposed by Danilov almost to linearize the space charge force, minimizing space charge tune spread. In the theoretically ideal case this so-called Danilov distribution has uniform charge distribution, elliptical envelope in real-space, and a vanishing 4D transverse emittance. Such a beam can be maintained throughout injection. The Danilov distribution has implications for increasing beam intensity beyond the conventional space charge limit through a reduction of both tune spread and shift, and increasing collider performance. This talk will present current limits on beam quality, and details of the preparation of the optics in the SNS accumulator ring, including the installation of new solenoid magnets. The status of experiments to improve beam quality and characterize the interesting dynamical implications of the defining features of the Danilov distribution will also be discussed.

Slides WEC3I1 [2.687 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-WEC3I1

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Received ※ 28 September 2023 — Revised ※ 10 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 23 October 2023

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WEC3I2

Mitigation of Space Charge Effects in RHIC and Its Injectors

booster, space-charge, injection, polarization

264

V. Schoefer, C.J. Gardner, K. Hock, H. Huang, K. Zeno
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 RHIC collider physics program, in particular its polarized proton and low energy heavy ion components, present unique challenges for maintaining collider performance in the presence of space charge effects. Polarized beam performance is especially sensitive to emittance increases, since they decrease both the luminosity and polarization. Operation of the collider with gold beams at sub-injection energies (down to 3.85 GeV/n Au) with space charge tune shifts up to 0.1 required special care to optimize both the ion lifetime and its interaction with the electron-beam cooler. We describe the operational experience in these modes and some of the mitigation efforts.

Slides WEC3I2 [10.503 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-WEC3I2

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Received ※ 29 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 14 October 2023

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WEC3C2

High Energy Cooling

electron, proton, undulator, linac

274

V.A. Lebedev
Fermilab, Batavia, Illinois, USA

The paper considers methods of particle cooling applicable to beam cooling in high energy hadron colliders at the collision energy. Presently, there are two major methods of the cooling the electron cooling and stochastic cooling. The later, in application to colliders, requires exceptionally large frequency band of cooling system. Presently two methods are considered. They are the optical stochastic cooling (OSC) and the coherent electron cooling (CEC). OSC and CEC are essentially extensions of microwave stochastic cooling, operating in 1-10 GHz frequency range, to the optical frequencies enabling bands up to 30-300 THz. The OSC uses undulators as a pickup and a kicker, and an optical amplifier for signal amplification, while the CEC uses an electron beam for all these functions. We discuss major limitations, advantages and disadvantages of electron and stochastic cooling systems.

Slides WEC3C2 [1.054 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-WEC3C2

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Received ※ 26 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 30 October 2023

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WEA4I1

Development of Non-Destructive Beam Envelope Measurements Using BPMs for Low Beta Heavy Ion Beams in SRF Cavities

simulation, cavity, quadrupole, heavy-ion

284

T. Nishi, O. Kamigaito, N. Sakamoto, T. Watanabe, K. Yamada
RIKEN Nishina Center, Wako, Japan
T. Adachi
RIKEN, Saitama, Japan

Accurate measurement and control of the beam envelope are crucial issues, particularly in high-power accelerator facilities. However, the use of destructive monitors is limited to low-intensity beams. Furthermore, in the case of beam transport between superconducting cavities, these destructive monitors are avoided to prevent the generation of dust particles and outgassing. In the Superconducting RIKEN LINAC, or SRILAC [1], we utilize 8 non-destructive Beam Energy Position Monitors (BEPMs)[2] to measure beam positions and energies. Recently we are developing a method for estimating the beam envelope by combining the quadrupole moments from BEPMs, which consist of four cosine-shape electrodes, with transfer matrix[3]. While this method has been applied to electron and proton beams, it has not been practically demonstrated for heavy ion beams in beta ¿0.1 regions. By combining BEPM simulations, we are making progress toward the reproduction of experimental results, overcoming specific issues associated with low beta. This development will present the possibility of a new method for beam envelope measurement in LEBT and MEBT, especially for hadron beam facilities.
[1] K. Yamada et al., in Proc. SRF2021, paper MOOFAV01(2021).
[2] T. Watanabe et al., in Proc. IBIC2020, paper FRAO04 (2020).
[3] R. H. Miller et al., in Proc. HEAC¿83, pp. 603¿605 (1983).

Slides WEA4I1 [10.867 MB]

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reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA4I1

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Received ※ 12 October 2023 — Revised ※ 13 October 2023 — Accepted ※ 18 October 2023 — Issued ※ 01 November 2023

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WEA4I2

Linac4 Source and Low Energy Experience and Challenges

rfq, linac, solenoid, simulation

290

E. Sargsyan, G. Bellodi, F.D.L. Di Lorenzo, J. Etxebarria, J.-B. Lallement, A.M. Lombardi, M. O’Neil
CERN, Meyrin, Switzerland

At the end of Long Shutdown 2 (LS2), in 2020 Linac4 became the new injector of CERN’s proton accelerator complex. The previous version of the Linac4 H⁻ ion source (IS03), produced an operational pulsed peak beam current of 35 mA, resulting in 27 mA after the Radio-Frequency Quadrupole (RFQ). This limited transmission was mainly due to the extracted beam emittance exceeding the acceptance of the RFQ. A new geometry of the Linac4 source extraction electrodes has been developed with the aim of decreasing the extracted beam emittance and increasing the transmission through the RFQ. The new source (IS04) has been studied and thoroughly tested at the Linac4 source test stand. At the start of the 2023 run, the IS04 was installed as operational source in the Linac4 tunnel and is being successfully used for operation with 27 mA peak current after the RFQ. During high-intensity tests, the source, the linac, and the transfer-line to the Proton Synchrotron Booster (PSB) were also tested with a peak beam current of up to 50 mA from the source resulting in 35 mA at the PSB injection. This paper discusses the recent developments, tests, and future plans for the Linac4 H⁻ ion source.

Slides WEA4I2 [2.217 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA4I2

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Received ※ 27 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 29 October 2023

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WEA4C1

Beam Loss Studies in the CSNS Linac

linac, DTL, operation, lattice

297

J. Peng, X.Y. Feng, Y. Han, H.C. Liu, X.B. Luo
IHEP CSNS, Guangdong Province, People’s Republic of China
S. Fu, M.Y. Huang, Y. Li, Z.P. Li, X. Liu, S. Wang, Y. Yuan
IHEP, Beijing, People’s Republic of China
S.Y. Xu
DNSC, Dongguan, People’s Republic of China

The China Spallation Neutron Source¿CSNS¿accelerator comprises an 80MeV linac and a 1.6GeV rapid cycling synchrotron. It started operation in 2018, and the beam power delivered to the target has increased from 20kW to 140kW, step by step. Various beam loss studies have been performed through the accelerator to improve the beam power and availability. For the CSNS linac, the primary source of the beam loss is the halo generated by beam mismatches. In the upgrade plan of the CSNS, the beam current will increase five times, which requires more strict beam loss control. Much work is done during the design phase to keep the loss down to 1W/m of loss limit. This paper will report results obtained from beam experiments and optimization methods applied to the CSNS linac upgrade design.

Slides WEA4C1 [3.736 MB]

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reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA4C1

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Received ※ 01 October 2023 — Revised ※ 06 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 13 October 2023

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THC1C1

Transverse Emittance Reconstruction Along the Cycle of the CERN Antiproton Decelerator

electron, operation, antiproton, proton

358

G. Russo, B. Dupuy, D. Gamba, L. Ponce
CERN, Meyrin, Switzerland

The precise knowledge of the transverse beam emittances on the different energy plateaus of the CERN Antiproton Decelerator (AD) ring is important for assessing the machine performance and beam quality. This paper presents a methodology for reconstructing transverse beam profiles from scraper measurements employing the Abel transform. The proposed methodology provides a precise, reproducible and user independent way of computing the beam emittance, as well as a useful tool to qualitatively track machine performance in routine operation. As discussed in this paper, its application has already been proven crucial for the operational setting-up of the stochastic cooling and for determining the proper functioning of the electron cooling in AD. It also opens up the possibility for detailed benchmarking studies of the cooling performance in different machine and beam conditions.

Slides THC1C1 [2.426 MB]

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reference for this paper ※ doi:10.18429/JACoW-HB2023-THC1C1

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Received ※ 30 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 18 October 2023

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THA2C1

Measurement of Transverse Beam Emittance for a High-Intensity Proton Injector

solenoid, space-charge, simulation, beam-transport

363

D.-H. Kim, H.S. Kim, H.-J. Kwon, S. Lee
KOMAC, KAERI, Gyeongju, Republic of Korea

Funding: This work was supported through "KOMAC operation fund" of KAERI by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (KAERI-524320-23)
We propose a simple and fast diagnostics method for the transverse beam emittance using a solenoid magnet. The solenoid scan data is analyzed employing the hard edge solenoid model and thick lens approximation. The analytical method is validated by beam dynamics simulations with varying input beam parameters. To address the space charge effect in a simplified manner, the space charge force is linearized and incorporated between segments of the drift-solenoid transfer matrix. For intense hadron injectors with higher beam current accounting for space charge prove to be more effective for correction. Building upon the method validated through beam simulation, experiments are conducted on space charge compensation at the beam test stand in the Korea Multipurpose Accelerator Complex (KOMAC). In a constant ion source operating condition, beam emittance is measured from solenoid scans while varying the flow rate of krypton gas injection. Notable shifts are observed in transverse beam emittance attributable to krypton gas injection, implying some optimal gas flow rate for mitigating emittance growth.

Slides THA2C1 [3.438 MB]

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reference for this paper ※ doi:10.18429/JACoW-HB2023-THA2C1

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Received ※ 23 October 2023 — Revised ※ 28 October 2023 — Accepted ※ 30 October 2023 — Issued ※ 20 November 2023

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THA2C2

Comparison of Longitudinal Emittance of Various RFQs

rfq, simulation, focusing, linac

368

M. Comunian, L. Bellan, A. Pisent
INFN/LNL, Legnaro (PD), Italy

In various projects a large variety of RFQs has been developed, for different application, with different average current, frequency, and energy range. On this article a comparison, in a scaled way, will be done, using the build RFQs of IFMIF, ESS, SPES, ANTHEM, PIAVE. On particular the beam dynamics characteristics will be analyzed, like transmission, output longitudinal emittance and real performance versus simulation.

Slides THA2C2 [6.261 MB]

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reference for this paper ※ doi:10.18429/JACoW-HB2023-THA2C2

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Received ※ 30 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 16 October 2023

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THAFP04

Investigation of Tail-dominated Instability in the Fermilab Recycler Ring

space-charge, operation, diagnostics, coupling

403

O. Mohsen, R. Ainsworth, A.V. Burov
Fermilab, Batavia, Illinois, USA

In our recent operational run, a single bunch, tail-dominated instability was observed in the Fermilab Recycler ring. This instability exclusively occurs in the vertical plane when the chromaticity is close to zero. In this study, we conduct a detailed analysis of this instability under different operational parameters. We investigate the impact of space charge on the head-tail motion and propose potential interpretations of the underlying mechanism of the instability. Moreover, we explore methods to mitigate this instability in the future.

Slides THAFP04 [1.429 MB]

Poster THAFP04 [0.892 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP04

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Received ※ 25 September 2023 — Revised ※ 09 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 29 October 2023

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THAFP07

Preliminary Results on Transverse Phase Space Tomography at KOMAC

linac, proton, quadrupole, diagnostics

415

S. Lee, J.J. Dang, D.-H. Kim, H.S. Kim, H.-J. Kwon, S.P. Yun
KOMAC, KAERI, Gyeongju, Republic of Korea

Funding: This work has been supported through KOMAC operation fund of KAERI by Ministry of Science and ICT, the Korean government (KAERI ID no. : 524320-23)
Beam loss is a critical issue to be avoid in high power proton accelerators due to machine protection from radiation. Nonlinear processes add higher order moments and cause halo and tail structures to a beam, resulting in beam losses. Hence it becomes more important to characterize beams for high power accelerators. Conventional beam diagnostic methods can measure only approximate elliptical features of a beam and are not suitable for high power beams. Tomography method reconstructs a multidimensional distribution from its lower-dimensional projections. We used this method to reconstruct the 4D transverse (x, x’, y, y’) phase space distribution of the beam from the accelerator at KOMAC (Korea Multipurpose Accelerator Complex). RFQ BTS (Radio Frequency Quadrupole Beam Test System) was constructed and commissioned in 2022. In the BTS, we performed tomography experiements and obtained preliminary results on 4D transverse phase space beam distribution. We also have applied the tomography measurement techniques to the 100 MeV proton linac. In this paper, we describe the tomography measurement system and present the preliminary results obtained from the BTS and the 100 MeV proton linac.

Slides THAFP07 [2.018 MB]

Poster THAFP07 [1.035 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP07

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Received ※ 01 October 2023 — Revised ※ 05 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 13 October 2023

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THAFP08

Performance of the Ion Chain at the CERN Injector Complex and Transmission Studies During the 2023 Slip Stacking Commissioning

injection, linac, MMI, extraction

418

M. Slupecki, S.C.P. Albright, R. Alemany-Fernández, M.E. Angoletta, T. Argyropoulos, H. Bartosik, P. Baudrenghien, G. Bellodi, M. Bozzolan, R. Bruce, C. Carli, J. Cenede, H. Damerau, A. Frassier, D. Gamba, G. Hagmann, A. Huschauer, V. Kain, G. Khatri, D. Küchler, A. Lasheen, K.S.B. Li, E. Mahner, G. Papotti, G. Piccinini, A. Rey, M. Schenk, R. Scrivens, A. Spierer, G. Tranquille, D. Valuch, F.M. Velotti, R. Wegner
CERN, Meyrin, Switzerland
E. Waagaard
EPFL, Lausanne, Switzerland

The 2023 run has been decisive for the LHC Ion Injector Complex. It demonstrated the capability of producing full trains of momentum slip stacked lead ions in the SPS. Slip stacking is a technique of interleaving particle trains, reducing the bunch spacing in SPS from 100 ns to 50 ns. It is needed to reach the total ion intensity requested by the HL-LHC project, as defined by updated common LIU/HL-LHC target beam parameters. This paper reviews the lead beam characteristics across the Ion Injector Complex, including transmission efficiencies up to the SPS extraction. It also documents the difficulties found during the commissioning and the solutions put in place.

Slides THAFP08 [1.114 MB]

Poster THAFP08 [1.995 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP08

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Received ※ 01 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 21 October 2023

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THBP06

RFQ Upgrades for IFMIF-DONES

rfq, simulation, neutron, toolkit

451

M. Comunian, L. Bellan, A. Palmieri, A. Pisent
INFN/LNL, Legnaro (PD), Italy

In the framework of IFMIF-DONES (International Fusion Materials Irradiation Facility- DEMO-Oriented Neutron Early Source) ¿ a powerful neutron irradiation facility for studies and certification of materials to be used in fusion reactors is planned as part of the European roadmap to fusion electricity. A possible RFQ upgrade has been designed. In this article the beam dynamics of an RFQ able to handle CW 200 mA of Deuterium, based on experience of IFMIF RFQ, will be presented.

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP06

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Received ※ 24 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 15 October 2023

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THBP09

Pushing High Intensity and High Brightness Limits in the CERN PSB after the LIU Upgrades

resonance, brightness, space-charge, injection

458

F. Asvesta, S.C.P. Albright, H. Bartosik, C. Bracco, G.P. Di Giovanni, T. Prebibaj
CERN, Meyrin, Switzerland

After the successful completion of the LHC Injectors Upgrade (LIU) project, the CERN Proton Synchrotron Booster (PSB) has produced beams with up to two times higher brightness. However, the efforts to continuously improve the beam quality for the CERN physics experiments are ongoing. In particular, the high brightness LHC beams show non-Gaussian tails in the transverse profiles that can cause losses in the downstream machines, and even at LHC injection. As a result, alternative production schemes based on triple harmonic capture are being investigated in order to preserve brightness and reduce transverse tails at the same time. In addition, in view of a possible upgrade to the ISOLDE facility that would require approximately twice the number of protons per ring, the ultimate intensity reach of the PSB is explored. In this context, injection schemes using painting both transversely and longitudinally in order to mitigate the strong space charge effects are developed.

Poster THBP09 [0.751 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP09

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Received ※ 28 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 20 October 2023

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THBP12

Slow vs Fast Landau Damping Threshold Measurement at the LHC and Implications for the HL-LHC

octupole, damping, experiment, simulation

470

X. Buffat, L. Giacomel, N. Mounet
CERN, Meyrin, Switzerland

The mechanism of Loss of Landau Damping by Diffusion (L2D2) was observed in dedicated experiments at the LHC using a controlled external source of noise. Nevertheless, the predictions of stability threshold by L2D2 models are plagued by the poor knowledge of the natural noise floor affecting the LHC beams. Experimental measurements of the stability threshold on slow and fast time scales are used to better constrain the model. The improved model is then used to quantify requirements in terms of Landau damping for the HL-LHC.

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP12

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Received ※ 29 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 30 October 2023

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THBP15

Optimizing Resonance Driving Terms Using MAD-NG Parametric Maps

optics, resonance, injection, octupole

483

L. Deniau, S. Kostoglou, E.H. Maclean, K. Paraschou, T.H.B. Persson, R. Tomás García
CERN, Meyrin, Switzerland

In 2023, a review of the LHC octupolar resonance driving terms at injection was carried out, motivated by two observations: (i) unwanted losses during the injection process with strongly powered octupoles and (ii) an expected reduction in emittance growth from e-cloud effects in simulations with weaker octupolar resonances. The MAD-NG code was used to simultaneously optimise the main octupolar resonances: 4Qx, 4Qy, and 2Qx-2Qy by adjusting 16 quadrupole families and 16 octupole families, for a total of 32 parameters. These knobs were introduced as parameters in the transfer map, allowing the Jacobian required by the optimiser to be calculated in a single pass, saving 32 additional optics evaluations and avoiding finite difference approximations. Constraints on tunes, amplitude detuning and optics around the machine were also considered as part of the optimisation process. This paper reviews the parametric optimisation with MAD-NG and compares the results with MADX-PTC.

Poster THBP15 [0.938 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP15

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Received ※ 02 October 2023 — Revised ※ 06 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 17 October 2023

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THBP16

Emittance Growth From Electron Clouds Forming in the LHC Arc Quadrupoles

simulation, resonance, optics, electron

487

K. Paraschou, H. Bartosik, L. Deniau, G. Iadarola, E.H. Maclean, L. Mether, Y. Papaphilippou, G. Rumolo, R. Tomás García
CERN, Meyrin, Switzerland
T. Pieloni, J.M.B. Potdevin
EPFL, Lausanne, Switzerland

Operation of the Large Hadron Collider with proton bunches spaced 25 ns apart favours the formation of electron clouds. In fact, a slow emittance growth is observed in proton bunches at injection energy (450 GeV), showing a bunch-by-bunch signature that is compatible with electron cloud effects. The study of these effects is particularly relevant in view of the planned HL-LHC upgrade, which relies on significantly increased beam intensity and brightness. Particle tracking simulations that take into account both electron cloud effects and the non-linear magnetic fields of the lattice suggest that the electron clouds forming in the arc quadrupoles are responsible for the observed degradation. In this work, the simulation results are studied to gain insight into the mechanism which drives the slow emittance growth. Finally, it is discussed how optimising the optics of the lattice can allow the mitigation of such effects.

Poster THBP16 [3.432 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP16

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Received ※ 29 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 11 October 2023

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THBP19

Experimental Investigations on the High-Intensity Effects Near the Half-Integer Resonance in the PSB

resonance, space-charge, experiment, brightness

499

T. Prebibaj, F. Antoniou, F. Asvesta, H. Bartosik
CERN, Meyrin, Switzerland
G. Franchetti
GSI, Darmstadt, Germany

Space charge effects are the main limitation for the brightness performance of the Proton Synchrotron Booster (PSB) at CERN. Following the upgrades of the LHC Injectors Upgrade (LIU) project, the PSB delivered unprecedented brightness even exceeding the projected target parameters. A possibility for further increasing the brightness is to operate above the half-integer resonance 2Q_y=9 in order to avoid emittance blow-up from resonances at Q_x,y=4 due to the strong space charge detuning. The half-integer resonance can be compensated to a great extent using the available quadrupole correctors in the PSB, and also deliberately excited in a controlled way. The control of the half-integer resonance and the flexibility of the PSB to create a variety of different beam and machine conditions allowed the experimental characterization of space charge effects near this resonance. This contribution reports the experimental observations of the particle trapping during the dynamic crossing of the half-integer, as well as systematic studies of the beam degradation from space charge induced resonance crossing.

Poster THBP19 [3.077 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP19

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Received ※ 30 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 23 October 2023

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THBP22

On Liouvillian High Power Beam Accumulation

injection, closed-orbit, accumulation, linac

511

J.-M. Lagniel
GANIL, Caen, France
M.E. Eshraqi, N. Milas
ESS, Lund, Sweden

Funding: This work is co-funded by the European Union
It is acknowledged that the injection of high power proton beams into synchrotrons must be done using stripping injection of H⁻ beams which are accelerated by an injector, as done in many facilities worldwide such as ISIS, JPARC, SNS and CERN. However, this technique is not necessarily the only way of accumulation and in some cases might not represent the best choice. For example in the case of the ESSnuSB Accumulator Ring, accelerating the protons injecting them to the ring could represent savings in capital cost, reduced risk of losses in the linac and transfer lines and simplification to the overall project. This work presents the development of a method allowing to optimize the 4D Liouvillian accumulation of high-power proton and heavy ion beams and finishes with a discussion on the pros and cons of proton injection compared to more traditional H⁻ stripping injection method.

Poster THBP22 [2.126 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP22

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Received ※ 01 October 2023 — Revised ※ 05 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 28 October 2023

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THBP23

Exploring Space Charge and Intra-beam Scattering Effects in the CERN Ion Injector Chain

space-charge, scattering, injection, operation

515

E. Waagaard
EPFL, Lausanne, Switzerland
H. Bartosik
CERN, Meyrin, Switzerland

As of today, the LHC ion physics programme is mostly based on Pb ion collisions. The ALICE3 detector proposal requests significantly higher nucleon-nucleon luminosities, as compared to today¿s operation. This improved performance could be potentially achieved with lighter ion species than Pb. In this respect, the CERN Ion Injector chain (consisting of Linac3, LEIR, PS and SPS) will need to provide significantly higher beam intensities with light ion beams as compared to the present ones, whereas operational experience with such beams is limited. We present space charge and intra-beam scattering studies across the Ion Injector chain and strategies to build benchmarked simulation models for optimised ion performance. This is the first step for identifying the ideal ion isotopes and charge states for maximised LHC luminosity production.

Poster THBP23 [2.744 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP23

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Received ※ 29 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 24 October 2023

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THBP24

RCS and Accumulator Rings Designs for ISIS II

injection, space-charge, proton, lattice

519

D.J. Adams
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
H.V. Cavanagh, I.S.K. Gardner, B.S. Kyle, H. Rafique, C.M. Warsop, R.E. Williamson
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK, which provides 0.2 MW of beam power via a 50 Hz, 800 MeV proton RCS. Detailed studies are now underway to find the optimal configuration for a next generation, short-pulsed neutron source that will define a major ISIS upgrade, with construction beginning ~2031. Determining the optimal specification for such a facility is the subject of an ongoing study involving neutron users, target and instrument experts. The accelerator designs being considered for the MW beam powers required, include proposals exploiting FFA rings as well as conventional accumulator and RCS rings. This paper summarises work on physics designs for the conventional rings. Details of lattice designs, injection and extraction systems, correction systems as well as detailed 3D PIC simulations used to ensure 0.1% losses and low foil hits are presented. Designs for a 0.4 to 1.2 GeV RCS and 1.2 GeV AR are outlined. Work on the next stages of the study are also summarised to benchmark and minimise predicted losses, and thus maximise the high intensity limit of designs.

Poster THBP24 [3.231 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP24

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Received ※ 28 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 22 October 2023

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THBP34

PSI Injector II and the 72 MeV Transfer Line: MinT-Simulation vs. Measurements

cyclotron, space-charge, simulation, extraction

547

C. Baumgarten, H. Zhang
PSI, Villigen PSI, Switzerland

PSI’s Injector II cyclotron is the only cyclotron worldwide that makes use of the so-called "Vortex effect", in which strong space charge forces generate the counter-intuitive effect to "roll up" bunches thus keeping them longitudinally compact. The effect has been verified by bunch shape measurements and the PIC-code OPAL. However, PSI’s new fast matrix code MinT allows to reproduce the Vortex effect by a linear matrix model which is computational much cheaper than PIC simulations, and is suitable for "online use" in Control rooms. Furthermore it provides the second moments of matched distributions.

Poster THBP34 [0.840 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP34

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Received ※ 30 September 2023 — Revised ※ 03 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 31 October 2023

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THBP38

Two-Dimensional Longitudinal Painting at Injection into the CERN PS Booster

injection, linac, target, synchrotron

563

S.C.P. Albright, F. Asvesta, B. Bielawski, C. Bracco, P.K. Skowroński, R. Wegner
CERN, Meyrin, Switzerland

To inject highest beam intensities at the transfer from Linac4 into the four rings of the PS Booster (PSB) at CERN, protons must be accumulated during up to 148 turns in total. With the conventional, fixed chopping pattern this process results in an approximately rectangular distribution in the longitudinal phase space. As the bucket shape in the PSB does not correspond to this distribution, the process leads to longitudinal mismatch, contributing to emittance growth and reduced transmission. The field in the last accelerating cavity of Linac4 can be modulated, which leads to fine corrections of the extracted beam energy. At the same time, the chopping pattern can be varied. Combining both allows injecting a near uniform longitudinal distribution whose boundary corresponds to an iso-Hamiltonian contour of the RF bucket, hence significantly reducing mismatch. In an operational context, the longitudinal painting must be controlled in a way that allows easy intensity variation, and can even require different painting configurations for each of the four PSB rings. This contribution presents the first demonstration of longitudinal painting in the PSB, and its impact on beam performance.

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP38

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Received ※ 30 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 24 October 2023

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THBP44

ImpactX Modeling of Benchmark Tests for Space Charge Validation

space-charge, focusing, cavity, proton

583

C.E. Mitchell, M. Garten, A. Huebl, R. Lehé, J. Qiang, R.T. Sandberg, J.-L. Vay
LBNL, Berkeley, California, USA

The code ImpactX represents the next generation of the particle-in-cell code IMPACT-Z, featuring s-based symplectic tracking with 3D space charge, parallelism with GPU acceleration, adaptive mesh-refinement, and modernized language features. With such a code comes a renewed need for space charge validation using well-defined benchmarks. For this purpose, the code is continuously checked against a test suite of exactly-solvable problems. The suite includes field calculation tests, dynamical tests involving coasting or stationary beams, and beams matched to periodic focusing channels. To study the long-time multi-turn performance of the code in a more complex setting, we investigate problems involving high-intensity storage rings, such as the GSI benchmark problem for space charge induced trapping. Comparisons against existing codes are made where possible.

Poster THBP44 [1.020 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP44

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Received ※ 01 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 26 October 2023

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THBP53

Commissioning and Operation of the Collimation System at the RCS of CSNS

collimation, controls, proton, MMI

615

S.Y. Xu, J. Chen, S. Wang
IHEP, Beijing, People’s Republic of China
K. Zhou
IHEP CSNS, Guangdong Province, People’s Republic of China

For high-intensity proton synchrotrons, minimizing particle losses during machine operation is essential to avoid radiation damage. Uncontrolled beam loss posed a significant challenge to achieving higher beam intensity and power for high-intensity proton synchrotrons. The beam collimation system can remove halo particles and to localize the beam loss. The use of collimation system is an important means of controlling uncontrolled beam loss in high-power proton accelerators. To reduce the uncontrolled beam loss, a transverse collimation system was designed for the RCS of CSNS. The design transverse collimator is a two-stage collimator. During the beam commissioning of CSNS, the designed two-stage collimator has been changed to one-stage collimator to overcome the problem of low collimation efficiency caused by insufficient phase shift between the primary and secondary collimators. By optimizing the collimation system, the beam loss is well localized in the collimator area, effectively reducing uncontrolled beam loss. The beam power of CSNS achieved the design value of 100 kW with small uncontrolled beam loss.

Poster THBP53 [0.780 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP53

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Received ※ 30 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 10 October 2023

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FRC1I2

High Beam Current Operation with Beam Diagnostics at LIPAc

operation, diagnostics, neutron, beam-diagnostic

649

S. Kwon, T. Akagi, A. De Franco, K. Hirosawa, K. Kondo, K. Masuda, M. Ohta
QST Rokkasho, Aomori, Japan
F. Bénédetti, Y. Carin, F. Cismondi, D. Gex
IFMIF/EVEDA, Rokkasho, Japan
B. Bolzon, N. Chauvin
CEA-IRFU, Gif-sur-Yvette, France
D. Jimenez-Rey, I. Podadera, A. Rodríguez Páramo, V. Villamayor
CIEMAT, Madrid, Spain
L. Maindive
UGR, Granada, Spain
J. Marroncle
CEA-DRF-IRFU, France
J.C. Morales Vega, I. Podadera
Consorcio IFMIF-DONES España, Granada, Spain
M. Poggi
INFN/LNL, Legnaro (PD), Italy

The Linear IFMIF Prototype Accelerator (LIPAc) is under commissioning in Rokkasho Fusion Institute in Japan and aims to accelerate 125 mA D⁺ at 9 MeV in CW mode for validating the IFMIF accelerator design. To insure a fine characterization and tuning of the machine many beam diagnostics are installed such as CTs, profile/position/loss/bunch length monitors spanning from Injector to the beam dump (BD). The beam operations in 1.0 ms pulsed D⁺ at 5 MeV was successfully completed with a low power BD (Phase B) in 2019. Despite the challenges posed by the pandemic, the crucial transition to a new linac configuration was also finalized to enable operation in 1.0 ms to CW D⁺ at 5 MeV with the high-power BD (Phase B+). Thanks to the efforts of the entire team, the 1st beam operation of Phase B+ was carried out in 2021. We present the experiences and challenges encountered during the beam operations, particularly the findings from the interceptive devices to measure the beam profile and emittance using tungsten wires rackets, SEMGrid. We also discuss the quick results on other beam diagnostics from the beam operation of Phase B+ toward HDC, which are currently conducting in this Summer.

Slides FRC1I2 [9.323 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-FRC1I2

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Received ※ 02 October 2023 — Revised ※ 06 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 23 October 2023

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