HB2023 - List of Keywords (experiment)

Paper	Title	Other Keywords	Page
MOA1I2	FRIB from Commissioning to Operation	linac, target, operation, emittance	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
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUA3I1	SPIRAL2 Commissioning and Operations	linac, cavity, MMI, operation	106
	A.K. Orduz, M. Di Giacomo, J.-M. Lagniel, G. Normand GANIL, Caen, France D.U. Uriot CEA-DRF-IRFU, France
	The SPIRAL2 linac is now successfully commissioned; H⁺, 4He2+, D⁺ and 18O6+ have been accelerated up to nominal parameters and 18O7+ and 40Ar14+ beams have been also accelerated up to 7 MeV/A. The main steps with 5 mA H⁺, D⁺ beams and with 0.6 mA 18O6+ are described. The general results of the commissioning of the RF, cryogenic and diagnostics systems, as well as the preliminary results of the first experiments on NFS are presented. In addition of an improvement of the matching to the linac, the tuning procedures of the 3 Medium Energy Beam Transport (MEBT) rebunchers and 26 linac SC cavities were progressively improved to reach the nominal parameters in operation, starting from the classical ¿signature matching method¿. The different cavity tuning methods developed to take into account our particular situation (very low energy and large phase extension) are described. The tools developed for an efficient linac tuning in operation, e.g. beam energy and intensity changes are also discussed.
	Slides TUA3I1 [9.358 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-TUA3I1
About •	Received ※ 01 October 2023 — Revised ※ 06 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 24 October 2023
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TUA3I4	SARAF MEBT Commissioning	MEBT, linac, rfq, proton	123
	N. Pichoff, A. Chancé, J. Dumas, F. Gougnaud, F. Senée, D.U. Uriot CEA-IRFU, Gif-sur-Yvette, France A. Kreisel, J. Luner, A. Perry, E. Reinfeld, R. Weiss-Babai, L. Weissman Soreq NRC, Yavne, Israel
	SNRC in Israel is in the process of constructing a neutron production accelerator facility called SARAF. The facility will utilize a linac to accelerate a 5 mA CW deuteron and proton beam up to 40 MeV. In the first phase of the project, SNRC completed construction and operation of a linac (referred to as SARAF Phase I) which included an ECR ion source, a Low-Energy Beam Transport (LEBT) line, and a 4-rod RFQ. The second phase of the project involves collaboration between SNRC and Irfu in France to manufacture the linac. The injector control system has been updated and the Medium Energy Beam Transport (MEBT) line has been installed and integrated into the infrastructure. Recent testing and commissioning of the injector and MEBT with 5 mA CW protons and 5 mA pulsed Deuterons, completed in 2022 and 2023, will be presented and discussed. A special attention will be paid to the experimental data processing with the Bayesian inference of the parameters of a digital twin.
	Slides TUA3I4 [2.559 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-TUA3I4
About •	Received ※ 04 October 2023 — Revised ※ 06 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 29 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUC3I3	Laser Stripping of H⁻ Beam	laser, injection, proton, resonance	141
	T.V. Gorlov, A.V. Aleksandrov, S.M. Cousineau, Y. Liu, A.R. Oguz ORNL, Oak Ridge, Tennessee, USA N.J. Evans ORNL RAD, Oak Ridge, Tennessee, USA P.K. Saha JAEA/J-PARC, Tokai-mura, Japan
	Basic principles of laser assisted charge exchange injection for H⁻ ion andH⁰ beams are presented. Theoretical aspects of electromagnetic interaction of laser with hydrogen atom and H⁻ ions are discussed. Laser excitation, photoionizatio and interaction of atoms and ions with a strong electro-magnetic field are discussed and compared. Different techniques of LACE for stripping of high current stochastic beams are presented. The optimum parameters of LACE are estimated and compared for various ion beam energies. Experimental development of laser stripping at the SNS are reviewed. Future plans of LACE at the SNS and J-PARC are discussed.
	Slides TUC3I3 [1.790 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC3I3
About •	Received ※ 04 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 01 November 2023
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TUC4C2	Mitigating Collimation Impedance and Improving Halo Cleaning with New Optics and Settings Strategy of the HL-LHC Betatron Collimation System	optics, impedance, collimation, simulation	183
	B. Lindström, R. Bruce, X. Buffat, R. De Maria, L. Giacomel, P.D. Hermes, D. Mirarchi, N. Mounet, T.H.B. Persson, S. Redaelli, R. Tomás García, F.F. Van der Veken, A. Wegscheider CERN, Meyrin, Switzerland
	Funding: Work supported by the HL-LHC project With High Luminosity Large Hadron Collider (HL-LHC) beam intensities, there are concerns that the beam losses in the dispersion suppressors around the betatron cleaning insertion might exceed the quench limits. Furthermore, to maximize the beam lifetime it is important to reduce the impedance as much as possible. The collimators constitute one of the main sources of impedance in HL-LHC, given the need to operate with small collimator gaps. To improve this, a new optics was developed which increases the beta function in the collimation area, as well as the single pass dispersion from the primary collimators to the downstream shower absorbers. Other possible improvements from orbit bumps, to further enhance the locally generated dispersion, and from asymmetric collimator settings were also studied. The new solutions were partially tested with 6.8 TeV beams at the LHC in a dedicated machine experiment in 2022. In this paper, the new performance is reviewed and prospects for future operational deployment are discussed.
	Slides TUC4C2 [2.222 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC4C2
About •	Received ※ 01 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 28 October 2023
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WEA2I1	Compensation of Third-order Resonances in the High Intensity Regime	resonance, sextupole, space-charge, operation	215
	C.E. Gonzalez-Ortiz MSU, East Lansing, Michigan, USA R. Ainsworth Fermilab, Batavia, Illinois, USA P.N. Ostroumov FRIB, East Lansing, Michigan, USA
	As the Fermilab Accelerator Complex enters the high-intensity era, the Recycler Ring (RR) needs to mitigate the detrimental effect of third-order resonance crossing. Third-order resonance lines can be compensated to first order by cancelling out the global Resonance Driving Terms (RDTs) using the response matrix method. This compensation scheme has been proven to work at low intensities, i.e., in the single-particle regime. In order to evaluate the effectiveness of this compensation scheme at higher intensities, this study looks at dynamic and static tune scans, with and without resonance compensation, and different space charge tune shifts. Special care was taken in order to disentangle effects from space charge tune shift, structure resonances and space charge driven resonances.
	Slides WEA2I1 [6.714 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA2I1
About •	Received ※ 02 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 09 October 2023
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WEA2C2	Measurement of Transverse Statistical Dependence for Non-Gaussian Beam Distributions via Resonances in the CERN PSB	resonance, space-charge, factory, luminosity	231
	E.R. Lamb, F. Asvesta, H. Bartosik, G. Sterbini CERN, Meyrin, Switzerland E.R. Lamb EPFL, Lausanne, Switzerland
	This work addresses the origins and the effects of the statistical dependence in non-Gaussian beam distributions with the ultimate goal to identify the most representative case for tracking simulations across the CERN accelerator complex. Starting from the observation that non-Gaussian heavy-tailed transverse beam profiles can be reconstructed from 4D phase space distributions under two different conditions (statistical independence or dependence in the x-y plane), we consider space charge dominated beams interacting with the lattice nonlinear resonances to perform measurements to study the mechanisms that lead to non-Gaussian distributions. Finally, we explore the beam dynamics implications of the above hypotheses in terms of dependent loss processes across the transverse planes.
	Slides WEA2C2 [1.249 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA2C2
About •	Received ※ 30 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 21 October 2023
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WEC3I1	Self-Consistent Injection Painting for Space Charge Mitigation	space-charge, injection, emittance, solenoid	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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THA1I3	Predominantly Electric Storage Ring with Nuclear Spin Control Capability	storage-ring, scattering, proton, lattice	338
	R.M. Talman Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	A predominantly electric storage ring with weak superimposed magnetic bending is shown to be capable of storing two different nuclear isotope bunches, such as helion and deuteron, co-traveling with different velocities on the same central orbit. ‘‘Rear-end’’ collisions occurring periodically in a full acceptance particle detector/polarimeter, allow the (previously inaccessible) direct measurement of the spin dependence of nuclear transmutation for center of mass (CM) kinetic energies ranging from hundreds of keV up toward pion production thresholds. These are ‘‘rear-end collisions’’ occurring as faster stored bunches pass through slower bunches. An inexpensive facility capable of meeting these requirements is described, with nuclear channel h + d arrow α + p as example.
	Slides THA1I3 [0.860 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THA1I3
About •	Received ※ 07 December 2023 — Accepted ※ 11 December 2023 — Issued ※ 25 December 2023
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THAFP03	Measurement of Stability Diagram at IOTA at Fermilab	kicker, damping, pick-up, impedance	400
	M.K. Bossard, Y.K. Kim University of Chicago, Chicago, Illinois, USA R. Ainsworth, N. Eddy Fermilab, Batavia, Illinois, USA
	Funding: Fermilab Nonlinear focusing elements can enhance the stability of particle beams in high-energy colliders by means of Landau Damping, through the tune spread which is introduced. We propose an experiment at Fermilab’s Integrable Optics Test Accelerator (IOTA) to investigate the influence of nonlinear focusing elements on the transverse stability of the beam. In this experiment, we employ an anti-damper, an active transverse feedback system, as a controlled mechanism to induce coherent beam instability. By utilizing the anti-damper, we can examine the impact of the nonlinear focusing element on the beam’s transverse stability. The stability diagram, a tool used to determine the system’s stability, will be measured using a recently demonstrated method at the LHC. This measurement is carried out experimentally by selecting specific threshold gains and measuring them for a range of phases. The stability diagram is represented by gei¿ on the complex plane. The experiment at IOTA adds insight towards the stability diagram measurement method by supplying a reduced machine impedance, to investigate the impedance’s effect on the stability diagram, as well as a larger range of phase measurements.
	Slides THAFP03 [1.331 MB]
	Poster THAFP03 [1.692 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP03
About •	Received ※ 06 October 2023 — Revised ※ 09 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 12 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, simulation, emittance	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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THBP19	Experimental Investigations on the High-Intensity Effects Near the Half-Integer Resonance in the PSB	resonance, space-charge, emittance, 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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THBP27	Experimental Investigation of Nonlinear Integrable Optics in a Paul Trap	lattice, octupole, resonance, space-charge	523
	J.A.D. Flowerdew University of Oxford, Oxford, United Kingdom D.J. Kelliher, S. Machida STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom S.L. Sheehy STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	Funding: Work supported by Royal Society grants Octupoles are often used to damp beam instabilities caused by space charge. However, in general the insertion of octupole magnets leads to a nonintegrable lattice which reduces the area of stable particle motion. One proposed solution to this problem is Quasi-Integrable Optics (QIO), where the octupoles are inserted between a specially designed lattice called a T-insert. An octupole with a strength that scales as 1/β³(s) is applied in the drift region to create a time-independent octupole field, leading to a lattice with an invariant Hamiltonian. This means that large tune spreads can be achieved without reducing the dynamic aperture. IBEX is a Paul trap which confines low energy ions with an RF voltage, simulating the transverse dynamics of an alternating gradient accelerator. IBEX has recently undergone an upgrade to allow for octupole fields to be created in the trap in addition to quadrupole focusing. We present our first experimental results from testing QIO with the IBEX trap. jake.flowerdew@physics.ox.ac.uk
	Poster THBP27 [4.163 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP27
About •	Received ※ 30 September 2023 — Revised ※ 09 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 31 October 2023
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THBP48	Latest Advances in Targetry Systems at CERN and Exciting Avenues for Future Endeavours	target, proton, antiproton, neutron	599
	R. Franqueira Ximenes, O. Aberle, M. Calviani, R. Esposito, J.L. Grenard, T. Griesemer, A.R. Romero Francia, C. Torregrosa CERN, Meyrin, Switzerland
	CERN’s accelerator complex offers diverse target systems for a range of scientific pursuits, including varying beam energies, intensities, pulse lengths, and objectives. Future high-intensity fixed target experiments aim to advance this field further. This contribution highlights upgraded operational target systems, enhancing CERN’s physics endeavours. One example is the third-generation n_TOF spallation neutron target, using a nitrogen-cooled pure lead system impacted by a 20 GeV/c proton beam. Another focuses on recent antiproton production target upgrades, with a high-intensity 26 GeV/c beam colliding with a narrow-air-cooled iridium target. Looking ahead, new high-power target systems are planned. One aims to discover hidden particles using a 350-kW high-Z production target, while another enhances kaon physics through a 100 kW low-Z target. This article provides an overview of current target systems at CERN, detailing beam-intercepting devices and engineering aspects. It also previews upcoming facilities that could soon be implemented at CERN.
	Poster THBP48 [63.760 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP48
About •	Received ※ 07 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 10 October 2023
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THBP50	Fermilab Main Injector and Recycler Operations in the Megawatt Era	operation, proton, booster, electron	607
	A.P. Schreckenberger Fermilab, Batavia, Illinois, USA
	Significant upgrades to Fermilab¿s accelerator complex have accompanied the development of LBNF and DUNE. These improvements will facilitate 1-MW operation of the NuMI beam for the first time this year through changes to the Recycler slip-stacking procedure and shortening of the Main Injector ramp time. The modifications to the Recycler slip-stacking and effort to reduce the Main Injector ramp time will be discussed. Additionally, details regarding further shortening of the ramp time and the impact on future accelerator operations are presented.
	Poster THBP50 [0.923 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP50
About •	Received ※ 25 September 2023 — Revised ※ 09 October 2023 — Accepted ※ 12 October 2023 — Issued ※ 12 October 2023
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FRA2I1	Summary of the Working Group A: Beam Dynamics in Rings	space-charge, resonance, simulation, impedance	662
	H. Bartosik, G. Rumolo CERN, Meyrin, Switzerland J.-L. Vay LBNL, Berkeley, California, USA N. Wang IHEP, Beijing, People’s Republic of China
	The HB-2023 workshop at CERN from October 9 to 13, 2023 is the continuation of the series of workshops, which started in 2002 at FNAL and rotates every two years between America, Europe and Asia. This contribution summarises the main highlights from Working Group A, Beam Dynamics in Rings, in terms of progress and challenges in the achievement of ever higher intensity and brightness hadron beams in accelerator rings around the world.
	Slides FRA2I1 [4.325 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-FRA2I1
About •	Received ※ 04 December 2023 — Accepted ※ 05 December 2023 — Issued ※ 01 January 2024
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Paper

Title

Other Keywords

Page

MOA1I2

FRIB from Commissioning to Operation

linac, target, operation, emittance

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

Cite •

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

TUA3I1

SPIRAL2 Commissioning and Operations

linac, cavity, MMI, operation

106

A.K. Orduz, M. Di Giacomo, J.-M. Lagniel, G. Normand
GANIL, Caen, France
D.U. Uriot
CEA-DRF-IRFU, France

The SPIRAL2 linac is now successfully commissioned; H⁺, 4He2+, D⁺ and 18O6+ have been accelerated up to nominal parameters and 18O7+ and 40Ar14+ beams have been also accelerated up to 7 MeV/A. The main steps with 5 mA H⁺, D⁺ beams and with 0.6 mA 18O6+ are described. The general results of the commissioning of the RF, cryogenic and diagnostics systems, as well as the preliminary results of the first experiments on NFS are presented. In addition of an improvement of the matching to the linac, the tuning procedures of the 3 Medium Energy Beam Transport (MEBT) rebunchers and 26 linac SC cavities were progressively improved to reach the nominal parameters in operation, starting from the classical ¿signature matching method¿. The different cavity tuning methods developed to take into account our particular situation (very low energy and large phase extension) are described. The tools developed for an efficient linac tuning in operation, e.g. beam energy and intensity changes are also discussed.

Slides TUA3I1 [9.358 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-TUA3I1

About •

Received ※ 01 October 2023 — Revised ※ 06 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 24 October 2023

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TUA3I4

SARAF MEBT Commissioning

MEBT, linac, rfq, proton

123

N. Pichoff, A. Chancé, J. Dumas, F. Gougnaud, F. Senée, D.U. Uriot
CEA-IRFU, Gif-sur-Yvette, France
A. Kreisel, J. Luner, A. Perry, E. Reinfeld, R. Weiss-Babai, L. Weissman
Soreq NRC, Yavne, Israel

SNRC in Israel is in the process of constructing a neutron production accelerator facility called SARAF. The facility will utilize a linac to accelerate a 5 mA CW deuteron and proton beam up to 40 MeV. In the first phase of the project, SNRC completed construction and operation of a linac (referred to as SARAF Phase I) which included an ECR ion source, a Low-Energy Beam Transport (LEBT) line, and a 4-rod RFQ. The second phase of the project involves collaboration between SNRC and Irfu in France to manufacture the linac. The injector control system has been updated and the Medium Energy Beam Transport (MEBT) line has been installed and integrated into the infrastructure. Recent testing and commissioning of the injector and MEBT with 5 mA CW protons and 5 mA pulsed Deuterons, completed in 2022 and 2023, will be presented and discussed. A special attention will be paid to the experimental data processing with the Bayesian inference of the parameters of a digital twin.

Slides TUA3I4 [2.559 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-TUA3I4

About •

Received ※ 04 October 2023 — Revised ※ 06 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 29 October 2023

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TUC3I3

Laser Stripping of H⁻ Beam

laser, injection, proton, resonance

141

T.V. Gorlov, A.V. Aleksandrov, S.M. Cousineau, Y. Liu, A.R. Oguz
ORNL, Oak Ridge, Tennessee, USA
N.J. Evans
ORNL RAD, Oak Ridge, Tennessee, USA
P.K. Saha
JAEA/J-PARC, Tokai-mura, Japan

Basic principles of laser assisted charge exchange injection for H⁻ ion andH⁰ beams are presented. Theoretical aspects of electromagnetic interaction of laser with hydrogen atom and H⁻ ions are discussed. Laser excitation, photoionizatio and interaction of atoms and ions with a strong electro-magnetic field are discussed and compared. Different techniques of LACE for stripping of high current stochastic beams are presented. The optimum parameters of LACE are estimated and compared for various ion beam energies. Experimental development of laser stripping at the SNS are reviewed. Future plans of LACE at the SNS and J-PARC are discussed.

Slides TUC3I3 [1.790 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC3I3

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Received ※ 04 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 01 November 2023

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TUC4C2

Mitigating Collimation Impedance and Improving Halo Cleaning with New Optics and Settings Strategy of the HL-LHC Betatron Collimation System

optics, impedance, collimation, simulation

183

B. Lindström, R. Bruce, X. Buffat, R. De Maria, L. Giacomel, P.D. Hermes, D. Mirarchi, N. Mounet, T.H.B. Persson, S. Redaelli, R. Tomás García, F.F. Van der Veken, A. Wegscheider
CERN, Meyrin, Switzerland

Funding: Work supported by the HL-LHC project
With High Luminosity Large Hadron Collider (HL-LHC) beam intensities, there are concerns that the beam losses in the dispersion suppressors around the betatron cleaning insertion might exceed the quench limits. Furthermore, to maximize the beam lifetime it is important to reduce the impedance as much as possible. The collimators constitute one of the main sources of impedance in HL-LHC, given the need to operate with small collimator gaps. To improve this, a new optics was developed which increases the beta function in the collimation area, as well as the single pass dispersion from the primary collimators to the downstream shower absorbers. Other possible improvements from orbit bumps, to further enhance the locally generated dispersion, and from asymmetric collimator settings were also studied. The new solutions were partially tested with 6.8 TeV beams at the LHC in a dedicated machine experiment in 2022. In this paper, the new performance is reviewed and prospects for future operational deployment are discussed.

Slides TUC4C2 [2.222 MB]

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reference for this paper ※ doi:10.18429/JACoW-HB2023-TUC4C2

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Received ※ 01 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 28 October 2023

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WEA2I1

Compensation of Third-order Resonances in the High Intensity Regime

resonance, sextupole, space-charge, operation

215

C.E. Gonzalez-Ortiz
MSU, East Lansing, Michigan, USA
R. Ainsworth
Fermilab, Batavia, Illinois, USA
P.N. Ostroumov
FRIB, East Lansing, Michigan, USA

As the Fermilab Accelerator Complex enters the high-intensity era, the Recycler Ring (RR) needs to mitigate the detrimental effect of third-order resonance crossing. Third-order resonance lines can be compensated to first order by cancelling out the global Resonance Driving Terms (RDTs) using the response matrix method. This compensation scheme has been proven to work at low intensities, i.e., in the single-particle regime. In order to evaluate the effectiveness of this compensation scheme at higher intensities, this study looks at dynamic and static tune scans, with and without resonance compensation, and different space charge tune shifts. Special care was taken in order to disentangle effects from space charge tune shift, structure resonances and space charge driven resonances.

Slides WEA2I1 [6.714 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA2I1

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Received ※ 02 October 2023 — Revised ※ 07 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 09 October 2023

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WEA2C2

Measurement of Transverse Statistical Dependence for Non-Gaussian Beam Distributions via Resonances in the CERN PSB

resonance, space-charge, factory, luminosity

231

E.R. Lamb, F. Asvesta, H. Bartosik, G. Sterbini
CERN, Meyrin, Switzerland
E.R. Lamb
EPFL, Lausanne, Switzerland

This work addresses the origins and the effects of the statistical dependence in non-Gaussian beam distributions with the ultimate goal to identify the most representative case for tracking simulations across the CERN accelerator complex. Starting from the observation that non-Gaussian heavy-tailed transverse beam profiles can be reconstructed from 4D phase space distributions under two different conditions (statistical independence or dependence in the x-y plane), we consider space charge dominated beams interacting with the lattice nonlinear resonances to perform measurements to study the mechanisms that lead to non-Gaussian distributions. Finally, we explore the beam dynamics implications of the above hypotheses in terms of dependent loss processes across the transverse planes.

Slides WEA2C2 [1.249 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA2C2

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Received ※ 30 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 21 October 2023

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WEC3I1

Self-Consistent Injection Painting for Space Charge Mitigation

space-charge, injection, emittance, solenoid

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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THA1I3

Predominantly Electric Storage Ring with Nuclear Spin Control Capability

storage-ring, scattering, proton, lattice

338

R.M. Talman
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

A predominantly electric storage ring with weak superimposed magnetic bending is shown to be capable of storing two different nuclear isotope bunches, such as helion and deuteron, co-traveling with different velocities on the same central orbit. ‘‘Rear-end’’ collisions occurring periodically in a full acceptance particle detector/polarimeter, allow the (previously inaccessible) direct measurement of the spin dependence of nuclear transmutation for center of mass (CM) kinetic energies ranging from hundreds of keV up toward pion production thresholds. These are ‘‘rear-end collisions’’ occurring as faster stored bunches pass through slower bunches. An inexpensive facility capable of meeting these requirements is described, with nuclear channel h + d arrow α + p as example.

Slides THA1I3 [0.860 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THA1I3

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Received ※ 07 December 2023 — Accepted ※ 11 December 2023 — Issued ※ 25 December 2023

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THAFP03

Measurement of Stability Diagram at IOTA at Fermilab

kicker, damping, pick-up, impedance

400

M.K. Bossard, Y.K. Kim
University of Chicago, Chicago, Illinois, USA
R. Ainsworth, N. Eddy
Fermilab, Batavia, Illinois, USA

Funding: Fermilab
Nonlinear focusing elements can enhance the stability of particle beams in high-energy colliders by means of Landau Damping, through the tune spread which is introduced. We propose an experiment at Fermilab’s Integrable Optics Test Accelerator (IOTA) to investigate the influence of nonlinear focusing elements on the transverse stability of the beam. In this experiment, we employ an anti-damper, an active transverse feedback system, as a controlled mechanism to induce coherent beam instability. By utilizing the anti-damper, we can examine the impact of the nonlinear focusing element on the beam’s transverse stability. The stability diagram, a tool used to determine the system’s stability, will be measured using a recently demonstrated method at the LHC. This measurement is carried out experimentally by selecting specific threshold gains and measuring them for a range of phases. The stability diagram is represented by gei¿ on the complex plane. The experiment at IOTA adds insight towards the stability diagram measurement method by supplying a reduced machine impedance, to investigate the impedance’s effect on the stability diagram, as well as a larger range of phase measurements.

Slides THAFP03 [1.331 MB]

Poster THAFP03 [1.692 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THAFP03

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Received ※ 06 October 2023 — Revised ※ 09 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 12 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, simulation, emittance

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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THBP19

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

resonance, space-charge, emittance, 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]

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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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THBP27

Experimental Investigation of Nonlinear Integrable Optics in a Paul Trap

lattice, octupole, resonance, space-charge

523

J.A.D. Flowerdew
University of Oxford, Oxford, United Kingdom
D.J. Kelliher, S. Machida
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
S.L. Sheehy
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

Funding: Work supported by Royal Society grants
Octupoles are often used to damp beam instabilities caused by space charge. However, in general the insertion of octupole magnets leads to a nonintegrable lattice which reduces the area of stable particle motion. One proposed solution to this problem is Quasi-Integrable Optics (QIO), where the octupoles are inserted between a specially designed lattice called a T-insert. An octupole with a strength that scales as 1/β³(s) is applied in the drift region to create a time-independent octupole field, leading to a lattice with an invariant Hamiltonian. This means that large tune spreads can be achieved without reducing the dynamic aperture. IBEX is a Paul trap which confines low energy ions with an RF voltage, simulating the transverse dynamics of an alternating gradient accelerator. IBEX has recently undergone an upgrade to allow for octupole fields to be created in the trap in addition to quadrupole focusing. We present our first experimental results from testing QIO with the IBEX trap.
jake.flowerdew@physics.ox.ac.uk

Poster THBP27 [4.163 MB]

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reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP27

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Received ※ 30 September 2023 — Revised ※ 09 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 31 October 2023

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THBP48

Latest Advances in Targetry Systems at CERN and Exciting Avenues for Future Endeavours

target, proton, antiproton, neutron

599

R. Franqueira Ximenes, O. Aberle, M. Calviani, R. Esposito, J.L. Grenard, T. Griesemer, A.R. Romero Francia, C. Torregrosa
CERN, Meyrin, Switzerland

CERN’s accelerator complex offers diverse target systems for a range of scientific pursuits, including varying beam energies, intensities, pulse lengths, and objectives. Future high-intensity fixed target experiments aim to advance this field further. This contribution highlights upgraded operational target systems, enhancing CERN’s physics endeavours. One example is the third-generation n_TOF spallation neutron target, using a nitrogen-cooled pure lead system impacted by a 20 GeV/c proton beam. Another focuses on recent antiproton production target upgrades, with a high-intensity 26 GeV/c beam colliding with a narrow-air-cooled iridium target. Looking ahead, new high-power target systems are planned. One aims to discover hidden particles using a 350-kW high-Z production target, while another enhances kaon physics through a 100 kW low-Z target. This article provides an overview of current target systems at CERN, detailing beam-intercepting devices and engineering aspects. It also previews upcoming facilities that could soon be implemented at CERN.

Poster THBP48 [63.760 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP48

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Received ※ 07 October 2023 — Revised ※ 08 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 10 October 2023

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THBP50

Fermilab Main Injector and Recycler Operations in the Megawatt Era

operation, proton, booster, electron

607

A.P. Schreckenberger
Fermilab, Batavia, Illinois, USA

Significant upgrades to Fermilab¿s accelerator complex have accompanied the development of LBNF and DUNE. These improvements will facilitate 1-MW operation of the NuMI beam for the first time this year through changes to the Recycler slip-stacking procedure and shortening of the Main Injector ramp time. The modifications to the Recycler slip-stacking and effort to reduce the Main Injector ramp time will be discussed. Additionally, details regarding further shortening of the ramp time and the impact on future accelerator operations are presented.

Poster THBP50 [0.923 MB]

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reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP50

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Received ※ 25 September 2023 — Revised ※ 09 October 2023 — Accepted ※ 12 October 2023 — Issued ※ 12 October 2023

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FRA2I1

Summary of the Working Group A: Beam Dynamics in Rings

space-charge, resonance, simulation, impedance

662

H. Bartosik, G. Rumolo
CERN, Meyrin, Switzerland
J.-L. Vay
LBNL, Berkeley, California, USA
N. Wang
IHEP, Beijing, People’s Republic of China

The HB-2023 workshop at CERN from October 9 to 13, 2023 is the continuation of the series of workshops, which started in 2002 at FNAL and rotates every two years between America, Europe and Asia. This contribution summarises the main highlights from Working Group A, Beam Dynamics in Rings, in terms of progress and challenges in the achievement of ever higher intensity and brightness hadron beams in accelerator rings around the world.

Slides FRA2I1 [4.325 MB]

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reference for this paper ※ doi:10.18429/JACoW-HB2023-FRA2I1

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Received ※ 04 December 2023 — Accepted ※ 05 December 2023 — Issued ※ 01 January 2024

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