Conveners
A: Performance Review of Space-Charge-Limited Facilities
- Foteini Asvesta (CERN)
A: Space-Charge Measurement and Compensation Studies, Part 1 of 2
- Giulio Stancari (Fermilab / UChicago)
A: Injection, Painting, Beam Splitting and Equilibrium Distributions
- Nicholas Evans (Oak Ridge National Laboratory)
A: Space-Charge Measurement and Compensation Studies, Part 2 of 2
- Giulio Stancari (Fermilab / UChicago)
A: Beam Loss and Halo Dynamics
- YOICHI SATO (KEK/J-PARC)
Description
Experiments and Operational Considerations
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Foteini Asvesta (CERN)30/09/2026, 08:45A-1. Performance Review of Space-Charge-Limited Facilities
Lead talk session A-1.
Beam performance achievements in the CERN accelerator complex in the LIU era:
The CERN injector complex underwent significant changes under the LHC Injectors Upgrade (LIU) project during Long Shutdown 2 (LS2). The primary goal of the LIU project was to prepare the complex for the High Luminosity LHC (HL-LHC) era, with a particular focus on extending the brightness...
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Pranab Saha (J-PARC/JAEA)30/09/2026, 09:05A-1. Performance Review of Space-Charge-Limited Facilities
The 3-GeV RCS (Rapid Cycling Synchrotron) of J-PARC accelerates 8.33E13 protons per pulse from 0.4 GeV to 3 GeV at a repetition rare of 25 Hz for 1 MW output beam power. We have already achieved stable operation at the designed 1 MW beam power by sufficiently minimizing the beam loss [1]. The residual beam loss is mostly caused by the unavoidable foil scattering beam loss, occurring around...
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Jiancheng Yang (Institute of Modern Physics, Chinese Academy of Sciences)30/09/2026, 09:20A-1. Performance Review of Space-Charge-Limited Facilities
The High Intensity heavy-ion Accelerator Facility (HIAF) is a next-generation accelerator complex designed to provide high-intensity heavy-ion beams for nuclear physics, atomic physics, high-energy-density matter, and related interdisciplinary research. Achieving the design beam intensity requires addressing a series of beam-dynamics and technical challenges, including high-current ion...
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Robert Ainsworth (Fermi National Accelerator Laboratory)30/09/2026, 09:35A-1. Performance Review of Space-Charge-Limited Facilities
The Fermilab Accelerator Complex currently delivers the worldโs most powerful neutrino beam, powered by a 1 MW, 120 GeV proton beam from the Main Injector. The forthcoming PIP-II upgrade will increase beam delivery demands, requiring the Main Injector and Recycler to stack and accelerate roughly 50% more beam with only limited upgrades to the existing complex.
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This talk will review recent... -
Yaoshuo Yuan (IHEP/CSNS)30/09/2026, 09:50A-1. Performance Review of Space-Charge-Limited Facilities
The beam commissioning of the CSNS RCS began in 2017. Over the years, the CSNS RCS has achieved step-by-step progress, including successful beam accumulation, acceleration to 1.6 GeV, and a gradual increase of beam power from 10 kW to over 185 kW on target.
Currently, the upgrade project of the CSNS (CSNS-II) is ongoing. The primary goal of CSNS-II is to further increase beam power to 500...
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Foteini Asvesta (CERN)30/09/2026, 10:05
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Giulio Stancari (Fermilab / UChicago)30/09/2026, 15:45A-2. Space-Charge Measurement and Compensation Studies
Lead talk session A-2.
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Cristhian Gonzalez-Ortiz (Fermilab)30/09/2026, 16:05A-2. Space-Charge Measurement and Compensation Studies
The interplay between space charge and collective beam instabilities is a central challenge for high-intensity circular accelerators. Understanding how space charge influences instability thresholds and coherent motion is essential for future high-power accelerator facilities. We present new experimental studies of collective beam dynamics in the Fermilab Recycler Ring using the Waker system,...
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Dr Markus Kirk (GSI)30/09/2026, 16:20A-2. Space-Charge Measurement and Compensation Studies
A pulsed electron lens for space charge compensation is being developed at GSI to increase the achievable beam intensities in the synchrotrons SIS-18 and SIS-100 of the FAIR project where space charge constitutes a major performance constraint during the process of injection of a primary beam into the synchrotron. Studies based on numerical simulations for SIS-100 have shown that a few...
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Austin Hoover, Nicholas Evans (Oak Ridge National Laboratory)01/10/2026, 14:00A-3. Injection, Painting, Beam Splitting and Equilibrium Distributions
Lead talk session A-3.
Phase space painting into non-planar modes for space charge mitigation:
Recent experiments at the Spallation Neutron Source have demonstrated a new technique referred to as 'Eigenpainting'. During charge exchange injection, phase space painting can be used to build the beam distribution in a ring by controlling the phase space coordinates throughout the injection...
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Guodong Shen (Institute of Modern Physics, Chinese Academy of Sciences)01/10/2026, 14:20A-3. Injection, Painting, Beam Splitting and Equilibrium Distributions
High Intensity Heavy-ion Accelerator Facility (HIAF) is a mega accelerator cluster under construction in China. Itโs designed to provide high intensity primary and secondary heavy ion beams. To achieve the challenging intensity goal under space charge effect and dynamic vacuum effect, an injection accumulation factor of 56 and an uncontrolled beam loss must remain below 5% is demanded. A...
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Onur Gilanliogullari (Uppsala University)01/10/2026, 14:35A-3. Injection, Painting, Beam Splitting and Equilibrium Distributions
Angular-momentum-dominated beams with a circular cross-section are referred to as circular-mode beams. The strong coupling introduced by angular momentum dominance produces a large asymmetry between the eigenmode emittances, known as intrinsic flatness: the beam is round in real space yet e๏ฌectively flat in eigenmode space. With proper optics design, both the angular momentum and the circular...
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Billy Kyle (ISIS, STFC, UKRI)01/10/2026, 14:50A-3. Injection, Painting, Beam Splitting and Equilibrium Distributions
The ISIS rapid-cycling synchrotron (RCS) delivers high-intensity 800 MeV proton beams to two target stations at a repetition rate of 50 Hz. This operating regime necessitates low beam losses to minimise hardware activation. Beam losses at ISIS primarily arise from three mechanisms: transverse injection losses from foil recirculation hits, trapping losses due to coasting beam injection, and...
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Massimo Giovannozzi (CERN)01/10/2026, 15:05A-3. Injection, Painting, Beam Splitting and Equilibrium Distributions
In this presentation, I will review the principles of multi-turn extraction, and I will present the key experimental evidence of space-charge effects for split beams. I will present initial attempts to interpret it, pointing out the current research in this domain also summarised in a poster at this workshop. Finally, I will review possible new applications of non-linear beam dynamics manipulations.
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Nicholas Evans (Oak Ridge National Laboratory), Shinji Machida01/10/2026, 15:20
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Yu Du (Institute of Modern Physics, Chinese academic of Sciences)01/10/2026, 16:15A-2. Space-Charge Measurement and Compensation Studies
Phase space tomography of intense beams is challenged by a self-consistency problem: space charge depends on the unknown distribution. We introduce a transport-free tomography frameworkโ that reconstructs high-dimensional phase space using single-optics, single-location measurement schemes, thereby eliminating the need to model space charge. We discuss measurement schemes that extract...
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Ippei Yamada (J-PARC Center, Japan Atomic Energy Agency)01/10/2026, 16:30A-2. Space-Charge Measurement and Compensation Studies
In low energy beam transport (LEBT), space charge neutralization/compensation (SCN) plays an important role in focusing a beam and keeping the emittance low for a high intensity hadron accelerator. At J-PARC LEBT, the gas pressure is in a range from 10$^{-1}$ to 10$^{-4}$ Pa with H$_2$ gas flowing out from the ion source, and sufficient SCN is considered to occur for a 50 mA, 50 keV, 500...
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Giulio Stancari (Fermilab / UChicago)01/10/2026, 16:45
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YOICHI SATO (KEK/J-PARC)02/10/2026, 13:30A-4. Beam Loss and Halo Dynamics
Lead talk session A-4.
High intensity beam operation of J-PARC main ring in fast extraction mode:
The J-PARC main ring in fast-extraction mode supplies a high-intensity proton beams, having world highest protons per pulse, for the T2K experimental program in the neutrino target. In JFY2025, we have provided 900-kW stable beams for user operation and demonstrated 1-MW operation...
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Mr Trent Thompson (University of Tennessee, Knoxville)02/10/2026, 13:50A-4. Beam Loss and Halo Dynamics
The goal of on-going research at the SNS Beam Test Facility is to improve modeling and understanding of halo formation in the early stages of the SNS linac. The experiment at the BTF includes two phase space measurement stations separated by 9.5 FODO cells. By controlling beam mismatch in the FODO section, we systematically explore the dependence of beam halo formation on the mismatch...
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Shouyan Xu02/10/2026, 14:05A-4. Beam Loss and Halo Dynamics
The design betatron tune of the Rapid Cycling Synchrotron (RCS) of China Spallation Neutron Source (CSNS) is (4.86, 4.80), which allows for incoherent tune shifts to avoid serious systematic betatron resonances. However, at the design tune, severe horizontal beam instability and vertical beam loss induced by half-integer resonance under space charge detuning were observed when the beam...
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ESMAEIL AHMADI (STFC)02/10/2026, 14:20A-4. Beam Loss and Halo Dynamics
Current studies at ISIS aim to improve the measurement, modelling, and control of ring beam dynamics, with the broader goal of optimising operational setup and benchmarking beam-loss predictions for ISIS and the proposed megawatt-class upgrade, ISIS-II. Beam loss in high-intensity synchrotrons can arise from the combined effects of non-linear resonances, machine non-linearities, and space...
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YOICHI SATO (KEK/J-PARC)02/10/2026, 14:35