Keyword: space-charge
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MOPAB175 Advanced Concepts and Technologies for Heavy Ion Synchrotrons laser, synchrotron, heavy-ion, electron 594
 
  • P.J. Spiller, O. Boine-Frankenheim, L.H.J. Bozyk, S. Klammes, H. Kollmus, D. Ondreka, I. Pongrac, N. Pyka, C. Roux, K. Sugita, St. Wilfert, T. Winkler, D.F.A. Winters
    GSI, Darmstadt, Germany
 
  New concepts and technologies are developed to advance the performance of heavy ion synchrotrons. Besides fast ramping of superconducting magnets, extreme UHV technologies to stabilize dynamic vacuum and charge related loss, broad band MA cavities, space charge compensation by means of electron lenses and new cooling technologies, e.g. laser cooling, show great promise to advance the forefront of beam parameters. Several of these technologies and concepts are developed and tested at GSI/FAIR. Progress and plans will be reported.  
poster icon Poster MOPAB175 [1.367 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB175  
About • paper received ※ 11 May 2021       paper accepted ※ 21 May 2021       issue date ※ 20 August 2021  
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MOPAB207 Design Guideline for Minimizing Space-Charge-Induced Emittance Growth emittance, rfq, proton, linac 682
 
  • C. Zhang
    GSI, Darmstadt, Germany
 
  Space-charge-induced emittance growth is a big concern for designing low-energy and high-intensity linacs. The Equipartitioning Principle was introduced to minimize space-charge-induced emittance growth by removing free energy between the transverse and longitudinal degrees of freedom. In this study, a different design guideline is being proposed. It suggests holding the ratio of longitudinal emittance to transverse emittance around one and take advantage of low emittance transfer for minimizing emittance growth. Using a high-intensity RFQ accelerator as an example, a comparison between the two design methods has been made.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB207  
About • paper received ※ 17 May 2021       paper accepted ※ 21 May 2021       issue date ※ 01 September 2021  
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MOPAB295 Simulation Study of Emittance Measurement Using a Genetic Algorithm for Space Charge Dominated Beams emittance, quadrupole, simulation, lattice 935
 
  • H.D. Zhang, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C.P. Welsch, H.D. Zhang
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: This work was supported by the HL-LHC-UK phase II project funded by STFC under Grant Ref: ST/T001925/1 under and the STFC Cockcroft core grant No. ST/G008248/1.
The quadrupole scan method is one of the traditional ways to measure beam emittance in an accelerator. The required devices are simple: several quadrupole magnets and a beam profile monitor. Beam sizes are measured from the beam profile monitor with different quadrupole settings to bring the beam through its waist and then fitted to a quadratic equation to determine the Twiss parameters. measured data from a quadrupole scan taking the beam through its waist is fitted to a quadratic equation and this allows determining the Twiss parameters. However, with increasing beam intensity, the transfer function becomes non-linear and this causes a deviation of the fitted emittance from its real value, making it no longer useful. In this contribution, a genetic algorithm is applied to find the optimum quadrupole scan fit in space-charge dominated electron beams. Results from simulations using different space charge levels are presented and scenarios identified where this method can be applied.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB295  
About • paper received ※ 19 May 2021       paper accepted ※ 28 May 2021       issue date ※ 02 September 2021  
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TUPAB181 Demonstration of Electron Cooling using a Pulsed Beam from an Electrostatic Electron Cooler electron, experiment, timing, emittance 1827
 
  • M.W. Bruker, S.V. Benson, A. Hutton, K. Jordan, T. Powers, R.A. Rimmer, T. Satogata, A.V. Sy, H. Wang, S. Wang, H. Zhang, Y. Zhang
    JLab, Newport News, Virginia, USA
  • J. Li, F. Ma, X.M. Ma, L.J. Mao, X.P. Sha, M.T. Tang, J.C. Yang, X.D. Yang, H.W. Zhao
    IMP/CAS, Lanzhou, People’s Republic of China
  • H. Zhao
    BNL, Upton, New York, USA
 
  Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.
Electron cooling continues to be an invaluable technique to reduce and maintain the emittance in hadron storage rings in cases where stochastic cooling is inefficient and radiative cooling is negligible. Extending the energy range of electron coolers beyond what is feasible with the conventional, electrostatic approach necessitates the use of RF fields for acceleration and, thus, a bunched electron beam. To experimentally investigate how the relative time structure of the two beams affects the cooling properties, we have set up a pulsed-beam cooling device by adding a synchronized pulsing circuit to the conventional electron source of the CSRm cooler at Institute of Modern Physics *. We show the effect of the electron bunch length and longitudinal ion focusing strength on the temporal evolution of the longitudinal and transverse ion beam profile and demonstrate the detrimental effect of timing jitter as predicted by theory and simulations. Compared to actual RF-based coolers, the simplicity and flexibility of our setup will facilitate further investigations of specific aspects of bunched cooling such as synchro-betatron coupling and phase dithering.
* M. W. Bruker et al., Phys. Rev. Accel. Beams 24, 012801 (2021)
 
poster icon Poster TUPAB181 [3.699 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB181  
About • paper received ※ 19 May 2021       paper accepted ※ 15 June 2021       issue date ※ 21 August 2021  
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TUPAB192 Studies on Momentum Collimation for CSNS-RCS Upgrades collimation, bunching, betatron, emittance 1855
 
  • Y.W. An, J. Chen, S.Y. Xu, Y. Yuan
    IHEP, Beijing, People’s Republic of China
  • X.H. Lu, J.B. Yu
    IHEP CSNS, Guangdong Province, People’s Republic of China
 
  The CSNS project was a high intensity pulsed facility, and achieved the the design goal of 100kW in 2020. The upgrades of the CSNS are proposed, and the momentum collimator is a component of the upgrades. This paper will show the design scheme of the momentum collimator and the simulation results are also presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB192  
About • paper received ※ 18 May 2021       paper accepted ※ 15 June 2021       issue date ※ 28 August 2021  
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TUPAB196 Achievement of 100-kW Beam Operation in CSNS/RCS injection, MMI, acceleration, bunching 1869
 
  • S.Y. Xu, Y.W. An, J. Chen, L. Huang, M.Y. Huang, Y. Li, S. Wang
    IHEP, Beijing, People’s Republic of China
  • H.Y. Liu, X.H. Lu
    IHEP CSNS, Guangdong Province, People’s Republic of China
 
  The China Spallation Neutron Source (CSNS) is an accelerator-based science facility. CSNS is designed to accelerate proton beam pulses to 1.6 GeV kinetic energy, striking a solid metal target to produce spallation neutrons. CSNS has two major accelerator systems, a linear accelerator (80 MeV Linac) and a 1.6 GeV rapid cycling synchrotron(RCS). The RCS accumulates and accelerates the proton beam to 1.6 GeV and then extracts the beam to the target at the repetition rate of 25 Hz. The Beam commissioning of CSNS/RCS had been started since April 2017. The most important issue in high-power beam commissioning is the beam loss control, as well as the control of induced activities, to meet the requirement of manual maintenance. A series of beam loss optimization work had been done to reduce the uncontrolled beam loss. At the end of February 2020, the CSNS reached the design beam power of 100 kW with very low uncontrolled beam loss.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB196  
About • paper received ※ 19 May 2021       paper accepted ※ 31 May 2021       issue date ※ 28 August 2021  
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TUPAB200 Status of the Electron Lens for Space Charge Compensation in SIS18 electron, gun, solenoid, cathode 1880
 
  • K. Schulte-Urlichs, S. Artikova, D. Ondreka, P.J. Spiller
    GSI, Darmstadt, Germany
  • P. Apse-Apsitis, I. Steiks
    Riga Technical University, Riga, Latvia
  • M. Droba, O. Meusel, H. Podlech, K.I. Thoma
    IAP, Frankfurt am Main, Germany
 
  At GSI a project has been initiated to investigate the option of space charge compensation (SCC) by use of an electron lens in order to overcome space charge (SC) limits in the synchrotrons SIS18 and SIS100 for the Facility for Antiproton and Ion Research (FAIR). The repeated crossing of resonance lines due to the synchrotron motion in bunched beams is considered one of the main drivers of SC induced beam loss in the synchrotrons. Electron lenses provide a compensation of ion beam SC by virtue of their negative charge interacting with the ions in the overlap region while a time-varying compensation can be achieved by the modulation of the electron beam. In order to demonstrate space charge compensation of bunched ion beams, an electron lens is under development for the application in SIS18. In this contribution, the status of the electron lens design will be reported putting special emphasis on its main components: the RF modulated electron gun, that is being developed within an ARIES collaboration, and the magnet system.  
poster icon Poster TUPAB200 [1.869 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB200  
About • paper received ※ 19 May 2021       paper accepted ※ 23 June 2021       issue date ※ 17 August 2021  
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TUPAB206 Matching of Intense Beam in Six-Dimensional Phase Space emittance, focusing, framework, quadrupole 1897
 
  • Y.K. Batygin
    LANL, Los Alamos, New Mexico, USA
 
  Funding: Work supported by US DOE under contract 89233218CNA000001
Beam matching is a common technique that is routinely employed in accelerator design to minimize beam losses. Despite being widely used, a full theoretical understanding of beam matching in 6D phase space remains elusive. Here, we present an analytical treatment of 6D beam matching of a high-intensity beam onto an RF structure. We begin our analysis within the framework of a linear model, and apply the averaging method to attain a matched solution for a set of 3D beam envelope equations. We then consider the nonlinear regime, where the beam size is comparable with the separatrix size. Starting with a Hamiltonian analysis in 6D phase space, we attain a self-consistent beam profile and show that it is significantly different from the commonly used ellipsoidal shape. Subsequently, we analyze the special case of equilibrium with equal space charge depression between all degrees of freedom. A comparison of beam dynamics for equipartitioned, equal space charge depression, and equal emittances beams is given.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB206  
About • paper received ※ 14 May 2021       paper accepted ※ 28 May 2021       issue date ※ 24 August 2021  
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TUPAB218 Fully Covariant Two-Particle Space-Charge Dynamics Using the Liénard-Wiechert Potentials electromagnetic-fields, electron, FEL, dipole 1931
 
  • B.T. Folsom, E. Laface
    ESS, Lund, Sweden
 
  Space charge models typically assume instantaneous propagation of the electromagnetic fields between particles in a bunch, describing forces in the frame of the reference particle. In this paper, we construct a space-charge tracking code from the retarded Liénard-Wiechert potentials, which are covariant by design, in a Lagrangian formulation. Such potentials are manipulated with covariant derivatives to produce the necessary equations of motion that will be solved in a test system of two particles at various relative energies. Magnetic dipole moment dynamics are also evaluated where applicable.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB218  
About • paper received ※ 19 May 2021       paper accepted ※ 19 July 2021       issue date ※ 11 August 2021  
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TUPAB252 Minimization of NICA Collider Impedance impedance, collider, simulation, resonance 2043
 
  • S.A. Melnikov, I.N. Meshkov
    JINR, Dubna, Moscow Region, Russia
  • K.G. Osipov
    JINR/VBLHEP, Dubna, Moscow region, Russia
 
  The paper presents the results of the longitudinal impedance minimization for the beam tube section in the arches of the NICA collider ring, consisting of a pumping pipe, a BPM station, and a bellows assembly, and considers the contribution of the impedance of this section to the ion beam stability in the NICA collider ring. To confirm the efficiency of the optimized design, a BPM prototype was fabricated, and a test bench was built for further laboratory measurements.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB252  
About • paper received ※ 13 May 2021       paper accepted ※ 14 June 2021       issue date ※ 10 August 2021  
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TUPAB263 The Phase Loop Status of the RF System in CSNS/RCS proton, feedback, cavity, MMI 2076
 
  • L. Huang, X. Li, S. Wang
    IHEP, Beijing, People’s Republic of China
  • M.T. Li, H.Y. Liu
    IHEP CSNS, Guangdong Province, People’s Republic of China
  • Y. Liu
    DNSC, Dongguan, People’s Republic of China
 
  The Rapid Cycling Synchrotron (RCS) of the China Spallation Neutron Source (CSNS) is a high intensity proton accelerator. The acceleration system consists of eight ferrite loaded cavities. The RCS is the space charge dominant machine and it is mitigated through the bunch factor optimization in the beam commissioning, so the injected beam will occupy a larger bucket size and unavoidable mismatch with the bucket, thus the dipole oscillation is excited. The phase loop scheme is designed to restrict the oscillation in the RF system, but the transmission efficiency is reduced by the phase loop and the bunch factor also increases, so the phase loop scheme is studied. To keep the phase loop but also maintain the transmission efficiency, we optimized the original phase loop scheme, but the beam loss still increases small when the loop on.  
poster icon Poster TUPAB263 [1.548 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB263  
About • paper received ※ 13 May 2021       paper accepted ※ 02 June 2021       issue date ※ 21 August 2021  
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TUPAB417 Pushing Spatial Resolution Limits In Single-Shot Time-Resolved Transmission Electron Microscopy at the UCLA Pegasus Laboratory electron, gun, simulation, cavity 2506
 
  • P.E. Denham, P. Musumeci
    UCLA, Los Angeles, USA
 
  Funding: This work was supported by DOESTTR grant No. DE-SC0013115 and by by the National Science Foundation under STROBE Science and Technology Center Grant No. DMR-1548924
We present the design of a high-speed single shot relativistic electron microscope planned for implementation at the UCLA PEGASUS Laboratory capable of imaging with less than 30~nm spatial resolution and image acquisition time on the order of 10~ps. This work is based on a multi-cavity acceleration scheme for producing relativistic beams (3.75 MeV) with suppressed rms energy spread (σδ ≈5e-5), and a means to reduce smooth space charge aberrations by generating a quasi-optimal 4D particle distribution at the sample plane. start-to-end simulation results are used to validate the entire setup. Ultimately, a feasible working point is demonstrated.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB417  
About • paper received ※ 19 May 2021       paper accepted ※ 28 July 2021       issue date ※ 01 September 2021  
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WEXB08 Beam Losses and Emittance Growth Studies at the Record High Space-Charge in the Booster booster, emittance, proton, operation 2552
 
  • V.D. Shiltsev, J.S. Eldred, V.A. Lebedev, K. Seiya
    Fermilab, Batavia, Illinois, USA
 
  Comprehensive studies of high intensity proton beams in the 0.4-8 GeV FNAL Booster synchrotron have revealed interesting nonlinear dynamics of the beam losses and emittance growth at the record high dQSC=0.6. We report the results of the studies and directions of further improvements to prepare the Booster to the era of even higher intensity operation with new 0.8 GeV PIP-II linac.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXB08  
About • paper received ※ 24 May 2021       paper accepted ※ 02 July 2021       issue date ※ 17 August 2021  
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WEPAB018 Space-Charge Effects in Ionization Beam Profile Monitors proton, booster, electron, synchrotron 2628
 
  • V.D. Shiltsev
    Fermilab, Batavia, Illinois, USA
 
  Ionization profile monitors (IPMs) are widely used in accelerators for non-destructive and fast diagnostics of high energy particle beams. At high beam intensities, the space-charge forces make the measured IPM profiles significantly different from those of the beams. We analyze dynamics of the secondaries in IPMs and develop an effective algorithm to reconstruct the beam sizes from the measured IPM profiles. Efficiency of the developed theory is illustrated in application to the Fermilab 8 GeV proton Booster IPMs.  
poster icon Poster WEPAB018 [0.731 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB018  
About • paper received ※ 19 May 2021       paper accepted ※ 24 June 2021       issue date ※ 20 August 2021  
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WEPAB093 Space Charge Effects in Low Energy Magnetized Electron Beam cathode, laser, electron, solenoid 2806
 
  • S.A.K. Wijethunga, J.R. Delayen, G.A. Krafft
    ODU, Norfolk, Virginia, USA
  • J.F. Benesch, G.A. Krafft, M.A. Mamun, M. Poelker, R. Suleiman, S. Zhang
    JLab, Newport News, Virginia, USA
 
  Funding: This work is supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177 and Laboratory Directed Research and Development program.
Magnetized electron cooling is one of the major approaches towards obtaining the required high luminosity in the proposed Electron-Ion Collider (EIC). In order to increase the cooling efficiency, a bunched electron beam with a high bunch charge and high repetition rate is required. At Jefferson Lab, we generated magnetized electron beams with high bunch charge using a new compact DC high voltage photogun biased at -300 kV with bialkali-antimonide photocathode and a commercial ultra-fast laser. This contribution discusses how magnetization affects space charge dominated beams as a function of magnetic field strength, gun high voltage, and laser pulse width, and spot size in comparison with simulations performed using General Particle Tracer.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB093  
About • paper received ※ 19 May 2021       paper accepted ※ 08 June 2021       issue date ※ 02 September 2021  
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WEPAB101 An Improved Model for Photoemission of Space Charge Dominated Picosecond Electron Bunches: Theory and Experiment cathode, electron, experiment, laser 2829
 
  • S.M. Polozov, V.I. Rashchikov
    MEPhI, Moscow, Russia
  • M. Krasilnikov
    DESY Zeuthen, Zeuthen, Germany
 
  The emission of a short highly charged electron bunch in a radiofrequency photogun is discussed. The traditional space charge limited emission numerical model is extended by an introduction of positively charged ions arising in the cathode region and dynamically changing during the emission. Estimates on the time characteristics of the charge migrating process in the semiconductor region are given. The numerical results are compared with the results of other numerical models and with experimental observations at the Photo Injector Test facility at DESY in Zeuthen (PITZ).  
poster icon Poster WEPAB101 [1.601 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB101  
About • paper received ※ 08 May 2021       paper accepted ※ 07 June 2021       issue date ※ 19 August 2021  
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WEPAB147 Simulations of Nanoblade-Enhanced Laser-Induced Cathode Emissions and Analyses of Yield, MTE, and Brightness electron, simulation, laser, brightness 2957
 
  • J.I. Mann, G.E. Lawler, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • T. Arias, J.K. Nangoi
    Cornell University, Ithaca, New York, USA
 
  Funding: This work was supported by the Center for Bright Beams, National Science Foundation Grant No. PHY-1549132 and DOE HEP Grant DE-SC0009914.
Laser-induced field emission of electrons from metallic nanotips has been well studied. Unfortunately, nanotips suffer low damage thresholds with enhanced fields around 10 GV/m. The nanoblade, akin to a nanotip extruded in one lateral dimension, may reach upwards of 40 GV/m due to its robust thermomechanical properties. This increased surface field promises brighter electron emissions. We perform simulations of strong-field emissions from metallic nanoblades via the 1-D time-dependent Schr\"odinger equation with effective Jellium and nonlinear collective image charge potentials, including the strong field gradients induced by the nanostructure. We measure spectra and yields and compare to recent experiments. Potential analytical forms of image potential limited yield for a spectrally rich emission are presented. Calculations of mean transverse energy are provided as well as a prospective method of mitigation with the goal of increasing brightness.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB147  
About • paper received ※ 19 May 2021       paper accepted ※ 06 July 2021       issue date ※ 01 September 2021  
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WEPAB215 Simulation of Intra-Beam Scattering in PyHEADTAIL scattering, emittance, simulation, proton 3134
 
  • V. Rodin, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • A. Oeftiger
    GSI, Darmstadt, Germany
  • V. Rodin, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 721559
High-intensity beams in low-energy synchrotrons are subject to space charge as well as intra-beam scattering (IBS). Accurate modelling of both effects becomes essential when the transverse emittances and minimum bunch length are determined through heating processes and resonances induced by machine errors. To date, only very few tools available to the general public allow to simultaneously study space charge and IBS in self-consistent simulations. In this contribution, we present our recent development of an IBS module for PyHEADTAIL, an open-source 6D multi-particle tracking tool, which already includes various 2.5D and 3D space-charge models based on the self-consistent particle-in-cell algorithm. A simulation example of high-intensity bunch rotation demonstrates the joint impact of applied heating effects. Our model is based on the Martini and Bjorken-Mitingwa theories. Benchmarks of our implementation against IBS modules provided in the MAD-X and JSPEC codes are shown.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB215  
About • paper received ※ 23 May 2021       paper accepted ※ 14 July 2021       issue date ※ 13 August 2021  
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WEPAB224 Update of the Transverse Proton Synchrotron Impedance Model impedance, factory, vacuum, injection 3149
 
  • S. Joly, N. Mounet, B. Salvant
    CERN, Geneva, Switzerland
  • S. Joly
    La Sapienza University of Rome, Rome, Italy
  • M. Migliorati
    INFN-Roma1, Rome, Italy
  • M. Migliorati
    Sapienza University of Rome, Rome, Italy
 
  The CERN Proton Synchrotron (PS) was recently upgraded to allow reaching the ambitious performance goal of the High-Luminosity LHC Project. This upgrade is part of the LHC Injectors Upgrade project. The final part of the upgrade was performed during Long Shutdown 2 (LS2) to allow injection at higher energy from the PS Booster and a twofold increase in beam intensity and brightness. These changes must be considered in the PS impedance model. The effect on the impedance of the removal of obsolete injection equipment, changes of several accelerator components and new injection energy will be reviewed, as well as the wall impedance of the elliptic beam pipe, thanks to a newly developed code that allows taking into account both the ellipticity and the non-ultra-relativistic nature of the beam.  
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DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB224  
About • paper received ※ 17 May 2021       paper accepted ※ 27 July 2021       issue date ※ 17 August 2021  
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WEPAB238 Modeling Short Range Wakefield Effects in a High Gradient Linac wakefield, linac, alignment, dipole 3185
 
  • F. Bosco, M. Carillo, L. Faillace, L. Giuliano, M. Migliorati, A. Mostacci, L. Palumbo
    Sapienza University of Rome, Rome, Italy
  • M. Behtouei, L. Faillace, A. Giribono, B. Spataro, C. Vaccarezza
    INFN/LNF, Frascati, Italy
  • F. Bosco, M. Migliorati
    INFN-Roma1, Rome, Italy
  • L. Giuliano, A. Mostacci, L. Palumbo
    INFN-Roma, Roma, Italy
  • J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
 
  Funding: This work is supported by DARPA GRIT under contract no. 20204571 and partially by INFN National committee V through the ARYA project.
The interaction of charged beams with the surrounding accelerating structures requires a thorough investigation due to potential negative effects on the phase space quality. Indeed, the wakefields acting back on the beam are responsible for emittance dilution and instabilities, such as the beam break-up, which limit the performances of electron-based radiation sources and linear colliders. Here we introduce a new tracking code which is meant to investigate the effects of short-range transverse wakefields in linear accelerators. The tracking is based on quasi-analytical models for the beam dynamics which, in addition to the basic optics specified by the applied fields, include dipole wakefield forces and a simple approach to account for space-charge effects. Such features provide a reliable tool which easily allows to inspect the performances of a linac. To validate the model, a parallel analysis for a reference case is performed with well-known beam dynamics codes, and comparisons are shown. As an illustrative application, we discuss a study on alignment tolerances evaluating the emittance growth induced by misaligned accelerating sections.
 
poster icon Poster WEPAB238 [1.747 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB238  
About • paper received ※ 18 May 2021       paper accepted ※ 07 July 2021       issue date ※ 01 September 2021  
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WEPAB248 Kurth Vlasov-Poisson Solution for a Beam in the Presence of Time-Dependent Isotropic Focusing focusing, emittance, simulation, proton 3213
 
  • C.E. Mitchell, K. Hwang, R.D. Ryne
    LBNL, Berkeley, California, USA
 
  Funding: This work was supported by the Director, Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The well-known K-V distribution provides an exact solution of the self-consistent Vlasov-Poisson system describing an unbunched charged particle beam with nonzero temperature in the presence of time-dependent linear transverse focusing. We describe a lesser-known exact solution of the Vlasov-Poisson system that is based on the work of Kurth in stellar dynamics. Unlike the K-V distribution, the Kurth distribution is a true function of the phase space variables, and the solution may be constructed on either the 4D or 6D phase space, for the special case of isotropic linear focusing. Numerical studies are performed for benchmarking simulation codes, and the stability properties of a 4D Kurth distribution are compared with those of a K-V distribution.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB248  
About • paper received ※ 19 May 2021       paper accepted ※ 14 July 2021       issue date ※ 02 September 2021  
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WEPAB249 Model of Curvature Effects Associated with Space Charge for Long Beams in Dipoles vacuum, dipole, emittance, shielding 3217
 
  • C.E. Mitchell, K. Hwang, R.D. Ryne
    LBNL, Berkeley, California, USA
 
  Funding: This work was supported by the Director, Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
For modeling the dynamics within a dipole of a bunch whose length is much larger than the vacuum pipe radius, it is typical to use a 2D (or 2.5D) Poisson solver, with arc length taken as the independent variable. However, sampled at a fixed time, the beam is curved, space charge is not truly 2D, and the usual cancellation between E and B contributions to the Lorentz force need not exactly hold. The size of these effects is estimated using an idealized model of a uniform torus of charge rotating inside a toroidal conducting pipe. Simple expressions are provided for the correction of the electric and magnetic fields to first order in the reciprocal of the curvature radius.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB249  
About • paper received ※ 19 May 2021       paper accepted ※ 02 July 2021       issue date ※ 02 September 2021  
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WEPAB250 Interplay Between Space Charge, Intra-Beam Scattering, and Synchrotron Radiation Effects resonance, emittance, damping, synchrotron 3220
 
  • M. Zampetakis, F. Antoniou, H. Bartosik, Y. Papaphilippou
    CERN, Geneva, Switzerland
  • M. Zampetakis
    University of Crete, Heraklion, Crete, Greece
 
  The objective of this research is to study the interplay of synchrotron radiation, intra-beam scattering, and space charge in the vicinity of excited resonances. In this respect, two modules were developed to simulate intra-beam scattering and synchrotron radiation effects and plugged into pyORBIT to be used together with its space charge module. Different regimes of synchrotron motion were used to study the response of the beam to a lattice resonance when space charge, intra-beam scattering and synchrotron radiation are present.  
poster icon Poster WEPAB250 [0.536 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB250  
About • paper received ※ 17 May 2021       paper accepted ※ 21 July 2021       issue date ※ 25 August 2021  
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WEPAB384 Design and Beam Dynamics of the Electron Lens for Space Charge Compensation in SIS18 electron, simulation, solenoid, dipole 3614
 
  • S. Artikova, D. Ondreka, K. Schulte-Urlichs, P.J. Spiller
    GSI, Darmstadt, Germany
 
  An electron lens for space charge compensation is being developed at GSI to increase the ion beam intensities in SIS18 for the FAIR project. It uses an electron beam of 10A maximum current at 30keV. The maximum magnetic field on-axis is 0.6T, considerably higher than the field of the existing electron cooler. The magnetic system of the lens consists of solenoids and toroids. The toroids’ vertical field component creates a significant horizontal orbit deflection in the circulating low rigidity ion beam. To correct this deflection, four correction dipoles have been introduced. As common for electron lenses, the high-power electron beam is not dumped at ground potential, but rather in a collector with a small bias potential with respect to the cathode. The present design foresees a collector at -27kV, leading to a power dissipation of 30kW, distributed over a large surface area by placing the collector in an appropriately shaped magnetic field of a pre-collector solenoid. This contribution reports on the design of the lens and presents the results of beam transport simulations for the electron beam (with space charge) and a representative ion beam, performed using the 3D CST STUDIO.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB384  
About • paper received ※ 20 May 2021       paper accepted ※ 05 July 2021       issue date ※ 31 August 2021  
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THXA01 Beyond RMS: Understanding the Evolution of Beam Distributions in High Intensity Linacs simulation, rfq, quadrupole, MEBT 3681
 
  • K.J. Ruisard, A.V. Aleksandrov, S.M. Cousineau, A.P. Shishlo, A.P. Zhukov
    ORNL, Oak Ridge, Tennessee, USA
 
  Funding: This work has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy.
Understanding the evolution of beams with space charge is crucial to design and operation of high intensity linacs. While the community holds a broad understanding of the mechanisms leading to emittance growth and halo formation, there is outstanding discrepancy between measurements and beam evolution models that precludes prediction of halo losses. This may be due in part to insufficient information of the initial beam distribution. This talk will describe work at the SNS Beam Test Facility to directly measure the 6D beam distribution. Full-and-direct 6D measurement has revealed hidden but physically significant dependence between the longitudinal distribution and transverse coordinates. This nonlinear correlation is driven by space charge and reproduced by self-consistent simulation of the RFQ. Omission of this interplane correlation, common when bunches are reconstructed from lower-dimensional measurements, degrades downstream predictions. This talk will also describe the novel diagnostics supporting this work. This includes ongoing improvements to efficiency of the 6D phase space measurement as well as recent achievement of six orders of dynamic range in 2D phase space.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THXA01  
About • paper received ※ 20 May 2021       paper accepted ※ 23 July 2021       issue date ※ 17 August 2021  
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THPAB106 Optimization of a High Bunch Charge ERL Injection Merger for PERLE emittance, linac, booster, cavity 3983
 
  • B. Hounsell, M. Klein, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • S.A. Bogacz
    JLab, Newport News, Virginia, USA
  • C. Bruni, B. Hounsell, W. Kaabi
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  • B. Hounsell, B.L. Militsyn, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • B.L. Militsyn
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  Delivery of high charge electron bunches into the main loop of an ERL (energy recovery linac) while preserving the emittance is challenging. This is because at the typical injection momentum, space charge forces still have a significant effect on the beam dynamics. In this work we consider the design of the merger for PERLE, an ERL test facility to be based at IJCLab in France. Previous simulations have shown that the baseline DC gun based injector can achieve the required emittance at the booster linac exit. The quality of the 500 pC bunches must then be preserved with space charge through the merger at total beam energy of 7 MeV keeping the emittance below 6 mm mrad. The beam dynamics in the merger were simulated using the code OPAL and optimised using a genetic algorithm. Three possible merger schemes were investigated. The goal of the optimisation was to minimise the emittance growth while also achieving the required Twiss parameters to match onto the spreader at the main linac exit. A three dipole solution is then examined in more detail.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB106  
About • paper received ※ 19 May 2021       paper accepted ※ 16 July 2021       issue date ※ 12 August 2021  
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THPAB165 5 MW Beam Power in the ESSnuSB Accumulator: A Way to Manage Foil Stripping Injection at 14 Hz Linac Pulse Rate emittance, linac, injection, proton 4072
 
  • H. Schönauer
    CERN, Geneva, Switzerland
  • Y. Zou
    Uppsala University, Uppsala, Sweden
 
  Funding: This work is supported by the European Union’s Horizon 2020 research and innovation program under grant agreement No 777419.
In the past, the scenario for foil stripping consisted of splitting a linac pulse into 4 rings, or 3 or 4 intermediate pulses, and one ring. At present, the scenario, in view of laser stripping, consists of one ring, one pulse, split into four batches. Conventional stripping geometry would lead to foil evaporation under this beam load. One way out appears to be replacing the standard corner foil by a single-edge foil rotated to about 45deg. The tilted foil allows moving the injection point together with the painting bumps along the foil edge, distributing the deposited beam power over a larger foil area. Simulation results obtained with the same tools as in the past scenarios are presented. They show peak foil temperatures, which compare with the best results obtained from the past scenarios.
 
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DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB165  
About • paper received ※ 11 May 2021       paper accepted ※ 21 June 2021       issue date ※ 18 August 2021  
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THPAB180 Simulation of 4D Emittance Measurement at the Spallation Neutron Source emittance, quadrupole, simulation, optics 4119
 
  • A.M. Hoover
    UTK, Knoxville, Tennessee, USA
  • N.J. Evans
    ORNL RAD, Oak Ridge, Tennessee, USA
 
  Similar to the KV distribution, the Danilov distribution has an elliptical shape and uniform density in the transverse plane and maintains these properties under any linear transport. Efforts are underway at the Spallation Neutron Source (SNS) to paint a Danilov distribution in the accumulator ring. After the beam has been painted, the level to which it approximates an ideal Danilov distribution must be quantified. One way to do this is to measure the four-dimensional emittance, which is ideally zero due to linear relationships between the phase space variables. To measure this emittance, we will utilize a standard method of reconstructing the covariance matrix using various optics settings in conjunction with beam profile measurements. We present the results of preliminary simulations which aim to optimize this measurement scheme for the SNS Ring to Target Beam Transport (RTBT) line.  
poster icon Poster THPAB180 [2.525 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB180  
About • paper received ※ 19 May 2021       paper accepted ※ 12 July 2021       issue date ※ 25 August 2021  
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THPAB183 New Longitudinal Beam Production Methods in the CERN Proton Synchrotron Booster emittance, proton, resonance, cavity 4130
 
  • S.C.P. Albright, F. Antoniou, F. Asvesta, H. Bartosik, C. Bracco, E. Renner
    CERN, Meyrin, Switzerland
  • E. Renner
    TU Vienna, Wien, Austria
 
  As part of the LHC Injectors Upgrade (LIU) project, significant improvements were made to the CERN Proton Synchrotron Booster (PSB) during the 2019/2020 long shutdown, including a new Finemet-based wideband RF system, renovated longitudinal beam control, and a new magnetic cycle. To meet the requirements of the diverse experimental program, the PSB provides beams with intensities spanning three orders of magnitude and a large range of longitudinal emittances. To maximize the brightness, in particular for the LHC beams, the voltages at low energy are designed to reduce the impact of transverse space charge using a second RF harmonic in bunch lengthening mode. At high energies, the risk of longitudinal microwave instability is avoided by optimizing the longitudinal distribution to raise the instability threshold. RF phase noise is applied to provide controlled longitudinal emittance blow-up and to shape the longitudinal distribution. This paper discusses the design of the RF functions used to meet the beam specifications, whilst ensuring longitudinal stability.  
poster icon Poster THPAB183 [6.692 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB183  
About • paper received ※ 18 May 2021       paper accepted ※ 22 July 2021       issue date ※ 20 August 2021  
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THPAB186 Review of Proton Linac Beam Dynamic Simulation Code linac, simulation, proton, software 4137
 
  • X.Y. Feng, J. Peng
    IHEP CSNS, Guangdong Province, People’s Republic of China
 
  CSNS-II project design a linac accelerates 40 mA H beam from 3.8 MeV to 300 MeV, which should not only overcome the space-charge effect at low energy but also have high efficiency at high energy. Therefore, lots of simulation studies should be done on a variety of codes. Each of them has its own characteristics. For example, MAD can easily match quadrupole fast while it couldn’t do the multiparticle calculation. This paper will introduce some common and efficient code used to design linac and study beam dynamic performance.  
poster icon Poster THPAB186 [0.880 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB186  
About • paper received ※ 17 May 2021       paper accepted ※ 08 July 2021       issue date ※ 11 August 2021  
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THPAB202 Problem and Solution with the Longitudinal Tracking of the ORBIT Code simulation, acceleration, emittance, synchrotron 4176
 
  • L.H. Zhang, J.Y. Tang
    IHEP, Beijing, People’s Republic of China
  • Y.K. Chen
    IHEP CSNS, Guangdong Province, People’s Republic of China
  • L.H. Zhang
    University of Chinese Academy of Sciences, Beijing, People’s Republic of China
 
  The ORBIT code has been widely used for beam dynamics simulations including injection and acceleration in high-intensity hadron synchrotrons. When the ORBIT’s 1D longitudinal tracking was employed for the acceleration process in CSNS/RCS, the longitudinal emittance in eV-s was found decreasing substantially during acceleration, though the adiabatic condition is still met during this process. This is against the Liouville theorem that predicts the preservation of the emittance during acceleration. The recent machine study in the accelerator and the simulations with a self-made code demonstrate that the longitudinal emittance is almost invariant, which further indicates that the ORBIT longitudinal tracking might be incorrect. A detailed check-over in the ORBIT code source finds that the longitudinal finite difference equation used in the code is erroneous when applied to an acceleration process. The new code format PyORBIT has the same problem. After the small secondary factor is included in the code, ORBIT can produce results keeping the longitudinal emittance invariant. This paper presents some details about the study.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB202  
About • paper received ※ 14 May 2021       paper accepted ※ 01 July 2021       issue date ※ 21 August 2021  
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THPAB203 Update of the Tracking Code RF-Track laser, wakefield, simulation, scattering 4180
 
  • A. Latina
    CERN, Geneva, Switzerland
 
  During the last couple of years, the RF-Track particle tracking code has seen a tremendous increase in the number of its applications: medical linacs, compact injector electron guns, and positron sources are among the main ones. Following a work of consolidation of its internal structure, new simulation capabilities have been introduced, together with several new effects: arbitrary orientation of elements in space, full element overlap, short- and long-range wakefields, and laser-beam interaction through Compton scattering are the most significant ones. In this paper, some of these new features are presented and discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB203  
About • paper received ※ 14 May 2021       paper accepted ※ 02 August 2021       issue date ※ 01 September 2021  
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THPAB206 Validating pyORBIT for Modeling Beam Dynamics in the IOTA Ring proton, octupole, emittance, dynamic-aperture 4190
 
  • R. Li
    UW-Madison/PD, Madison, Wisconsin, USA
  • J.-F. Ostiguy, T. Sen
    Fermilab, Batavia, Illinois, USA
 
  Funding: Supported by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics.
The Integrable Optics Test Accelerator (IOTA) ring is a new Fermilab facility dedicated to beam physics experiments, currently operating with 150 MeV electrons. Space charge effects are expected to be significant when it operates with 2.5 MeV protons. In this contribution, we present results of a suite of validation tests of PyORBIT, a PICstyle space charge code. Single particle dynamics of quasiintegrable optics using an octupole string in IOTA is compared with MADX, and shown to be in good agreement. Requirements for the convergence of space charge computations are systematically established and when possible, tests involving space charge are compared with theoretical predictions.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB206  
About • paper received ※ 19 May 2021       paper accepted ※ 08 July 2021       issue date ※ 12 August 2021  
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THPAB207 Beam Dynamics Simulation about the Dual Harmonic System by PyORBIT simulation, bunching, synchrotron, acceleration 4194
 
  • H.Y. Liu, X.Y. Feng, L. Huang, M.T. Li, X.H. Lu
    IHEP CSNS, Guangdong Province, People’s Republic of China
  • S. Wang, S.Y. Xu
    IHEP, Beijing, People’s Republic of China
 
  The space charge effect is a strong limitation in high-intensity accelerators, especially for low- and medium-energy proton synchrotrons. And for CSNS-II, the number of particles in the RCS is 3.9·1013 ppp, which is five times of CSNS. To mitigate the effects of the strong space charge effect, CSNS-II/RCS (Rapid Cycling Synchrotron) will use a dual harmonic system to increase the bunching factor during the injection and the initial acceleration phase. For studying the beam dynamics involved in a dual harmonic RF system, PyORBIT is used as the major simulation code, which is developed at SNS to simulate beam dynamics in accumulation rings and synchrotrons. We modified parts of the code to make it applicable to the beam dynamic in RCS. This paper includes the major code modification of the Dual Harmonic RF system and some benchmark results. The preliminary simulation results of the dual-harmonic system in CSNS-II/RCS simulated by the particle tracking code PyORBIT will also be discussed.  
poster icon Poster THPAB207 [0.354 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB207  
About • paper received ※ 16 May 2021       paper accepted ※ 05 July 2021       issue date ※ 11 August 2021  
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THPAB227 MACH-B: Fast Multipole Method Approaches in Particle Accelerator Simulations for the Computational and Intensity Frontiers multipole, simulation, framework, embedded 4237
 
  • M.H. Langston, R. Lethin, P.D. Letourneau, J. Wei
    Reservoir Labs, New York, USA
  • M.J. Morse
    Courant Institute of Mathematical Sciences, New York University, New York, USA
 
  Funding: U.S. Department of Energy DOE SBIR Phase I Project DE-SC0020934
The MACH-B (Multipole Accelerator Codes for Hadron Beams) project is developing a Fast Multipole Method (FMM**)-based tool for higher fidelity modeling of particle accelerators for high-energy physics within the next generation of Fermilab’s Synergia* simulation package. MACH-B incorporates (1) highly-scalable, high-performance and generally-applicable FMM-based algorithms to accurately model space-charge effects in high-intensity hadron beams and (2) boundary integral approaches to handle singular effects near the beam pipe using advanced quadratures. MACH-B will allow for more complex beam dynamics simulations that more accurately capture bunch effects and predict beam loss. Further, by introducing an abstraction layer to hide FMM implementation and parallelization complexities, MACH-B removes one of the key impediments to the adoption of FMMs by the accelerator physics community.
* J. Amundson et al. "Synergia: An accelerator modeling tool with 3-D space charge". J.C.P. 211.1 (2006) 229-248.
** L. Greengard. "Fast algorithms for classical physics". Science (Aug 1994) 909-914.
 
poster icon Poster THPAB227 [0.984 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB227  
About • paper received ※ 19 May 2021       paper accepted ※ 14 July 2021       issue date ※ 27 August 2021  
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THPAB229 Energy-Binning Fast Multipole Method for Electron Injector Simulations simulation, electron, multipole, cathode 4244
 
  • S.A. Schmid, H. De Gersem, E. Gjonaj
    TEMF, TU Darmstadt, Darmstadt, Germany
 
  In a high brilliance electron injector, small beam energy and large charge density give rise to strong space charge effects. Furthermore, a large relative energy spread during the beam generation modifies the space charge interaction between different regions of the particle bunch. Therefore, modeling the phase space evolution in an electron injector requires a numerically efficient particle tracking code that can handle space charge interactions of spatially and energetically strongly inhomogeneous particle distributions. We implemented an energy-binning scheme for a meshless fast multipole method (FMM). The energy-binning approximates the momentum distribution of the beam by assigning particles to adaptive tree structures defined at different Lorentz frames. Based on the tree structures, the FMM computes a hierarchical approximation for the space charge interaction of the particle bunch. We use the energy-binning FMM to simulate the beam generation in the photoinjector of the European XFEL developed at DESY-PITZ. Furthermore, we present numerical convergence and performance studies and compare the simulation results to direct particle-particle methods.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB229  
About • paper received ※ 19 May 2021       paper accepted ※ 12 July 2021       issue date ※ 25 August 2021  
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THPAB241 Examination of Semi-Analytic Model for Mode Coupling Instabilities simulation, coupling, transverse-dynamics, damping 4278
 
  • M.A. Balcewicz, Y. Hao
    FRIB, East Lansing, Michigan, USA
  • M. Blaskiewicz
    BNL, Upton, New York, USA
 
  Funding: Work supported by by Brookhaven Science Associates, LLC under contract number 364776.
A semianalytic model for studying beams at high SC tune shift is shown. It is a generalization of SWM ** /ABS ** for an arbitrary number of longitudinal phase space cycles, yielding more realistic longitudinal physics. The consequences of this generalization are explored; model is benchmarked against TRANFT *** and analytical methods.
* Blaskiewicz, Michael. Phys. Rev. ST Accel. Beams, vol. 1, p. 044201, 1998.
** Burov, Alexey. Phys. Rev. Accel. Beams, vol. 22, p. 034202, 2019.
*** M. Blaskiewicz, in Proc. PAC07, Albuquerque,
 
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DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB241  
About • paper received ※ 19 May 2021       paper accepted ※ 14 July 2021       issue date ※ 14 August 2021  
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THPAB359 Simulations of the Stage 2 FFA Injection Line of LhARA for Evaluating Beam Transport Performance injection, simulation, laser, target 4495
 
  • W. Shields
    JAI, Egham, Surrey, United Kingdom
  • A. Kurup, H.T. Lau, K.R. Long, J. Pasternak
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
 
  A new, novel facility for radiobiological research, the Laser-hybrid Accelerator for Radiobiological Applications (LhARA), has recently been proposed. LhARA will be a two-stage facility with the first stage employing laser-target acceleration to produce intense proton bunches of energies up to 15 MeV. The second stage will accelerate the beam in an FFA ring up to 127 MeV. Optimal performance of stage 2, however, will require an emittance reduction of the stage 1 beam due to the FFA’s nominal dynamical acceptance. Here, we demonstrate a new optical configuration of LhARA’s stage 1 lattice that will provide this reduced emittance. The profile of the laser-target generated beam is far from an ideal Gaussian, therefore two start-to-end Monte Carlo particle tracking codes have been used to model beam transport performance from the laser-target source through to the end of the stage 2 FFA injection line. The Geant4-based Beam Delivery Simulation (BDSIM) was used to model beam losses and the collimation that is crucial to LhARA’s energy selection system, and General Particle Tracer (GPT) was used to model the space-charge effects that may impact performance given the emittance reduction.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB359  
About • paper received ※ 19 May 2021       paper accepted ※ 07 July 2021       issue date ※ 18 August 2021  
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