Author: Qiang, J.
Paper Title Page
WEPAB008 Numerical Noise Study in EIC Beam-Beam Simulations 2592
 
  • D. Xu, Y. Hao
    FRIB, East Lansing, Michigan, USA
  • Y. Luo, C. Montag
    BNL, Upton, New York, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
 
  In the Electron-Ion Collider (EIC) design, a flat beam collision scheme is adopted to achieve 1e34 luminosity. We found that the vertical growth of the proton beam is much larger than of the round beam. In this article we present the numerical noise study about the number of macroparticles, the electron slice number, and the electron bunch length. Both weak-strong and strong-strong simulation methods are used. It turns out the proton emittance growth in the strong-strong simulation mainly comes from the numberical noise. This study helps us to perform beam-beam simulation correctly for EIC.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB008  
About • paper received ※ 17 May 2021       paper accepted ※ 31 August 2021       issue date ※ 31 August 2021  
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WEPAB009 Study of Harmonic Crab Cavity in EIC Beam-Beam Simulations 2595
 
  • D. Xu, Y. Hao
    FRIB, East Lansing, Michigan, USA
  • Y. Luo, C. Montag
    BNL, Upton, New York, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
 
  In the Electron-Ion Collider (EIC) design, crab cavities are adopted to compensate the geometric luminosity loss from the crossing angle. From previous studies, higher-order synchro-betatron resonances are excited since the hadron beam is long and the crossing angle is large. To reduce the luminosity degradation rate, different combinations of harmonic crab cavities are studied with both weak-strong and strong-strong simulation methods. The frequency map analysis (FMA) is also used for comparison. This study helps determine the crab cavity parameters for the future EIC.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB009  
About • paper received ※ 17 May 2021       paper accepted ※ 23 June 2021       issue date ※ 28 August 2021  
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WEPAB010 Full Range Tune Scan Studies Using Graphics Processing Units with CUDA in EIC Beam-Beam Simulations 2598
 
  • D. Xu, Y. Hao
    FRIB, East Lansing, Michigan, USA
  • Y. Luo, C. Montag
    BNL, Upton, New York, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
 
  The hadron beam in the Electron-Ion Collider (EIC) suffers high order betatron and synchro-betatron resonances. In this paper, we present a weak-strong full range (0.0~0.5) fractional tune scan with a step size as small as 0.001. Multiple Graphics Processing Units (GPUs) are used to speed up the simulation. A code parallelized with MPI and CUDA is implemented. The good tune region from weak-strong scan is further checked by the self-consistent strong-strong simulation. This study provides beam dynamics guidance in choosing proper working points for the future EIC.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB010  
About • paper received ※ 17 May 2021       paper accepted ※ 23 June 2021       issue date ※ 12 August 2021  
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WEPAB251 Beam Dynamics Optimization of LCLS-II HE Linear Accelerator Design 3224
 
  • J. Qiang
    LBNL, Berkeley, California, USA
  • T.O. Raubenheimer, M.D. Woodley
    SLAC, Menlo Park, California, USA
 
  The LCLS-II-HE as a high energy upgrade of the high repetition rate X-ray FEL under construction at SLAC will provide great opportunities for scientific discovery by generating coherent, high brightness hard X-ray radiation. In this paper, we report on beam dynamics optimization of the LCLS-II HE linear accelerator design with a 100pC and a 20pC charge beam to attain high quality electron beam for X-ray FEL radiation. We also present preliminary results of beam dynamics optimization of a 100pC beam from a low emittance superconducting injector.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB251  
About • paper received ※ 18 May 2021       paper accepted ※ 21 June 2021       issue date ※ 30 August 2021  
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WEPAB252 Transient Beam-Beam Effect During Electron Bunch Replacement in the EIC 3228
 
  • J. Qiang
    LBNL, Berkeley, California, USA
  • M. Blaskiewicz, Y. Luo, C. Montag, F.J. Willeke, D. Xu
    BNL, Upton, New York, USA
  • Y. Hao
    FRIB, East Lansing, Michigan, USA
 
  The high luminosity, high polarization electron-ion collider (EIC) will provide great opportunities in nuclear physics study. In order to maintain high polarization, the electron beam will be replaced every few minutes during the collider operation. This frequent replacement of electron beams can affect proton beam quality during the collision. In this paper, we report on the study of the transient effect of electron beam replacement on proton beam emittance growth through strong-strong beam-beam simulation. The effect of electron beam injection imperfection will be included in the study.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB252  
About • paper received ※ 17 May 2021       paper accepted ※ 21 June 2021       issue date ※ 02 September 2021  
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THPAB015 Studies of the Imperfection in Crab Crossing Scheme for Electron-Ion Collider 3784
 
  • Y. Hao, J.S. Berg, D. Holmes, Y. Luo, C. Montag
    BNL, Upton, New York, USA
  • V.S. Morozov
    JLab, Newport News, Virginia, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
  • D. Xu
    FRIB, East Lansing, Michigan, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
Crab crossing scheme is the essential scheme that accommodates large crossing angle without loss of luminosity in the design of Electron-Ion collider (EIC). The ideal optics and phase advances of the crab cavity pair are set to create a local crabbing bump in the interaction region (IR). However, there are always small errors in the actual lattice of IR. In this article, we will present the simulation and analytical studies on the imperfections in the crab crossing scheme in the EIC design. The tolerance of the imperfection and the possible remedies can be concluded from these studies.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB015  
About • paper received ※ 17 May 2021       paper accepted ※ 16 July 2021       issue date ※ 12 August 2021  
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THPAB028 Beam-Beam Related Design Parameter Optimization for the Electron-Ion Collider 3808
 
  • Y. Luo, J.S. Berg, M. Blaskiewicz, W. Fischer, X. Gu, H. Lovelace III, C. Montag, R.B. Palmer, S. Peggs, V. Ptitsyn, F.J. Willeke
    BNL, Upton, New York, USA
  • Y. Hao, D. Xu
    FRIB, East Lansing, Michigan, USA
  • H. Huang
    ODU, Norfolk, Virginia, USA
  • E.A. Nissen, T. Satogata
    JLab, Newport News, Virginia, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The design luminosity goal for the Electron-Ion Collider (EIC) is 1e34 cm-2s−1. To achieve such a high luminosity, the EIC design adopts high bunch intensities, flat beams at the interaction point (IP) with a small vertical β*-function, and a high collision frequency, together with crab cavities to compensate the geometrical luminosity loss due to the large crossing angle of 25mrad. In this article, we present our strategies and approaches to obtain the design luminosity by optimizing some key beam-beam related design parameters. Through our extensive strong-strong and weak-strong beam-beam simulations, we found that beam flatness, electron and proton beam size matching at the IP, electron and proton working points, and synchro-betatron resonances arising from the crossing angle collision play a crucial role in proton beam size growth and luminosity degradation. After optimizing those parameters, we found a set of beam-beam related design parameters to reach the design luminosity with an acceptable beam-beam performance.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB028  
About • paper received ※ 17 May 2021       paper accepted ※ 28 July 2021       issue date ※ 25 August 2021  
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THPAB029 Dynamic Aperture Evaluation for the Hadron Storage Ring in the Electron-Ion Collider 3812
 
  • Y. Luo, J.S. Berg, M. Blaskiewicz, W. Fischer, X. Gu, H. Lovelace III, C. Montag, R.B. Palmer, S. Peggs, V. Ptitsyn, F.J. Willeke, H. Witte
    BNL, Upton, New York, USA
  • Y. Hao, D. Xu
    FRIB, East Lansing, Michigan, USA
  • H. Huang
    ODU, Norfolk, Virginia, USA
  • V.S. Morozov, E.A. Nissen, T. Satogata
    JLab, Newport News, Virginia, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The Electron-Ion Collider (EIC) is aiming at a design luminosity of 1e34 cm-2s−1. To maintain such a high luminosity, both beams in the EIC need an acceptable beam lifetime in the presence of the beam-beam interaction. For this purpose, we carried out weak-strong element-by-element particle tracking to evaluate the long-term dynamic aperture for the hadron ring lattice design. We improved our simulation code SimTrack to treat some new lattice design features, such as radially offset on-momentum orbits, coordinate transformations in the interaction region, etc. In this article, we will present the preliminary dynamic aperture calculation results with β*- function scan, radial orbit shift, crossing angle collision, and magnetic field errors.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB029  
About • paper received ※ 17 May 2021       paper accepted ※ 01 September 2021       issue date ※ 28 August 2021  
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THPAB221 Multi-Objective Optimization with ACE3P and IMPACT 4223
 
  • D.A. Bizzozero, J. Qiang
    LBNL, Berkeley, California, USA
  • L. Ge, Z. Li, C.-K. Ng, L. Xiao
    SLAC, Menlo Park, California, USA
 
  Funding: This work is supported by the Director of the Office of Science of the US Department of Energy under contracts DE-AC02-05-CH11231 and DE-AC02-76-SF00515.
Photo injector design is an important consideration in the construction of next-generation accelerators. In current injector optimization, components (e.g. RF cavities) are individually shape-optimized for performance subject to requirements such as peak surface field, shunt impedance, and resonant frequency. Once these component shapes are determined, beam dynamics simulations optimize the injector lattice by adjusting parameters such as the amplitude and phase of the driving fields. However, this form of beam dynamics optimization is restricted by the fixed geometry and field profile of the components. To optimize accelerator design more generally, a coupled optimization of the cavity shape and beam parameters is required. For this coupled optimization problem, we have created an integrated ACE3P-IMPACT workflow. Within this workflow, component geometries are adjusted, field modes are computed with Omega3P (a module in the ACE3P suite), and beam dynamics are simulated with IMPACT-T. This workflow is encapsulated into a multi-objective optimization algorithm using the DEAP* and libEnsemble** Python libraries to yield a Pareto-optimal set of solutions for a simple injector model.
* F.-A. Fortin et al, DEAP: Evolutionary Algorithms Made Easy, J Mach Learn Res, 13, 2171-2175, July 2012
** S. Hudson et al, libEnsemble User Manual, Argonne National Laboratory, Rev 0.7.1, 2020
 
poster icon Poster THPAB221 [1.842 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB221  
About • paper received ※ 19 May 2021       paper accepted ※ 02 August 2021       issue date ※ 14 August 2021  
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