01 Circular and Linear Colliders
A19 Electron-Hadron Colliders
Paper Title Page
MOPMF005 Beam Formation in the Alternative JLEIC Ion Complex 91
 
  • B. Mustapha, J.L. Martinez Marin
    ANL, Argonne, USA
  • Y.S. Derbenev, F. Lin, V.S. Morozov, Y. Zhang
    JLab, Newport News, Virginia, USA
 
  Funding: Work supported by the U.S. Department of Energy / ONP, under Contract No. DE-AC02-06CH11357 for ANL and by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
The proposed alternative design approach for the JLab-EIC (JLEIC) ion complex uses a more compact linac and pre-booster, and consolidates the electron storage ring (e-ring) as a large booster for the ions. Following a parameter study* showing the feasibility of this alternative design approach, we have adapted the e-ring lattice by adding RF sections to accelerate ion beams**. In this study, we focus on the beam formation for protons and lead ions from the linac to the pre-booster, then into the e-ring until injection to the ion collider ring. Effects such as space charge, intra-beam scattering and the need for beam cooling will determine the total accumulated charge in each ring and the time required from injection from the injector linac to collision in the collider ring.
* B. Mustapha et al, Proceedings of NAPAC-2016, October 9-14, Chicago, IL.
** B. Mustapha et al, Proceedings of IPAC-2017, May 14-19, Copenhagen, Denmark.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF005  
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MOPMF006 Test of Stepwise Electron Bunch Replacement in eRHIC Using an Electron Lens in RHIC 95
 
  • W. Fischer, M.R. Costanzo, A.V. Fedotov, X. Gu, A. Marusic, M.G. Minty, C. Montag, Y. Tan, P. Thieberger
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy.
The electron-ion collider eRHIC requires an electron bunch replacement about every second to maintain both high luminosity and polarization. If the bunch can be replaced in several steps, the requirements for both the electron gun and the electron accelerator are greatly reduced due to the reduced bunch charge. However, a stepwise replacement of electron bunches in eRHIC will give rise to transient effects from the beam-beam interaction that will lead to emittance growth. Such a scheme was tested using one of the RHIC electron lenses with a multiple step increase of the electron current. The test provides an order-of-magnitude estimate of the effect without any further mitigating measures.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF006  
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MOPMF013 eRHIC EIC: Plans for Rapid Acceleration of Polarized Electron Bunch at Cornell Synchrotron 108
 
  • F. Méot, E.C. Aschenauer, H. Huang, C. Montag, V. Ptitsyn, V.H. Ranjbar, E. Wang, Z. Zhao
    BNL, Upton, Long Island, New York, USA
  • I.V. Bazarov, D. L. Rubin
    Cornell University, Ithaca, New York, USA
  • L. Cultrera, G.H. Hoffstaetter, K.W. Smolenski, R.M. Talman
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • D. Gaskell, O. Glamazdin, J.M. Grames
    JLab, Newport News, Virginia, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
An option as an injector into the polarized-electron storage ring of eRHIC EIC is a rapid-cycling synchrotron (RCS). Cornell's 10 GeV RCS injector to CESR presents a good opportunity for dedicated polarized bunch rapid-acceleration experiments, it can also serve as a test bed for source and polarimetry developments in the frame of the EIC R&D, as polarized bunch experiments require disposing of a polarized electron source, and of dedicated polarimetry in the linac region and in the RCS proper. This is as well an opportunity for a pluri-disciplinary collaboration between Laboratories. This paper is an introduction to the topic, and to on-going activities towards that EIC R&D project.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF013  
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MOPMF014 Polarization at eRHIC Electron Storage Ring, an Ergodic Approach 112
 
  • F. Méot
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Based on considerations of ergodicity of the dynamical system of an electron bunch at equilibrium, the preservation of polarization in an electron storage ring is estimated from the tracking of a very limited number of electrons. This has a substantial impact on required High Power Computing resources, in noticeable contrast with the method generally used that tracks tens of electron bunches, each comprised of thousands of particles, for several thousands of turns. It is also shown that a minimum number of tracking turns is required in order to ensure the numerical convergence of the linear regressions that yield depolarizing time constant values from tracking, in both methods.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF014  
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MOPMF020 Higher Order Mode Coupling Options for the eRHIC Crab Cavity 121
 
  • Q. Wu, I. Ben-Zvi, S. Verdú-Andrés, B. P. Xiao
    BNL, Upton, Long Island, New York, USA
  • I. Ben-Zvi
    Stony Brook University, Stony Brook, USA
 
  Funding: This work was supported by the US Department of Energy via Brookhaven Science Associates LLC under contract no. DE-SC0012704.
The eRHIC crab cavity adopts the double quarter wave structure developed at Brookhaven National Lab for the LHC Hi-Lumi upgrade crab cavities. The cavity's fundamental mode is at 338 MHz with the first higher order mode more than 180 MHz above that. We looked into the higher order mode distribution up to 2 GHz, and considered various locations and geometries of the coupling scheme. The cylindrical outer shell of the cavity allowed various possibilities for coupler port openings on all the walls, which were difficult for the narrow waist of the LHC double quarter wave crab cavities. Beam pipe absorbers are also options for simpler high frequency modes damping. Some preliminary high pass filter design will also be discussed in this paper.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF020  
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MOPMF071 Polarization Studies for the eRHIC electron Storage Ring 292
 
  • E. Gianfelice-Wendt
    Fermilab, Batavia, Illinois, USA
  • S. Tepikian
    BNL, Upton, Long Island, New York, USA
 
  Funding: Manuscript authored by Fermi Res. All., LLC under Contr. No. DE-AC02-07CH11359 and Brookhaven Sc. Ass., LLC under Contr. No. DE-AC02-98CH10886 with the U.S. DOE, Office of Science, Office of HEP.
A hadron/lepton collider with polarized beams has been under consideration by the scientific community since some years, in the U.S. and Europe. Among the various proposals, those by JLAB and BNL with polarized electron and proton beams are currently under closer study in the U.S. Experimenters call for the simultaneous storage of electron bunches with both spin helicity. In the BNL based Ring-Ring design, electrons are stored at top energy in a ring to be accommodated in the existing RHIC tunnel. The transversely polarized electron beam is injected into the storage ring at variable energies, between 5 and 18 GeV. Polarization is brought into the longitudinal direction at the IP by a couple of spin rotators. In this paper results of first studies of the attainable beam polarization level and lifetime in the storage ring at 18 GeV are presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF071  
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MOPMK010 Study Progress of the Coupling Resonance of the Crab Crossing Scheme in Electron-Ion Collider 368
 
  • Y. Hao
    FRIB, East Lansing, USA
  • Y. Luo, V. Ptitsyn
    BNL, Upton, Long Island, New York, 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.
Crab crossing scheme is essential collision scheme to achieve high luminosity for the future electron-ion collider (EIC). The bunch length effect of the ion beam cannot be ignored even when cooling is present compared with the wavelength of the crab cavity, therefore, the nonlinear dependence of the crabbing kick may present a challenge to the beam dynamics of the ion beam, hence an impact to the luminosity lifetime. In this paper, we present the result of numerical beam dynamics studies of the crab crossing scheme. The result indicates that there is a special coupling resonance in the nonlinear relation of the crab crossing scheme of the EIC, which dominates the luminosity degradation. And we will discuss the possible remedies for such resonance.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK010  
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MOPMK016 Calculations of Beam-Beam Effect and Luminosity for Crab Dynamics Simulations in JLEIC 386
 
  • H. Huang, V.S. Morozov, A.V. Sy
    JLab, Newport News, Virgina, USA
 
  Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contracts DE-AC05-06OR23177 and DE-AC02-06CH11357.
Crab crossing is an integral part of the Jefferson Lab Electron-Ion Collider (JLEIC) design to achieve high luminosity while meeting the detection and physics pro-gram requirements. The crab crossing scheme provides a head-on beam-beam collision for beams with a nonzero crossing angle. Simulations of crabbing dynamics currently do not include beam-beam effects. We describe a framework for accurate simulation of beam-beam effects on crabbing dynamics by applying a numerical calculation of the Bassetti-Erskine analytic solution to symplectic particle tracking codes. The numerical calculation is benchmarked against the analytic solution by calculating the luminosity reduction for several colliding beam scenarios. Benchmarking results show good agreement be-tween the numerical calculation and analytic solution, paving the way for implementation of the beam-beam kick to Elegant tracking simulations.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK016  
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MOPML006 Multi-Stage Electron Cooling Scheme for JLEIC 397
 
  • H. Zhang, S.V. Benson, Y.S. Derbenev, Y. Roblin, Y. Zhang
    JLab, Newport News, Virginia, USA
 
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357.
JLEIC is the future electron ion collider under design at Jefferson Lab, which will provide a luminosity up to 1034 cm-2s-1. Electron cooling is essential for JLEIC to overcome the intrabeam scattering effect, reduce the ion beam emittance and thus achieve the high luminosity. The cooling time is approximately in proportion to the square of the energy and the 6D emittance. To avoid the difficulty of cooling the ion beam with large emittance at high energy, a multi-stage cooing scheme was designed for JLEIC. The ion beam was cooled at the low energy to reduce the emittance. Then it was ramped up to the collision energy. During the collision, electron cooling is implemented to maintain the emittance and the luminosity. Simulations for proton beam and lead ion beam at various stages are presented in this paper.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPML006  
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MOPML007 Analysis of Spin Response Function at Beam Interaction Point in JLEIC 400
 
  • V.S. Morozov, Y.S. Derbenev, F. Lin, Y. Zhang
    JLab, Newport News, Virginia, USA
  • Y. Filatov
    MIPT, Dolgoprudniy, Moscow Region, Russia
  • A.M. Kondratenko, M.A. Kondratenko
    Science and Technique Laboratory Zaryad, Novosibirsk, Russia
 
  Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under con-tracts DE-AC05-06OR23177 and DE-AC02-06CH11357.
The spin response function is determined by a collid-er's magnetic lattice and allows one to account for con-tributions of perturbing fields to spin resonance strengths. The depolarizing effect of an incoming beam depends significantly on the response function value at the interaction point (IP). We present an analytic calcula-tion of the response function for protons and deuterons at the IP of Jefferson Lab Electron Ion Collider (JLEIC) over its whole momentum range. We find a good agreement of the analytic calculation with our numerical modeling results obtained using a spin tracking code, Zgoubi.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPML007  
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MOPML008 JLEIC Electron Ring Dynamic Aperture with Non-linear Field Errors 404
 
  • Y.M. Nosochkov, Y. Cai
    SLAC, Menlo Park, California, USA
  • F. Lin, V.S. Morozov, G.H. Wei, Y. Zhang
    JLab, Newport News, Virginia, USA
 
  Funding: Authored by Jefferson Science Associates, LLC under US DOE Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357. Work supported by the US DOE Contract DE-AC02-76SF00515.
We present results of dynamic aperture study for the updated electron ring lattice of the Jefferson Lab Electron-Ion Collider (JLEIC). The lattice design features low emittance arcs with local compensation of sextupole non-linear effects, and low emittance non-linear chromaticity correction sections. Dynamic aperture tracking simulations are performed to evaluate the effects of non-linear field errors, the sensitivity to betatron tune, and the impact of momentum error. Dynamic aperture is also evaluated with the measured PEP-II field errors. Preliminary tolerances to the non-linear field errors in the Final Focus quadrupoles are estimated.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPML008  
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TUXGBD3 Ideas and Concepts for Future Electron Ion Colliders 590
 
  • F.C. Pilat
    ORNL, Oak Ridge, Tennessee, USA
 
  Different versions of future electron-ion colliders have been proposed by Brookhaven National Laboratory (BNL) and Thomas Jefferson National Laboratory (JLAB), one based on colliding protons in a ring with electrons from an Energy Recovery Linac (ERL), the other two based on ring-ring colliders. To attain the luminosity goal strong hadron cooling is required, as could be provided with several proposed new cooling schemes. Polarization of both colliding beams is essential. This invited talk will compare the various designs and highlight some of the novel ideas and concepts.  
slides icon Slides TUXGBD3 [76.613 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUXGBD3  
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TUYGBD3 eRHIC Design Status 628
 
  • V. Ptitsyn, G. Bassi, J. Beebe-Wang, J.S. Berg, M. Blaskiewicz, A. Blednykh, J.M. Brennan, S.J. Brooks, K.A. Brown, K.A. Drees, A.V. Fedotov, W. Fischer, D.M. Gassner, W. Guo, Y. Hao, A. Hershcovitch, H. Huang, W.A. Jackson, J. Kewisch, C. Liu, H. Lovelace III, Y. Luo, F. Méot, M.G. Minty, C. Montag, R.B. Palmer, B. Parker, S. Peggs, V.H. Ranjbar, G. Robert-Demolaize, S. Seletskiy, V.V. Smaluk, K.S. Smith, S. Tepikian, P. Thieberger, D. Trbojevic, N. Tsoupas, W.-T. Weng, F.J. Willeke, H. Witte, Q. Wu, W. Xu, A. Zaltsman, W. Zhang
    BNL, Upton, Long Island, New York, USA
  • E. Gianfelice-Wendt
    Fermilab, Batavia, Illinois, 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 eRHIC aims at a luminosity around 1034cm-2sec-1, using strong cooling of the hadron beam. Since the required cooling techniques are not yet readily available, an initial version with a peak luminosity of 3*1033cm-2sec-1 is being developed that can later be outfitted with strong hadron cooling. We will report on the current design status and the envisioned path towards 1034cm-2sec-1 luminosity.
 
slides icon Slides TUYGBD3 [11.795 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUYGBD3  
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TUYGBD4 Beam Loss Background and Collimator Design in CEPC Double Ring 632
 
  • S. Bai, J. Gao, H. Geng, D. Wang, Y. Wang, C.H. Yu, Y. Zhang
    IHEP, Beijing, People's Republic of China
 
  The Circular Electron Positron Collider (CEPC) is a proposed Higgs factory with center of mass energy of 240 GeV to measure the properties of Higgs boson and test the standard model accurately. Beam loss background in detectors is an important topic at CEPC. Radiative Bhabha scattering and Beamstrahlung effects are dominant mechanism of the beam induced backgrounds at CEPC due to the beam lifetime. In this paper, we evaluated the beam loss background in simulation and designed a series of collimators to suppress the radiation level on the machine and the detector.  
slides icon Slides TUYGBD4 [0.796 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUYGBD4  
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