IPAC2021 - Classification: MC1: Circular and Linear Colliders / A19 Electron-Hadron Colliders

Paper	Title	Page
MOPAB015	Feasibility of Polarized Deuteron Beam in the EIC	87
	H. Huang, F. Méot, V. Ptitsyn, V.H. Ranjbar, T. Roser BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The physics program in the EIC calls for polarized neutron beam at high energies. The best neutron carriers are 3He nuclei and deuterons. Both neutron carries are expected to be used by spin physics program in the EIC. Due to the small magnetic moment anomaly of deuteron particles, much higher magnetic fields are required for spin rotation, so full Siberian snake is not feasible. However, the resonance strength is in general weak and the number of resonances is also small. It is possible to deal with individual resonances with conventional methods, such as betatron tune jump for intrinsic depolarizing resonances; and a weak partial snakes for imperfection resonances. The study shows that accelerating polarized deuteron beyond 100GeV/n is possible in the EIC.
	Poster MOPAB015 [0.977 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB015
About •	paper received ※ 16 May 2021 paper accepted ※ 28 May 2021 issue date ※ 13 August 2021
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TUPAB037	The Design of a High Charge Polarized Preinjector for the Electron-Ion Collider	1428
	E. Wang, W. Liu, V.H. Ranjbar, J. Skaritka, N. Tsoupas BNL, Upton, New York, USA J.M. Grames, J. Guo JLab, Newport News, Virginia, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy The design of the electron pre-injector of the Electron-Ion Collider (EIC) project to generate 4 x 7 nC bunch has been advancing to meet the requirements for injection into the Rapid Cycling Synchrotron (RCS). The major challenges are high charge transport and achieving small energy spread from 3 GHz traveling-wave plate(TWP). The designed preinjector includes the polarized electron source, bunching section, TWP Linac, zigzag phase space manipulation and spin rotator. In this report, we will discuss the RF frequency selection and the way to reduce energy spread down to 0.2% by longitudinal phase space manipulate. We will also report the results of beamline simulation using space charge code and the conceptual design of spin rotator.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB037
About •	paper received ※ 16 May 2021 paper accepted ※ 15 June 2021 issue date ※ 27 August 2021
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TUPAB040	Design Concept for the Second Interaction Region for Electron-Ion Collider	1435
	B.R. Gamage, V. Burkert, R. Ent, Y. Furletova, D.W. Higinbotham, A. Hutton, F. Lin, T.J. Michalski, V.S. Morozov, R. Rajput-Ghoshal, D. Romanov, T. Satogata, A. Seryi, A.V. Sy, C. Weiss, M. Wiseman, W. Wittmer, Y. Zhang JLab, Newport News, Virginia, USA E.C. Aschenauer, J.S. Berg, A. Jentsch, A. Kiselev, C. Montag, R.B. Palmer, B. Parker, V. Ptitsyn, F.J. Willeke, H. Witte BNL, Upton, New York, USA C. Hyde ODU, Norfolk, Virginia, USA P. Nadel-Turonski SBU, Stony Brook, New York, USA
	Funding: Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177 and Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. The possibility of two interaction regions (IRs) is a design requirement for Electron-Ion Collider (EIC). There is also a significant interest from the nuclear physics community to have a 2nd IR with measurement capabilities complementary to those of the 1st IR. While the 2nd IR will be in operation over the entire energy range of ~20GeV to ~140GeV center of mass (CM). The 2nd IR can also provide an acceptance coverage complementary to that of the 1st. In this paper, we present a brief overview and the current progress of the 2nd IR design in terms of the parameters, magnet layout, and beam dynamics.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB040
About •	paper received ※ 24 May 2021 paper accepted ※ 31 August 2021 issue date ※ 30 August 2021
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TUPAB041	Detector Solenoid Compensation for the Electron-Ion Collider	1439
	B.R. Gamage, T.J. Michalski, V.S. Morozov, R. Rajput-Ghoshal, A. Seryi, W. Wittmer, Y. Zhang JLab, Newport News, Virginia, USA E. Gianfelice-Wendt Fermilab, Batavia, Illinois, USA A. Kiselev, H. Lovelace III, B. Parker, S. Peggs, S. Tepikian, F.J. Willeke, H. Witte, Q. Wu BNL, Upton, New York, USA
	Funding: Jefferson Science Associates, LLC Contract No. DE-AC05-06OR23177, Fermi Research Alliance, LLC Contract No. DE-AC02-07CH11359, and Brookhaven Science Associates, LLC Contract No. DE-SC0012704 The central detector in the present EIC design includes a 4 m long solenoid with an integrated strength of up to 12 Tm. The electron beam passes on-axis through the solenoid, but the hadron beam has an angle of 25 mrad. Thus the solenoid couples horizontal and vertical betatron motion in both electron and hadron storage rings, and causes a vertical closed orbit excursion in the hadron ring. The solenoid also couples the transverse and longitudinal motions of both beams, when crab cavities are also considered. In this paper, we present schemes for closed orbit correction and coupling compensation at the IP, including crabbing.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB041
About •	paper received ※ 28 May 2021 paper accepted ※ 31 August 2021 issue date ※ 12 August 2021
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TUPAB042	Large Radial Shifts in the EIC Hadron Storage Ring	1443
	S. Peggs, J.S. Berg, K.A. Drees, X. Gu, C. Liu, H. Lovelace III, Y. Luo, G.J. Marr, A. Marusic, F. Méot, R.J. Michnoff, V. Ptitsyn, G. Robert-Demolaize, M. Valette, S. Verdú-Andrés BNL, Upton, New York, USA K.E. Deitrick Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA B.R. Gamage JLab, Newport News, Virginia, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. The Electron Ion Collider will collide hadrons in the Hadron Storage Ring (HSR) with ultra-relativistic electrons in the Electron Storage Ring. The HSR design trajectory includes a large radial shift over a large fraction of its circumference, in order to adjust the hadron path length to synchronize collisions over a broad range of hadron energies. The design trajectory goes on-axis through the magnets, crab cavities and other components in the six HSR Insertion Regions. This paper discusses the issues involved and reports on past and future beam experiments in the Relativistic Heavy Ion Collider, which will be upgraded to become the HSR.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB042
About •	paper received ※ 18 May 2021 paper accepted ※ 15 June 2021 issue date ※ 21 August 2021
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WEXA04	The RCS Design Status for the Electron Ion Collider	2521
	V.H. Ranjbar, M. Blaskiewicz, Z.A. Conway, D.M. Gassner, C. Hetzel, B. Lepore, H. Lovelace III, I. Marneris, F. Méot, C. Montag, J. Skaritka, N. Tsoupas, E. Wang, F.J. Willeke BNL, Upton, New York, USA J.M. Grames, J. Guo, F. Lin, V.S. Morozov, T. Satogata JLab, Newport News, Virginia, USA D. Sagan Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The design of the Electron-Ion Collider Rapid Cycling Synchrotron (RCS) to be constructed at Brookhaven National Laboratory is advancing to meet the injection requirements for the Electron Storage Ring (ESR). Over the past year activities are focused on developing the approach to inject two 28 nC bunches every second, up from the original design of one 10nC bunch every second. The solution requires several key changes concerning the injection and extraction kickers, charge accumulation via bunch merging and a carefully calibrated RF acceleration profile to match the longitudinal emittance required by the ESR.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXA04
About •	paper received ※ 19 May 2021 paper accepted ※ 31 August 2021 issue date ※ 10 August 2021
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WEPAB001	Accelerator Challenges of the LHeC Project	2570
	B.J. Holzer, K.D.J. André, O.S. Brüning CERN, Geneva, Switzerland S.A. Bogacz JLab, Newport News, Virginia, USA M. Klein The University of Liverpool, Liverpool, United Kingdom
	The LHeC project studies the design of a future electron-proton collider at CERN that will run in parallel to the standard LHC operation. For this purpose, the existing LHC storage ring will be combined with an Energy Recovery Linac (ERL), to accelerate electrons up to kinetic energy of 50 GeV. This concept - also applicable to the FCC-eh collider and studied at the PERLE project as prototype version - allows a peak luminosity of 10³⁴ cm^-2 s^-1. A sophisticated design of the RF structures, linacs, arcs, and interaction region is required. The electrons are accelerated and, after the interaction point, their energy is recovered through the same RF structures. While this energy recovery concept is a very promising approach, severe challenges are set by the layout of the interaction region, the beam separation concept and the design of the linac and arc lattice for the highest possible momentum acceptance. Emittance control and beam-beam effect of both, electron and proton beams, have been studied in front-to-end simulations and will be presented. We summarise the design principles of the ERL, the optimization of the arc lattice, and the main parameters of the project.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB001
About •	paper received ※ 17 May 2021 paper accepted ※ 21 June 2021 issue date ※ 21 August 2021
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WEPAB002	The Interaction Region of the Electron-Ion Collider EIC	2574
	H. Witte, J. Adam, M. Anerella, E.C. Aschenauer, J.S. Berg, M. Blaskiewicz, A. Blednykh, W. Christie, J.P. Cozzolino, K.A. Drees, D.M. Gassner, K. Hamdi, C. Hetzel, H.M. Hocker, D. Holmes, A. Jentsch, A. Kiselev, P. Kovach, H. Lovelace III, Y. Luo, G.J. Mahler, A. Marone, G.T. McIntyre, C. Montag, R.B. Palmer, B. Parker, S. Peggs, S.R. Plate, V. Ptitsyn, G. Robert-Demolaize, C.E. Runyan, J. Schmalzle, K.S. Smith, S. Tepikian, P. Thieberger, J.E. Tuozzolo, F.J. Willeke, Q. Wu, Z. Zhang BNL, Upton, New York, USA B.R. Gamage, T.J. Michalski, V.S. Morozov, M.L. Stutzman, W. Wittmer JLab, Newport News, Virginia, USA M.K. Sullivan SLAC, Menlo Park, California, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. This paper presents an overview of the Interaction Region (IR) design for the planned Electron-Ion Collider (EIC) at Brookhaven National Laboratory. The IR is designed to meet the requirements of the nuclear physics community . The IR design features a ±4.5 m free space for the detector; a forward spectrometer magnet is used for the detection of hadrons scattered under small angles. The hadrons are separated from the neutrons allowing detection of neutrons up to ±4 mrad. On the rear side, the electrons are separated from photons using a weak dipole magnet for the luminosity monitor and to detect scattered electrons (e-tagger). To avoid synchrotron radiation backgrounds in the detector no strong electron bending magnet is placed within 40 m upstream of the IP. The magnet apertures on the rear side are large enough to allow synchrotron radiation to pass through the magnets. The beam pipe has been optimized to reduce the impedance; the total power loss in the central vacuum chamber is expected to be less than 90 W. To reduce risk and cost the IR is designed to employ standard NbTi superconducting magnets, which are described in a separate paper. An Assessment of U.S.-Based Electron-Ion Collider Science. (2018). Washington, D.C.: National Academies Press. https://doi.org/10.17226/25171
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB002
About •	paper received ※ 18 May 2021 paper accepted ※ 25 June 2021 issue date ※ 31 August 2021
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WEPAB004	Electron-Ion Luminosity Maximization in the EIC	2582
	W. Fischer, E.C. Aschenauer, M. Blaskiewicz, K.A. Drees, A.V. Fedotov, H. Huang, C. Montag, V. Ptitsyn, D. Raparia, V. Schoefer, K.S. Smith, P. Thieberger, F.J. Willeke BNL, Upton, New York, USA Y. Zhang JLab, Newport News, Virginia, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. The electron-ion luminosity in EIC has a number of limits, including the ion intensity available from the injectors, the total ion beam current, the electron bunch intensity, the total electron current, the synchrotron radiation power, the beam-beam effect, the achievable beta functions at the interaction points (IPs), the maximum angular spreads at the IP, the ion emittances reachable with stochastic or strong cooling, the ratio of horizontal to vertical emittance, and space charge effects. We map the e-A luminosity over the center-of-mass energy range for some ions ranging from deuterons to uranium ions. For e-Au collisions the present design provides for electron-nucleon (e-Au) peak luminosities of 1.7x1033 cm^-2s⁻¹ with stochastic cooling, and 4.7x1033 cm^-2s⁻¹ with strong hadron cooling.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB004
About •	paper received ※ 18 May 2021 paper accepted ※ 21 June 2021 issue date ※ 20 August 2021
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WEPAB005	Design Status Update of the Electron-Ion Collider	2585
	C. Montag, E.C. Aschenauer, G. Bassi, J. Beebe-Wang, J.S. Berg, M. Blaskiewicz, A. Blednykh, J.M. Brennan, S.J. Brooks, K.A. Brown, Z.A. Conway, K.A. Drees, A.V. Fedotov, W. Fischer, C. Folz, D.M. Gassner, X. Gu, R.C. Gupta, Y. Hao, A. Hershcovitch, C. Hetzel, D. Holmes, H. Huang, W.A. Jackson, J. Kewisch, Y. Li, C. Liu, H. Lovelace III, Y. Luo, M. Mapes, D. Marx, G.T. McIntyre, F. Méot, M.G. Minty, S.K. Nayak, R.B. Palmer, B. Parker, S. Peggs, B. Podobedov, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, S. Seletskiy, V.V. Smaluk, K.S. Smith, S. Tepikian, R. Than, P. Thieberger, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, S. Verdú-Andrés, E. Wang, D. Weiss, F.J. Willeke, H. Witte, Q. Wu, W. Xu, A. Zaltsman, W. Zhang BNL, Upton, New York, USA S.V. Benson, J.M. Grames, F. Lin, T.J. Michalski, V.S. Morozov, E.A. Nissen, J.P. Preble, R.A. Rimmer, T. Satogata, A. Seryi, M. Wiseman, W. Wittmer, Y. Zhang JLab, Newport News, Virginia, USA Y. Cai, Y.M. Nosochkov, G. Stupakov, M.K. Sullivan SLAC, Menlo Park, California, USA K.E. Deitrick, C.M. Gulliford, G.H. Hoffstaetter, J.E. Unger Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA E. Gianfelice-Wendt Fermilab, Batavia, Illinois, USA T. Satogata ODU, Norfolk, Virginia, USA D. Xu FRIB, East Lansing, Michigan, USA
	Funding: Work supported by BSA, LLC under Contract No. DE-SC0012704, by JSA, LLC under Contract No. DE-AC05-06OR23177, and by SLAC under Contract No. DE-AC02-76SF00515 with the U.S. Department of Energy. The design of the electron-ion collider EIC to be constructed at Brookhaven National Laboratory has been continuously evolving towards a realistic and robust design that meets all the requirements set forth by the nuclear physics community in the White Paper. Over the past year activities have been focused on maturing the design, and on developing alternatives to mitigate risk. These include improvements of the interaction region design as well as modifications of the hadron ring vacuum system to accommodate the high average and peak beam currents. Beam dynamics studies have been performed to determine and optimize the dynamic aperture in the two collider rings and the beam-beam performance. We will present the EIC design with a focus on recent developments.
	Poster WEPAB005 [2.095 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB005
About •	paper received ※ 14 May 2021 paper accepted ※ 22 June 2021 issue date ※ 16 August 2021
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WEPAB006	EIC Crab Cavity Multipole Analysis	2589
	Q. Wu, Y. Luo, B.P. Xiao BNL, Upton, New York, USA S.U. De Silva ODU, Norfolk, Virginia, USA J.A. Mitchell CERN, Geneva, Switzerland
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. Crab cavities are specialized RF devices designed for colliders targeting high luminosities. It is a straightforward solution to retrieve head-on collision with crossing angle existing to fast separate both beams after collision. The Electron Ion Collider (EIC) has a crossing angle of 25 mrad, and will use local crabbing to minimize the dynamic aperture requirement throughout the rings. The current crab cavity design for the EIC lacks axial symmetry. Therefore, their higher order components of the fundamental deflecting mode have a potential of affecting the long-term beam stability. We present here the multipole analysis and preliminary particle tracking results from the current crab cavity design.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB006
About •	paper received ※ 18 May 2021 paper accepted ※ 25 June 2021 issue date ※ 16 August 2021
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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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THPAB002	Lattice Design for BEPCII Upgrade	3756
	H. Geng, W.B. Liu, J. Qiu, J. Xing, C.H. Yu, Y. Zhang IHEP, Beijing, People’s Republic of China
	The Beijing Electron Positron Collider II (BEPCII) has achieved a series of achievements in high-energy physics study. Along with the deepening of the research, more important physics is expected in higher energy regions (>2.1 GeV). As the upper limit of BEPCII design energy is 2.1GeV, an urgent upgrade is required for BEPCII. To achieve a higher luminosity at higher energy, the number of RF cavities is expected to be doubled. In this paper, the lattice design for the upgrade of BEPCII is studied. The dynamic aperture tracking result shows that the lattice could meet the injection requirement of the BEPCII beam with a reasonable margin.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB002
About •	paper received ※ 14 May 2021 paper accepted ※ 17 June 2021 issue date ※ 14 August 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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Paper

Title

Page

Feasibility of Polarized Deuteron Beam in the EIC

87

H. Huang, F. Méot, V. Ptitsyn, V.H. Ranjbar, T. Roser
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The physics program in the EIC calls for polarized neutron beam at high energies. The best neutron carriers are 3He nuclei and deuterons. Both neutron carries are expected to be used by spin physics program in the EIC. Due to the small magnetic moment anomaly of deuteron particles, much higher magnetic fields are required for spin rotation, so full Siberian snake is not feasible. However, the resonance strength is in general weak and the number of resonances is also small. It is possible to deal with individual resonances with conventional methods, such as betatron tune jump for intrinsic depolarizing resonances; and a weak partial snakes for imperfection resonances. The study shows that accelerating polarized deuteron beyond 100GeV/n is possible in the EIC.

Poster MOPAB015 [0.977 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB015

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paper received ※ 16 May 2021 paper accepted ※ 28 May 2021 issue date ※ 13 August 2021

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TUPAB037

The Design of a High Charge Polarized Preinjector for the Electron-Ion Collider

1428

E. Wang, W. Liu, V.H. Ranjbar, J. Skaritka, N. Tsoupas
BNL, Upton, New York, USA
J.M. Grames, J. Guo
JLab, Newport News, Virginia, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy
The design of the electron pre-injector of the Electron-Ion Collider (EIC) project to generate 4 x 7 nC bunch has been advancing to meet the requirements for injection into the Rapid Cycling Synchrotron (RCS). The major challenges are high charge transport and achieving small energy spread from 3 GHz traveling-wave plate(TWP). The designed preinjector includes the polarized electron source, bunching section, TWP Linac, zigzag phase space manipulation and spin rotator. In this report, we will discuss the RF frequency selection and the way to reduce energy spread down to 0.2% by longitudinal phase space manipulate. We will also report the results of beamline simulation using space charge code and the conceptual design of spin rotator.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB037

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paper received ※ 16 May 2021 paper accepted ※ 15 June 2021 issue date ※ 27 August 2021

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TUPAB040

Design Concept for the Second Interaction Region for Electron-Ion Collider

1435

B.R. Gamage, V. Burkert, R. Ent, Y. Furletova, D.W. Higinbotham, A. Hutton, F. Lin, T.J. Michalski, V.S. Morozov, R. Rajput-Ghoshal, D. Romanov, T. Satogata, A. Seryi, A.V. Sy, C. Weiss, M. Wiseman, W. Wittmer, Y. Zhang
JLab, Newport News, Virginia, USA
E.C. Aschenauer, J.S. Berg, A. Jentsch, A. Kiselev, C. Montag, R.B. Palmer, B. Parker, V. Ptitsyn, F.J. Willeke, H. Witte
BNL, Upton, New York, USA
C. Hyde
ODU, Norfolk, Virginia, USA
P. Nadel-Turonski
SBU, Stony Brook, New York, USA

Funding: Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177 and Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
The possibility of two interaction regions (IRs) is a design requirement for Electron-Ion Collider (EIC). There is also a significant interest from the nuclear physics community to have a 2nd IR with measurement capabilities complementary to those of the 1st IR. While the 2nd IR will be in operation over the entire energy range of ~20GeV to ~140GeV center of mass (CM). The 2nd IR can also provide an acceptance coverage complementary to that of the 1st. In this paper, we present a brief overview and the current progress of the 2nd IR design in terms of the parameters, magnet layout, and beam dynamics.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB040

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paper received ※ 24 May 2021 paper accepted ※ 31 August 2021 issue date ※ 30 August 2021

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TUPAB041

Detector Solenoid Compensation for the Electron-Ion Collider

1439

B.R. Gamage, T.J. Michalski, V.S. Morozov, R. Rajput-Ghoshal, A. Seryi, W. Wittmer, Y. Zhang
JLab, Newport News, Virginia, USA
E. Gianfelice-Wendt
Fermilab, Batavia, Illinois, USA
A. Kiselev, H. Lovelace III, B. Parker, S. Peggs, S. Tepikian, F.J. Willeke, H. Witte, Q. Wu
BNL, Upton, New York, USA

Funding: Jefferson Science Associates, LLC Contract No. DE-AC05-06OR23177, Fermi Research Alliance, LLC Contract No. DE-AC02-07CH11359, and Brookhaven Science Associates, LLC Contract No. DE-SC0012704
The central detector in the present EIC design includes a 4 m long solenoid with an integrated strength of up to 12 Tm. The electron beam passes on-axis through the solenoid, but the hadron beam has an angle of 25 mrad. Thus the solenoid couples horizontal and vertical betatron motion in both electron and hadron storage rings, and causes a vertical closed orbit excursion in the hadron ring. The solenoid also couples the transverse and longitudinal motions of both beams, when crab cavities are also considered. In this paper, we present schemes for closed orbit correction and coupling compensation at the IP, including crabbing.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB041

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paper received ※ 28 May 2021 paper accepted ※ 31 August 2021 issue date ※ 12 August 2021

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TUPAB042

Large Radial Shifts in the EIC Hadron Storage Ring

1443

S. Peggs, J.S. Berg, K.A. Drees, X. Gu, C. Liu, H. Lovelace III, Y. Luo, G.J. Marr, A. Marusic, F. Méot, R.J. Michnoff, V. Ptitsyn, G. Robert-Demolaize, M. Valette, S. Verdú-Andrés
BNL, Upton, New York, USA
K.E. Deitrick
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
B.R. Gamage
JLab, Newport News, Virginia, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
The Electron Ion Collider will collide hadrons in the Hadron Storage Ring (HSR) with ultra-relativistic electrons in the Electron Storage Ring. The HSR design trajectory includes a large radial shift over a large fraction of its circumference, in order to adjust the hadron path length to synchronize collisions over a broad range of hadron energies. The design trajectory goes on-axis through the magnets, crab cavities and other components in the six HSR Insertion Regions. This paper discusses the issues involved and reports on past and future beam experiments in the Relativistic Heavy Ion Collider, which will be upgraded to become the HSR.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB042

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paper received ※ 18 May 2021 paper accepted ※ 15 June 2021 issue date ※ 21 August 2021

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WEXA04

The RCS Design Status for the Electron Ion Collider

2521

V.H. Ranjbar, M. Blaskiewicz, Z.A. Conway, D.M. Gassner, C. Hetzel, B. Lepore, H. Lovelace III, I. Marneris, F. Méot, C. Montag, J. Skaritka, N. Tsoupas, E. Wang, F.J. Willeke
BNL, Upton, New York, USA
J.M. Grames, J. Guo, F. Lin, V.S. Morozov, T. Satogata
JLab, Newport News, Virginia, USA
D. Sagan
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The design of the Electron-Ion Collider Rapid Cycling Synchrotron (RCS) to be constructed at Brookhaven National Laboratory is advancing to meet the injection requirements for the Electron Storage Ring (ESR). Over the past year activities are focused on developing the approach to inject two 28 nC bunches every second, up from the original design of one 10nC bunch every second. The solution requires several key changes concerning the injection and extraction kickers, charge accumulation via bunch merging and a carefully calibrated RF acceleration profile to match the longitudinal emittance required by the ESR.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXA04

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paper received ※ 19 May 2021 paper accepted ※ 31 August 2021 issue date ※ 10 August 2021

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WEPAB001

Accelerator Challenges of the LHeC Project

2570

B.J. Holzer, K.D.J. André, O.S. Brüning
CERN, Geneva, Switzerland
S.A. Bogacz
JLab, Newport News, Virginia, USA
M. Klein
The University of Liverpool, Liverpool, United Kingdom

The LHeC project studies the design of a future electron-proton collider at CERN that will run in parallel to the standard LHC operation. For this purpose, the existing LHC storage ring will be combined with an Energy Recovery Linac (ERL), to accelerate electrons up to kinetic energy of 50 GeV. This concept - also applicable to the FCC-eh collider and studied at the PERLE project as prototype version - allows a peak luminosity of 10³⁴ cm^-2 s^-1. A sophisticated design of the RF structures, linacs, arcs, and interaction region is required. The electrons are accelerated and, after the interaction point, their energy is recovered through the same RF structures. While this energy recovery concept is a very promising approach, severe challenges are set by the layout of the interaction region, the beam separation concept and the design of the linac and arc lattice for the highest possible momentum acceptance. Emittance control and beam-beam effect of both, electron and proton beams, have been studied in front-to-end simulations and will be presented. We summarise the design principles of the ERL, the optimization of the arc lattice, and the main parameters of the project.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB001

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paper received ※ 17 May 2021 paper accepted ※ 21 June 2021 issue date ※ 21 August 2021

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WEPAB002

The Interaction Region of the Electron-Ion Collider EIC

2574

H. Witte, J. Adam, M. Anerella, E.C. Aschenauer, J.S. Berg, M. Blaskiewicz, A. Blednykh, W. Christie, J.P. Cozzolino, K.A. Drees, D.M. Gassner, K. Hamdi, C. Hetzel, H.M. Hocker, D. Holmes, A. Jentsch, A. Kiselev, P. Kovach, H. Lovelace III, Y. Luo, G.J. Mahler, A. Marone, G.T. McIntyre, C. Montag, R.B. Palmer, B. Parker, S. Peggs, S.R. Plate, V. Ptitsyn, G. Robert-Demolaize, C.E. Runyan, J. Schmalzle, K.S. Smith, S. Tepikian, P. Thieberger, J.E. Tuozzolo, F.J. Willeke, Q. Wu, Z. Zhang
BNL, Upton, New York, USA
B.R. Gamage, T.J. Michalski, V.S. Morozov, M.L. Stutzman, W. Wittmer
JLab, Newport News, Virginia, USA
M.K. Sullivan
SLAC, Menlo Park, California, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
This paper presents an overview of the Interaction Region (IR) design for the planned Electron-Ion Collider (EIC) at Brookhaven National Laboratory. The IR is designed to meet the requirements of the nuclear physics community *. The IR design features a ±4.5 m free space for the detector; a forward spectrometer magnet is used for the detection of hadrons scattered under small angles. The hadrons are separated from the neutrons allowing detection of neutrons up to ±4 mrad. On the rear side, the electrons are separated from photons using a weak dipole magnet for the luminosity monitor and to detect scattered electrons (e-tagger). To avoid synchrotron radiation backgrounds in the detector no strong electron bending magnet is placed within 40 m upstream of the IP. The magnet apertures on the rear side are large enough to allow synchrotron radiation to pass through the magnets. The beam pipe has been optimized to reduce the impedance; the total power loss in the central vacuum chamber is expected to be less than 90 W. To reduce risk and cost the IR is designed to employ standard NbTi superconducting magnets, which are described in a separate paper.
* An Assessment of U.S.-Based Electron-Ion Collider Science. (2018). Washington, D.C.: National Academies Press. https://doi.org/10.17226/25171

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB002

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paper received ※ 18 May 2021 paper accepted ※ 25 June 2021 issue date ※ 31 August 2021

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WEPAB004

Electron-Ion Luminosity Maximization in the EIC

2582

W. Fischer, E.C. Aschenauer, M. Blaskiewicz, K.A. Drees, A.V. Fedotov, H. Huang, C. Montag, V. Ptitsyn, D. Raparia, V. Schoefer, K.S. Smith, P. Thieberger, F.J. Willeke
BNL, Upton, New York, USA
Y. Zhang
JLab, Newport News, Virginia, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
The electron-ion luminosity in EIC has a number of limits, including the ion intensity available from the injectors, the total ion beam current, the electron bunch intensity, the total electron current, the synchrotron radiation power, the beam-beam effect, the achievable beta functions at the interaction points (IPs), the maximum angular spreads at the IP, the ion emittances reachable with stochastic or strong cooling, the ratio of horizontal to vertical emittance, and space charge effects. We map the e-A luminosity over the center-of-mass energy range for some ions ranging from deuterons to uranium ions. For e-Au collisions the present design provides for electron-nucleon (e-Au) peak luminosities of 1.7x1033 cm^-2s⁻¹ with stochastic cooling, and 4.7x1033 cm^-2s⁻¹ with strong hadron cooling.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB004

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paper received ※ 18 May 2021 paper accepted ※ 21 June 2021 issue date ※ 20 August 2021

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WEPAB005

Design Status Update of the Electron-Ion Collider

2585

C. Montag, E.C. Aschenauer, G. Bassi, J. Beebe-Wang, J.S. Berg, M. Blaskiewicz, A. Blednykh, J.M. Brennan, S.J. Brooks, K.A. Brown, Z.A. Conway, K.A. Drees, A.V. Fedotov, W. Fischer, C. Folz, D.M. Gassner, X. Gu, R.C. Gupta, Y. Hao, A. Hershcovitch, C. Hetzel, D. Holmes, H. Huang, W.A. Jackson, J. Kewisch, Y. Li, C. Liu, H. Lovelace III, Y. Luo, M. Mapes, D. Marx, G.T. McIntyre, F. Méot, M.G. Minty, S.K. Nayak, R.B. Palmer, B. Parker, S. Peggs, B. Podobedov, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, S. Seletskiy, V.V. Smaluk, K.S. Smith, S. Tepikian, R. Than, P. Thieberger, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, S. Verdú-Andrés, E. Wang, D. Weiss, F.J. Willeke, H. Witte, Q. Wu, W. Xu, A. Zaltsman, W. Zhang
BNL, Upton, New York, USA
S.V. Benson, J.M. Grames, F. Lin, T.J. Michalski, V.S. Morozov, E.A. Nissen, J.P. Preble, R.A. Rimmer, T. Satogata, A. Seryi, M. Wiseman, W. Wittmer, Y. Zhang
JLab, Newport News, Virginia, USA
Y. Cai, Y.M. Nosochkov, G. Stupakov, M.K. Sullivan
SLAC, Menlo Park, California, USA
K.E. Deitrick, C.M. Gulliford, G.H. Hoffstaetter, J.E. Unger
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
E. Gianfelice-Wendt
Fermilab, Batavia, Illinois, USA
T. Satogata
ODU, Norfolk, Virginia, USA
D. Xu
FRIB, East Lansing, Michigan, USA

Funding: Work supported by BSA, LLC under Contract No. DE-SC0012704, by JSA, LLC under Contract No. DE-AC05-06OR23177, and by SLAC under Contract No. DE-AC02-76SF00515 with the U.S. Department of Energy.
The design of the electron-ion collider EIC to be constructed at Brookhaven National Laboratory has been continuously evolving towards a realistic and robust design that meets all the requirements set forth by the nuclear physics community in the White Paper. Over the past year activities have been focused on maturing the design, and on developing alternatives to mitigate risk. These include improvements of the interaction region design as well as modifications of the hadron ring vacuum system to accommodate the high average and peak beam currents. Beam dynamics studies have been performed to determine and optimize the dynamic aperture in the two collider rings and the beam-beam performance. We will present the EIC design with a focus on recent developments.

Poster WEPAB005 [2.095 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB005

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paper received ※ 14 May 2021 paper accepted ※ 22 June 2021 issue date ※ 16 August 2021

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WEPAB006

EIC Crab Cavity Multipole Analysis

2589

Q. Wu, Y. Luo, B.P. Xiao
BNL, Upton, New York, USA
S.U. De Silva
ODU, Norfolk, Virginia, USA
J.A. Mitchell
CERN, Geneva, Switzerland

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
Crab cavities are specialized RF devices designed for colliders targeting high luminosities. It is a straightforward solution to retrieve head-on collision with crossing angle existing to fast separate both beams after collision. The Electron Ion Collider (EIC) has a crossing angle of 25 mrad, and will use local crabbing to minimize the dynamic aperture requirement throughout the rings. The current crab cavity design for the EIC lacks axial symmetry. Therefore, their higher order components of the fundamental deflecting mode have a potential of affecting the long-term beam stability. We present here the multipole analysis and preliminary particle tracking results from the current crab cavity design.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB006

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paper received ※ 18 May 2021 paper accepted ※ 25 June 2021 issue date ※ 16 August 2021

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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.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB008

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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.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB009

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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.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB010

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paper received ※ 17 May 2021 paper accepted ※ 23 June 2021 issue date ※ 12 August 2021

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THPAB002

Lattice Design for BEPCII Upgrade

3756

H. Geng, W.B. Liu, J. Qiu, J. Xing, C.H. Yu, Y. Zhang
IHEP, Beijing, People’s Republic of China

The Beijing Electron Positron Collider II (BEPCII) has achieved a series of achievements in high-energy physics study. Along with the deepening of the research, more important physics is expected in higher energy regions (>2.1 GeV). As the upper limit of BEPCII design energy is 2.1GeV, an urgent upgrade is required for BEPCII. To achieve a higher luminosity at higher energy, the number of RF cavities is expected to be doubled. In this paper, the lattice design for the upgrade of BEPCII is studied. The dynamic aperture tracking result shows that the lattice could meet the injection requirement of the BEPCII beam with a reasonable margin.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB002

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paper received ※ 14 May 2021 paper accepted ※ 17 June 2021 issue date ※ 14 August 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.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB015

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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.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB028

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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

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paper received ※ 17 May 2021 paper accepted ※ 01 September 2021 issue date ※ 28 August 2021

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