Paper | Title | Page |
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WEPOST031 | RHIC Polarized Proton Operation in Run 22 | 1765 |
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The Relativistic Heavy Ion Collider (RHIC) Run 22 physics program consisted of collisions with vertically po- larized proton beams at a single collision point (the STAR detector). During initial startup of the collider, power out- ages damaged two of the coils in one of the RHIC helical dipole snake magnets used for polarization preservation in the Blue ring. That snake was reconfigured for use as a partial snake. We will outline some of the remediating mea- sures taken to maximize polarization transmission in this configuration. These measures included changing the col- liding beam energy from 255 GeV to 254.2 GeV to adjust the spin closed orbit at store and adjustment of the field in the other helical dipole in the Blue ring to improve injection spin matching. Later in the run, the primary motor gener- ator for the AGS (the injector to RHIC) failed and a lower voltage backup had to be used, resulting in a period of lower polarization. Other efforts include detailed measurement of the stable spin direction at store and the commissioning of a machine protection relay system to prevent spurious firing of the RHIC abort kickers. | ||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST031 | |
About • | Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 04 July 2022 | |
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WEPOPT032 | Summary of the 3-year Beam Energy Scan II operation at RHIC | 1908 |
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Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Beam Energy Scan phase II (BES-II) operation in the Relativistic Heavy Ion Collider (RHIC), aiming to explore the phase transition between quark-gluon plasma (QGP) and hadronic gas, exceeded the goal of a four-fold increase in the average luminosity over the range of five gold beam energies (9.8, 7.3, 5.75, 4.59 and 3.85 GeV/nucleon) compared to those achieved during Beam Energy Scan phase I (BES-I). We will present the achievements in BES-II together with a summary of the measures taken to improve RHIC performance in the presence of several beam dynamics effects, and details on improvements made during the operation at 3.85 GeV/nucleon in 2021. |
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DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT032 | |
About • | Received ※ 06 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 17 June 2022 | |
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WEPOPT033 | Report of RHIC Beam Operation in 2021 | 1912 |
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Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The first priority of RHIC operation in 2021 was the Au+Au collisions at 3.85 GeV/nucleon, which is the lowest energy to complete the 3-year Beam Energy Scan II physics program, with RF-based electron cooling. In addition, RHIC also operated for several other physics programs including fixed target experiments, O+O at 100 GeV/nucleon, Au+Au at 8.65 GeV/nucleon, and d+Au at 100 GeV/nucleon. This report presents the operational experience and the results from RHIC operation in 2021. With Au+Au collisions at 3.85 GeV/nucleon reported in a separate report, this paper focuses on the operation conditions for the other programs mentioned above. |
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DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT033 | |
About • | Received ※ 06 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 05 July 2022 | |
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WEPOPT036 | Dependence of Beam Size Growth on Macro-Particle’s Initial Actions in Strong-Strong Beam-Beam Simulation for the Electron-Ion Collider | 1924 |
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Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 and Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177. The Electron-Ion Collider (EIC) presently under construction at Brookhaven National Laboratory will collide polarized high energy electron beams with hadron beams with design luminosities up to 1×1034cm-2s-1 in the center mass energy range of 20-140 GeV. We simulated the planned electron-proton collision of flat beams with Particle-In-Cell (PIC) based Poisson solver in strong-strong beam-beam simulation. We observed a much larger proton emittance growth rate than that from weak-strong simulation. To understand the numerical noises further, we calculate the beam size growth rate of macro-particles as function of their initial longitudinal and transverse actions. This method is applied to both strong-strong and weak-strong simulations. The purpose of this study is to identify which group of macro-particles contributes most of the artificial emittance growth in strong-strong beam-beam simulation. |
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DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT036 | |
About • | Received ※ 22 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 22 June 2022 | |
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WEPOPT037 | Dynamic Aperture Evaluation for EIC Hadron Storage Ring with Crab Cavities and IR Nonlinear Magnetic Field Errors | 1927 |
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Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 and Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177. The electron ion collider (EIC) presently under construction at Brookhaven National Laboratory will collider polarized high energy electron beams with hadron beams with luminosities up to 1034 cm-2s-1 in the center mass energy range of 20-140 GeV. In this article, we evaluate the dynamic aperture of the Hadron Storage Ring (HSR) with symplectic element-by-element tracking. Crab cavities, nonlinear magnetic field errors, and weak-strong beam-beam interaction are included. We compared the dynamic aperture from head-on collision to crossing-angle collision and found the reason for the dynamic aperture drop. We also studied the field error tolerances for IR magnets and for some particular magnets. |
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DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT037 | |
About • | Received ※ 22 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 27 June 2022 | |
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WEPOPT038 | Summary of Numerical Noise Studies for Electron-Ion Collider Strong-Strong Beam-Beam Simulation | 1931 |
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Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy The Electron-Ion Collider (EIC) presently under construction at Brookhaven National Laboratory will collide polarized high energy electron beams with hadron beams, reaching luminosities up to 1×1034cm-2s-1 in center mass energy range of 20-140 GeV. We studied the planned electron-proton collisions using a Particle-In-Cell (PIC) based Poisson solver in strong-strong beam-beam simulation. We observed a much larger proton emittance growth rate than in weak-strong simulation. To understand the numerical noise and its impact on strong-strong simulation results, we carried out extensive studies to identify all possible causes for artificial emittance growth and quantify their contributions. In this article, we summarize our study activities and findings. This work will help us better understand the simulated emittance growth and the limits of the PIC based strong-strong beam-beam simulation. |
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DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT038 | |
About • | Received ※ 19 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 05 July 2022 | |
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WEPOPT039 | Fine Decoupling Test and Simulation Study to Maintain a Large Transverse Emittance Ratio in Hadron Storage Rings | 1935 |
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Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy I In previous and existing hadron storage rings, the horizontal and vertical emittances are normally the same or very close. For the Hadron Storage Ring (HSR) of the Electron-Ion Collider (EIC), the design proton transverse emittance ratio is 10:1. To maintain this large emittance ratio, we need to have an online fine decoupling system to prevent transverse emittance exchange. For this purpose, we carried out fine decoupling experiments in the Relativistic Heavy Ion Collider (RHIC) and reviewed its previous operational data. Analytical prediction and numerical simulation are preformed to estimate how small the global coupling coefficient should be to maintain a 10:1 emittance ratio. |
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DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT039 | |
About • | Received ※ 19 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 28 June 2022 | |
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WEPOPT040 | Numerical Noise Error of Particle-In-Cell Poisson Solver for a Flat Gaussian Bunch | 1939 |
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Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy and Jefferson Science Associates, LLC under Contract No. DE-AC05-06OR23177. The Electron-Ion Collider (EIC) presently under construction at Brookhaven National Laboratory will collider polarized high energy electron beams with hadron beams with luminosity up to 1×1034cm-2s-1 in the center mass energy range of 20-140 GeV. We simulated the planned electron-proton collision of flat beams with Particle-In-Cell (PIC) based Poisson solver in strong-strong beam-beam simulation. We observed a much larger proton emittance growth rate than that from weak-strong simulation. To better understand the emittance growth rate from the strong-strong simulation, we compare the beam-beam kicks between the PIC method and the analytical calculation and calculate the RMS variation in beam-beam kicks among 1000 sets of random Gaussian particle distributions. The impacts of macro-particle number, grid number, and bunch flatness are also studied. |
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DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT040 | |
About • | Received ※ 23 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 03 July 2022 | |
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WEPOPT041 | Strong-Strong Simulations of Coherent Beam-Beam Effects in the EIC | 1942 |
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The high luminosity electron ion collider (EIC) will provide great opportunities in nuclear physics study and is under active design. The coherent effects due to the beam-beam interaction of two colliding beams can cause beam size blow-up and degrade the luminosity in the EIC. In this paper, we report on the study of coherent beam-beam effects in the EIC design using self-consistent strong-strong simulations. These simulations show the coherent dipole and quadrupole mode instabilities in the tune working point scan and bunch intensity scan. | ||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT041 | |
About • | Received ※ 18 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 23 June 2022 | |
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WEPOPT044 | Electron-Ion Collider Design Status | 1954 |
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Funding: Work supported under Contract No. DE-SC0012704, Contract No. DE-AC05-06OR23177, Contract No. DE-AC05-00OR22725, and Contract No. DE-AC02-76SF00515 with the U.S. Department of Energy. The Electron-Ion Collider (EIC) is being designed for construction at Brookhaven National Laboratory. Activities have been focused on beam-beam simulations, polarization studies, and beam dynamics, as well as on maturing the layout and lattice design of the constituent accelerators and the interaction region. The latest design advances will be presented. |
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DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT044 | |
About • | Received ※ 03 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 03 July 2022 | |
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MOPOST009 | EIC Crab Cavity Multipole Analysis and Their Effects on Dynamic Aperture | 66 |
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Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. Crab cavity is essential for retrieving the loss in luminosity due to the large crossing angle in the two colliding beam lines of the Electron Ion Collider (EIC). Due to the asymmetric design of the proton beam crab cavity, the fundamental mode consists of contributions from higher order multipoles. These multipole modes may change during fabrication and installation of the cavities, and therefore affect the local dynamic aperture. Thresholds for each order of the multipoles are applied to ensure dynamic aperture requirements at these crab cavities. In this paper, we analyzed the strength of the multipoles due to fabrication and installation accuracies, and set limitations to each procedure to maintain the dynamic aperture requirement. |
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DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST009 | |
About • | Received ※ 06 June 2022 — Revised ※ 17 June 2022 — Accepted ※ 22 June 2022 — Issue date ※ 10 July 2022 | |
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WEIXGD1 | EIC Beam Dynamics Challenges | 1576 |
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The Electron Ion Collider aims to produce luminosities of 1034 cm-2s-1 . The machine will operate over a broad range of collision energies with highly polarized beams. The coexistence of highly radiative electrons and nonradiative ions produce a host of unique effects. Strong hadron cooling will be employed for the final factor of 3 luminosity boost. | ||
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Slides WEIXGD1 [3.952 MB] | |
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEIXGD1 | |
About • | Received ※ 06 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 14 June 2022 | |
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WEPOPT049 | Beam-Beam Interaction for Tilted Storage Rings | 1968 |
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In the Electron-Ion Collider (EIC) design, to avoid vertical orbit bumps in the Electron Storage Ring (ESR) at some crossing points with Hadron Storage Ring (HSR) to preserve the electron polarization, we plan to tilt the ESR plane by 200 ’rad with an axis connecting IP6 and IP8. In this article, we study the beam-beam interaction when two rings are not in the same plane. The Lorentz boost formula is derived and the required vertical crabbing strength is calculated to compensate the dynamic effect The strong-strong simulations are performed to validate the theory. | ||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT049 | |
About • | Received ※ 16 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 06 July 2022 | |
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WEPOPT050 | Detector Solenoid Compensation in the EIC Electron Storage Ring | 1972 |
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The Electron Ion Collider (EIC) uses crab cavities to restore the geometrical luminosity loss. Due to the space limitation, the detector solenoid cannot be compensated locally. This paper presents the lattice design to compensate the detector solenoid without interfering the crab cavities. The skew quadrupoles are employed to avoid additional crab cavities. The correction scheme is checked by beam-beam simulation. | ||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT050 | |
About • | Received ※ 19 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 28 June 2022 | |
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