Author: Marusic, A.
Paper Title Page
MOYBA6 Accelerator Performance During the Beam Energy Scan II at RHIC in 2019 26
 
  • C. Liu, I. Blacker, M. Blaskiewicz, K.A. Brown, D. Bruno, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, C.E. Giorgio, X. Gu, T. Hayes, H. Huang, R.L. Hulsart, D. Kayran, N.A. Kling, Y. Luo, D. Maffei, G.J. Marr, B. Martin, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, C. Naylor, S. Nemesure, I. Pinayev, S. Polizzo, V.H. Ranjbar, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, S. Tepikian, P. Thieberger, A. Zaltsman, K. Zeno, I.Y. Zhang, W. Zhang
    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.
RHIC provided Au-Au collisions at beam energies of 9.8, 7.3, 4.59 and 3.85 GeV/nucleon during the first year of the Beam Energy Scan II in 2019. The physics goals at the first two higher beam energies were achieved. At the two lower beam energies, bunched electron beam cooling has been demonstrated successfully. The accelerator performance was improved compared to when RHIC was operated at these energies in earlier years. This article will introduce the challenges to operate RHIC at low energies and the corresponding countermeasures, and review the improvement of accelerator performance during the operation in 2019.
 
slides icon Slides MOYBA6 [6.579 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOYBA6  
About • paper received ※ 21 August 2019       paper accepted ※ 06 September 2019       issue date ※ 08 October 2019  
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TUPLO05 Fixed Target Operation at RHIC in 2019 542
 
  • C. Liu, I. Blacker, M. Blaskiewicz, K.A. Brown, D. Bruno, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, C.E. Giorgio, X. Gu, T. Hayes, H. Huang, R.L. Hulsart, D. Kayran, N.A. Kling, Y. Luo, D. Maffei, G.J. Marr, B. Martin, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, C. Naylor, S. Nemesure, I. Pinayev, S. Polizzo, V.H. Ranjbar, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, S. Tepikian, P. Thieberger, A. Zaltsman, K. Zeno, I.Y. Zhang, W. Zhang
    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.
RHIC operated in fixed target mode at beam energies 4.59, 7.3, and 31.2 GeV/nucleon in 2019 as a part of the Beam Energy Scan II program. To scrape beam halo effectively at the fixed target which is 2.05 m away from the center of the STAR detectors, lattice design with relative large beta function at STAR was implemented at the two lower energies. The kickers of the base-band tune (BBQ) measurement system were engaged to dilute the beam transversely to maintain the event rate except for 31.2 GeV/nucleon. In addition, beam orbit control, tune and chromaticity adjustments were used to level the event rate. This paper will review the operational experience of RHIC in fixed target mode at various energies.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLO05  
About • paper received ※ 21 August 2019       paper accepted ※ 15 September 2019       issue date ※ 08 October 2019  
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TUPLO12 Off-Momentum Optics Correction in RHIC 556
 
  • G. Robert-Demolaize, A. Marusic, V. Ptitsyn
    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.
Future operations of the electron-ion collider eRHIC call for beams circulating off of the magnetic center of all arc elements. In order to ensure that both stable beam conditions and the desired circumference change can be achieved, dedicated experiments were conducted during RHIC Run18, which included the first off-momentum linear optics correction. This article reviews the experimental setup as well as the dedicated algorithm for optics correction, and presents the measured radial excursion and residual off-momentum beta-beat.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLO12  
About • paper received ※ 27 August 2019       paper accepted ※ 15 September 2019       issue date ※ 08 October 2019  
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THZBA5 First Electron Cooling of Hadron Beams Using a Bunched Electron Beam 957
 
  • A.V. Fedotov, Z. Altinbas, M. Blaskiewicz, J.M. Brennan, D. Bruno, J.C. Brutus, M.R. Costanzo, K.A. Drees, W. Fischer, J.M. Fite, M. Gaowei, D.M. Gassner, X. Gu, J. Halinski, K. Hamdi, L.R. Hammons, T. Hayes, R.L. Hulsart, P. Inacker, J.P. Jamilkowski, Y.C. Jing, P.K. Kankiya, D. Kayran, J. Kewisch, D. Lehn, C.J. Liaw, C. Liu, J. Ma, G.J. Mahler, M. Mapes, A. Marusic, K. Mernick, C. Mi, R.J. Michnoff, T.A. Miller, M.G. Minty, S.K. Nayak, L.K. Nguyen, M.C. Paniccia, I. Pinayev, S. Polizzo, V. Ptitsyn, T. Rao, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, L. Smart, K.S. Smith, H. Song, A. Sukhanov, R. Than, P. Thieberger, S.M. Trabocchi, J.E. Tuozzolo, P. Wanderer, E. Wang, G. Wang, D. Weiss, B.P. Xiao, T. Xin, W. Xu, A. Zaltsman, H. Zhao, Z. Zhao
    BNL, Upton, New York, USA
 
  Funding: Work supported by the U.S. Department of Energy.
The Low Energy RHIC electron Cooler (LEReC) was recently constructed and commissioned at BNL. The LEReC is the first electron cooler based on the RF acceleration of electron bunches (previous electron coolers all used DC beams). Bunched electron beams are necessary for cooling hadron beams at high energies. The challenges of such an approach include generation of electron beams suitable for cooling, delivery of electron beams of the required quality to the cooling sections without degradation of beam emittances and energy spread, achieving required small angles between electrons and ions in the cooling sections, precise energy matching between the two beams, high-current operation of the electron accelerator, as well as several physics effects related to bunched beam cooling. Following successful commissioning of the electron accelerator in 2018, the focus of the LEReC project in 2019 was on establishing electron-ion interactions and demonstration of cooling process using electron energy of 1.6MeV (ion energy of 3.85GeV/n), which is the lowest energy of interest. Here we report on the first demonstration of Au ion cooling in RHIC using this new approach.
 
slides icon Slides THZBA5 [16.417 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THZBA5  
About • paper received ※ 16 August 2019       paper accepted ※ 31 August 2019       issue date ※ 08 October 2019  
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