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Zelenski, A.

Paper Title Page
TUODKI04 Accelerating Polarized Protons to 250 GeV 745
  • M. Bai, L. Ahrens, I. G. Alekseev, J. G. Alessi, J. Beebe-Wang, M. Blaskiewicz, A. Bravar, J. M. Brennan, K. A. Brown, D. Bruno, G. Bunce, J. J. Butler, P. Cameron, R. Connolly, T. D'Ottavio, J. DeLong, K. A. Drees, W. Fischer, G. Ganetis, C. J. Gardner, J. W. Glenn, T. Hayes, H.-C. Hseuh, H. Huang, P. F. Ingrassia, J. S. Laster, R. C. Lee, A. U. Luccio, Y. Luo, W. W. MacKay, Y. Makdisi, G. J. Marr, A. Marusic, G. T. McIntyre, R. J. Michnoff, C. Montag, J. Morris, P. Oddo, B. Oerter, J. Piacentino, F. C. Pilat, V. Ptitsyn, T. Roser, T. Satogata, K. Smith, S. Tepikian, D. Trbojevic, N. Tsoupas, J. E. Tuozzolo, M. Wilinski, A. Zaltsman, A. Zelenski, K. Zeno, S. Y. Zhang
    BNL, Upton, Long Island, New York
  • D. Svirida
    ITEP, Moscow
  Funding: The work was performed under the US Department of Energy Contract No. DE-AC02-98CH1-886, and with support of RIKEN(Japan) and Renaissance Technologies Corp.(USA)

The Relativistic Heavy Ion Collider~(RHIC) as the first high energy polarized proton collider was designed to provide polarized proton collisions at a maximum beam energy of 250GeV. It has been providing collisions at a beam energy of 100GeV since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during the acceleration from injection to 100GeV with careful control of the betatron tunes and the vertical orbit distortions. However, the intrinsic spin resonances beyond 100GeV are about a factor of two stronger than those below 100GeV making it important to examine the impact of these strong intrinsic spin resonances on polarization survival and the tolerance for vertical orbit distortions. Polarized protons were accelerated to the record energy of 250GeV in RHIC with a polarization of 45\% measured at top energy in 2006. The polarization measurement as a function of beam energy also shows some polarization loss around 136GeV, the first strong intrinsic resonance above 100GeV. This paper presents the results and discusses the sensitivity of the polarization survival to orbit distortions.

slides icon Slides  
FROAAB01 Towards a 100% Polarization in the RHIC Optically Pumped Polarized Ion Source 3771
  • A. Zelenski, J. G. Alessi, A. Kponou, J. Ritter, V. Zubets
    BNL, Upton, Long Island, New York
  The main depolarization factors in the multi-step spin-transfer polarization technique and basic limitations on maximum polarization in the different OPPIS (Optically-Pumped Polarized H- Ion Source) schemes will be discussed. Detailed studies of polarization losses in the RHIC OPPIS and the source parameters optimization resulted in the OPPIS polarization increase to 86?1.5 %. This contributed to AGS and RHIC polarization increase to 65-70%.  
slides icon Slides  
FRPMS112 Absolute Measurement of the Polarization of High Energy Proton Beams at RHIC 4369
  • Y. Makdisi, A. Bravar, G. Bunce, R. L. Gill, H. Huang, A. Khodinov, A. Kponou, Z. Li, W. Meng, A. N. Nass, S. Rescia, A. Zelenski
    BNL, Upton, Long Island, New York
  • I. G. Alekseev, D. Svirida
    ITEP, Moscow
  • M. Chapman, W. Haeberli, T. Wise
    UW-Madison/PD, Madison, Wisconsin
  • S. Dhawan
    Yale University, Physics Department, New Haven, CT
  • O. Eyser
    UCR, Riverside, California
  • O. Jinnouchi, I. Nakagawa
    RBRC, Upton, Long Island, New York
  • H. Okada, N. Saito
    Kyoto University, Kyoto
  • E. J. Stephenson
    IUCF, Bloomington, Indiana
  Funding: Work supported by the Department of Energy Contract no. DE-AC02-98CH10886 and the RIKEN BNL Research Center.

The spin physics program at the Relativistic Heavy Ion Collider (RHIC) requires knowledge of the proton beam polarization to better than 5%. To achieve this goal, a polarized hydrogen jet target was installed in RHIC where it intersects both beams. The premise is to utilize the precise knowledge of the jet proton polarization to measure the analyzing power in the proton - proton elastic scattering process in the Coulomb Nuclear Interference (CNI) region at the prescribed RHIC proton beam energy, then use the reverse reaction to measure the degree of the beam polarization, and finally confront the results with simultaneous measurements by the fast high statistics polarimeter that measure the p-Carbon elastic scattering process in the CNI region to calibrate the latter. In this presentation, the polarized jet target mechanics, operation, detector systems and the p-Carbon polarimeter are described. The statistical accuracy attained as well as the systematic uncertainties will be discussed. Such techniques may well become the standard for high energy polarized proton beams planned elsewhere in Russia and Japan.