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Kponou, A.

Paper Title Page
TUPAS083 Design and Performance of the Matching Beamline between the BNL EBIS and an RFQ 1844
 
  • J. G. Alessi, E. N. Beebe, J. Brodowski, A. Kponou, M. Okamura, A. I. Pikin, D. Raparia, J. Ritter, L. Snydstrup, V. Zajic
    BNL, Upton, Long Island, New York
 
  Funding: Work performed under the auspices of the U. S. Department of Energy and the U. S. National Aeronautics and Space Administration.

A part of a new EBIS-based heavy ion preinjector, the low energy beam transport (LEBT) section between the high current EBIS and the RFQ is a challenging design, because it must serve many functions. In addition to the requirement to provide an efficient matching between the EBIS and the RFQ, this line must serve as a fast switchyard, allowing singly charged ions from external sources to be transported into the EBIS trap region, and extracted, highly charged ions to be deflected to off-axis diagnostics (time-of-flight, or emittance). The space charge of the 5-10 mA extracted heavy ion beam is a major consideration in the design, and the space charge force varies for different ion beams having Q/m from 1-0.16. The line includes electrostatic lenses, spherical and parallel-plate deflectors, magnetic solenoid, and diagnostics for measuring current, charge state distributions, emittance, and profile. A prototype of this beamline has been built, and results of tests will be presented.

 
TUPAS102 End-to-End Simulation for the EBIS Preinjector 1874
 
  • D. Raparia, J. G. Alessi, A. Kponou, A. I. Pikin, J. Ritter
    BNL, Upton, Long Island, New York
  • S. Minaev, U. Ratzinger, A. Schempp, R. Tiede
    IAP, Frankfurt am Main
 
  Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH1-886 with the U. S. Department of Energy. .

The EBIS (Electron Beam Ion Source) Project at Brookhaven National Laboratory is in the second year of a four-year project. It will replace the Tandem Van de Graaff accelerators with an EBIS, an RFQ, and one IH Linac cavity as the heavy ion preinjector for the Relativistic Heavy Ion Collider (RHIC), and for the NASA Space Radiation Laboratory (NSRL). The preinjector will provide all ions species, He to U, (Q/m>0.16) at 2 MeV/amu at a repetition rate of 5 Hz, pulse length of 10–40 μs, and intensities of ~2.0 mA. End-to-end simulations (from EBIS to the Booster injection) as well as error sensitivity studies will be presented and physics issues will be discussed.

#Raparia@bnl.gov

 
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  
FRYAB02 High-Performance EBIS for RHIC 3782
 
  • J. G. Alessi, E. N. Beebe, O. Gould, A. Kponou, R. Lockey, A. I. Pikin, D. Raparia, J. Ritter, L. Snydstrup
    BNL, Upton, Long Island, New York
 
  Funding: Work performed under the auspices of the U. S. Department of Energy and the U. S. National Aeronautics and Space Administration.

An Electron Beam Ion Source (EBIS), capable of producing high charge states and high beam currents of any heavy ion species in short pulses, is ideally suited for injection into a synchrotron. An EBIS-based, high current, heavy ion preinjector is now being built at Brookhaven to provide increased capabilities for the Relativistic Heavy Ion Collider (RHIC), and the NASA Space Radiation Laboratory (NSRL). Benefits of the new preinjector include the ability to produce ions of any species, fast switching between species to serve the simultaneous needs of multiple programs, and lower operating and maintenance costs. A state-of-the-art EBIS, operating with an electron beam current of up to 10 A, and producing multi-milliamperes of high charge state heavy ions, has been developed at Brookhaven, and has been operating very successfully on a test bench for several years. The present performance of this high-current EBIS will be presented, along with details of the design of the scaled-up EBIS for RHIC, and the status of its construction. Other aspects of the project, including design and construction of the heavy ion RFQ, Linac, and matching beamlines, will also be mentioned.

 
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.