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Ptitsyn, V.

Paper Title Page
MOPLT148 Progress of the eRHIC Electron Ring Design 887
 
  • F. Wang, M. Farkhondeh, W. Franklin, W. Graves, R. Milner, C. Tschalaer, J. Van der Laan, D. Wang, A. Zolfaghari, T. Zwart
    MIT/BLAC, Middleton, Massachusetts
  • D.P. Barber
    DESY, Hamburg
  • C. Montag, S. Peggs, V. Ptitsyn
    BNL, Upton, Long Island, New York
  • A.V. Otboev, Y.M. Shatunov
    BINP SB RAS, Novosibirsk
  • J. Shi
    KU, Lawrence, Kansas
  
  Over the past year, a baseline design of the electron ring for the eRHIC hadron-lepton collider has been developed.This site-specific design is based on the understanding of the existing RHIC machine performance and its possible upgrades.The design includes a full energy polarized electron beam injector to ensure operational reliability and to provide high integrated luminosity.The electron ring energy range is 5 to 10 GeV.The electron beam emittance, the electron beam path length and the interaction region optics have to be adjusted over a wide range to match the hadron beam of various species and variable energies.We describe the expected machine perfomance, the interaction region and the lattice design. We also discuss the possible approaches leading to the 1033 cm-2s-1 luminosity for the collisions between 10 GeV polarized electron beam and 250 GeV polarized proton beam.  
MOPLT170 eRHIC, Future Electron-ion Collider at BNL 923
 
  • V. Ptitsyn, L. Ahrens, M. Bai, J. Beebe-Wang, I. Ben-Zvi, M. Blaskiewicz, J.M. Brennan, R. Calaga, X. Chang, E.D. Courant, A. Deshpande, A.V. Fedotov, W. Fischer, H. Hahn, J. Kewisch, V. Litvinenko, W.W. MacKay, C. Montag, S. Ozaki, B. Parker, S. Peggs, T. Roser, A. Ruggiero, B. Surrow, S. Tepikian, D. Trbojevic, V. Yakimenko, S.Y. Zhang
    BNL, Upton, Long Island, New York
  • D.P. Barber
    DESY, Hamburg
  • M. Farkhondeh, W. Franklin, W. Graves, R. Milner, C. Tschalaer, J. Van der Laan, D. Wang, F. Wang, A. Zolfaghari, T. Zwart
    MIT/BLAC, Middleton, Massachusetts
  • A.V. Otboev, Y.M. Shatunov
    BINP SB RAS, Novosibirsk
  
  The paper reviews the progress made lately in the design of eRHIC, proposed future electron-ion collider on the basis of the existing RHIC machine. The eRHIC aims to provide collisions of electrons and positrons on ions and protons in center mass energy range of 25-70 GeV. The goal luminosities are in 1032-1033 1/(s*cm2) values for e-p and in 1030-1031 1/(s*cm2) values for e-Au collisions. An essential design requirement is to provide longitudinally polarized beams of electrons and protons (and, possibly lighter ions) at the collision point. The eRHIC ZDR has been recently developed which considers various aspects of the accelerator design. An electron accelerator, which delivers about 0.5A polarized electron beam current in the electron energy range of 5 to 10 GeV, should be constructed at the BNL near existing ion rings of the RHIC collider and should intersect an ion ring at least in one of the available ion ring interaction regions. In order to reach the luminosity goals some upgrades in ion rings also would be required. Ways to reach lower beam emmittances (electron cooling) and higher beam intensities have to be realized.  
MOPLT172 Quest for a New Working Point in RHIC 929
 
  • R. Tomas, M. Bai, W. Fischer, V. Ptitsyn, T. Roser, T. Satogata
    BNL, Upton, Long Island, New York
  
  The beam-beam interaction is a limiting factor in RHIC's performance, particularly in proton operation. Changing the working point is a strategy to minimize the beam-beam effect and improve the performance of the machine. Experiments at injection energy and simulations have been performed for a set of working points in order to determine what are the best candidates.  
TUPLT012 Adjusting the IP Beta-functions in RHIC. 1156
 
  • W. Wittmer, F. Zimmermann
    CERN, Geneva
  • F.C. Pilat, V. Ptitsyn, J. Van Zeijts
    BNL, Upton, Long Island, New York
  
  The beta- functions at the IP can be adjusted without perturbation of other optics functions via several approaches. In this paper we describe a scheme based on a vector knob, which assigns fixed values to the different tuning quadrupoles and scales them by a common multiplier. The values for the knob vector were calculated for a lattice without any errors using MADX. Previous studies for the LHC have shown that this approach can meet the design goals. A specific feature of the RHIC lattice is the nested power supply system. To cope with the resulting problems a detailed response matrix analysis has been carried out and different sets of knobs were calculated and compared. The knobs are tested at RHIC during the 2004 run and preliminary results maybe discussed. Simultaneously a new approach to measure the beam sizes of both colliding beams at the IP, based on the tune ability provided by the knobs, was developed and tested.  
TUPLT182 Measuring Local Gradient and Skew Quadrupole Errors in RHIC IRs 1553
 
  • J.F. Cardona
    UNAL, Bogota D.C
  • S. Peggs, F.C. Pilat, V. Ptitsyn
    BNL, Upton, Long Island, New York
  
  The measurement of local linear errors at RHIC interaction regions using an "action and phase" analysis of difference orbits has already been presented [*]. This paper evaluates the accuracy of this technique using difference orbits that were taken when known gradient errors and skew quadrupole errors were intentionally introduced. It also presents action and phase analysis of simulated orbits when controlled errors are intentionally placed in a RHIC simulation model.

* J. Cardona, S. Peggs, T. Satogata, F. Pilat and V. Ptitsyn,"Determination of Linear and Non Linear Components in RHIC Interaction Regions from difference Orbit Measurements", EPAC 2002, Paris, 2002, p.311-313.

 
THPLT179 MADX-UAL Suite for Off-line Accelerator Design and Simulation 2870
 
  • N. Malitsky, R.P. Fliller III, F.C. Pilat, V. Ptitsyn, S. Tepikian, J. Wei
    BNL, Upton, Long Island, New York
  • F. Schmidt
    CERN, Geneva
  • R.M. Talman
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  
  We present here an accelerator modeling suite that integrates the capability of MADX and UAL packages, based on the Standard eXchange Format (SXF) interface. The resulting environment introduces a one-stop collection of accelerator applications ranging from the lattice design to complex beam dynamics studies. The extended capabilities of the MADX-UAL integrated approach have been tested and effectively used in two accelerator projects: RHIC, where direct comparison of operational and simulated data is possible, and the SNS Accumulator Ring, still in its design phase.  
MOPLT165 Luminosity Increases in Gold-gold Operation in RHIC 917
 
  • W. Fischer, L. Ahrens, J. Alessi, M. Bai, D. Barton, J. Beebe-Wang, M. Blaskiewicz, J.M. Brennan, D. Bruno, J. Butler, R. Calaga, P. Cameron, R. Connolly, T. D'Ottavio, J. DeLong, K.A. Drees, W. Fu, G. Ganetis, J. Glenn, T. Hayes, P. He, H.-C. Hseuh, H. Huang, P. Ingrassia, U. Iriso, R. Lee, Y. Luo, W.W. MacKay, G. Marr, A. Marusic, R. Michnoff, C. Montag, J. Morris, T. Nicoletti, B. Oerter, C. Pearson, S. Peggs, A. Pendzick, F.C. Pilat, V. Ptitsyn, T. Roser, J. Sandberg, T. Satogata, C. Schultheiss, A. Sidi-Yekhlef, L. Smart, S. Tepikian, R. Tomas, D. Trbojevic, N. Tsoupas, J. Tuozzolo, J. Van Zeijts, K. Vetter, K. Yip, A. Zaltsman, S.Y. Zhang, W. Zhang
    BNL, Upton, Long Island, New York
  
  After an exploratory phase, during which a number of beam parameters were varied, the RHIC experiments now demand high luminosity to study heavy ion collisions in detail. Presently RHIC operates routinely above its design luminosity. In the first 4 weeks of its current operating period (Run-4) the machine has delivered more integrated luminosity that during the 14 weeks of the last gold-gold operating period (Run-2). We give an overview of the changes that increased the instantaneous luminosity and luminosity lifetime, raised the reliability, and improved the operational efficiency.  
MOPLT167 RHIC Operation with Longitudinally Polarized Protons 920
 
  • H. Huang, M. Bai, J. Beebe-Wang, M. Blaskiewicz, J.M. Brennan, K.A. Drees, W. Fischer, A.U. Luccio, W.W. MacKay, C. Montag, F.C. Pilat, V. Ptitsyn, T. Roser, T. Satogata, S. Tepikian, D. Trbojevic, J. Van Zeijts, A.Y. Zelinsky, S.Y. Zhang
    BNL, Upton, Long Island, New York
  
  Longitudinally polarized proton beams have been accelerated, stored and collided at 100GeV in the Relativistic Heavy Ion Collider (RHIC) to study spin effects in the hadronic reactions. The essential equipment includes four Siberian snakes, eight spin rotators and a fast relative polarimeters in each of the two RHIC rings as well as local polarimeters at the STAR and PHENIX detectors. This paper summarizes the performance of RHIC as a polarized proton collider.  
MOPLT178 RHIC Pressure Rise 944
 
  • S.Y. Zhang, J. Alessi, M. Bai, M. Blaskiewicz, P. Cameron, K.A. Drees, W. Fischer, R.P. Fliller III, D. Gassner, J. Gullotta, P. He, H.-C. Hseuh, H. Huang, U. Iriso, R. Lee, Y. Luo, W.W. MacKay, C. Montag, B. Oerter, S. Peggs, F.C. Pilat, V. Ptitsyn, T. Roser, T. Satogata, L. Smart, P. Thieberger, D. Trbojevic, J. Van Zeijts, L. Wang, J. Wei, K. Zeno
    BNL, Upton, Long Island, New York
  
  Beam induced pressure rise remains an intensity limit at the RHIC for both heavy ion and polarized proton operations. The beam injection pressure rise at warm sections has been diagnosed due to electron cloud effect. In addition, pressure rise of heavy ion operation at the beam transition has caused experiment background problem in deuteron-gold run, and it is expected to take place in gold-gold run at high intensities. This type of pressure rise is related to beam momentum spread, and the electron cloud seems not dominant. Extensive approaches for both diagnosis and looking-for-remedies are undergoing in the current gold operation, RUN 4. Results of beam scrubbing, NEG pipe in RHIC ring, beam scraping test of ion desorption, beam momentum effect at the transition, beam gap effect, solenoid effect, and NEG pipe ion desorption test stand will be presented.