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Zolfaghari, A.

Paper Title Page
MOPKF084 Beam Instabilities in Lepton Ring of eRHIC 515
 
  • D. Wang, M. Farkhondeh, C. Tschalaer, J. Van der Laan, F. Wang, A. Zolfaghari, T. Zwart
    MIT/BLAC, Middleton, Massachusetts
  • M. Blaskiewicz, Y. Luo, L. Wang
    BNL, Upton, Long Island, New York
 
  The eRHIC is a high luminosity lepton-hadron collider planned to be built in Brookhaven National Lab, Upton, New York, USA. The lepton machine of eRHIC is a completely newly designed machine complex to provide highly polarized lepton beams at up to 10 GeV energy for the high luminosity lepton-hadron collisions. This paper decribes major issues of collective effects in this lepton storage ring. Besides conventional impedance-driven instabilities, the electron cloud effects in positron operation and fast beam-ion effects in electron operation are of major conserns. The analytical and numerical estimats for major collective effects are made with different machine operation conditions.  
TUPKF065 Comparison of Klystron and Inductive Output Tubes (IOT) Vacuum-electron Devices for RF Amplifier Service in Free-electron Laser 1093
 
  • A. Zolfaghari, P. MacGibbon, W. North
    MIT/BLAC, Middleton, Massachusetts
 
  The MIT X-Ray Laser project, conceived to produce output in the 0.3 to 100 nanometer range, is based on a super-conducting 4-GEV linear accelerator, using 24 multi-cavity cryo-modules, each with its own dedicated RF amplifier, operating at 1.3 GHz. The continuous output of each amplifier is nominally 15 kW, with an optional repetitive pulse-modulation mode of 0.1 second pulse duration at one pulse per second. Although there are no fundamental restraints which preclude the consideration of any RF amplifier type, including solid-state or conventional triode or tetrode, the most appropriate current technology includes the Klystron and the IOT (Inductive Output Tube), also known by the CPI trade-name, Klystrode. The mechanisms by which the devices convert DC input power into RF output power are discussed. The devices are then compared with regard to availability (developmental or off-the-shelf), conversion efficiency, means of pulse-modulation, RF power gain, phase and amplitude stability (pushing factors), and acquisition and life-cycle costs.  
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.