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Alessi, J.G.

Paper Title Page
MOPA007 Polarized Proton Collisions at RHIC 600
 
  • M. Bai, L. Ahrens, J.G. Alessi, J. Beebe-Wang, M. Blaskiewicz, A. Bravar, J.M. Brennan, 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. Glenn, T. Hayes, H.-C. Hseuh, H. Huang, P. Ingrassia, U. Iriso, 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, T. Nicoletti, P. Oddo, B. Oerter, O. Osamu, F.C. Pilat, V. Ptitsyn, T. Roser, T. Satogata, K. Smith, S. Tepikian, R. Tomas, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, K. Vetter, M. Wilinski, A. Zaltsman, A. Zelenski, K. Zeno, S.Y. Zhang
    BNL, Upton, Long Island, New York
  • I.G. Alekseev, D. Svirida
    ITEP, Moscow
 
  Funding: The work was performed under the auspices of the U.S. Department of Energy and RIKEN Japan.

The Relativistic Heavy Ion Collider~(RHIC) provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC to avoid depolarizing resonances. In 2003, polarized proton beams were accelerated to 100~GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. RHIC polarized proton run experience demonstrates that optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limited conditions are reported.

 
MOPB004 Progress on Test EBIS and the Design of an EBIS-Based RHIC Preinjector 363
 
  • J.G. Alessi, E.N. Beebe, O. Gould, A. Kponou, R. Lockey, A.I. Pikin, K. Prelec, D. Raparia, J. Ritter, L. Snydstrup
    BNL, Upton, Long Island, New York
 
  Funding: Work supported under the auspices of the U.S. DOE.

Following the successful development of the Test EBIS at BNL,* we now have a design for an EBIS-based heavy ion preinjector which would serve as an alternative to the Tandem Van de Graaffs in providing beams for RHIC and the NASA Space Radiation Laboratory. This baseline design includes an EBIS producing mA-level currents of heavy ions (ex. Au 32+) in ~ 10-20 microsecond pulses, injecting into an RFQ which accelerates the beams to 300 keV/amu, followed by an IH linac accelerating to 2 MeV/amu. Some details of this design will be presented, as well recent experimental results on the Test EBIS.

*E.N. Beebe et al., Proc. Ninth International Symposium on Electron Beam Ion Sources and Traps, Journal of Physics: Conference Series 2 (2004) 164–173.

 
TPAT095 Beam Induced Pressure Rise at RHIC 4308
 
  • S.Y. Zhang, J.G. Alessi, M. Bai, M. Blaskiewicz, P. Cameron, K.A. Drees, W. Fischer, J. Gullotta, P. He, H.-C. Hseuh, H. Huang, U. Iriso, R.C. Lee, V. Litvinenko, W.W. MacKay, T. Nicoletti, B. Oerter, S. Peggs, F.C. Pilat, V. Ptitsyn, T. Roser, T. Satogata, L. Smart, L. Snydstrup, P. Thieberger, D. Trbojevic, L. Wang, J. Wei, K. Zeno
    BNL, Upton, Long Island, New York
 
  Beam induced pressure rise in RHIC warm sections is currently one of the machine intensity and luminosity limits. This pressure rise is mainly due to electron cloud effects. The RHIC warm section electron cloud is associated with longer bunch spacings compared with other machines, and is distributed non-uniformly around the ring. In addition to the countermeasures for normal electron cloud, such as the NEG coated pipe, solenoids, beam scrubbing, bunch gaps, and larger bunch spacing, other studies and beam tests toward the understanding and counteracting RHIC warm electron cloud are of interest. These include the ion desorption studies and the test of anti-grazing ridges. For high bunch intensities and the shortest bunch spacings, pressure rises at certain locations in the cryogenic region have been observed during the past two runs. Beam studies are planned for the current 2005 run and the results will be reported.

Work performed under the auspices of the US Department of Energy.

 
FPAE029 Setup and Performance of the RHIC Injector Accelerators for the 2005 Run with Copper Ions 2068
 
  • C.J. Gardner, L. Ahrens, J.G. Alessi, J. Benjamin, M. Blaskiewicz, J.M. Brennan, K.A. Brown, C. Carlson, J. DeLong, J. Glenn, T. Hayes, W.W. MacKay, G.J. Marr, J. Morris, T. Roser, F. Severino, K. Smith, D. Steski, N. Tsoupas, A. Zaltsman, K. Zeno
    BNL, Upton, Long Island, New York
 
  Funding: Work performed under the auspices of the U.S. Department of Energy.

Copper ions for the 2005 run of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory are accelerated in the Tandem, Booster and AGS prior to injection into RHIC. The setup and performance of this chain of accelerators will be reviewed.

 
FPAE050 Injector Linac for the BNL Super Neutrino Beam Project 3129
 
  • D. Raparia, J.G. Alessi, A. Ruggiero, W.-T. Weng
    BNL, Upton, Long Island, New York
 
  Funding: This work was performed under the auspices of the U.S. DOE, Contract No. DE-AC02-98H10886.

BNL plans to upgrade the AGS proton beam from the current 0.14 MW to higher than 1.0 MW and beyond for such a neutrino facility. We have examined possible upgrades to the AGS complex that would meet the requirements of the proton beam for a 1.0 MW neutrino superbeam facility. We are proposing to replace part of the existing 200 MeV linac with coupled cavity structure from 116 MeV to 400 MeV and then add additional 1.1 GeV superconducting linac to reach a final energy of 1.5 GeV for direct H- injection into the AGS. We will present possible choices for the upgrade and our choice and its design.