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Marr, G. J.

Paper Title Page
MOPAS098 Dynamic Collaborative Documentation at the Brookhaven National Laboratory Collider-Acclerator Department 658
 
  • J. Niedziela, W. Fu, M. Harvey, G. J. Marr, T. Satogata, V. Schoefer
    BNL, Upton, Long Island, New York
 
  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)

Centralization of information pertaining to accelerators can benefit accelerator operation and development. Further, retention and the changeable nature of information present challenges to accelerator operation, particularly in instances of turnover. MediaWiki is free, server-based software licensed under the GNU General Public License that uses PHP to render data stored in a MySQL database as interactive web documents, and is designed to produce collaborative documentation. The MediaWiki engine was implemented at BNL, and this paper describes the first year of use by the Operations, Controls, and RF groups at the Collider-Accelerator Department, including code modifications, common practices, and the use of the wiki as a training tool.

 
TUOCKI02 Summary of the RHIC Performance during the FY07 Heavy Ion Run 722
 
  • K. A. Drees, L. Ahrens, J. G. Alessi, M. Bai, D. S. Barton, J. Beebe-Wang, M. Blaskiewicz, J. M. Brennan, K. A. Brown, D. Bruno, J. J. Butler, R. Calaga, P. Cameron, R. Connolly, T. D'Ottavio, W. Fischer, W. Fu, G. Ganetis, J. W. Glenn, M. Harvey, T. Hayes, H.-C. Hseuh, H. Huang, J. Kewisch, R. C. Lee, V. Litvinenko, Y. Luo, W. W. MacKay, G. J. Marr, A. Marusic, R. J. Michnoff, C. Montag, J. Morris, B. Oerter, F. C. Pilat, V. Ptitsyn, T. Roser, J. Sandberg, T. Satogata, C. Schultheiss, F. Severino, K. Smith, S. Tepikian, D. Trbojevic, N. Tsoupas, J. E. Tuozzolo, A. Zaltsman, S. Y. Zhang
    BNL, Upton, Long Island, New York
 
  Funding: Work performed under Contract Number DE-AC02-98CH10886 under the auspices of the US Department of Energy.

After the last successful RHIC Au-Au run in 2004 (Run-4), RHIC experiments now require significantly enhanced luminosity to study very rare events in heavy ion collisions. RHIC has demonstrated its capability to operate routinely above its design average luminosity per store of 2x1026 cm-2 s-1. In Run-4 we already achieved 2.5 times the design luminosity in RHIC. This luminosity was achieved with only 40% of bunches filled, and with β* = 1 m. However, the goal is to reach 4 times the design luminosity, 8x1026 cm-2 s-1, by reducing the beta* value and increasing the number of bunches to the accelerator maximum of 111. In addition, the average time in store should be increased by a factor of 1.1 to about 60% of calendar time. We present an overview of the changes that increased the instantaneous luminosity and luminosity lifetime, raised the reliability, and improved the operational efficiency of RHIC Au-Au operations during Run-7.

 
slides icon Slides  
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  
TUPAS096 Setup and Performance of the RHIC Injector Accelerators for the 2007 Run with Gold Ions 1862
 
  • C. J. Gardner, L. Ahrens, J. G. Alessi, J. Benjamin, M. Blaskiewicz, J. M. Brennan, K. A. Brown, C. Carlson, W. Fischer, J. W. Glenn, M. Harvey, T. Hayes, H. Huang, G. J. Marr, J. Morris, F. C. Pilat, T. Roser, F. Severino, K. Smith, D. Steski, P. Thieberger, N. Tsoupas, A. Zaltsman, K. Zeno
    BNL, Upton, Long Island, New York
 
  Funding: Work performed under the auspices of the US Department of Energy.

Gold ions for the 2007 run of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) 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 with a focus on improvements in the quality of beam delivered to RHIC. In particular, more uniform stripping foils between Booster and AGS, and a new bunch merging scheme in AGS promise to provide beam bunches with reduced longitudinal emittance for RHIC.

 
TUPAS103 RHIC Challenges for Low Energy Operations 1877
 
  • T. Satogata, L. Ahrens, M. Bai, J. M. Brennan, D. Bruno, J. J. Butler, K. A. Drees, A. V. Fedotov, W. Fischer, M. Harvey, T. Hayes, W. Jappe, R. C. Lee, W. W. MacKay, G. J. Marr, R. J. Michnoff, B. Oerter, E. Pozdeyev, T. Roser, F. Severino, K. Smith, S. Tepikian, N. Tsoupas
    BNL, Upton, Long Island, New York
 
  Funding: Work supported by U. S. DOE under contract No DE-AC02-98CH1-886

There is significant interest in RHIC heavy ion collisions at c.m. energies of 5-50 GeV/u, motivated by a search for the QCD phase transition critical point. The low end of this energy range is well below the nominal RHIC injection c.m. energy of 19.6 GeV/u. There are several challenges that face RHIC operations in this regime, including longitudinal acceptance, magnet field quality, lattice control, and luminosity monitoring. We report on the status of work to address these challenges and include results from beam tests of low-energy RHIC operations with protons and gold.