• H. Huang, L. Ahrens, M. Bai, K. A. Brown, C. J. Gardner, J. W. Glenn, F. Lin, A. U. Luccio, W. W. MacKay, T. Roser, S. Tepikian, N. Tsoupas, K. Yip, K. Zeno
  BNL, Upton, Long Island, New York

Dual partial snake scheme has provided polarized proton beams with 1.5*10¹¹ intensity and 65% polarization for RHIC spin program. To overcome the residual polarization loss due to horizontal resonances in the AGS, a new string of quadrupoles have been added. The horizontal tune can now be set in the spin tune gap generated by the two partial snakes, such that horizontal resonances are avoided. This paper presents the accelerator setup and preliminary results.

• 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

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.

• 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

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.

• N. Tsoupas, L. Ahrens, K. A. Brown, I.-H. Chiang, C. J. Gardner, W. W. MacKay, P. H. Pile, A. Rusek
  BNL, Upton, Long Island, New York

Uniform irradiation of biological or material samples with charged particle beams is desired by experimentalist because it reduces radiation-dose-errors which are introduced by a non-uniform irradiation of the samples. In this paper we present results of uniform beams produced in the NASA SPACE RADIATION LABORATORY (NSRL) at the Brookhaven National Laboratory (BNL) by a method which was conceived theoretically and tested experimentally at BNL. This method* of producing uniform beams in the transverse beam direction, is based on purely magnetic focusing of the beam and requires no collimation of the beam or any other type of beam interaction with materials. The method is favorably compared with alternative methods** of producing uniform beam distributions normal to the beam direction and can be applied to the whole energy spectrum of the charged particle beams that are delivered by the Booster synchrotron at BNL.

*Uniform Particle Beam Distribution Produced by Octupole Focusing N. Tsoupas et. al. NSE: 126, 71-79 (1997)
**Review of Ion Beam Therapy: Present and Future J. Alonso LBNL EPAC 2000