The RHIC polarized proton run (Run-6) in 2006 started on February 1 and continued for 21 weeks. The Run-6 included the machine operation at different beam energies and with different orientation of beam polarization at the collision points. The machine operation at lOOGeV and 31.2 GeV provided physics data of polarized proton collisions to the STAR, PHENIX and BRAHMS experiments. Record levels of the luminosity (up to 3.5.1031 cm-* s-' peak) and proton beam polarization (up to 65%) were achieved during the lOOGeV operation. The beam polarization was preserved during the acceleration by using Siberian Snakes, based on helical magnets. The polarization orientation at STAR and PHENIX experiments was controlled with helical spin rotators. During different stages of the run the physics data were provided with longitudinal, vertical and horizontal orientations of the beam polarization at the collision points. Total luminosity integrals of 45 pb-' at 100 GeV and 0.35 pb" at 3 1.2 GeV were delivered to the experiments.
During Run-8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin-polarized proton beams at two interaction regions. Helical spin rotators at these two interaction regions were used to control the spin orientation of both beams at the collision points. Physics data were taken with different orientations of the beam polarization. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run-8.
A non-destructive internal emittance device has been built for the AGS, with separate units to measure the horizontal and vertical profiles of the circulating beam. Positive ions from collisions of the beam with background gas are collected in a 3-kV/cm electric field onto a 64-channel parallel strip detector. Because positive ions rather than electrons are collected, profile broadening due to space charge is small. Tests indicate that a quantitative, reproducible and accurate measurement of beam size throughout the acceleration cycle is provided.
Broo khaven National Laboratory P.O. Box 5000 Upton, NY 11973-5000 www. bnl.gov Managed by Brookhaven Science Associates, LLC for the United States Department of Energy under Contract No. DE-AC02-98CHlO886 This is a preprint of a paper intended for publication in a journal or proceedings. Sinqe changes may be made before publication, this preprint is made available with the understanding that ityill not be cited or reproduced without the permission of the author.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.