CERN Accelerating science

Article
Title	Beam Induced Pressure Rise at RHIC
Author(s)	Zhang, S Y ; Alessi, James ; Bai, Mei ; Blaskiewicz, Michael ; Cameron, Peter ; Drees, Angelika ; Fischer, Wolfram ; Gullotta, Justin ; He, Ping ; Hseuh Hsiao Chaun ; Huang, Haixin ; Iriso, Ubaldo ; Lee, Roger C ; Litvinenko, Vladimir N ; MacKay, William W ; Nicoletti, Tony ; Oerter, Brian ; Peggs, Steve ; Pilat, Fulvia Caterina ; Ptitsyn, Vadim ; Roser, Thomas ; Satogata, Todd ; Smart, Loralie ; Snydstrup, Louis ; Thieberger, Peter ; Trbojevic, Dejan ; Wang, Lanfa ; Wei, Jie ; Zeno, Keith
Affiliation	(BNL, Upton, Long Island, New York)
Publication	2005
In:	21st IEEE Particle Accelerator Conference, Knoxville, TN, USA, 16 - 20 May 2005, pp.4308
Subject category	Accelerators and Storage Rings
Abstract	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.