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Title: RHIC 100 GeV Polarized Proton Luminosity

A big problem in RHIC 100 GeV proton run 2009 was the significantly lower luminosity lifetime than all previous runs. It is shown in this note that the beam intensity decay in run 2009 is caused by the RF voltage ramping in store. It is also shown that the beam decay is not clearly related to the beam momentum spread, therefore, not directly due to the 0.7m. β* Furthermore, the most important factor regarding the low luminosity lifetime is the faster transverse emittance growth in store, which is also much worse than the previous runs, and is also related to the RF ramping. In 100 GeV proton run 2012a, the RF ramping was abandoned, but the β* was increased to 0.85m, with more than 20% loss of luminosity, which is not necessary. It is strongly suggested to use smaller β* in 100 GeV polarized proton run 2015/2016
Authors:
 [1]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.
Publication Date:
OSTI Identifier:
1119568
Report Number(s):
BNL--103712-2014-IR; BNL--C-A/AP/500
R&D Project: KBCH139; 18031; KB0202011; TRN: US1500093
DOE Contract Number:
AC02-98CH10886
Resource Type:
Technical Report
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States). Relativistic Heavy Ion Collider
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; PROTON BEAMS; BEAM LUMINOSITY; GEV RANGE 10-100; POLARIZED BEAMS; BROOKHAVEN RHIC; LIFETIME; ELECTRIC POTENTIAL; LOSSES; BEAM EMITTANCE Relativistic Heavy Ion Collider