Experience with Low-Energy Gold-Gold Operations in RHIC during FY 2010

摘要

During Run-10, RHIC operated at several different Au-Au collision energies, as requested mainly by the STAR collaboration in a quest to search for the critical point in the QGP phase diagram. The center-of-mass energies (radical)s(sub NN) are listed in Table 1, together with the respective start and end dates and the duration of the respective run at each energy. While STAR defines 'low energy' as anything below (radical)s(sub NN) = 39 GeV, we focus in the scope of this paper on energies below the regular RHIC injection energy of (radical)s(sub NN) (approx) 20 GeV, since this energy regime is particularly challenging for stable RHIC operations. Figures 1 and 2 show the evolution of beam intensity and luminosity during the course of the (radical)s(sub NN) = 7.7 GeV and 11.5 GeV run. In the following sections we will recapitulate the modifications during the run that led to significant performance improvements, and summarize what was learned at the various energies for possible application in future runs.