Polarization measurements and absolute polarization values evolution during proton beam acceleration in the RHIC accelerator complex

Abstract

The knowledge of absolute polarization measurements at different beam energies is very important for understanding of the polarization losses during acceleration and transport in the RHIC accelerator chain: Source-Linac-Booster-AGS-RHIC. In the RHIC accelerator complex there are two absolute proton polarimeters: the elastic proton-Carbon polarimeter at 200 MeV beam energy and the CNI H-jet polarimeter at 24-255 GeV in the RHIC ring. The polarization transport simulations show that depolarization occurs at the edge of the beam and that the polarization of the beam core at the center of the 2-dimensional beam intensity profile should be preserved during acceleration. Polarization profile measurements by the scanning p- Carbon CNI polarimeters in the AGS and RHIC provide experimental data that support these expectations. The combination of polarization transport simulation and absolute polarization measurements tools at AGS injection and RHIC store energies provides complimentary information on polarization losses along the RHIC accelerator chain. In addition, an estimate for the upper limit on polarization in collisions is calculated from the absolute polarization measurements at beam energies 200 MeV, 100 GeV and 255 GeV.