BNL, Upton, Long Island, New York, USA
There are polarization losses in RHIC store due to various sources, such as emittance growth and higher order spin resonances. The beam polarization was measured several times over a store by the p-carbon polarimeters situated in both rings. These provide information on the polarization decay over time and also polarization profile development over time. A polarized jet was also used to monitor the polarization continuously through store, though with limited statistical accuracy. These polarization measurements and emittance measurements from the IPM are analyzed and the polarization loss from different sources are reviewed.
BNL, Upton, Long Island, New York, USA
Spin flipper experiments during RHIC Run 17 were performed to study its effectiveness as a method for polarization sign reversal during stores. Numerical simulations are reported here, which were performed in accompaniment of these, and are being pursued with the aim of accurately reproducing the experimental conditions and providing thorough insight in the role of various key parameters participating in the dynamics of the spin flip, such as the sweep rate of the AC dipole, chromatic orbit control at RHIC snakes, RF parameters, possible effects of non-linear spin resonances, mirror resonance, tolerance on flipper magnet parameters, etc. The ultimate goal is for these simulations to serve as a guidance toward perfect flip to allow routine use during physics Runs.