Rhic Polarized Proton New Working Point Commissioning

The RHIC 2003 polarized proton run showed a limitation on the luminosity due to the beam-beam effect at a betatron tune working point of (0.225,0.235). The integer parts of the horizontal and vertical betatron tunes are 28 and 29, respectively. The polarization transmission efficiency was also compromised because of the tight tune space due to the snake resonances. It was decided to explore the RHIC pp luminosity capability as well as the polarization capability with new working points during the RHIC pp 2004 Run. The working point (0.690.0.685) at a RHIC stored energy of 100GeVk was found to ameliorate the beam-beam effect, and also improve the polarization transmission efficiency as well as polarization lifetime during store. This paper reports the commissioning efforts and results of the new working point commissioning during the latest RHIC polarized proton run.