Overcoming depolarizing resonances in the AGS with two helical partial siberian snakes

Dual partial snake scheme has provided polarized proton beams with 1.5 times 10
¹¹
intensity and 65% polarization for the relativistic heavy ion collider (RHIC) spin program. To overcome the residual polarization loss due to horizontal resonances in the Brookhaven alternating gradient synchrotron (AGS), a new string of quadrupoles have been added. The horizontal tune can then be set in the spin tune gap generated by the two partial snakes, such that horizontal resonances can also be avoided. This paper presents the accelerator setup and preliminary results.