Spin Flipping in the Presence of a Full Siberian Snake

Abstract

We have demonstrated for the first time spin flipping of a polarized proton beam stored in a ring containing a nearly $100%$ Siberian snake; we did this using a ``snake'' depolarizing resonance induced by an rf solenoid magnet. By varying the rf solenoid's ramp time, frequency range, and voltage, we reached a spin-flip efficiency of about $91%$. This spin-flip efficiency was probably reduced because the horizontal stable spin direction was not perpendicular to the longitudinal field of the rf solenoid, and was possibly reduced by nearby synchrotron sideband resonances. The planned use of a vertical rf dipole may improve the spin-flip efficiency.