SPIN FLIPPING A STORED POLARIZED PROTON-BEAM

We recently studied the spin flipping of a vertically polarized, store d 139-MeV proton beam. To flip the spin, we induced an rf depolarizing resonance by sweeping our rf solenoid magnet's frequency through the resonance frequency. With multiple spin flips, we found a polarization loss of 0.0000 +/- 0.0005 per spin flip under the best conditions; th is loss increased significantly for small changes in the conditions. M inimizing the depolarization during each spin flip is especially impor tant because frequent spin flipping could significantly reduce the sys tematic errors in stored polarized-beam experiments.