First test of a partial Siberian snake during polarized beam acceleration

We recently studied the first acceleration of a spin-polarized beam through a depolarizing resonance using a partial Siberian snake. We accelerated polarized protons from 95 to 140 MeV while ramping a 10% partial Siberian snake along with the acceleration cycle. The 10% partial snake suppressed all observable depolarization due to the [ital G][gamma]=2 imperfection depolarizing resonance which occurred near 108 MeV during acceleration. However, 20% and 30% partial Siberian snakes apparently moved the [ital G][gamma]=7[minus][nu][sub [ital y]] intrinsic depolarizing resonance from near 177 MeV into our energy range; this caused some interesting but not-yet-fully understood depolarization.