RHIC Spin Flipper Commissioning Plan

1. RHIC Spin Flipper Commissioning Plan • Phase I • Spin tune measurement using spin flipper • How: use the spin flipper to induce large coherent spin precession and measure the projection of the spin vector in the horizontal plane • Challenge: use CNI to measure the turn by turn coherent spin precession • This is the key for successfully commissioning the spin flipper • This also is critical for optimizing the snake settings for machine operation • Phase II • Measure spin tune spread using spin flipper • Approach I: • use the spin flipper to induce a large coherent spin precession by sweeping its frequency and shuts off at the spin tune • Measure the total polarizaton of the beam. The total polarization should be preserved if the tune spread is zero • Approach II • Map the vertical beam polarization with different spin flipper frequency from below the spin tune to above the spin tune. The width of the vertical beam polarization as a function of the flipper tune around the spin tune is proportional to the spread of the spin tune

2. RHIC Spin Flipper Commissioning Plan • Phase III • Commissioning spin flipper • Evaulate the specs of the spin flipper • The strength of the magnet • The range that the frequency of the spin flipper is required to sweep for full spin flip • scan the spin flipping efficiency with • Different strength but the same frequency sweeping range • Different frequency sweep range but fixed strength