Operating experience with high beam currents and transient beam loading in the SLC damping rings

During the 1994 SLC run the nominal operating intensity in the damping rings was raised from 3.5 x 1010 to greater than 4 x 1010 particles per bunch (ppb). Stricter regulation of rf system parameters was required to maintain stability of the rf system and particle beam. Improvements were made in the feedback loops which control the cavity amplitude and loading angles. Compensation for beam loading was also required to prevent klystron saturation during repetition rate changes. To minimize the effects of transient loading on the rf system, the gain of the direct rf feedback loop and the loading angles were optimized