Design of the 26.7 MHz RF cavity for RHIC

The accelerating system for RHIC operates at 26.7 MHz (h=342) and must capture the injected beam, accelerate it to top energy, and shorten the bunches prior to rebucketing into the storage (h=2508) system. These different functions set the design parameters of the cavity. The frequency of 26.7 MHz has been chosen in order to provide large enough buckets to capture the injected beam from the AGS and a large linear region for debunching during a bunch rotation at top energy. Provision of the large linear region also dictates the voltage requirement of 400 kV per cavity. The cavity must be tuned /spl sim/90 kHz to compensate for the change in speed of the gold beam.