Synchronization of the Zero Gradient Synchrotron (ZGS) and the Fast-Cycling Booster II Injector

The planned method of booster injection into the ZGS requires the stacking of two booster beam bunches into the radial betatron phase space of the ZGS and necessitates precise synchronization of the two accelerators during the injection period. The requirement of maintaining independent radio-frequency (RF) steering control does not allow the frequencies of both accelerators to be locked. A synchronizer has been developed which detects a coincidence zero crossing of the two RFs, anticipates the next coincidence, and at that time, generates trigger pulses for the booster extraction and ZGS injection systems. It also maintains control of the sequence in which the total phase space area of the ZGS is loaded. Synchronizer accuracy is obtained by using high speed digital logic circuits. Design considerations and system operation are discussed.