Synchronous Transfer of Beam from the NAL Fast Cycling Booster Synchrotron to the NAL Main Ring System

Beam from successive cycles of the 15-Hz booster synchrotron is stacked end to end in the main synchrotron with constant magnetic field. Beam already injected into the main ring is held in stationary rf buckets, and the rest field is determined by the circulating beam. To capture beam from subsequent booster cycles into the empty buckets in the main ring, the phase and frequency of the rf beam bunches in the booster are locked to the main ring rf system before beam is transferred. The magnetic fields in the booster and the main ring are regulated separately and tuned for the correct orbit radii and particle momentum. The azimuth of the beam circulating in the main ring is monitored by counting main ring rf cycles, and the beam transfer system is timed to inject beam from successive booster cycles in the correct sequence around the main-ring circumference.