The Beam Bunching System for the Chalk River Superconducting Cyclotron

The bunching system for the tandem accelerator-superconducting cyclotron is of the buncher-rebuncher type. It consists of a low energy gridded buncher before the tandem that produces a time focus at the tandem stripper, combined with a high energy buncher between the tandem and the cyclotron to correct for debunching of the beam produced by energy straggling in the stripper. To meet the cyclotron design energy resolution of 5:10<4 the bunch length produced at the cyclotron has to be less than three degrees in rf phase.