Energy Control for External Cyclotron Beams

Abstract

A device is described which stabilizes the mean energy of the external beam from an FM cyclotron to better than 0.1 percent. This control is achieved by inspecting the end of the range of a sample of scattered particles, and then using this information to regulate the cyclotron magnet current. It is also used as an absolute instrument to measure the mean energy to 0.3 percent at the same time.