The Diagnostics of the Beam Phase Characteristics of the 240-cm Isochronous Cyclotron

Measuring and stabilizing equipment for beam phase characteristics of the 240-cm isochronous cyclotron are briefly described. A recording system determines the pulse shape of an accelerated ion bunch and measures the pulse duration with an error of no more than 1° for average beam currents up to l¿A in the cyclotron chamber as well as in the beam tube. The achieved accuracy of the stabilizing system for optimum phase position of the bunch at extraction radius was no worse than 2°. The use of the stabilizing system made it possible to simplify cyclotron adjustments and to enhance the extracted beam intensity and stability. Results obtained with the diagnostic equipment for proton beams up to 53 MeV are given.