The University of Maryland Isochronous Cyclotron

Design features of the University of Maryland Isochronous Cyclotron are discussed and a description of initial turn-on and operation is given. The four-sector magnetic field was designed with the aid of a one-third scale model magnet utilizing both the experience with the Grenoble Cyclotron and computer studies at the University of Maryland. The original maximum design energy was increased to 140 MeV protons by modification of the spiral angle after full-scale magnet measurements. The dual RF amplifier chain (25 mW to 250 kW per channel) drives two dees independently in both push-pull and push-push modes over a frequency range of 10-22 MHz from 20 to 90 kV.