Proton Beam Study in a Fixed-Frequency Cyclotron

Operational and theoretical experience with the ORNL 44-inch and 63-inch cyclotrons is used in estimating the time variation of proton beam current passing through the rf field between the dees of the ORNL 44-inch cyclotron. The proton current appears to have a significant reactive component. This result is probably typical of most fixed frequency cyclotrons whose ions make 30-100 orbits in being accelerated to maximum radius. The study is briefly related to problems which may be encountered in the design of a fixed-frequency rf system capable of accelerating hundreds of kilowatts of ions to be used for a purpose such as the production of radioisotopes.