Improved Magnetron Injection Guns for Gyrotrons

Recent gyrotron operations indicate that nonuniform cathode emission is prevalent in many, if not most, magnetron injection guns. A nonuniform emission can result in degradation of the RF performance and increase heating in the collector. This paper describes research to improve cathode emission by addressing temperature uniformity and work function issues. A new cathode design is proposed, and a facility for measuring both temperature and emission uniformity is described.