Evaluation and Influence of Gyrotron Cathode Emission Inhomogeneity

In order to evaluate the emission inhomogeneity of thermionic gyrotron cathode emitters, a novel definition of emission inhomogeneity and evaluating method from the current-voltage characteristics is described in this paper. Results for three different types of gyrotron oscillators at different emitter temperatures based on experimental data and mathematical treatment are considered in the investigation. The influence of emission inhomogeneity on gyrotron efficiency is numerically calculated using the 3-D codes ARIADNE and EURIDICE. The emitter inhomogeneity upper limits for the distributions of work function, temperature, and electric field are given at the end of this paper.