Study on Flake Graphite Cathode Surface Microstructure in Relativistic Magnetrons

Flake graphite has excellent explosive electron emission performance for its plenty surface micro-bulges and high graphitization degree, but advantages have rarely been studied in relativistic magnetrons. In this paper, flake cathodes with different fineness were used coaxial diodes magnetrons, the influence of microstructure cathode on magnetron is demonstrated first time. The result showed that mainly affected initiation stage emission. Moreover, delay time determined by degree graphite, plays a major role. Under applied voltage ~330kV-~490kV, finer possessed shorter facilitated microwave excitation. excitation ~3ns, ~5ns lager graphite. After several operations magnetron, edges blunted, appeared droplet-like areas formed anode atom sputtering. This work reveals fast priming thus shedding new light design magnetron.