A study on frequency stabilities of microwave emission from a reflex triode vircator

This paper presents experimental investigations on a reflex triode vircator driven by a 400 kV, 10 kA electron beam. Two types of cold cathodes, based on stainless steel and carbon fiber, were tested in this system. The microwave signals were discussed by time-frequency analysis. The stainless steel cathode exhibited an obvious frequency hopping observed from the microwave pulse. Interestingly, for the carbon fiber cathode, the microwave emission with a stable frequency was observed, and possible explanations for the nature behind these experimental results are given. As a whole, carbon fiber cathodes have great promise as cold cathode emitters for high-power microwave generation.