Self-consistent mechanism for high power generation under acting of two types oscillations of reflected electrons and of the virtual cathode

Abstract

Virtual cathode oscillators (vircators) are one of the promising microwave sources of gigawatt power level pulses, generating an efficiency level of 8-12% [1,2,3]. With the numerous reported studies the generation mechanism in vircator’s remains a task in progress discussion. Some studies [4,5] associate the generation frequency with the plasma frequency of the electron beam, while others associate it with the oscillation frequency of electrons in the "cathode-virtual cathode (VC)" potential well (see Fig. 1 (left)) [6]. There are studies that claim that these two frequencies always coincide [7]. In addition, research is still underway to determine the mutual influence of two different types of oscillations on generation processes. The presented work is devoted to numerical simulation of the generation processes occuring under acting of oscillations of the virtual cathode, as well as oscillations of electrons reflected by the virtual and real cathodes, are the source of powerful microwave radiation. The self-consistent mechanism for radiation generation is analyzed in investigated model using the code XOOPIC with considering cathode-anode gap processes.