The Effect of the Electron-Beam Parameter Spread on Microwave Generation in a Three-Cavity Axial Vircator

We study the behavior of the generation efficiency and radiation spectrum of a three-cavity axial vircator as a function of the injected electron-beam radius, impedance, and energy homogeneity. We show that for each geometry of a three-cavity resonator, there exist optimal (maximizing the generation efficiency) values of these parameters and determine the range over which they may vary without losing the efficiency of generation.