Excitation of Electromagnetic Waves in a Vircator by Radially Diverging Beam

摘要

This paper presents the theoretical and experimental study of the excitation of electromagnetic waves in the TEM-mode in coaxial vircator with radially divergent electron beam. Excitation of electromagnetic oscillations, emission spectrum, instability increment of electromagnetic oscillations, and formation of a virtual cathode are investigated using the kinetic equation and numerical simulation (PIC code KARAT). It was shown that the resonant interaction of the electron beam is most effectively done with the TEM-mode. The possibility of TEM-mode excitation with its subsequent transformation into TE_(10)-mode of a rectangular waveguide has been experimentally demonstrated.