Theoretical investigation of a novel high current diode with multipacting cathode

Abstract

In this paper, a novel high current diode with multipacting cathode is investigated theoretically with potential using in high-power microwave devices. Firstly, the electron dynamic equations, transit time and impact energies are analyzed theoretically. The electron trajectories, velocities, impact energies are discussed in the condition of different initial energies emitted from each direction. Secondly, for finding the multipacting cathode working area, the multipacting susceptibility equations are solved by using Vaughan's constant-k theory coupling electron dynamic equations, the susceptibility diagram is drawn and discussed in detail. Finally, the electron trajectories, velocities, transit time, impact energies and multipacting susceptibility diagram are simulated numerically by using Monte Carlo method. The simulation results agree with the theoretical one well. Both theoretical and numerical results demonstrate that the conception of the novel high current diode with multipacting cathode is feasible. By loading an appropriate electric field in axial and radial directions and a proper magnetic field in axial direction on a cylindrical dielectric surface with high secondary emission yield coating, the seed electrons from field induced emission moving with spiral advancing trajectories along axial direction could be increased effectively by each impact with multipacting interaction. This phenomenon will achieve electron current amplification until multipacting comes to saturation.