Implementation of anode grid model in particle-in-cell simulation

A rational physical model of anode grid, used to describe the electron scattering process in anode grid, was established based on the 3D Yee grid model and the time-discrete frog-leap model. According to the classical collision theory, the formulas of scattering angle and momentum were deduced. The anode grid scattering process of Gaussian electron beams in a radial vircator was simulated by Monte-Carlo method. The simulation results demonstrate an evident virtual cathode phenomenon. The average power is up to 0.60 GW, the efficiency of virtual cathode is 4.5%, the microwave frequency is 4.7 GHz, and the main mode is TM01. The results accord with the simulation data derived in previous papers.