Electromagnetic and Electrostatic Particle-in-Cell Simulations for Multipactor in Parallel-Plate Waveguide

This article introduced a multipactor threshold criterion based on collision and emission currents, and the simulation results were compared using a traditional method. The impact of macroparticle weight on multipactor saturation was studied using electromagnetic particle-in-cell (EM-PIC) simulations of CST Particle Studio. It was found that the simulation results converged when the macroparticle weight was less than 10 ^{\text{6}} . A model calculating accumulated charge on the dielectric surface was proposed and validated against theoretical calculations. The dynamic evolution of multipactor in dielectric-loaded parallel-plate waveguide was analyzed, and predictions were validated against results from the existing model. Finally, the effect of surface charge fields and space charge effect on the multipactor mechanism was studied. The results showed that the multipactor could be suppressed when the ratio of the number of accumulated electrons on the dielectric surface to the saturation electron population was greater than 3.96.