An Effective 3-D Particle-in-Cell Method With Particle Move Interpolation for the Simulation of the Multipactor

When simulating the multipactor with the traditional 3-D electromagnetic particle-in-cell (PIC) method, complete secondary electron movement calculations are required for each step. The more secondary electrons there are, the more time-consuming the part of the particle movement calculations becomes. To decrease the time cost of the particle movement part, this article adopts the interpolation and Boris method to update the secondary electrons' state of motion alternately for different time steps, presents a movement half interpolation (MHI) calculation method, and improves the 3-D EM-PIC method. Then, an impedance transformer is tested to verify that this improved PIC method can increase the simulation efficiency of the particle movement part and ensure the consistency of the phase space distribution of the secondary electrons at the same time. Finally, the multipactor process of the impedance transformer and a Ku -band ridge filter is researched by this improved PIC method. The multipactor threshold of the impedance transformer achieved by the simulation is 1700 W, and the experimental result is 1820 W. The discrepancy of the threshold results between the simulation and experiment is 0.296 dB. In addition, the Ku -band ridge filter's simulation threshold is 788 W. The difference between the simulation result and the experiment data (700 W) is 0.514 dB. The good agreement of the simulation with the measures illustrates the effectiveness of the improved PIC method in researching the multipactor and predicting the threshold of the high-power microwave components.