Two dimensional particle-in-cell simulation of electron multipactor on high power microwave dielectric window surface

Based on the particle-in-cell (PIC) simulation method of the first principle, this paper studies the situation about formation and development of the electron process on the dielectric window surface in high power microwave (HPM) devices. We establish a simple two-dimensional model that the TEM wave irradiates the dielectric window surface vertically with the PIC simulation software VORPAL, employ the Vaughans secondary electron emission model, utilize Monte Carlo collision model to deal with the elastic collision, the excitation collision and the ionization collision between electron and background gas, and acquire the electron multipactor images on the dielectric window surface. The simulation results show that the electron number on the dielectric window surface reaches saturation in a period of time and its oscillation frequency is twice as much as that of the incident electric field. Changing the initial emissive number of the seed electrons, the amplitude of the incident electric field and the pressure of the background gas, we can obtain the variation of the electron number on the dielectric window surface in different conditions.