Single and mixed gas breakdown characteristics induced by high power microwave

A Monte Carlo model is proposed to simulate the process of HPM single and mixed gas breakdowns, and a three-dimensional Monte Carlo code (3D-MCC) is compiled by analyzing the collision process between electrons and background gases. Aiming at Ar, N2 and N2/O2 mixture (air), the electron cloud formation process and the electron energy distribution function (EEDF) can be obtained by simulating the process of gas breakdown using 3D-MCC. The gas breakdown time, derived by analyzing the variation trend of the EEDF and the electron density along with time, has an intense dependence on the EEDF for Ar, but not for N2. The correctness of this model is verified by comparing with the fluid model. An experimental system allowing the air breakdown to be triggered in vacuum by a focused HPM is established. The air breakdown time is measured under different pressures at S-band when the electric field is 6.38 kV/cm. The simulation results are consistent with the experimental data.