Computational study of microwave-induced ionization process using PIC-MCC method

We have developed a two-dimensional PIC-MCC code which can describe interactions between input microwave and charged particles and collisions among the gas particles including neutrals in order to examine the mechanism of formation of a filamentary structure observed in a microwave-beaming thruster. Assuming that an initial discharge spot is created by an air-breakdown, an incident microwave is reflected and scattered at the spot, and a strong electric field is formed ahead of it. The region of the strong field is discretisely located at a quarter of microwave wavelength from the original spot as predicted by a simple model, and a newly discharged spot is created through electron impact ionization originating in background electrons in the strong field region. (authors)