Electron multipactor discharge on a dielectric in a finite geometry

Summary form only given. Electron multipactor breakdown of the dielectric window separating vacuum from a gas in a high power microwave system is a common problem that limits the output power of the system. This study examines the impact of finite waveguide geometries and low and moderate pressure gases on electron multipactor growth and power deposition on the dielectric window. The spatial and temporal evolution of the power deposition, electron number density, and average electron energy in vacuum and in low and moderate pressure (<200 torr) electropositive and electronegative gases is discussed. Results of the simulation show that the multipactor discharge starts at the edge and moves to the center of the dielectric given a large enough field. In addition, electron multipactor results from 1-D, 2-D, & pseudo-3D particle-in-cell (PIC) simulations are compared. A large discrepancy is shown to exist in the number of electrons produced between the 1-D, 2-D and pseudo-3D simulations due to electrons being lost to the waveguide wall