Self-consistent simulation of multipactor discharge at HPM dielectric windows

Summary form only given. Modeling multipactor discharges is important for understanding window breakdown and parasitic plasma discharges in high power microwave tubes. We have added new physics models to the ICEPIC (Improved Concurrent Electromagnetic Particle-In-Cell) code to study these phenomena, including a Vaughn model for secondary emission, and a Monte-Carlo collision package for studying the formation of plasma from ionization of background gas. We verify that the secondary model produces the expected behavior by comparing our results with theory and with the OOPIC 2d code. This paper compare and contrast 1d fully electromagnetic simulations (with full space-charge effects) with 1d theory without space-charge effects. Then we expand this model to be periodic transverse to the dielectric. Finally we show a multipactor discharge forming at a waveguide-dielectric window interface. This suite of simulations explore the effect of the finite electron hopping distance on the discharge. We analyze the transmitted and reflected power from the discharge and the distribution of electrons that impact the dielectric surface.