Numerical simulations of high power microwave dielectric interface breakdown involving outgassing

Abstract

With the development of high power microwave (HPM) technology, the power and pulse duration of the HPM source increase substantially, the breakdown of the dielectric window of the HPM source feed has been becoming the major factor of limiting the transmission and radiation of HPM. This paper presents an electrostatic particle-in-cell and Monte Carlo collisions method for simulating the breakdown on HPM dielectric surface and establishes a physical model of HPM dielectric surface breakdown involving outgassing. The breakdown process including the main physical mechanisms, such as the field emission, multipactor, outgassing, and collision of gas ionization, is simulated. The influence of outgassing on the dielectric window breakdown is studied by simulating the breakdown with different outgassing speeds. The similarity between the dc and HPM dielectric surface breakdown is discussed.