Simulation of Outgassing Breakdown Induced by Electromagnetic Radiation on a Thermal Control Layer

The actual working environment of spacecraft in space is highly harsh, among which space radiation is the primary harmful environmental factor leading to spacecraft failure in orbit. This study investigates field emission, multipacting, and outgassing ionization as effects of electromagnetic radiation on the thermal control layer (TCL) of spacecraft. Based on the particle-in-cell (PIC) simulation method coupled with Monte Carlo collisions (MCCs), a 2-D simulation model of particle motion in a vacuum is created to study the evolution of the point discharge process of electromagnetic irradiation breakdown to generate plasma. Simulated and analyzed results show the impact of various microwave amplitudes, frequencies, and gas densities on the interface breakdown of thermal control materials. According to the findings, the number of primary electrons generated and the energy attained by them in the microwave field increase with the electric field, speeding up secondary electron emission, and gaseous collision ionization; the time it takes for the electrons to return to bombard the surface of the material under the influence of the microwave field is shortened with increasing microwave frequency, which promotes electron multipacting; the frequency of collisions and ionization increases with gas density, which facilitates the occurrence of avalanche ionization. After the avalanche, there is a large energy deposition of plasma on the surface of the thermally controlled material, which results in a quick rise in temperature and subsequent damage.