Numerical Simulation of Plasma Plume Sheath and Secondary Electron Emission Based on DSMC-PIC Parallel Algorithm

The temporal and spatial evolution of plasma plume is accompanied by sheath, secondary electron emission (SEE), and other phenomena that have a crucial impact on the working characteristics and performance improvement of plasma devices. In this paper, a direct simulation Monte Carlo (DSMC) and particle-in-cell (PIC) hybrid parallel algorithm is employed for numerical simulation, which is a fully kinetic PIC method. Energy-based outlet and wall boundary conditions of charge conservation are investigated. This paper discusses the influence of different models on the flow field. First, four SEE energy spectrum models--the Mozorov model, the Furman model, the vertical model, and the three temperature model--are discussed. Then, four kinds of insulation wall materials--boron nitride, silicon carbide, alumina, and graphite--as simulated by the modified Mozorov coefficient model are investigated. Through the simulation of axisymmetric cases, the influence of SEE energy spectrum; secondary electron emission coefficient (SEC); electric field action; and other factors on the spatiotemporal evolution of H[sub.2], H, X, H2+, H[sup.+], and e in the flow field is demonstrated. This paper analyzes the structural characteristics of cloud images with different models through number densities in detail. The SEE energy spectrum has an important influence on the distribution of the field potential and the number density of charged particles, but it is not as important as the SEC.