Effect of magnetized secondary electron on the characteristics of sheath in Hall thruster

Abstract

In order to investigate the effects of the inner wall secondary electron emission on the performance of Hall thruster, a hydrodynamic model is used to study the characteristics of plasma sheath considering secondary electron magnetization. The Bohm criterion of the magnetized plasma sheath is obtained. The structures of plasma sheath in Hall thruster with different magnetic field magnitudes and directions, different secondary electron emission coefficients and different plasma species are discussed. Simulation results indicate that both particle density and wall potential increase while the sheath thickness decreases with the augment of secondary electron emission coefficient. The sheath potential and the particle density increase with the magnitude and azimuth angle of magnetic field increasing. Both the sheath thickness and the wall potential are different in different plasma species. These research results provide a theoretical explanation for the magnetism-ampere characteristic of the Hall thruster.