Particle Simulation of High Specific Impulse Operation of Low-Erosion Magnetic Layer Type Hall Thrusters

Abstract

High discharge voltage operation of a conceptual low-erosion magnetic layer type Hall thruster was modeled by an axial-radial two dimensional fully kinetic particle simulation code. No anomalous diffusion model was used to selfconsistently capture the physics of electron cross-field transport and wall erosion of the thruster. For the verification of the size of the computational domain, simulation was conducted on two computational domains with different radial size. It was shown that the size of the computational domain had significant impact (>30%) on wall erosion prediction, though its influence on thrust performance was minor (<3%). The performance of the designed conceptual thruster was predicted to be >50% in anode efficiency and <0.3 mm/kh wall erosion rate inside the discharge channel. Furthermore, >1.5 mm/kh erosion rate was observed for the front wall, which was consistent with the experimentally observed pole-piece erosion of "Magnetic Shielding" Hall thrusters. The cause of the front wall erosion was shown to be the ions produced outside the channel, and the plasma potential structure leading to the ion acceleration toward the front wall.