Simulation study on the influence of the peeling material position on the discharge process of a Hall thruster

The deposition layer on the discharge channel wall of a Hall thruster after long-term operation occasionally detaches from the wall and interferes with the plasma inside the channel, resulting in current pulse and threatening the power supply. To understand the generation mechanism of the current pulse, the interaction between the peeling material and the channel plasma was studied by the particle-in-cell and Monte Carlo collision (PIC/MCC) method. The plasma evolution and distribution in the Hall thruster channel when peeling material existed were simulated. Simulation results show that the peeling material changes the electron transportation and ionization, and the effects are related to the position of the peeling material. When the peeling material invades the zone where the ionization rate is originally the highest without peeling material, the ionization process is almost terminated. The ionization suppression by the peeling material will cause the propellant gas to refill the channel exit. As the peeling material moves away, gas discharge is induced near the channel exit, resulting in anode current pulse.