Influence of neutral gas supply position on wall erosion of Hall thruster studied by particle-in-cell simulation

In this work, we have carried out a simulation study on the discharge process of Hall thrusters under the conditions of different neutral gas radial supply positions based on the particle-in-cell (PIC) and Monte Carlo collision (MCC) methods. This paper compares the two-dimensional (2D) distributions of neutral gas, plasma and wall erosion-related parameters under different neutral gas supply positions. The comparison results show that the change of the neutral gas supply position affects the radial distribution uniformity of the neutral gas and plasma in the channel. From the comparison of the density peaks, it can be found that the neutral gas density and the plasma density peak under the upper gas supply condition are relatively low, and the plasma density peak is 22.49% lower than the density peak under the middle gas supply condition. Meanwhile, as the radial position of the gas supply moves from the lower gas supply to the upper gas supply, the position of the ionization zone also gradually moves toward the anode. The results of erosion-related parameter distribution comparison show that the change of gas supply location has an obvious influence on erosion rate and erosion range. In terms of erosion rate, the wall erosion rate is relatively low under the upper gas supply condition, and the peak erosion rates of the inner and outer walls are 33.3% and 29.9% lower than those under the other two conditions. In terms of erosion range, as the gas supply position moves from the lower gas supply position to the upper gas supply position, the erosion range gradually increases from 5 to 7.5 mm.