Research of influence of the effect of additional gas supply mode on the discharge performance of krypton Hall thruster by particle-in-cell simulation

Abstract With the growing demand for electric propulsion in large-scale space missions, the scarcity and high cost of Xenon have necessitated the search for alternative propellants. Krypton has emerged as a promising candidate; however, its application is hindered by a relatively low ionization rate compared to Xenon. Optimizing the neutral gas injection strategy offers a potential solution to mitigate this performance gap. This paper investigates the discharge characteristics of a Krypton Hall Effect Thruster using a two-dimensional Particle-In-Cell with Monte Carlo Collisions (PIC-MCC) simulation. The study systematically analyzes the effects of varying axial gas supply positions and velocity directions on neutral gas distribution, plasma parameters, and wall energy deposition. Simulation results demonstrate that opposite gas supply strategy significantly enhances the propellant accumulation within the discharge channel. Specifically, at optimized axial injection locations, the peak atom density increases by 42.1%–50.9% compared to vertical and forward supply schemes. Furthermore, this optimized gas distribution shifts the ionization zone downstream, thereby reducing the ion energy deposition power density on the inner and outer channel walls by 17.3% and 21.7%, respectively, relative to the anode-only gas supply condition, which is beneficial for mitigating channel erosion. Ultimately, the proposed counter-flow configuration achieves a thrust improvement of approximately 8% relative to the baseline, whereas other configurations exhibit performance deviations within 10%. These quantitative findings provide theoretical support for the structural design and optimization of high-efficiency Krypton Hall thrusters.