Gas inlet impact on neutral density and recycle pattern with a disk shaped antenna in a miniature ion thruster through particle simulation

The gas inlet configuration has a direct impact on the neutral density pattern within a miniature ion thruster. We aimed to investigate the impact the gas inlet configuration and neutral density pattern will have on the neutral recycle rate within a miniature ion thruster utilizing a disk shaped antenna. Four inlet configurations were considered for this study, and 3D electromagnetic particle-in-cell simulation was utilized to simulate the plasma inside the discharge chamber. The simulation results indicate a clear shift in neutral density toward the inlet, with the single horizontal inlet configuration having a 45% increase in neutral density in the vicinity of the inlet walls. The neutral recycle rate also experienced a clear shift toward the inlet walls, with the single bottom inlet configuration experiencing a 23% increase in the rate of ion loss near the inlet wall and a similar 22% increase for the single horizontal inlet while the four smaller inlets had a similar rate of neutral recycling throughout. These results are a novelty in this field as they clearly indicate the impact gas inlet and neutral density have on the miniature ion thruster’s performance and open a new area of research to further optimize the gas inlet configuration for miniature ion thrusters.