Plasma transport simulation under different conditions and optimization analysis of dual-stage grid ion thruster

In order to study the extraction and acceleration mechanism of the dual-stage grid, a three-dimensional model based on the Particle-In-Cell/ Monte Carlo Collision (PIC/MCC) method is performed. Dual-stage grid ion thruster is a new type of electrostatic ion thruster, which can break through the limitations of traditional gridded ion thrusters, and greatly improve the specific impulse. The high performance also makes the grid sensitive to operating parameters. In this paper, the influence of grid parameters on xenon ion thruster’s performance in a wide range is systematically simulated, and the optimal operating condition is given. Both the over-focusing of the plume, and the transparency of the screen grid are improved, and the grid corrosion is reduced through simulation optimization. The specific impulse under the given working conditions is 9877.24 s and the thrust is 7.28 mN. Based on the simulation optimization, the limitation of the dual-stage grid is discussed. The grid performs well under high voltage conditions (>3000 V) but not well under low voltage conditions (<2000 V). Finally, since argon is cheaper and more advantageous in future engineering applications, the plasma distribution and grid extraction ability under xenon and argon are analyzed and compared to study the flexibility of the dual-stage grid ion thruster. The simulation results show that a set of optimal parameters is only applicable to the corresponding propellant, which needs to be optimized for different propellant types.