离子推力器栅极束流引出特性仿真研究

Aiming at the design and optimization of dual-grid assembly for ion thrusters，a two-dimensional axisymmetric simulation model of grid aperture is established based on the particle-in-cell with Monte Carlo collision（PIC-MCC）method. The effects of seven grid design parameters，including grid spacing，aperture diameter，grid thickness and operating voltage，on beam extraction characteristics are systematically investigated. Simulation results clarify the perveance limit of the grid under different design parameters. It is revealed that the position and shape of the ion emission surface serve as the critical intermediate factor dominating the beam extraction performance. Parameters of the screen grid such as aperture diameter have a remarkable influence on the emission surface，whereas parameters of the accelerator grid show a weaker effect. This study uncovers the key performance trade-off in grid design and establishes the quantitative relationship between design parameters and beam performance，which can provide a theoretical reference for the refined design and performance optimization of ion thruster dual-grid assemblies.