Particle simulation of grid erosion in an ion thruster

A particle simulation computational code has been developed to study the effect of charge-exchange-induced grid erosion in electron bombardment ion thrusters. The code is based on the particle-in-cell (PIC) method to simulate the ion flow and a Monte Carlo method to calculate the charge exchange collisions. Both two- and three-dimensional versions of this code have been developed. The two-dimensional model provides a qualitative description of the details of the ion flow and the charge exchange collisions. The three-dimensional version has successfully predicted the experimentally observed erosion pattern in which the maximum erosion occurs at the geometric centers of accelerator grid apertures.