Particle Simulation of Three-Grid ECR Ion Thruster Optics and Erosion Prediction

Ion optics is a critical component of ion thrusters. A two-dimensional axisymmetric model is developed to study the characteristics of three-grid electron cyclotron resonance ion thruster optics. The code is based on a particle-in-cell combined with the Monte Carlo collision method to simulate ion dynamics and charge-exchange processes in the grid region. The simulation results show that the mode can give a reasonable estimate of the physics characteristics of the ion optics. The design of the ion optics satisfies the requirement of preventing electron backstreaming. Charge-exchange ions can cause damage to the grids, especially to the accelerator grid. ‘Barrel’ erosion can increase the accelerator grid aperture radius at a rate of 1.91×10 −11 m/s, while the decelerator grid plays an important role in reducing ‘pits-and-grooves’ erosion.