Barrel Erosion of Ion Thruster Accelerator Grid Under Different Operating Conditions

Abstract

The erosion of the accelerator grid affects the life of the ion thruster. One of the most important reasons for accelerator grid erosion is the bombardment of charge exchange (CEX) ions to the accelerator grid. There are two types of erosions caused by CEX ions: barrel erosion and pits and grooves erosion. The erosion mechanism of pits and grooves erosion is the CEX ion back flowed from the downstream of the optics. However, there is no unified conclusion on the erosion mechanism of barrel erosion since the erosion mechanism of barrel erosion developed in most of the current research is only applicable to the specific conditions set up in each research. In this paper, the 3-D IFE-PIC-MCC algorithm is used to simulate the beam ion motion, the CEX collision, and the erosion of CEX ion on the accelerator grid under different operation conditions. The erosion mechanism of barrel erosion under different operation conditions is studied. The results indicate that the main production areas of CEX ions which cause the barrel erosion are different under different operation conditions.