Fully Kinetic PIC Simulations of the Electrical Facility Effect on the Gridded Ion Thruster Testing

For gridded ion thrusters (GITs), one of the problems that are not well understood is beam neutralization and its effects on GIT-facility interactions [1]. The objective of this study is to understand the electrical facility effects associated with testing ion thrusters in vacuum chambers. The most significant difference between in-space and in-chamber is that the thruster is surrounded by metal walls, which creates a sheath and increases the background pressure by three orders of magnitude. Not only sheath formation but also the facility plasma (i.e., ions generated by collision with neutral) can change the electron motion. This study seeks to understand how the ion/electron current change in the vacuum chamber when changing neutralizer positions and background pressure.