Modeling of Ion Thruster Plume Neutralization using Kinetic Simulations

In this paper, we discuss various aspects of the plasma plume that forms when testing a Gridded Ion Thruster (GIT) inside a vacuum chamber. We use fully kinetic simulations of an ion engine using the hybrid MPI-CUDA code CHAOS which uses the PIC-DSMC method. The GIT is modeled as a separated source ion engine, with the neutralizer placed outside the ion source. The vacuum chamber is modeled as a symmetric rectangular domain, and the ion and electron sources are considered as being circular. We consider the plume to be made up of neutral Xenon atoms, singly charged Xenon ions, and electrons. The charge distributions in the plasma plume are calculated and analyzed at steady state. Comparisons are made to GIT plumes in space environments as well.