PIC simulation of SPT Hall thrusters : high power operation and wall effects

Abstract

The fully kinetic Hall Thruster simulation built by [1] and used by [2] is further refined and used to obtain results for the P5 SPT Hall thruster at 3kw and 5kw operation. Performance data agree well with experiments [3], although very low values of anomalous diffusivity must be used for convergence. Particle temperatures and plasma potentials in the chamber are similar to experimental results, although charged particles and peak ionization rates are found further upstream than is observed experimentally. Electron transport mechanisms and the magnetic field configuration are analyzed for their physical consistency and effect on particle placement. Electron mobility rates are found to be physical although the reason for high Hall parameter is still unclear. Strong magnetic mirror effects, that are not reported in experimental data, are found in the simulation. Meanwhile, two sputtering models are added to the simulation and tested. A yield model based on [4]'s theories and implemented with [5]'s functions is found to agree well with experimental yield data for 300eV to 1000eV sources, but produces small yields at thruster operating conditions.