Macroscopic response of a Hall thruster discharge from an axial-radial PIC model

A 2D Particle-In-Cell model is used to analyze the steady state plasma discharge in a simplified Hall Effect Thruster geometry. The kinetic solution yields the electron VDF, which is not Maxwellian. This leads to anisotropy in the electron temperature and includes non-standard contributions to macroscopic transport equations. In particular, it is found that gyroviscosity plays an important role in the azimuthal electron momentum equation. Simulation results are compared against previous 1D radial and axial solutions showing qualitative agreement. Furthermore, the validity of some of the assumptions taken by those reduced dimensionality models are discussed according to the 2D results obtained. Finally, the limitations of simple solutions to characterize plasma-wall interaction are highlighted. Wall interaction parameters required for quasineutral fluid models are computed, showing different behaviors in the anode and exit regions. Near the anode inertia is largest and the VDF deviates significantly from the Maxwellian solution.