A 2-D Hybrid Hall Thruster Simulation That Resolves the Electron Drift Direction

A 2-D axial-azimuthal model of an annular Hall thruster discharge is developed. We use a hybrid fluid-particle-in-cell (PIC) treatment to model a Xe-propellant Hall thruster. Using a PIC approach, the positive Xe+ ions are modeled as collisionless, nonmagnetized, discrete super-particles, whereas the electrons are treated as a magnetized 2-D fluid. The model includes a continuously replenished Xe neutral background, with an imposed radial magnetic field and an applied axial electric potential. Motivated by experimental evidence of anomalously high electron mobility across the magnetic field that has been attributed to quasi-coherent fluctuations in the plasma properties, we use the numerical model to resolve azimuthal electron dynamics and study the impact of fluctuations on electron transport. Representative low-voltage (100 V) operating condition simulations predict localized plasma properties similar to those observed in experiments. The simulations predict coherent azimuthally propagating disturbances which appear to contribute to enhanced electron transport beyond that due to classical scattering.