Electron Cross-Field Transport in 2D Hybrid Hall Thruster Simulation

Summary form only given. A two-dimensional radial-axial Hall thruster simulation has been developed with the intent of better understanding the physical phenomena governing Hall thruster operation. In the simulation, the electrons are treated as a one-dimensional fluid, while the ions and neutrals are advanced using a particle-in-cell approach. The two solutions are coupled assuming quasi-neutrality. At each timestep, the transient, spatially-varying electron temperature and plasma potential are calculated through solution of the electron energy equation, a generalized Ohm´s law, and a current conservation equation. The computational domain of the simulation corresponds to the interior channel of the Stanford Hall thruster and the near field plume region. Experimentally, electron diffusion across magnetic field lines is observed to be higher than predicted by classical diffusion theory. Therefore, the primary purpose of this study is to evaluate models for electron cross-field mobility through comparison of simulation results with experimental measurements in the Stanford Hall thruster. In addition to classical transport, models for the enhanced cross-field conductivity will also be examined, such as Bohm mobility and an experimentally based mobility. A third model will attempt to illustrate the cause of the anomalous diffusion through a transient determination of mobility using real-time calculations of the plasma properties. This transient mobility attempts to account for fluctuations and non-local effects including first order spatial and temporal derivatives in the electric field. These quantities modify transport by distorting the electron cyclotron orbit, and adjusting the classical expressions for polarization and cross-field drift. Substantial modifications to electron transport results