A full fluid, drift-diffusion, magnetized model of Hall Effect Thruster, Impact of Magnetic Field Configuration, and Experimental Data

Modeling of Hall Effect Thruster (HET) presents a challenge to the computational plasma physics, and there is a broad range of computational models, from the full PIC models to fluid description [1]. The fluid approaches have advantage of fast computational times and the ability to give quick design optimization guidelines, predict trends and uncover the underlying physical mechanism in a more transparent manner. In this work, we use a two-dimensional, axisymmetric model of HET based on a full fluid, magnetized approach. In this model the electron and ion species are described by the drift-diffusion (DD) approximation with tensor mobility and diffusion coefficients due to the presence of strong magnetic field coupled with the Poisson solver. The electron energy equation is solved in the same DD approximation which allows us to predict the spatial distribution of the electron temperature. The neutral species are solved for using a weakly compressible approach. The magnetic field profiles are computed using a range of available tools. The model predicts proper HET profiles and trends with such parameters as magnetic field strength and propellant gas type and density observed in the literature. The model is steady state but can be extended to pulsed operation. Our experimental capabilities include laser induced fluorescence (LIF). The LIF technique is extended to also track and measure neutral atoms and second ionization states of argon and xenon.

[1] J.-P. Boeuf, "Tutorial: Physics and modeling of Hall thrusters", J. Appl. Phys. 121, 011101 (2017) https://doi.org/10.1063/1.4972269