Comparison of Numerical and Experimental Near-Field Plasma Properties of the BHT-200-X3 Hall Thruster (Preprint)

摘要

Near-field ion velocity distributions of a BusekBHT-200-X3 xenon Hall thruster obtained through numerical simulation are compared with laser- induced fluorescence measurements taken for one nominal operating condition. The numerical code Hybrid-PIC Hall, a 2D hybrid particle-in-cell model, is used to simulate an axisymmetric cross section of the plasma acceleration zone. A set of nine HP Hall simulations are run using three different cathode positions and Bohm electron mobility coefficients to study the effects of these parameters on ion acceleration. Six additional cases were run in an attempt to better match the simulation results to the experimental data. For model validation, agreement between the numerical and experimental results is examined. The results show that it is difficult to match both the global operational parameters (i.e, thrust, discharge current, and beam current) and the ion velocity distributions. The shape of the axial velocity distributions can be closely matched by using high Bohm electron mobility values. However, this correlation comes at the expense of peak ion velocity and discharge current agreement. Radial velocity distributions are more closely matched by the simulations, but the simulations uniformly predict lower than measured inward and higher than measured outward radial velocity components (relative to the centerline) from the annular acceleration channel.