An analytical model for Hall thruster ionization efficiency on multiple propellants is derived and validated with experimental data. The experimental dataset includes previous results from a magnetically shielded Hall thruster operating on xenon and krypton over a wide discharge current range (Su et al 2024 J. Propl. Power 40 661-800) and new experimental results with the same thruster on argon and nitrogen. The analytical model is derived by integrating the neutral continuity equation along the length of the thruster channel. A series of scaling laws is then used to relate this model to key global operating characteristics of the thruster. The results indicate that with a learned characteristic channel length for the entire data set, the model accurately captures mass utilization trends as a function of a single parameter for all four propellants. The extensibility of the model beyond the range of experimental data is explored, and it is found that the dependence of the mass utilization on discharge voltage is consistent with the scaling exhibited by previously studied Hall thrusters.
Hurley et al. (Wed,) studied this question.