Similarity parameters and scaling laws for Hall thrusters

Abstract

Hall thrusters are one of the most successful and dominant electric propulsion technologies to date, and with constantly evolving space mission needs, there is continual interest in expanding operational envelopes to different power levels, and in the use of new propellants. Here, a stationary model of a Hall thruster is presented with the aim of directly obtaining important similarity parameters and scaling laws to aid thruster design. The model is verified with a recent analytical solution and validated using existing experimental data. We identify several key similarity parameters that govern thruster operation, behaviour, and performance, and we uncover a ‘family’ of scaling laws for important geometric and operating parameters (such as channel dimensions, magnetic field strength, and propellant mass flow rate). These scaling laws are then applied to the design and optimization of Hall thrusters both within the context of alternative propellants (including krypton and argon), and operation at lower and higher power levels.