One-Dimensional Analysis of Hall Thruster Operating Modes

摘要

The very simplicity of the Hall thruster structure with no screens or other control surfaces makes it difficult to understand the interrelationships which, in the end, localize and shape the various plasma regions existing in the accelerating channel. Since the radial magnetic field is usually shaped with a peak near the channel exit, the plasma structure has often been explained as simply a reflection of the magnetic field distribution. However, this is inadequate to explain the plasma dynamics inside the accelerating channel. We develop a macroscopic model gathering reliability and clarity. Quantitative accuracy in the predictions is not the main goal. Instead, emphasis is given to the consistency of the governing equations and their boundary conditions, and to include enough basic physics to illuminate the complex interplay of phenomena which shape the Hall thruster plasma. A basic model is presented along with a supplementary model of the radial interaction of the plasma with the lateral walls of the thruster. An analysis is presented of the effects of the radial plasma/wall interactions on the basic steady-state solution. The effects of heat conduction and plasma oscillations are discussed.