THEORETICAL ANALYSIS OF THE INFLUENCE OF THE POWER SUPPLY ON BREATHING OSCILLATIONS IN HALL THRUSTERS

摘要

The breathing mode is the best known low-frequency longitudinal bulk instability of Hall thrusters, capable of generating very wide, regular discharge current oscillations in the 10-30 kHz range. This study extends a recent theory of breathing mode oscillations to the case of a non-ideal voltage source. A simple equivalent circuit modeling the AC behavior of the thruster is derived, using R, L and C components. The equivalent circuit explains in a straightforward way why an impedance in series with the generator is usually able to damp oscillations. More generally, the derived equivalent circuit can be expected to greatly improve the understanding of interactions between the thruster and the power processing unit, and in turn to help the design of robust filters.