A Numerical Study of the Effect of Channel Insulator Discontinuity on Hall Thruster Discharge

* Presented as Paper IEPC-01-23 at the 27 International Electric Propulsion Conference, Pasadena, CA, 15-19 October, 2001. † Copyright © 2001 by the Electric Rocket Propulsion Society. All rights reserved. We present results from a numerical investigation of using a section of channel insulator with lower secondary electron emission coefficient to increase thrust and efficiency or reduce insulator erosion in an SPT-type Hall thruster. An evolved 2-D hybrid particle-incell numerical Hall thruster model, HPHall, was used. Various cases were run to compare the effect of location and width of the inserted insulator section on the plasma response. An SPT-70 geometry with channel insulator material similar to BN was used as a baseline configuration with sections of BNAlN ceramic. We found that a 6% reduction in total ion flux to the walls with a 3.7% reduction in the maximum ion flux to the walls near the thruster exit could be obtained. We also found that thrust and efficiency could be increased by 7% and 6% at the expense of a 30% increase in ion flux to the walls. We have shown that we might be able to modify the local plasma properties with this passive technique and it should be investigated experimentally.