Modeling of Hall Thruster Lifetime and Erosion Mechanisms (Preprint)
Abstract
An axisymmetric hybrid-PIC model of the Hall thruster plasma discharge has been upgraded to simulate the erosion of the thruster acceleration channel, the degradation of which is the main life-limiting factor of the propulsion system. Evolution of the thruster geometry as a result of material removal due to sputtering is modeled by calculating wall erosion rates, stepping the grid boundary by a chosen time step and altering the computational mesh between simulation runs. The code is first tuned to predict the nose cone erosion of a 200 W Busek Hall thruster, the BHT-200. Simulated erosion profiles from the first 500 hours of operation compare favorably to experimental data. The thruster is then subjected to a virtual life test that predicts a lifetime of 1,330 hours, well within the empirically determined range of 1,287-1,519 hours. The model is then applied to the BHT-600, a higher power thruster, to reproduce wear of its exit ring configuration over 932 hours of firing. Though some optimized code features remain the same, others need adjustment to achieve comparable erosion results. Better understanding of the physics of anomalous plasma transport and low-energy sputtering are identified as the most pressing needs for improved lifetime models.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2007
- Accession Number
- ADA473503
Entities
People
- Manuel Martinez-sanchez
- Shannon Y. Cheng
Organizations
- Massachusetts Institute of Technology