Framework for high fidelity plume simulations with facility carbon sputter tracking

Abstract

Facility effects induced by vacuum chambers in electric propulsion testing complicate the extrapolation from ground test results to space performance. Facility surface material sputtering by energetic plume particles and the re-deposition of that material onto other facility and thruster surfaces is a facility effect with critical thruster performance and lifetime implications. This work implements two reduced-order sputtering models that calculate surface sputter yields and introduces sputtered particle trajectories into a high fidelity three-dimensional Hall-effect thruster plume code. The implemented sputter models are verified within the plume code to produce expected sputter yields and sputter particle trajectories. The simulation tool is then applied to model a Hall-effect thruster plume sputtering experiment conducted in Vacuum Test Facility 2 at the Georgia Institute of Technology. Comparisons between the model and experimental measurements are made using both sputter models and two different electron fluid models. Additional simulations demonstrate the modeling framework’s ability to predict carbon sputtering throughout a vacuum chamber.