Measurement of 30-centimeter ion thruster discharge cathode erosion

Relative erosion rates of the discharge cathode assembly of a 30-cm ion engine are measured using laser-induced fluorescence. Molybdenum and tungsten erosion products are interrogated downstream of the discharge cathode assembly during beam extraction. Erosion of the discharge cathode assembly is characterized for both keepered and unkeepered configurations. The erosion increases with both discharge current and voltage, and spatially resolved measurements agree with observed erosion patterns. Erosion rates are calculated using data from previous wear tests. Magnitudes and trends in the rates are correlated with both previous and subsequent wear tests. Laser-induced fluorescence is demonstrated to be a technique to measure relative internal erosion rates, and a path is identified for measuring absolute rates. Copyright © 2008 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

Duke Scholars

Author Alec Gallimore Thomas Lord Department of Mechanical Engineering and Materia ...