FMT-2 discharge cathode erosion rate measurements via laser-induced fluorescence
Relative erosion-rates and impingement ion production mechanisms have been identified for the discharge cathode of a 30 cm ion engine using laser-induced fluorescence (LIF). Mo and W erosion products as well as neutral and singly ionized xenon were interrogated. The erosion increases with both discharge current and voltage and spatially resolved measurements agree with observed erosion patterns. Ion velocity mapping identified back-flowing ions near the regions of erosion with energies sufficient to generate the level of observed erosion. A potential-hill downstream of the cathode was indicated and is suggested to be responsible for the erosion. © 2000 by George Williams Published by the American Institute of Aeronautics and Astronautics with permission.
