High-frequency probing diagnostic for Hall current plasma thrusters

High-frequency oscillations (1-100 MHz) in Hall thrusters have not received sufficient experimental scrutiny. A diagnostic setup, consisting of a single Langmuir probe, a special shielded probe connector-positioner, and an electronic impedance-matching circuit, was successfully built and calibrated. Through simultaneous high-frequency probing of the Hall-thruster plasma at multiple locations, high-frequency plasma waves have been successfully identified and characterized (Ref. 1). (C) 2002 American Institute of Physics.