Advanced Electric Propulsion MPD (Magnetoplasmadynamic).
Final rept. 15 Aug 79-31 May 86,
PRINCETON UNIV NJ DEPT OF MECHANICAL AND AEROSPACE ENGINEERING
Pagination or Media Count:
An in-situ method of measuring MPDMagnetoplasmadynamic thruster component erosion has been developed and tested on a reference multimegawatt thruster configuration. The technique involves activation of selected areas on the components to be studied by precisely controlled high energy Me4V ion beam bombardment. Monitoring the decrease in activity during thruster operation provides a precise sub-micron accuracy, quantitative measure of the amount of material removed from the surface. In preliminary tests, erosion of the tungsten cathode occurred at all operating conditions, but a number of factors contributed to the lack of detectable erosion of the copper anode or the boron nitride insulator. These results tentatively indicate that cathode erosion is linearly related to the charge transfer, but scatter in the individual test sequence erosion rate data prevents a more definitive conclusion to be drawn at this time. Nevertheless, a comparison of erosion data obtained at two different pulse lengths 1 msec, 2 msec indicates that cathode material loss is generally independent of the number of current transients. Work is continuing in a broad effort to refine the Surface Layer Activation SLA technique and to obtain a data base for additional thrusters.
- Plasma Physics and Magnetohydrodynamics
- Electric and Ion Propulsion