Advanced Electric Propulsion MPD (Magnetoplasmadynamic).
Abstract
An in-situ method of measuring MPD(Magnetoplasmadynamic) 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.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1986
- Accession Number
- ADA169792
Entities
People
- A. J. Kelley
- J. Polk
- R. G. Jahn
- W. Von Jaskowsky
Organizations
- Princeton University