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Onset phenomena in MPD thrustersAn experimental study has clarified some aspects of MPD thruster onset phenomena. The steep increase in terminal voltage that occurs as the onset current is approached may have different causes, depending on the propellant injection geometry. For propellant injection at the cathode radius, terminal voltage increase corresponds to a growing anode fall voltage; for injection at a larger radius, the increase is related to the back emf in the near-cathode plasma. The formation of the onset current pattern within the arc has been mapped experimentally as the thruster responds to an input current step which rises from below onset to the onset value. The appearance of terminal voltage hash at onset correlates with the extension into the exhaust region of a significant fraction of the arc current.
Document ID
19860026255
Document Type
Conference Paper
Authors
Barnett, J. W. (R&D Associates Alexandria, VA, United States)
Jahn, R. G. (Princeton University NJ, United States)
Date Acquired
August 12, 2013
Publication Date
September 1, 1985
Subject Category
SPACECRAFT PROPULSION AND POWER
Report/Patent Number
AIAA PAPER 85-2038
Funding Number(s)
CONTRACT_GRANT: JPL-954997
Distribution Limits
Public
Copyright
Other