Title:

IR-Assisted Discharge Initiation in Pulsed Plasma Thrusters

Authors:

James E. Cooley and Edgar Y. Choueiri


Document type:

AIAA Paper: AIAA-2002-4274, Presented at the 38th Joint Propulsion Conference, Indianapolis, IN, July 9-12, 2002.

Access:

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Abstract:

It is demonstrated that a discharge can be initiated in a pulsed plasma thruster (PPT) at an undervoltage by shining an IR laser pulse on the thruster’s backplate. The technique has the potential for achieving uniform and erosion-free discharge initiation. Three candidate mechanisms are investigated: thermionic emission, cathode vaporization, and gas desorption. Mass spectroscopic measurements and theoretical calculations implicate water desorption from the backplate as the likely explanation for the observed effects. It is then shown that while thermionic emission was not operative in the experiments, it can be used as the basis of the design of a discharge initiator. Keywords: