(Received March 11, 1991; accepted for publication March 29, 1991)
The occurrance of onset in (magneto-plasma-dynamic) MPD thrusters is investigated by means of a steady MPD formulation and an onset hypothesis. The onset boundary curve for Argon propellant is obtained and is found to be consistent with experimental observations. It is shown that in order to attain high specific impulse before occurrance of onset, it is necessary to increase the low temperature plasma electrical conductivity.
KEYWORDS:MPD thruster, onset phenomena, onset boundary curve, Argon propellant