Abstract
The ion engine is one of the most promising electric thrusters for satellite control because of its high specific impulse.
The discharge stability is the most fundamental requirement for an ion engine operation. The thermal control of an engine for optimum ignition and upkeep of discharge, and the compatibility between the discharge plasma and the power supply are described in this paper from the view of discharge stability.
The mathematical thermal model of a discharge chamber is derived, and design criteria for the thermal conductance of an engine and for the heater power distribution of a power conditioner are obtained. Next, the propellant flow control loop for the discharge chamber which includes nonlinear and time lag elements is analyzed. The offset and the stability condition are derived with respect to the gain parameter. Furthermore, the compatibility between the plasma and power supply is investigated experimentally. The important conclusion is that the capacitance of output filter is the dominant factor to cause an undesirable intermittent discharge.
