Super MPD Thrusters for Interplanetary Travel

The magnetoplasmadynamic (MPD) thruster is a high specific impulse (I_sp) and thrust electric propulsion concept which is used on some satellites for station keeping and orbit transfer. In this paper, I investigate a super MPD thruster that has substantially greater I_sp than conventional thrusters, and so may be a part of a viable propulsion system for deep space exploration These super MPD thrusters are driven by much larger electrical currents than usual. Using the MACH2 computer code, I perform a series of numerical experiments to investigate the acceleration of argon from the sound speed at the inflow point to an average exhaust velocity of up to 600 times the sound speed with four different nozzle designs. I conclude that a straight nozzle performs poorly, but nozzles of 30° and 45° generate an I_sp of up to 2 x 10⁴s. A 60° nozzle also produces large I_sp, but at such a severe angle, the flow begins to separate from the nozzle wall, and this nozzle may be too large for some applications.