Numerical study of cathode emission constraints on cylindrical, self-field MPD thruster performance

A stability equation relating thruster discharge current, argon propellant mass flow rate, and electrode geometry has been solved for a variety of cylindrical self‐field MPD thruster configurations and discharge currents code was employed to provide better estimates of the maximum achievable specific impulse, thrust, and flow efficiency for cases of interest. The model results indicate that long life, cyclindrical self‐field MPD thrusters operated with argon propellant may not be able to provide specific impulse values in excess of 2100 s. Alternate electrode geometries, applied magnetic fields, and/or low molecular weight propellants may be necessary to achieve higher values of specific impulse.