Steady-state permanent magnet magnetoplasmadynamic thruster

A steady-state 10-kW -range magnetoplasmadynamic (MPD) thruster with permanent magnets has been made. The effect of the permanent magnets on thruster performance (specific impulse and thrust efficiency) and plasma-accelerating mechanism were examined through measurements of thrust, chamber pressure, current densities, and plasma properties in the exhaust plume. Nomenclature At = cross-sectional area of nozzle throat Cf = thrust coefficient g = gravitational constant Id = discharge current /sp = specific impulse J = current per unit axial length m = propellant mass flow rate N = plasma number density Pa = ambient pressure Pc = arc chamber pressure T = thrust Ta = aerodynamic force Te = electron temperature Tm = electromagnetic force related to applied magnetic field Ts = self-magnetic force Vd = discharge voltage Vs = space potential Z = distance from throat center 77 = thrust efficiency