Pulsed plasma thruster performance for miniaturised electrode configurations and low energy operation

Abstract

A one-dimensional electromechanical model based on accurate calculations of inductance and a detailed description of the inhomogeneous magnetic field distribution which accelerates the plasma discharge produced by a miniaturised pulsed plasma thruster ( μ PPT ) has been developed. The analytical model relates μ PPT performance to electrode geometry parameters and circuit parameters and shows good agreement with experimental results. The theoretical study has shown that flared electrode geometries enhance performance by optimising the inductance gradient and hence the energy available to accelerate the plasma sheet. Thruster performance has been experimentally characterised for a discharge energy range of 1–8 J for propellant surface areas of 0.15–1.5 cm 2. The performance of parallel electrode configurations has been shown to display a strong dependence on aspect ratio relative to that of flared geometries. Rectangular flared electrodes produce impulse bits considerably higher than parallel geometries under the same operating conditions. Results show that for configurations where aspect ratio may influence performance increases in electrode separation rather than decreases in electrode width produce enhanced performance for the same propellant surface area.