Hollow cathode thrusters for all-electric spacecraft

This paper characterizes thrust performance of a variant of the T6 hollow cathode modified for improved operational characteristics. The device displays promising performance and highlights the potential for application as a microthruster. The T6 cathode is able to produce specific impulse of over 1050s with xenon and argon; however the dominant acceleration mechanism at low flow rates is shown to be almost entirely electromagnetic effectively constituting a low power, magneto-plasma-dynamic thruster. The modified cathode also displayed very low discharge voltages ~12V and stable operation while carrying currents as high as 30-Amps on flow rates of less than 0.1mgs-1 down to 0.04mgs-1 with xenon. This investigation also highlights the importance of electrode geometry in hollow cathode thruster design and indeed in all other applications of hollow cathode where flow rates should be minimize