Performance of a Conducting-Wall, Magnetically-Shielded Hall Thruster at 3000-s Specific Impulse

A magnetically shielded Hall thruster with a graphite channel electrically tied to the anode was operated for the first time at 800 V discharge voltage and 3000 s specific impulse. Electrical isolation issues were absent with the conducting channel and the operating characteristics were virtually indistinguishable from boron nitride walls. Thrust efficiency between boron nitride and graphite walls changed by an average of just -1.6% over 300-800 V. At 800 V, 12 kW, the measured thrust, total specific impulse, and total efficiency were 496 mN, 3000 s, and 60%, respectively. High-power density operation demonstrated a stable plasma response up to 18 kW discharge power. The results pave the way towards the next generation of low-mass, high specific impulse Hall thrusters that will be needed for future robotic and human exploration missions of the solar system.