Performance characteristics of a cluster of 5-kW laboratory hall thrusters

Performance characteristics of a 2 × 1 cluster of 5-kW Hall effect thrusters are investigated. The cluster and each thruster are evaluated over the power range of 1.5-6 kW at three facility pumping speeds. Analysis of the monolithic thrust measurements shows that as facility backpressure increases, the discharge current and thrust increase. The percent difference between the measured cluster thrust and the sum of the thrust for each monolithic thruster for the 10.46 mg/s anode flow rate varies from 11 to 16% as the operating pressure increases from 7.1 × 10-4 Pa-Xe (5.3 × 10 -6 Torr-Xe) to 3.7 × 10-3 Pa-Xe (2.8 × 10 -5 Torr-Xe). The percent difference in thrust for the 5.25 mg/s flow rate varies from 0 to 6% as the operating pressure increases from 4.7 × 10-4 Pa-Xe (3.5 × 10-6 Torr-Xe) to 2.0 × 10-3 Pa-Xe (1.5 × 10-5 Torr-Xe). Comparison of the cluster and the monolithic thruster performance characteristics for conditions of nearly equal operating pressure shows that for the 5.25 mg/s anode flow rate, the cluster thrust is equal to the addition of the two monolithic thrusters and the anode efficiency and specific impulse are approximately equal to those of the monolithic thruster. An unproved backpressure correction technique based on incremental current change was demonstrated to predict thrust changes within -4% to +2%, significantly better than a simple random flux calculation that uses the facility pressure and chamber wall temperature.

Duke Scholars

Author Alec Gallimore Thomas Lord Department of Mechanical Engineering and Materia ...