Neutral flow evolution in a six-kilowatt hall thruster

Laser-induced fluorescence velocimetry measurements obtained from the interior of a 6-kW Hall thruster using the Xe I 6s[3/2]⁰2 → 6p[3=2]2 transition at 823.4 nm (vacuum) and the Xe I 6s'[1/2]⁰1 → 6p'[3/2]2 transition at 834.9 nm (vacuum) are presented. The thruster is operated under seven conditions, with discharge voltages ranging from 150 to 600 V and anode mass flow rates ranging from 10 to 30 mg/s. Velocimetry results along the channel centerline show that the neutral propellant leaves the anode at a bulk axial velocity of ̃100 m/s and accelerates to 300-400 m/s by the exit plane. The temperature of the neutrals starts out at 1000-1600 Knear the anode but cools down to 500-800 K near the exit plane. The anode mass flow rate appears to have a bigger influence on the bulk velocity and temperature of the neutrals than the discharge voltage. Radial sweeps across the channel exit plane revealed the presence of near-wall boundary layers approximately a few millimeters thick. The experimental results are compared with MONACO and HPHall-2 simulation results. The comparison suggests that the neutral-flow acceleration is due to a combination of wall thermalization, hydrodynamic, and ionization effects. Copyright © 2011 by the American Institute of Aeronautics and Astronautics, Inc.

Duke Scholars

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