Date of Award

3-21-2019

Document Type

Thesis

Degree Name

Master of Science in Astronautical Engineering

Department

Department of Aeronautics and Astronautics

First Advisor

Carl R. Hartsfield, PhD

Abstract

A Busek 100W low-power annular Hall effect thruster was characterized to determine the thruster’s best operating parameter range and to study plasma oscillations within the thruster. These experiments were conducted using xenon gas in the Space Propulsion Analysis and System Simulator chamber at the Air Force Institute of Technology on Wright-Patterson Air Force Base. The thruster’s performance characteristics were evaluated at nominal discharge voltages and constant total mass flow rate, solenoid current, and keeper current to determine the operating conditions optimizing divergence angle, beam efficiency, and discharge loss. This was accomplished using a Faraday probe to determine the plume’s current density profile at four radial distances. The plume’s divergence was between 24.29° and 35.95° with the smallest divergence at 275 volts, the beam efficiency ranged from 50.23% to 64.43% with greatest efficiency at 275 volts, and the discharge loss was between 383 and 438 W/A with the least loss at 200 volts. The thruster was also used to investigate the correlation between oscillating modes and thruster operation by collecting time-synchronous measurements of relative azimuthal intensity across the channel using high-speed imagery and global discharge current with an oscilloscope. Breathing oscillations during nominal operation occurred at 79 kHz according to discharge current measurements and 78.12 kHz with a standard deviation of 6.75 kHz as determined by the mean channel intensity. When the discharge power was decreased by 52.81% and the total mass flow rate was increased by 19.62% the breathing oscillations were 41 kHz according to discharge current measurements and 39.10 kHz with a standard deviation of 4.28 kHz according to the mean channel intensity. No rotating spokes were observed by the high-speed camera.

AFIT Designator

AFIT-ENY-MS-19-M-231

DTIC Accession Number

AD1073901

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