Establishing a Facility for Making Non-Intrusive, Near-Real-Time Electric Propulsion Thruster Erosion Measurements via Simultaneous Two-Frequency Laser Induced Fluorescence

摘要

DURIP funds were used to purchase three cryopumps, a state-of-the-art tunable-diode laser, a dye-to-Ti:sapphire conversion kit for a ring laser (for enhanced IR capability), and a commercial ion-sputtering source. The new cryopumps increased the xenon pumping speed of the Large Vacuum Test Facility (LVTF) at the University of Michigan's Plasmadynamics and Electric Propulsion Laboratory (PEPL) from 140,000 to 240,000 1/s. The new lasers will be used in conjunction with our tunable ring laser to make Two-Wavelength Simultaneous Laser Induced Fluorescence (TWSLIF) measurements for Hall thruster discharge channel erosion characterization. TWSLIF will first be demonstrated in a smaller vacuum facility with a commercial ion source and a boron nitride substrate. Once perfected in the smaller chamber, TWSLIF will be used in the LVTF to characterize discharge channel erosion of the P5 Hall thruster. This capability will not only enhance PEPL, but will establish a national facility where thruster erosion and spacecraft integration issues are investigated.