Laser Thomson Scattering Measurements of Electron Temperature and Density in the Near-Field Plume of a Hall-Effect Thruster

Non-invasive measurements of electron temperature and density in the near-field plume of a Hall-effect thruster were performed using a laser Thomson scattering diagnostic. Laser measurements were processed using a maximum likelihood estimation method and results were compared to electrostatic double probe measurements. Electron temperature ranged from approximately 1 – 40 eV and density ranged from 1.0 × 10 m−3 to 1.3 × 10 m−3 over discharge voltages from 250 to 450 V and mass flow rates of 40 to 80 SCCM.