PPPL-3905 is available in pdf format (820 KB).

Temperature Gradient in Hall Thrusters

Authors: D. Staack, Y. Raitses, and N.J. Fisch

Date of PPPL Report: November 2003

Submitted to: Applied Physics Letters

Plasma potentials and electron temperatures were deduced from emissive and cold floating probe measurements in a 2 kW Hall thruster, operated in the discharge voltage range of 200-400 V. An almost linear dependence of the electron temperature on the plasma potential was observed in the acceleration region of the thruster both inside and outside the thruster. This result calls into question whether secondary electron emission from the ceramic channel walls plays a significant role in electron energy balance. The proportionality factor between the axial electron temperature gradient and the electric field is significantly smaller than might be expected by models employing Ohmic heating of electrons.