Measurements of Secondary Electron Emission Effects in the Hall Thruster Discharge
Authors: Y. Raitses, A. Smirnov, D. Staack and N.J. Fisch
Date of PPPL Report: December 2005
Submitted to: Physics of Plasmas
The dependence of the maximum electron temperature on the discharge voltage is studied for two Hall thruster configurations, in which a collisionless plasma is bounded by channel walls made of materials with different secondary electron emission (SEE) properties. The linear growth of the temperature with the discharge voltage, observed in the channel with a low SEE yield, suggests that SEE is responsible for the electron temperature saturation in the thruster configuration with the channel walls having a higher SEE yield. The fact that the values of the electron temperature at saturation are rather high may indirectly support the recently predicted kinetic regime of the space charge saturation of the near-wall sheath in the thruster discharge. We also observed a correlation between the effects of the channel wall material on the electron temperature and the electron cross-field current.