Open AccessSecondary Electron Emission from Dielectric Materials of a Hall Thruster with Segmented Electrodes
Author(s) -
A. Dunaevsky,
Yevgeny Raitses,
Nathaniel J. Fisch
Publication year - 2003
Language(s) - English
Resource type - Reports
DOI - 10.2172/812024
Subject(s) - secondary emission , electron , secondary electrons , atomic physics , yield (engineering) , dielectric , electrode , hall effect , materials science , ion , physics , electrical resistivity and conductivity , optoelectronics , nuclear physics , composite material , quantum mechanics
The discharge parameters in Hall thrusters depend strongly on the yield of secondary electron emission from channel walls. Comparative measurements of the yield of secondary electron emission at low energies of primary electrons were performed for several dielectric materials used in Hall thrusters with segmented electrodes. The measurements showed that at low energies of primary electrons the actual energetic dependencies of the total yield of secondary electron emission could differ from fits, which are usually used in theoretical models. The observed differences might be caused by electron backscattering, which is dominant at lower energies and depends strongly on surface properties. Fits based on power or linear laws are relevant at higher energies of primary electrons, where the bulk material properties play a decisive role