Emission of negative ions from surfaces with high emissivity. IEEE Transactions on Plasma Science Volume 41, Issue 8, 2013, Article number 6542735, Pages 2113-2116

Spectra of the negative ion fraction in the low field emission from MPG-8 graphite with rough surface and tungsten surface with nano fuzz as a function of the residual gas composition and pressure are measured and analyzed. The intensity of the emitted negative ions increases linearly with the pressure of the working gas in the range of 10-5 to 10-7 Torr} and depends on the atomic mass of the residual gas. A simple model based on the secondary negative ion emission of adsorbed particles under positive ion bombardment of the cathode is proposed.
Indexed keywords
Adsorbed particles; Atomic mass; High emissivity; Residual gas; Residual gas composition; Rough surfaces; Simple modeling; Working gas