Photoelectron emission from solid Ne tested by impurity adsorption

Abstract

Electron emission is obtained from a solid Ne sample growing from the gas phase on a low temperature substrate. The surface of the sample is irradiated by the light of an open-source microwave discharge running in the gaseous Ne. A second gas flow of CH4 is simultaneously passed onto the substrate, avoiding the discharge zone. Free electrons ejected into a vacuum chamber during the sample growth are detected by means of the electron cyclotron resonance (ECR) technique. The electron yield is found to decrease with increasing CH4 flow. Fitting curves to the experimental data show that the surface CH4 impurities play the major role in emission quenching. A temperature effect was observed in which a 4.2K sample was much more sensitive to CH4 doping than a 1.6K one. Based on the experimental results, a model is proposed for the surface sites where electrons escape the solid.