Photoelectron emission from solid Ne tested by impurity adsorption

Abstract

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