Discrepancy in Energy Transfer between Medium Energy Noble-Gas Ions and Neutral Atoms Bombarding Metal Surfaces

Publisher Website
Google Scholar
Abstract
Experiments using thermoelectric detectors for neutral particles have shown differences in the energy transfer properties of noble-gas ions and neutral atoms. The focused and collimated beams of ions and atoms bombard a platinum-receiving disk spot welded to the thermojunction, formed of Chromel and Constantan wires. Neutral atoms and ions of Ne and Ar have been studied in the energy range 500 to 2500 eV. For ions, the fraction of the kinetic energy used to generate thermo-emf in the detector was observed to be independent of their incident kinetic energy. However, for the neutral atoms, the energy transfer coefficient was found to be a monotonically increasing function of kinetic energy always less than that for ions. No attempt has been made to measure the absolute energy transfer coefficients. This discrepancy has been qualitatively explained by the experimental observation that energetic neutral atoms are specularly reflected more than ions of the same species and kinetic energy from the platinum disk of the detector.

This publication has 3 references indexed in Scilit: