Accommodation Coefficients of the Noble Gases and the Specific Heat of Tungsten

Abstract

By the use of the specific heat theory developed by A. H. Compton and a simple one-dimensional model, a semi-classical treatment of the problem of the thermal accommodation coefficients for monatomic gases against solid surfaces has been obtained. Application of this theory to the data of Roberts gives a satisfactory fit if the heats of absorption of helium and neon on tungsten are taken as 50 cal. per gram atom and 278 cal. per gram atom, respectively. The Compton characteristic temperature for tungsten is found to be 148°K, which leads to the conclusion that the excess specific heat of tungsten above the classical value is partially due to anharmonic terms in the potential energy of the atomic oscillators, as suggested by Born and Brody.