Experimental and theoretical thermal diffusion factors in gaseous mixtures: III. Ternary mixtures

Abstract

Observations have been carried out with HeAr, HeNe, H 2Ne and NeAr mixtures which have been regarded as multicomponent mixtures, mainly to study the variation of the thermal diffusion factors for Neon and Argon isotopes with the concentration of an added gas. The thermal diffusion factor of Argon isotopes, 36Ar and 40Ar, increases with increasing concentration of helium and neon. A marked decrease was observed for the thermal diffusion factor of 20Ne 22Ne with increasing concentrations of helium, hydrogen and argon. All the inverses of thermal diffusion factors which could be measured in the above multicomponent mixtures over sufficiently large concentration range, do appear to be linearly dependent on concentration. The 20Ne 22Ne case with addition of Ar is very unreliable however. Experimental results are in qualitative agreement with the elementary theory which has been developed. The variation of the isotopic thermal diffusion factor with concentration is markedly determined by the ‘hardness’ of the added gas.