Measurement of diffusion coefficients via diffusion in flowing gas II. Results

Abstract

We have applied the back-diffusion method, described in a previous publication (part I), to several noble-gas mixtures; the results are presented here (part II). In the measurements one of the two gases was present always in a relatively small concentration (1%). The diffusion coefficients D determined at gas pressure p were converted to values Ds for 1 atm, and further to values Ds, 50 for an equimolar gas mixture (50%/50%). Tables and graphs of Ds(T) and Ds, 50(T) are given

The text includes: the conversion Ds→Ds, 50 (with the relevant parameter values),the results of a number of checks (such as variation of tube diameter, gas flow velocity, gas pressure), the results of the measurements for the ten combinations of the five noble gases and for a neon-neon isotope combination (each for the temperature range T≈300–1300 K), a simple fitting formula (Ds, 50≈cTγ with γ≈1.7), and a comparison with the results of other methods.