DIFFUSION-COEFFICIENTS AND INTERACTION POTENTIAL FOR NA+ IONS IN ARGON GAS

Experimental values of the ratio, D(T)/K, of the transverse diffusion coefficient to mobility for Na+ ions drifting in Ar gas have been dete rmined with greater accuracy and at higher E/N (electric field to neut ral gas density ratio) regions than previously. Results at a drift tub e temperature of about 303 K are reported with estimated accuracies of +/-3% at E/N values ranging from 5 to 500 Td. Furthermore, the reduce d mobility, K0, and the ratios D(T,L)/K of the transverse and longitud inal diffusion coefficients respectively to mobility, were calculated using Monte Carlo simulations (MCS). Comparisons between the experimen tal values of D(T)/K and those calculated using the interaction potent ial of Koutselos, Mason and Viehland suggest that this interaction is a good representation of the true potential in the long and intermedia te ranges.