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 determined with greater accuracy and at higher E/N (electric field to neutral gas density ratio) regions than previously. Results at a drift tube temperature of about 303 K are reported with estimated accuracies of +/-3% at E/N values ranging from 5 to 500 Td. Furthermore, the reduced mobility, K0, and the ratios D(T,L)/K of the transverse and longitudinal diffusion coefficients respectively to mobility, were calculated using Monte Carlo simulations (MCS). Comparisons between the experimental values of D(T)/K and those calculated using the interaction potential of Koutselos, Mason and Viehland suggest that this interaction is a good representation of the true potential in the long and intermediate ranges.