Pp. Ong et al., INTERATOMIC POTENTIAL AND TRANSPORT-PROPERTIES OF NA+ IONS IN HE, Journal of physics. B, Atomic molecular and optical physics, 26(16), 1993, pp. 2649-2658
Hitherto unavailable experimental values of the ratio, D(T)/K, of the
transverse diffusion coefficient to mobility for Na+ ions drifting in
helium gas are reported. Results were obtained with estimated accuraci
es of better than 3% at temperatures between 302 and 304 K, and at ele
ctric field to neutral gas density ratios, E/N, ranging from 5 to 400
Td. By an independent approach, the three transport parameters are als
o computed by Monte Carlo simulation using the modified Tang-Toennies
potential and the Koutselos, Mason and Viehland potential as input, se
parately. Comparison between the simulated results and available exper
imental data suggests that the latter potential represents fairly well
the true interaction in the long and intermediate ranges, but its sho
rt-range repulsive region is too soft.