Reexamination of theLi+-He interaction potential

Abstract

Using various recently proposed interaction potentials for the Li+-He system, elaborate calculations of the mobility, longitudinal, and transverse diffusion coefficients of Li+ swarms in helium have been made by high-speed Monte Carlo simulations (MCS s). In addition, the transverse diffusion coefficients for this ionneutral-atom pair have been experimentally measured with total errors of +3/o. The close agreement of the present experimental results with those of Skullerud, Eide, and Stefansson [J. Phys. D 19, 197 (1986)] as well as the faithful MCS reproduction of all three transport coefficients using the interaction potential proposed by Larsen et al. [J. Phys. B 21, 2519[J. Phys. B 21, (1988] over the entire range of E/N (electric field to neutra1-particle number density ratio) studied not only provides confirmation of their transport coefficient values, but also lends strong support for their proposed interaction potential. In comparison, the more recent potentials of Ahlrichs et a!. [J. Chem. Phys. 88, 6290 {1988)] and of Koutselos, Mason, and Viehland [J. Chem. Phys. 93, 7125 (1990)] did not reproduce the experimental data quite as well. As a benchmark the MCS calculations have also provided evidence of the accuracy of the Kramers-Moyal expansion method in calculating the transport coefficients.PACS number(s): 34.20. Cf, 51.50.+v, 52.25.Fi

Long-range dispersion coefficients for Li, Li+, and Be+ interacting with the rare gases

“…[18][19][20] The dispersion interaction can also play an important part of binding between metal ions and the rare gases. [25][26][27][28][29][30][31][32][33] The data for most transport experiments are obtained at room temperatures where the small size of Li + -RG dispersion interaction will not have much influence. [22][23][24] Experimental investigations of the transport of the Li + ion in the rare gases have prompted investigations of the interaction potentials between Li + and the rare gases.…”

Experimental and Monte Carlo simulation studies of transport properties of swarms drifting in Ne and Ar gases

“…The accurate determination of the transport coefficients of gaseous ions in a neutral gas with an electric field is of fundamental importance [1,2]. In this paper, we continue the experimental measurements of the transverse diffusion coefficient-to-mobility ratio, D T /K, of alkali ion-rare gas pairs [3,5] by reporting the results for a dilute swarm of Cs + ions drifting in Ne and Ar gases at values of electric field-to-neutral gas number density ratio E/N in the range 5-600 Td and at temperature 303 ± 1 K. Monte Carlo simulation (MCS) calculations [4] are reported for mobility (K) and for longitudinal and transverse diffusion coefficient-to-mobility (D L /K and D T /K) ratios to adjudicate between the accuracies of the two available interaction potentials for these ion-neutral species pairs, namely those due to Koutselos, Mason and Viehland (KMV) [6] and the modified Tang-Toennies (MTT) [7] calculations, respectively.…”

Transverse diffusion measurements and Monte Carlo simulation studies of Rb+ ions in Kr and Xe

“…[1][2][3][4][5][6][7] However, there is a dearth of experimental data for D T or D T /K of sufficient accuracy. [3][4][5][6][7][8][9][10][11][12][13][14][15] The only experimental data reported for both Rb ϩ -Kr and Rb ϩ -Xe systems are values of the reduced mobility ͑K 0 ͒, 16 and the product of the neutral gas number density and longitudinal diffusion coefficient ͑ND L ͒. 17 These data were compiled in numerical form by Ellis et al 18 To our knowledge, no transverse diffusion data has yet been reported for Rb ϩ ions drifting in Kr and Xe gases.…”