Af. Borghesani et al., LOW-TEMPERATURE O2- MOBILITY IN HIGH-DENSITY NEON GAS, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 48(2), 1993, pp. 1379-1389
We report measurements of the drift mobility of O2- ions in supercriti
cal neon gas at high density at a temperature T = 45.03 K, 0.6 K above
the critical temperature. Our measurements span a very large density
range, up to values comparable with those of a liquid [(15-240) x 10(2
0) cm-3), and cover the transition region from the kinetic to the hydr
odynamic regime. We show that the classical hydrodynamic Stokes formul
a for the drag on a sphere moving through a fluid describes accurately
enough the ionic mobility as a function of the gas density, if it is
modified to take into account the spatial dependence of the gas densit
y and viscosity around the ion due to electrostriction.