Thermodynamic Model for the Mobility of OxygenAnions in Dense Neon Gas

International audienceRecently a thermodynamic model has been developedto describe and predict the ion mobility in He. It aims atcomputing the free volume available for the ionic drift motionthrough the medium. The radius of the free volume per particleis the hydrodynamic effective radius in the Stokes formula whosevalidity is extended to the region of large Knudsen numberby using the Millikan-Cunningham slip factor correction. Weused this model to describe new data of O2 ion mobility insupercritical Ne on several isotherms in a broad density range.The model parameters are adjusted once and for all by fittingthe data on the isotherm closest to the critical one and allowsthe description of the density dependence of the mobility up totemperatures well above room temperatur