Drift velocity of Xe/sup +/ ions in Xe//sup 3/He mixtures

The drift velocities and diffusion coefficients of Xe/sup +/ ions in gaseous Xe//sup 3/He mixtures, at atmospheric pressures, for Xe concentrations between 1 and 30 %, and reduced electric field strengths, E/p, from about 1 to 22.5 V cm/sup -1/ torr/sup -1/ at 300 K are calculated using a detailed Monte Carlo programme. The Monte Carlo simulation uses a set of integral and differential elastic collision cross sections for Xe/sup +/ ions with neutral He and Xe atoms previously calculated by the authors using a modified Tang-Toennies ion-atom interaction potential and the JWKB approximation to calculate the phase shifts. The calculated drift velocities of Xe/sup +/ depend strongly on the concentration of Xe in the mixtures.