Monte Carlo Calculation of Drift Velocities and Diffusion Coefficients for Ar+ Ions in Gaseous Argon

Drift velocities and longitudinal and transverse diffusion coefficients for Ar⁺ ions in gaseous Ar, at atmospheric pressures p = 160 Torr, T = 293 K and reduced electric fields, E/N, in the 1 to 500 Td range, are calculated using a three-dimensional Monte Carlo simulation model. The integral and differential elastic collision cross-sections used were the ones calculated before by the authors, for center-of-mass energies in the 1 meV to 10 eV range, using a modified Tang-Toennies ion-atom potential and a semi-classical approximation with phase shifts calculated by the JWKB approximation. The calculated reduced mobilities, K₀, for Ar⁺ ions in Ar, range from 1.431 cm² V^-1 s^-1 at 1 Td to 0.759 cm² V^-1 s^-1 at 500 Td for Ar⁺ ions in the ²P_3/2 ground state and from 1.414 cm² V^-1 s^-1 at 1 Td to 0.758 cm² V^-1 s^-1 at 500 Td, for the ²P_frac12 metastable state. The results obtained for the drift velocities and diffusion coefficients are compared with the experimental data available and discussed.