Monte Carlo and Boltzmann calculations of the density gradient expanded energy distribution functions of electron swarms in gases

An arbitrary-collision sampling technique has been developed for Monte Carlo calculations of the diffusion term in the density gradient expanded energy distribution functions. The technique is shown to provide for an alternative and accurate Monte Carlo calculation of the diffusion coefficients. Comparisons of the diffusion distribution function for the cases of electron swarm transport in the ramp model gas and CH4 show excellent agreement with the results obtained by the Boltzmann method of Pitchford and Phelps (1982). However, there remains a discrepancy for the case of N2.