Monte Carlo simulation of electron transport in carbon tetrafluoride discharge plasma

Abstract

The Monte Carlo technique was used to investigate electron transport in the carbon tetrafluoride discharge plasma. A set of total elastic and inelastic cross sections was assembled on the basis of the critical survey of Christophorou, Olthoff, and Rao [J. Phys. Chem. Ref. Data 25, 1341 (1996)]. Particular attention was given to the derivation of the total and angular elastic cross sections at energies close to the Ramsauer minimum. The experimental angular elastic cross sections were fitted to analytic functions suitable for implementation in the Monte Carlo calculations. Angular inelastic cross sections were analytically represented using a simple Born approximation. Superelastic collisions were included in the calculations in an effort to account properly for the behavior of electrons at low energies. The transport coefficients obtained with the direct simulation agreed with the measurements for the electric field to gas density ratios (E/N) in the range 0.01⩽E/N⩽300 Td. Agreement between calculated and measured reaction-rate coefficients was obtained for E/N below 200 Td. The effect of both elastic and inelastic anisotropic scattering on electron transport in carbon tetrafluoride was studied in detail. This system is typical of molecular systems with a Ramsauer minimum in the elastic cross section.