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.

Non-conservative electron transport in CF4in electric and magnetic fields crossed at arbitrary angles

“…In that respect, Biagi has adopted the method proposed by Longo and Capitelli [37] in his Monte Carlo code to include the angular distribution of both elastic and inelastic collisions [26]. For CF 4 , it was shown by Vasenkov [38] that the errors in transport coefficients, resulting from the assumption of isotropic scattering are less than about 3% for E/n 0 below 0.1 Td. For higher E/n 0 , the errors increase rapidly up to 35%.…”

Monte Carlo studies of electron transport in crossed electric and magnetic fields in CF4

“…Here it is of interest to establish how they affect the transport properties in the presence of magnetic fields and also possibly to predict how they affect the performance of plasma reactors. Finally, in addition to the published papers that concern both experimental data [46] and swarm analysis in the electric field only [47][48][49][50], the numerical modelling performed here in E × B fields can be useful for comprehensive modelling of a wide range of CF 4 discharges including dc discharges [51][52][53], rf and microwave discharges [54][55][56], studies of gas discharge opening switches [57] and technology of gaseous dielectrics [58].…”

Monte Carlo Simulation of Electron Swarm Parameters in the SF6/CF4 Gas Mixtures

“…13) The indirect vibrational excitation and attachment CSs are obtained from Christophorou et al 2) Larin et al 3) pointed out that a scaling method with several chosen CSs is necessary to fit the experimental data, even for such a well-studied gas as SF 6 irrespective of the computational method. They summarized different methods of scaling the CSs, mainly combining the direct multiplication of separate CSs, 16) conserving their dependence vs electron energy, with the local modifications of the momentum transfer CS. 10,17) In our study, we perform modifications for the SF 6 and CF 4 CSs to fit the calculated electron swarm parameters to the experimental data.…”