Continuum absorption coefficient in SF₆and SF₆-N₂mixture plasmas

Abstract

The computation of continuous absorption coefficient for SF6 plasmas has been carried out taking into account free-free radiation, using the scaled Thomas-Fermi potential for the determination of the terms resulting from the radiative recombination. The authors have computed the continuum absorption coefficient K' in SF6-N2 mixtures (for pressure values between 1 and 8 bar, in the temperature range 8000 to 24000 K) assuming that the plasma is in local thermodynamic equilibrium, by combining their results obtained in the case of SF6 with those concerning N2 from the literature. The evolution of K' with nu is explained in terms of electronic configuration of the species and of the variations of electron and ion densities with pressure, temperature and SF6 proportion.

Net Emission Coefficients of Radiation in Air and SF6 Thermal Plasmas

“…The biggest differences between these two approaches can be seen for the air plasma at higher radiation frequencies. But it should be noticed that radiation frequencies above 5 9 10 15 s -1 have negligible effect on the radiation energy transfer itself [8].…”

“…1 and 2 our calculated absorption coefficients of continuum radiation are compared with those of Refs. [8,9]. The discrepancies are mainly due to different treatment of ionic cross sections of photo-recombination.…”

“…with m -3 , while in Refs. [8,9] more realistic evolution of the cross sections is used based on the extrapolation of the scale factor in the STF method. The biggest differences between these two approaches can be seen for the air plasma at higher radiation frequencies.…”

Net emission coefficient for CO–H2 thermal plasmas with the consideration of molecular systems

“…The atomic continuum theory was thoroughly studied in the previous papers of Gleizes et al [77], Liani et al [78] and Cressault [79].…”

“…It was calculated according to the method of the Scaled Thomas-Fermi potential. Assuming LTE, the expression of the monochromatic emission coefficient is given by Gleizes et al [77] and requires the Biberman-Schlüter factor introduced by Biberman and Norman [80,81] which is a correction of the simplified classical hydrogenoid model. This factor was calculated by Hofsaess for oxygen, carbon [82].…”