Self-absorption coefficients of sulfur emission lines

摘要

A theoretical approach is developed to calculate the mean probability of photon capture for the resonance lines emitted by a neutral sulfur atom in the vacuum ultraviolet spectral region in the case of a thermal plasma mixture. The calculations are to estimate the self-absorption effect in a quantitative way assuming a Voigt line profile. The variation of the probability of photon capture with the temperature, the SF6 proportions in SF6-N-2 thermal plasma mixture, and the size of the plasma are considered. The results obtained may be of practical importance in plasma modeling and plasma diagnostics. They may also be applied to find out self-absorption-free emission lines appropriate for laser-induced breakdown spectroscopy experiments used for analytical purposes because of their simplicity. Influence of three parameters (temperature, plasma size, and SF6 proportion) on the probability of photon capture has been studied using a Voigt line profile.