Formation of the contour of a spectral line upon partial frequency redistribution

The problem of the radiation transfer in an atomic gas in a laser radiation field is numerically solved under the conditions of partial frequency redistribution and cylindrical geometry of the medium. The light scattering by atoms is modeled by the angle-averaged distribution function R _III. The influence of the partial frequency redistribution on the formation of the sodium emission line λ = 589.6 nm and on the characteristic deexcitation time of the sodium vapor is studied in relation to the vapor optical thickness.