Modelling of radiation transfer at partial frequency redistribution

The model of radiation transfer at partial frequency redistribution is constructed. The condition of a medium was described by the rate balance equations of the two-level atomic population. Spectral intensity of scattered radiation was calculated from the stationary transfer equation. Scattering of light by atoms was modelled by the line combination of the angle-averaged redistribution functions $R_{II}$ and $R_{III}$. The received system of the integrodifferential equations was solved numerically with taken into account of radiation transfer to cylindrical gas volume. Influence of the partial redistribution effects on resonance-line profile of the sodium atom ($\lambda=589$ нм) and the effective afterglow time of a vapors, depending on their optical thickness, is investigated