On non-stationary radiation fields in an infinity one-dimensional homogeneous medium

Abstract

This paper considers the non-stationary monochromatic radiative transfer in an infinite one-dimensional homogeneous medium. It is believed that the medium is illuminated by a momentary isotropic point energy source. Optical properties of the medium are characterized by the absorption coefficient α, the single-scattering albedo λ, the mean time t1 of the stay of a photon in the absorbed state and the mean time t2 of its stay on the path between two consecutive scatterings. The exact solution of the nonstationary radiative transfer equation was derived for the case t = t1. Asymptotic expressions were found for the source function of average intensity and flux when points of the medium located on the large optical distances from the power source |τ| ≫ 1 and scattering close to the light conservative (1 − λ ≪ 1) assuming that t1 ≫ t2, t1 ≪ t2, or t1 = t2. These expressions are more precise than previously known. Refs 13.