Time resolved multiple scattering of resonance photons

A simple one-dimensional model is used to calculate analytically the probability that a resonance photon is scattered exactlyn times within a finite region containing absorbing atoms. The probability distributions are used to analyze time dependent fluorescence light signals from the mercury 253.7 nm line with the mean number of scatteringss _m of about three. A comparison between exact one-dimensional results with more realistic two- and three-dimensional Monte-Carlo simulations of multiple scattering shows that the one-dimensional model is a good approximation for smalls _m and isotropic scattering. Therefore it may well serve as a fast method to analyze measured signals whereas fine details need more refined calculations.