Af. Molisch et al., RADIATION TRAPPING WITH PARTIAL FREQUENCY REDISTRIBUTION - COMPARISONOF APPROXIMATIONS AND EXACT-SOLUTIONS, Journal of quantitative spectroscopy & radiative transfer, 53(3), 1995, pp. 269-275
We treat radiation trapping with partial frequency redistribution. We
solve the generalized Holstein equation by reducing it to an algebraic
eigenvalue problem. In contrast to the complete frequency redistribut
ion case, the eigensolutions depend not only on space but also on freq
uency. We compare results obtained with exact angle-averaged frequency
redistribution functions to various commonly used approximations. For
pure Doppler broadening, the assumption of CFR gives less than 10% er
ror. For Doppler plus natural broadening, the well-known Jefferies-Whi
te approximation can lead to serious errors at high opacities.