A MODIFIED FEAUTRIER METHOD.

Abstract A modification of the Feautrier method of solving transfer problems is presented that allows advantage to be taken of such simplifications as isotropic scattering and complete frequency redistribution. The method has timing and storage requirements comparable to integral equation methods, but retains the ease of formulation of differential methods. The case of a two-level atom is treated in detail, and an appropriate generalization is sketched for the treatment of multi-level cases by means of a complete linearization technique.