Solution of the radiative transfer equation on parallel computer systems

A new technique for modeling three-dimensional radiative energy transfer in the framework of a code intended for the predictive simulation of high energy density plasmas on parallel computer systems is proposed. A well-scalable algorithm that takes into account the angular dependence of the radiation intensity and is free of the ray effect is constructed as based on the solution of a second-order equation with a selfadjoint operator. A feature of the algorithm is that it involves a preliminary rotation transformation, which eliminates the mixed spatial derivatives, simplifies the structure of the difference operator, and accelerates the convergence of the iterative solution of the equation. It is shown that the method proposed correctly reproduces limiting cases, namely, isotropic radiation and directed radiation with a delta-shaped angular distribution.