For the classic diffusion description of radiative transfer, the specific intensity can be represented by a small angular deviation of the local Planckian equilibrium. In a transparent media, the angular anisotropy becomes strong and one has to solve the general transfer equation. We propose a hierarchy of models that can describe the regime that lies between those two limits. Every member of this family is hyperbolic, flux-limited, and possesses a locally dissipated entropy. This hierarchy also formally recovers the diffusion limit. This study demonstrates that the two-polynomial model is already capable of capturing strong anisotropies.

The article presents the multigroup kinetic approximation of radiation transport in hohlraum systems. The view factor-based method of numerical solution is proposed. Its advantages are a detailed account of the problem geometry and accurate handling of the solution angular anisotropy and discontinuities. The method is computationally efficient and easily parallelizable. Coupled to the kinetic + hydro description of the wall dynamics, it represents a powerful tool for integrated investigation of the systems with strongly inhomogeneous optical properties.