Angular and spatial moments for half-space albedo transport problems

• Review of Case eigenmode method with Chandrasekhar H-function.
• Angular moments of the intensity emerging from a half-space.
• Spatial moments of the density within a half-space.
• Honors Mike Williams and Ivan Kuščer for their transport theory research.

Two classic problems of radiative transfer and neutron transport are solved for a spatially-uniform semi-infinite medium with isotropic scattering. General analytical equations are derived for (1) angular moments of the outward current and (2) spatial moments of the total flux within the half-space. Such moments, for example, can provide analytically explicit equations for determining the surface albedo of the medium as well as the mean depth and mean square distance of travel within the medium. The analysis is done with the Case-style eigenmode method as expressed in terms of the Chandrasekhar H-function and its moments.