Multiple scattering of light by densely packed random media of spherical particles: Dense media vector radiative transfer equation

The theory of light scattering by systems of spherical particles is applied to study the light scattering by discrete random media. A microphysical approach of statistical electromagnetics is used to derive the vector radiative transfer equation for semi-infinite densely packed media composed of identical spherical particles. The equation obtained corresponds to the sum of the ladder diagrams in the diagrammatic representation of the Bethe-Salpeter equation. The new vector radiative transfer equation is compared with that for sparse media. The effective refractive index as it enters in our equation is calculated from the known generalization of the Lorentz-Lorenz equation. Some numerical results of calculations of the reflection matrix are presented and compared with those for sparse media. The differences between the theoretical description of light scattering by closely packed and sparse media are discussed in detail.