Relationship between the morphology and the light scattering cross section of optically soft aggregates

The purpose of this paper is to establish the suitable analytical expressions for the light scattering cross section of aggregates constituted by optically soft primary particles. The used optical approximation is the well-known Rayleigh-Debye-Gans approximation. The geometrical description of the aggregate is based on the pair, or distance, distribution density function describing at once the two spatial scales (primary particle and aggregate). Firstly, a study of the two-particle set is presented. An exact and an approximated formulations are proposed for the distance distribution density and the scattering cross section. Then the corresponding results are extended to the aggregates.