Attenuation constant of a coherent field in a dense distribution of particles

In a dense distribution of particles, the propagation characteristics of the coherent field are strongly affected by the pair-correlated distributions of scatterers. This paper presents an optical experimental study to show that, when the particle density is greater than about 0.1%, the attenuation constant departs markedly from the formula based on an uncorrected scatter assumption. It decreases sharply when ka < 1, whereas it shows a slight increase when ka ≫ 1. Experimental data are shown for the volume densities ranging from 10−3 to 40% and ka ranging from 0.529 to 82.793. Comparisons are given with some theoretical calculations.