Determination of the number of scatterers in a finite volume by the statistical analysis of scattered light intensity.

Light scattering by a random assemblage of independent particles in a finite volume is studied. The statistics of the scattered intensity is found to deviate from a negative exponential law if the number of scatterers exceeds some critical value N/sub c/, determined by the volume, applied wavelength, and scattering angle. A new, nonuniform phase distribution function is presented and utilized in the derivation of the formula specifying the dependence of N/sub c/ on the scattering angle. A practical method leading to the determination of the (large) number of scatterers is proposed and applied to experiments on vapor deposited silica glass.