MONTE-CARLO SIMULATIONS OF THE EXTINCTION RATE OF DENSELY PACKED SPHERES WITH CLUSTERED AND NONCLUSTERED GEOMETRIES

Scattering and absorption coefficients are presented from Monte Carlo simulations of electromagnetic wave propagation in a volume of densely packed, random dielectric, absorptive spheres. The particles are mode led both with and without a surface adhesion that causes them to form clustered groups. Results for scatterer densities greater than a few p ercent by volume differ significantly from those obtained under the in dependent-scattering assumption. The extinction rates agree well with analytic dense-medium theory. Results also show that, on account of lo cal fields experienced by the particles, the system absorption is diff erent from that predicted with an assumption of independent absorption . Scattering is increased when the spheres are deposited with surface adhesion that causes them to cluster and to form larger particles.