Characteristics of Multiple Light Scattering on Highly Concentrated Mono-Dispersed Aerosol Particles

Abstract

The properties of multiple light scattering of highly concentrated mono-dispersed aerosol particles are numerically and experimentally investigated in terms of particle size and number concentration. The numerical results show that by increasing the order of multiple scattering, the angular distribution function of scattering intensity becomes simple and is finally independent of the scattering angle. In the case where the collection angle for detecting the scattered light is in a wide range of 0-π radian, the relationship between the scattering intensity and the particle number concentration for each particle size is consolidated into a simple expression by introducing the multiple scattering factor, defined as the ratio of the multiple/singular scattering intensities for a single particle. Results of experiments performed in a highly resonanced laser beam using mono-dispersed polystyrene latex, indicate that multiple light scattering occurs even at relatively low particle number concentration. It is also confirmed that the measuring data on the multiple scattering factor obtained from the scattering intensity are quantitatively in good agreement with the numerical results.