Monte Carlo multiple-scattering simulation and data correction in small-angle static light scattering

Monte Carlo methods usually employed for gamma- and x-ray problems have recently been utilized for simulating multiple Rayleigh light scattering to all orders. Here a technique is discussed to separate the two-dimensional problem of generating the polar and azimuthal scattering angles into two independent one-dimensional samplings, thus increasing the computational efficiency. Although the method has quite a general applicability, this paper is focused on small-angle light-scattering simulations, and an artifice is introduced which reduces the inherent poor efficiency of the polar angle sampling in conjunction with differential scattering cross sections that are sharply peaked in the forward direction. As a test, the technique was used to correct two sets of experimental data affected by multiple scattering. Microporous membrane filters under quasi-index-matching conditions were investigated, and two stacks of different thickness were used. While the raw data are of course appreciably different for different sample thicknesses, the corrected scattered intensity distributions are the same, thus providing evidence of the method effectiveness in retrieving the single-scattered intensity distributions.