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 hav e recently been utilized for simulating multiple Rayleigh light scatte ring to all orders. Here a technique is discussed to separate the two- dimensional problem of generating the polar and azimuthal scattering a ngles 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 s imulations, and an artifice is introduced which reduces the inherent p oor efficiency of the polar angle sampling in conjunction with differe ntial scattering cross sections that are sharply peaked in the forward direction. As a test, the technique was used to correct two sets of e xperimental 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 co rrected scattered intensity distributions are the same, thus providing evidence of the method effectiveness in retrieving the single-scatter ed intensity distributions.