B. D. Sleeman Abstract. 6 Ultrasound spectroscopy is a new technique for studying particle size that has great potential due to its ability to size concentrated dispersions such as food emulsions.
Successful particle sizing using spectroscopic techniques requires an accurate scattering theory.
Single particle scattering theory, first developed by Rayleigh and refined by Epstein and Carhart, is an exact theory for an isolated particle suspended in a medium. The theory involves expansion of the scattered fields as a series of Hankel functions, which, when solved in the far field, give the scattering coefficients. However, the numerical solution for these coefficients is badly conditioned and as a result, it is not possible to guarantee under all circumstances accurate results for calculation of the scattering coefficients. It is also difficult to solve the scattering problem for shapes other than ellipsoids and to account for scattering by more than one particle. Herein is presented a low frequency, asymptotic approximation to single particle scattering theory that is accurate and is easily generalized to arbitrary shapes and to more than one particle.