Development Method to Estimate the Complex Index of Refraction of Dielectric Aerosols

A method to estimate the complex refractive indices of dielectric aerosols is developed. The three-dimensional radiative transfer problem in an absorbing-scattering medium is solved by the Monte Carlo method. Mie scattering theory is used to handle particle scattering and absorption. Magnesium oxide aerosol, with its well-known complex index of refraction, is selected as an example of a dielectric aerosol. Magnesium is burnt to produce MgO aerosol and the transmission of the radiation from a black body furnace through the aerosol layer is measured. The analytical results of the transmitted energy profiles along the wall facing the emission source, a black body furnace, were obtained for a wide range of complex indices of refraction and compared with the experimental results. It is shown that the value of the complex refractive index of an aerosol can be estimated.