Absorption and Scattering Properties of Aerosols of Aggregated Particles in the Infrared Spectral Region

摘要

This report concerns the extension of a theory of particulate scattering to the difficult case of aggregated aerosols. Photoacoustic measurements of absorption and scattering in the infrared and visible spectral regions have been made for Silicon Dioxide and Carbon smokes to test the validity of the theory. The development of suitable screening materials for infrared radiation, particularly in the 3-5 and 8-13 micrometer regions is required by developments of modern infrared detection technology. Such smokescreen materials derive their value from either absorption or scattering phenomena or some combination of the two. Because scattering phenomena may be optimized with regard to wavelength of effective operation by suitable choice of particle size and refractive index, the corrollary is also true: viz. no one scattering material is likely to be equally valuable over all wavelengths.