Two-dimensional angular optical scattering (TAOS) by environmental specimens: preliminary results

Two-dimensional angular optical scattering (TAOS) is a non destructive means of investigating small particles. Three types of materials are studied: a) polycrystalline tryptophan aggregates, which serve as reference, b) a mixture of tire debris and talc crystals coming from laboratory wear tests, c) dust from a residential, urban area collected by an electrostatic precipitator. Particles are produced from water suspension by an ink-jet aerosol generator and then illuminated by a laser beam. The scattered intensity is recorded within a solid angular sector in the backward domain. The goals of this investigation are 1) to obtain signatures of materials, based on scattering patterns and 2) to justify the experimental results by numerically solving the forward scattering problem.