Abstract View
Design of a Multi-Angle Light Scattering Setup Covering the Whole Scattering Angle Range (0.32° to 177.6°) and Interpretation of Light Scattering Data Under Q-Space Analysis
PRAKASH GAUTAM, Justin Maughan, Christopher Sorensen, Kansas State University
Abstract Number: 84
Working Group: Aerosol Physics
Abstract
We designed and built a laboratory light scattering apparatus for aerosols based on a novel optical scheme covering the scattering angle range 0.32º ≤ θ ≤ 177.6º, an extreme forward to the backscattering regime, involving 46 angles. The apparatus allows for a quick and efficient procurement of data, ensuring the elimination of the effects of possible in-homogenous of the aerosols. The experimentally observed scattered intensity is plotted in terms of scattering wave vector q on a double logarithmic scale, i.e., Q-space analysis, in addition to the conventional linear plot versus θ. Scattering data for hematite (Fe2O3) aggregates and molybdenum disulfide (MoS2) particles, both having large real and imaginary part of the refractive index, were plotted under Q-space analysis that uncovered an extended Guinier regime with two Guinier crossovers for hematite and a single regime for MoS2 particles, consistent with the microscopic pictures. The hematite showed an anomalous enhanced backscattering [1, 2]. In addition, scattering data we will be presented for irregularly shaped Al2O3 abrasive and Arizona road dust particles for whole scattering angle range with an emphasis on the backscattering regime.
References
[1] Gautam P, Sorensen CM. A light-scattering study of highly refractive, irregularly shaped MoS2 particles. Journal of Quantitative Spectroscopy and Radiative Transfer 2020;242:106757. https://doi.org/10.1016/j.jqsrt.2019.106757.
[2] Gautam P, Maughan JB, Ilavsky J, Sorensen CM. Light Scattering Study of Highly Absorptive, Non-fractal, Hematite Aggregates. Journal of Quantitative Spectroscopy and Radiative Transfer 2020:106919. https://doi.org/10.1016/j.jqsrt.2020.106919.