In this study, we examine the single-scattering properties of aggregates of nano-sized spherical scattering centers (spherules) of different sizes and refractive indices, with an emphasis on contrasting the single-scattering properties of ordered and disordered aggregates, holding all other parameters constant. The ordered aggregates are constructed by arranging the spherules in a simple cubic configuration, while the disordered aggregates are constructed using an ideal amorphous solid algorithm. The single-scattering properties of both kinds of aggregates are computed using the superposition T-matrix method. We find that, in most cases, the scattering and absorption and hence extinction of radiation by ordered aggregates is stronger than for disordered aggregates: for the cases we examine, the average percent difference in scattering efficiency is 14%, and the maximum percent difference in scattering efficiency is 44%; the average percent difference in absorption efficiency is 5.3%, and the maximum percent difference in absorption efficiency is 18%; the average percent difference in extinction efficiency is 12%, and the maximum percent difference in extinction efficiency is 40%. These differences have implications regarding radiative transfer in systems of amorphous particles in general.
Bibliographical noteFunding Information:
MIT International Science and Technology Initiatives (MISTI)Israel Seed Fund (2017-2018); Israel Science Foundation (1872/17). The authors thank Daniel J. Cziczo, Jesse H. Kroll, and Wesam Al Madhoun for the collaboration leading to the idea for the work presented in this manuscript. The authors also thank Zbigniew H. Stachurski for providing us with the MATLAB code for implementing the IAS algorithm and for helpful consultation on its use. The authors thank two anonymous reviewers for their helpful comments.
Funding. MIT International Science and Technology Initiatives (MISTI)-Israel Seed Fund (2017-2018); Israel Science Foundation (1872/17).
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