Optical Scattering Characteristics of 3D Lunar Regolith Particles Measured using X-Ray Nano Computed Tomography
Edward Garboczi, Ann Chiaramonti Debay, Somen Baidya, Ahmed M. Hassan, Andrew Sharits, Jay D. Goguen, Thomas Lafarge, Mikolas Melius
Shape is a critical property, besides size and material composition, which has a strong effect on the optical scattering characteristics of a particle. In this work, we computationally study how the measured three-dimensional shapes of lunar regolith particles affect two fundamental optical scattering characteristics, the resonance frequency and the corresponding peak scattering cross- section. The shapes of 25 lunar regolith particles collected during the Apollo 11 mission were measured using X-ray Nano Computed Tomography (XCT). The scattering cross-sections of particles that ranged in size between 400 nm to 1000 nm were computed using the open-source DDSCAT software in the visible to the infra-red frequency range. The orientation-averaged scattering cross-section of the lunar regolith particles was then compared to that of spheres of the same volume. The comparison shows that the shape of lunar regolith particles decreases the resonance wavelength by 20 %, on average, compared to spheres of the same volume. This difference highlights the importance of accounting for particle shape variations in understanding the optical response of lunar regolith particles that compose lunar dust. The peak scattering cross-section is found to be nearly independent of shape for the suite of particles studied.
, Chiaramonti Debay, A.
, Baidya, S.
, Hassan, A.
, Sharits, A.
, Goguen, J.
, Lafarge, T.
and Melius, M.
Optical Scattering Characteristics of 3D Lunar Regolith Particles Measured using X-Ray Nano Computed Tomography, IEEE Geoscience and Remote Sensing Letters, [online], https://doi.org/10.1109/LGRS.2021.3073344
(Accessed March 3, 2024)