Characterization of oriented microstructures through anisotropic small-angle scattering by 2D neutron dark-field imaging

Citation

Valsecchi, J., Strobl, M., Harti, R. P., Carminati, C., Trtik, P., Kaestner, A., ... & Kagias, M. (2020). Characterization of oriented microstructures through anisotropic small-angle scattering by 2D neutron dark-field imaging. Communications Physics, 3(1), 1-10). https://doi.org/10.1038/s42005-020-0308-4

Keywords

• Neutron Imaging
• Dark-field Imaging
• Grating Interferometry
• Small-angle Scattering (SAS)
• Anisotropic Scattering
• Oriented Microstructures
• 2D Real-space Correlation Functions
• Carbon Fibers

Brief

This article describes a new neutron grating interferometer that uses a single-shot mode to perform 2D directional dark-field image acquisition in addition to conventional attenuation contrast, enabling quantitative small-angle scattering analyses of anisotropic microstructures.

Summary

This article presents a novel neutron grating interferometer (nGI) technique for characterizing anisotropic microstructures. Here's a summary of the key points:

• Existing nGI methods rely on line gratings, which can only detect scattering in one direction. To study anisotropic scattering structures, researchers have to rotate either the sample or the gratings. This new technique overcomes this limitation.
• This article introduces a new nGI setup that uses a 2D-design consisting of small circular gratings arranged in a square array. This design allows for single-shot, broadband, 2D dark-field imaging with directional sensitivity. This means that the scattering pattern of the sample can be captured in a single measurement, without the need for rotation.
• By varying the distance between the sample and the detector, researchers can systematically scan different autocorrelation lengths, enabling quantitative analysis of the sample's scattering properties. This method allows for quantitative and spatially resolved studies of anisotropic and strongly oriented systems.
• Researchers tested this new technique using a sample of carbon fibers oriented in different directions. The results demonstrate that this nGI setup can clearly distinguish between the different fiber orientations in a single measurement.
• This new technique has the potential to significantly simplify the study of anisotropic microstructures and could find applications in fields such as polymer science, soft condensed matter physics, rheology, and non-destructive testing.

Origin: https://www.nature.com/articles/s42005-020-0308-4.pdf