Materials Testing

Grating-based X-ray imaging provides additional information about the inner structure of materials which are not visible in conventional X-ray attenuation imaging.

The imaging technique enables an enhanced detection of defects and inhomogenities in the field of non-destructive testing. In particular the X-ray dark-field image is generated by fibrous or porous structures on scales below the position resolution of the imaging system. This enables easier detection of fine cracks, air inclusions, porosity and similar (micro-)structural defects.

For example the non-destructive investigation of ancient relicts is an interesting field of application. The analysis of archaeological findings (Figure 1) or historical documents (Figure 2) has been done by our group.

Figure 1: Attenuation (left), differential phase (middle) and dark-field image (right) of an ancient iron fibula (From Ref. V. Ludwig et al., Non-Destructive Testing of Archaeological Findings by Grating-Based X-Ray Phase-Contrast and Dark-Field Imaging, 2018, Journal of Imaging, 4(4), 58. DOI: 10.3390/jimaging4040058; used under Creative Commons CC-BY 4.0 license).
Figure 2: Attenuation (left) and dark-field image (right) of the word ‘Gescheit’ written with thorn ink on 90 g/m2 cotton paper. The scale bar is 3 mm wide in the object plane (From Ref. B. Akstaller et al.,  X-ray Dark-Field Imaging for Improved Contrast in Historical Handwritten Literature, 2022, Journal of Imaging, 8(9), 226. DOI:  10.3390/jimaging8090226; used under Creative Commons CC-BY 4.0 license).

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