Research project

Dark-field x-ray imaging is a novel imaging modality that allows visualizing small-angle scattering effects. Such images are typically created by a Talbot-Lau measurement setup. The method uses several gratings to capture the x-ray wave front that arrives at the detector. From this data three different information sources can be extracted: A conventional x- ray absorption image, a differential phase image, and a dark-field image. The phase- contrast images visualize the phase accumulated by x-rays in a material. This causes a deflection of the x-ray wave front. While the phase signal is a measure of the large scale variation of the wave front, the dark-field images describe the small scale irregularity of the wave front which is caused by objects smaller than the pixel size. Thus, the dark-field gives information on structural variations and density fluctuation.

In Germany, there are only few groups that are able to acquire dark-field images with the Talbot-Lau method. It is a completely new modality and is currently under investigation for various applications. Reconstruction of scalar and vectorial components in dark-filed tomography still remains largely unexplored. Our research focus on exploring the great potential of dark-field imaging. We expect that it will be beneficial for medical imaging and nondestructive testing in future.