Using Prior Knowledge for the Solution of Ill-Posed Inverse Problems in X-Ray Microscopy

DASHH Doctoral Researcher: Johannes Dora

Supervisors: Prof. Christian Schroer (DESY, UHH), Dr. Johannes Hagemann (DESY), Prof. Tobias Knopp (TUHH)

The X rays produced in accelerator-based radiation sources, as for example PETRA III at DESY, allow to implement coherent imaging techniques which are not possible at a lab source. One of these techniques is X-ray microscopy using the divergent beam of a nano focusing optics (< 100 nm) in a lens-less setting i.e., in contrast to a conventional microscope the objective lens is missing. Thus, the image recorded is an interference pattern, a so-called hologram. The actual image of the sample is obtained from reconstruction algorithms. The main goal of this project is to develop new robust algorithms which can be applied easily to a wide range of samples.