*Mikhail Lyubomirskiy1, Bart Schurink2, Igor Makhotkin2, Felix Wittwer1, Maik Kahnt1, Martin Seyrich1, Dennis Brueckner1,3, Fred Bijkerk2, Christian Schroer1,4
(1. Deutsches Elektronen-Synchrotron DESY, 2. Industrial Focus Group XUV Optics, MESA+ Institute for Nanotechnology, 3. Ruhr-University Bochum, Faculty of Chemistry and Biochemistry, 4. Department Physik Universität Hamburg)