High-resolution X-ray imaging for lab-based materials research

The extension of limits of X-ray imaging techniques – in terms of spatial and temporal resolution as well as of material contrast – in the energy range from 5 to 70 keV has long exclusively taken place at third generation synchrotron beamlines. Yet, by using the latest generation of lab-sources together with novel X-ray detectors, results from microas well as sub-micrometer imaging are obtained with the same accuracy and quality as known from the state-of-the-art synchrotron experiments. In particular phase contrast imaging, which was long exclusively used at synchrotrons, is now an inherent feature of laboratory X-ray images, the origin and optimization of which will be discussed. This report shows both concepts and first results of two new imaging stations which are built at the University of Würzburg, as well as results from the current state-of-the-art CT experiments at the Fraunhofer Center Development X-ray Technology (EZRT, Fuerth). Based on state-of-the-art SEM machines, the XRM I and XRM II feature highest spatial resolution, so called nano-sources operating in the range from 10 keV to 30 keV. Depending on the target, source sizes of 100 nm and smaller can be realized. Comparing the XRM I with a sub-micrometer transmission tube as well as with imaging experiments from the BAMline (BESSY-II light source) we demonstrate the phase-contrast imaging capability of these setups. Shorter exposure times as well as higher X-ray energies (up to 70 keV), are available with a liquid-metal X-ray source, which when combines with a high-resolution detector is also capable of producing phase contrast images.