X-ray tomographic microscopy at TOMCAT

Synchrotron-based X-ray Tomographic Microscopy is a powerful technique for fast, non-destructive, high resolution quantitative volumetric investigations on diverse samples. At the TOMCAT (TOmographic Microscopy and Coherent radiology experimenTs) beamline at the Swiss Light Source (SLS), synchrotron light is delivered by a 2.9 T superbend. The main optical component, a Double Crystal Multilayer Monochromator, covers an energy range between 8 and 45 keV. The standard TOMCAT detector offers field of views ranging from 0.75x0.75 mm2 up to 12.1x12.1mm2 with a theoretical resolution of 0.37 μm and 5.92 μm, respectively. The beamline design and flexible endstation setup make a large range of investigations possible. In addition to routine measurements, which exploit the absorption contrast, the high coherence of the source also enables phase contrast tomography, implemented with two complementary techniques. Differential Phase Contrast (DPC) imaging has been fully integrated in terms of fast acquisition and data reconstruction. Scans of samples within an aqueous environment are also feasible. The second phase contrast method is a Modified Transport of Intensity approach that yields a good approximation of the 3D phase distribution of a weakly absorbing object from a single tomographic dataset. Typical acquisition times for a tomogram are in the order of few minutes, ensuring high throughput and allowing for semi-dynamical investigations and in-situ experiments. Raw data are automatically post-processed online and full reconstructed volumes are available shortly after a scan with minimal user intervention. In addition to a beamline overview, a selection of high-impact tomographic applications will be presented.