National Synchrotron Light Source Seminar

High brightness is a fundamental property of third generation synchrotron facilities. Those deliver coherent beams, which intrinsically provide access to the phase information from a sample. The Swiss Light Source operates TOMCAT, a beamline dedicated to TOmographic Microscopy and Coherent rAdiology experimenTs. Our group develops cutting-edge equipment for non-destructive tomographic investigations and provides the necessary instrumentation for phase contrast imaging at spatial resolution ranging over four orders of magnitude as well as the acquisition of 3D volumes within a fraction of a second. This presentation will illustrate how phase contrast imaging can be implemented with applications in human radiology down to nanotomographic imaging of single cells. A brief review of the most advanced phase contrast imaging techniques will be provided, with particular emphasis on full-field Zernike microscopy, free-space propagation and grating-interferometry. Each of these methods has shown to be particularly suited for selected investigations. Applications criteria as well as limitations for each technique will be presented, with the illustrative support of examples taken from daily experiments carried out at modern, third generation synchrotron facilities. Particular emphasis will be devoted to applications involving the investigation of life sciences relevant material like cells (organelles identification), soft tissue biopsies (tumor visualization, Alzheimer plaques detection), bones (canaliculi detection and statistical nano-morphometry), insects (biomechanics of tethered flight) and breast tissue (early cancer detection