Speaker
Description
Following the upgrade of the Swiss Light Source to SLS 2.0, the cSAXS beamline at the Paul Scherrer Institute is being recommissioned for coherent X-ray imaging and small-angle X-ray scattering experiments. The increased source brightness, together with a new undulator and upgraded beamline optics, is expected to provide substantially higher coherent flux while preserving beam quality and stability. First commissioning experiments already demonstrate promising performance. Ptychographic X-ray tomography (PXCT) measurements have reached spatial resolutions in the range of approximately 15-20 nm, while scanning SAXS measurements demonstrate spatially resolved mapping of nanoscale structural orientation.
The second part of the talk focuses on high-resolution three-dimensional X-ray imaging of radiation-sensitive soft materials, using brain tissue as an example. Mapping fine neuronal structures requires imaging over large fields of view while maintaining nanoscale spatial resolution. Critical-point-dried, heavy-metal-stained brain tissue provides strong X-ray contrast, but undergoes progressive radiation-induced deformation during data acquisition. To address this challenge, non-rigid tomographic reconstruction was used to account for sample deformation during the measurement, improving the estimated FSC resolution from approximately 73 nm with conventional rigid reconstruction to approximately 28 nm. Further denoising improves the visibility of fine structural features. These developments demonstrate the potential of PXCT for nanoscale three-dimensional characterization of complex, radiation-sensitive materials.