Coherent X-ray Scattering Group (CXS)
The Coherent X-ray Scattering (CXS) group develops techniques in scanning- and time-resolved SAXS and high-resolution scanning X-ray microscopy at the cSAXS beamline. In collaboration with research groups, within PSI and international universities and research institutes, we apply these techniques to a wide range of problems in the fields of biology, biomedical research and materials science.
We will open position at cSAXS for small-angle scattering tensor tomography in combination with ptychographic tomography. Contact us for details.
Scientific Highlights
Nanoworlds in 3-D
Tomographic images from the interior of fossils, brain cells, or computer chips are yielding new insights into the finest of structures. These 3-D images are made possible by the X-ray beams of the Swiss Light Source SLS, together with detectors and sophisticated computer algorithms developed at PSI.
Short film of a magnetic nano-vortex
Using a newly developed imaging method, researchers were able to visualise the magnetic structure inside a material with nanoscale resolution. They succeeded in creating a short "film" consisting of seven movie frames that shows, for the first time in 3D, how tiny vortices of the magnetisation deep within a material change over time.
Soft X-ray Laminography: 3D imaging with powerful contrast mechanisms
3D imaging using synchrotron radiation is a widely used tool that allows access to the inner structure of complex objects. An international and interdisciplinary consortium of scientists from the Swiss Light Source (PolLux and cSAXs), the Friedrich-Alexander-Universität Erlangen-Nürnberg, and the University of Cambridge developed the new 3D imaging technique of Soft X-ray Laminography (SoXL). SoXL allows for the investigation of thin and extended samples while taking advantage of the characteristic absorption contrast mechanisms in the soft X-ray range, providing 3D information with nm spatial resolution.
3D imaging for planar samples with zooming
Researchers of the Paul Scherrer Institut have previously generated 3-D images of a commercially available computer chip. This was achieved using a high-resolution tomography method. Now they extended their imaging approach to a so-called laminography geometry to remove the requirement of preparing isolated samples, also enabling imaging at various magnification. For ptychographic X-ray laminography (PyXL) a new instrument was developed and built, and new data reconstruction algorithms were implemented to align the projections and reconstruct a 3D dataset. The new capabilities were demonstrated by imaging a 16 nm FinFET integrated circuit at 18.9 nm 3D resolution at the Swiss Light Source. The results are reported in the latest edition of the journal Nature Electronics. The imaging technique is not limited to integrated circuits, but can be used for high-resolution 3D imaging of flat extended samples. Thus the researchers start now to exploit other areas of science ranging from biology to magnetism.
Glycation of collagen in decellularized pericardium tissue: pilot study
Aging populations and diabetics suffer from the effects of the glycation of collagen, the non-enzymatic formation of glucose bridges. While the secondary effects have been studied intensely, comparatively little is known on the direct effect of glycation on the structure of collagen. It has been demonstrated in this study, that the direct impact of glycation can be determined with sub-atomic precision, and that a model system based on abundantly available connective tissue of farm animals can be used for such studies. This opens new avenues for inspecting the effects of diabetes mellitus on connective tissues and the influence of therapies on the resulting secondary disorders.
Inside Batteries
Lithium ion batteries (LIB) are essential in modern everyday life, with increasing interest in enhancing their performance and lifetime. Secondary particles of Li-rich cathode material were examined with correlated ptychographic X-ray tomography and diffraction microscopy at different stages of cycling to probe the aging mechanism.
Insights into a well-known disease in ageing populations: Abdominal and popliteal aneurysm
Abdominal aortic aneurysm, an enlargement of the abdominal aorta, may lead to rupture and thus acute health issues and death. Scanning X-ray imaging enabled new insights in the nano-structure of calcifications associated with abdonimal and popliteal aneurysm and allowed mapping the distribution of nano- and micro-calcifications as well as of collagen, elastin and myofilament as building blocks of connective tissue across samples from human donors.
Virtual lens improves X-ray microscopy
A method developed by PSI researchers makes X-ray images of materials even better. The researchers took a number of individual images while moving an optical lens. From these, with the help of computer algorithms, they generated one overall image.
Helping chemists to understand degradation and stabilization of catalytic nanoporous gold structures
Catalytic materials are ubiquitously used in industrial processes to perform chemical reactions efficiently and in a sustainable manner. Nanoporous gold (npAu) is a monolithic sponge-like catalyst exhibiting a hierarchical structure with pores and connecting ligaments of typically 10 to 50 nm.