Diamond Concise Annual Review 2020/21

22 23 D I A M O N D L I G H T S O U R C E A N N U A L R E V I E W 2 0 2 0 / 2 1 T he Imaging and Microscopy Group at Diamond Light Source brings together eight experimental facilities (I08, J08, DIAD, I12, I13-1, I13-2, I14 and ePSIC, the Electron Physical Science Imaging Centre) which use electrons and X-rays to image samples under different experimental conditions across a diverse range of length scales and time scales. Studies fromthegroup this year included improving the imagingof Parkinson’s disease, new insights into themovement andflowofmagma, and optimising the manufacture of nickel superalloys used in the manufacture of high-temperature structural components. Developing newways of imaging Parkinson’s disease New synchrotron methods to characterise brain cell loss in Parkinson’s disease could provide greater understanding of this disease and other related disorders. Parkinson’s disease involves the loss of a particular group of brain cells that produce dopamine. These cells contain a dark pigment called neuromelanin and post-mortem staging of the disease can be confirmed according to the relative loss of pigment. However, current methods of assessment are limited and often rely on additional chemical staining which constrains further analysis. Researchers from the University ofWarwick used synchrotron X-ray microscopy to visualise neuromelanin without relying on visible pigmentation or chemical staining. They performed spectromicroscopy on Diamond Light Source's beamline I08 using low energy X-rays allowing them to probe the organic structure of neuromelanin, which revealed a characteristic feature in its absorption spectrum. The team used this to create maps of neuromelanin distributions, which matched those observed in stained tissue sections. They also used nanoscale X-ray Fluorescence (XRF) with high-energy X-rays on beamline I14, which showed that neuromelanin could be identified by its elevated sulfur content. These new ways of mapping neuromelanin could hold significant potential for non-destructive studies investigating the relationships between depigmentation, metal binding and neurodegeneration in Parkinson’s disease. Brooks J. et al. DOI: 10.1002/anie.202000239 Understanding howmagma moves Laboratory-based studies at Diamond Light Source to better understand the behaviour and movement of magma will improve our ability to predict the impact of volcanic eruptions. Researchers recreated flowing magma using a bespoke high temperature furnace and the XRheo rheological apparatus on the Joint Engineering Environmental and Processing (JEEP) beamline (I12). They used the high-speed X-ray imaging available on the beamline to watch the evolution of magmatic microstructure during flow for the first time. The project developed the technical tools to look at magma at high magnification during deformation and flow. The 4D data (3 dimensions plus time) showed, for the first time, howmuch the distribution of the three phases of magma (bubbles, liquid and crystals) changes during flow, howmany bubbles coalesce into larger bubbles, and how different regions of the sample behave very differently. The ground-breaking research opens up a new field in the study of magma rheology (movement and flow). Themethods developed in this study can also be used in other similar industrial systems with complex multi-phase fluids such as concrete, ceramics and certain foodstuffs. Dobson K.J. et al. DOI: 10.3389/feart.2020.00287 Optimising the manufacture of nickel superalloys Recent studies from a UK research group on both branchlines (I13-1 and I13-2) of beamline I13 at Diamond Light Source are helping to optimise the manufacture of valuable nickel-based superalloys and to reduce casting defects. Nickel-based superalloys have been widely used to produce high-temperature structural components in aircraft and land turbine engines, rocket engines, nuclear power and chemical processing plants. Metal carbides are an important constituent in the microstructure and strength of these superalloys, and they allow excellent high-temperature stability, but this can also cause casting defects during the solidification process as well as crack initiation and propagation during plastic deformation. Until now, the nucleation and growth dynamics of metal carbides, especially the true 3D network structure and morphology of metal carbides formed in different solidification conditions, have not been fully understood. The team used the two complementary synchrotron X-ray tomography techniques (microtomography and ptychography) on the branchlines to characterise metal carbide structures for the first time. These findings can assist scientists in ongoing quantitative measurement of crack initiation and propagation inmetal carbides during plastic deformation and will help to ensure optimal design and manufacture of these important industrial components in the future. Zhang Z. et al. DOI: https://doi.org/10.1016/j.scriptamat.2020.10.032 Imaging andMicroscopy Group X-ray ptychography image and tomography for the carbides in a superalloy sample.