For the X-ray Nanoprobe group, the year 2020 was strongly marked by the Extremely Brilliant Source (EBS) restart and the delays caused by the COVID-19 pandemic. For a group where source brilliance is an essential and limiting parameter, the impact of this source upgrade has had disruptive consequences on the performance and the scientific opportunities of the beamlines. It is thus most important to work on outreach to a diverse user community in order to increase the chances of maximising the impact of our new, world- leading imaging tools. To this end, our beamlines are working on improvements in a user-friendly, data-structure and data- acquisition environment as a requirement for a successful multidisciplinary user community.
The articles presented in this chapter reveal that, even within a single beamline, the scientific fields addressed cover multiple disciplines, ranging from medical research to renewable energy. In general, the combination of spectroscopy and diffraction, together with imaging, gives the the X-ray Nanoprobe group the potential to study systems of a complex nature, making it naturally suited for biological samples. This is shown in the highlights of ID13, concerning human bone and spider hair (pages 83 and 94), and of ID16A or ID21, where medical and environmental questions of metal distributions in organisms are investigated (pages 85 and 97). Of vast industrial importance, battery research is presented in unique studies resolving new types of electrodes with unrivalled 3D spatial resolution (page 95) or operando during lithiation using full-field diffraction microscopy in dark-field mode (page 82). Renewable energy plays a role in a study looking at the challenge of ever-increasing solar cell efficiency (page 87) and, in a wider sense, in an investigation of fundamental magnetic phenomena in solids that have potential for energy harvesting (page 91). Looking at the fundamental limits of energy conversion in semiconductors led users of ID16B to study the potential of nanowires as X-ray detectors (page 88). In the field of cultural heritage, where we host one of the world-leading X-ray beamlines, the ageing and degradation of paints is presented (page 89), in another example of the vastly transversal field of the chemistry of heavy metals and their organic compounds.
Although still resulting from the previous source, the 2020 selection of scientific highlights covers a broad range of topics of technological and societal relevance. With the improvements achieved on the source, and with much improved beamlines and data-acquisition routines, an increase in complexity and dynamics of the studied systems is expected. In 2021, all beamlines will exploit the EBS beam in User Service Mode (USM).
Essentially exploiting brilliance-limited techniques, ID01 confirmed the much-enhanced performance offered by EBS in the first week of March 2020. After the delay caused by the necessary site shutdown during the pandemic from March to May, the commissioning resumed in summer with no major set-backs and with the observation of the expected increase in coherent flux by a factor of 20-30. This has a major impact on the data-recording speeds for Bragg coherent diffraction imaging (BCDI) and on the achievable resolution of this technique. For scanning diffraction experiments, the enhanced flux density leaves the user greater flexibility in the compromise between beam size and available flux. Beam cross-sections of 25 nm have been achieved with monochromatic (from a Si(111) double-crystal monochromator (DCM)) fluxes of 1010 ph/s. 2021 will start with an extension of the 2D detector portfolio compatible with BCDI at higher energies and the routine installation of a fluorescence detector that should ease the navigation on complex samples.
The nano-imaging beamline ID16A has gone through major changes over the past year. The newly rebuilt end-station now includes an in-house-developed rotation stage for faster scanning and improved stability. The KB nano- focusing optics at 17 keV has been refurbished, providing a better nano-focus and improved beam quality for coherent imaging. The EBS gain in horizontal coherence has been found beneficial, especially in the field of coherent nano-imaging, with near-field ptychography being actively developed and increasingly used. Thanks to the involvement of new staff, the first user experiments were performed remotely in the field of energy materials and catalysis. Early next year, ID16A will return to its full cryo- microscopy capabilities, crucial for applications in the field of cellular biology and connectomics for neurosciences. The EBS twentyfold gain in nano-focus flux will boost the performance, pending the ongoing integration of new detector