Browsing by Author "Schrank, CE"

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    High speed free-run ptychography at the Australian Synchrotron
    (Australian Nuclear Science and Technology Organisation, 2021-11-26) Kewish, CM; Jones, MWM; van Riessen, GA; Phillips, NW; Hinsley, GN; Schrank, CE; Afshar, J; Reinhardt, J; de Jonge, MA
    The Australian Synchrotron X-ray Fluorescence Microscopy (XFM) beamline has recently implemented fast scanning ptychography, a scanning X-ray diffraction microscopy method. Ptychography creates super-resolution images from transmitted microdiffraction patterns acquired as the sample is scanned through the beam. Highspeed detectors and high-performance computers are required to iteratively reconstruct these complex images. The experimental methods and reconstruction algorithms have significantly evolved over the last decade and a half into a mature and user-friendly complementary imaging method to XFM. Here we present the implementation of high speed ptychography at the XFM beamline, which includes a free run data collection mode where detector dead time is eliminated, and the scan time is optimized. We show that free-run data collection is viable for fast and high-quality ptychography by demonstrating extremely high data rate acquisition covering areas up to 352,000 μm2 at up to 140 μm2/s, with 18× spatial resolution enhancement compared to the beam size. With these improvements, ptychography at velocities up to 250 μm/s is approaching speeds compatible with fast-scanning X-ray fluorescence microscopy. The combination of these methods provides morphological context for elemental and chemical information, enabling unique scientific outcomes. © The Authors
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    High-speed free-run ptychography at the Australian Synchrotron
    (International Union of Crystallography, 2022-03) Jones, MWM; van Riessen, GA; Phillips, NW; Schrank, CE; Hinsley, GN; Afshar, N; Reinhardt, J; de Jonge, MD; Kewish, CM
    Over the last decade ptychography has progressed rapidly from a specialist ultramicroscopy technique into a mature method accessible to non-expert users. However, to improve scientific value ptychography data must reconstruct reliably, with high image quality and at no cost to other correlative methods. Presented here is the implementation of high-speed ptychography used at the Australian Synchrotron on the XFM beamline, which includes a free-run data collection mode where dead time is eliminated and the scan time is optimized. It is shown that free-run data collection is viable for fast and high-quality ptychography by demonstrating extremely high data rate acquisition covering areas up to 352 000 μm2 at up to 140 μm2 s-1, with 13x spatial resolution enhancement compared with the beam size. With these improvements, ptychography at velocities up to 250 μm s-1 is approaching speeds compatible with fast-scanning X-ray fluorescence microscopy. The combination of these methods provides morphological context for elemental and chemical information, enabling unique scientific outcomes. © The Authors - Open Access CC-By Licence
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    Micro-scale dissolution seams mobilise carbon in deep-sea limestones
    (Springer Nature, 2021-08-27) Schrank, CE; Jones, MMW; Kewish, CM; van Riessen, GA; Elphick, KE; Sloss, CR; Nothdurft, LD; Webb, GE; Paterson, DJ; Regenauer-Lieb, K
    Measuring the amount of carbon captured in deep-sea limestones is fundamental to understanding the long-term carbon cycle because pelagic limestones represent Earth’s largest carbon sink since the mid-Mesozoic. However, their contribution to the long-term carbon cycle is poorly quantified. Here, we use X-ray fluorescence and scanning X-ray diffraction microscopy for high-resolution chemical and structural analysis of pelagic limestone from the Paleocene Kaiwhata Formation in New Zealand. We identify densely packed diagenetic micro-dissolution seams that are invisible to light and electron-beam microscopes in most cases. Mass-balance calculations indicate that individual seams remove ~50% of the calcite mud matrix while their bulk-sample carbon loss adds up to ~10%. The liberated carbon is trapped in situ as calcite cement or returned to the ocean during physical compaction or soft-sediment deformation. We suggest micro-dissolution structures may play an important role in the long-term carbon cycle by modulating carbon exchange between the geosphere and hydrosphere. © 2024 The Authors - Open Access - CC-BY 4.0