Spectroscopic imaging with single acquisition ptychography and a hyperspectral detector

We present a new method of single acquisition spectroscopic imaging with high spatial resolution. The technique is based on the combination of polychromatic synchrotron radiation and ptychographic imaging with a recently developed energy discriminating detector. We demonstrate the feasibility with a Ni-Cu test sample recorded at I13-1 of the Diamond Light Source, UK. The two elements can be clearly distinguished and the Ni absorption edge is identified. The results prove the feasibility of obtaining high-resolution structural and chemical images within a single acquisition using a polychromatic X-ray beam. The capability of resolving the absorption edge applies to a wide range of research areas, such as magnetic domains imaging and element specific investigations in biological, materials, and earth sciences. The method utilises the full available radiation spectrum and is therefore well suited for broadband radiation sources

X-Ray ptychography with a laboratory source

X-ray ptychography has revolutionized nanoscale phase contrast imaging at large-scale synchrotron sources in recent years. We present here the first successful demonstration of the technique in a small-scale laboratory setting. An experiment was conducted with a liquid metal jet x-ray source and a single photon-counting detector with a high spectral resolution. The experiment used a spot size of 5 mu m to produce a ptychographic phase image of a Siemens star test pattern with a submicron spatial resolution. The result and methodology presented show how high-resolution phase contrast imaging can now be performed at small-scale laboratory sources worldwide

Multiscale characterization of the 3D network structure of metal carbides in a Ni superalloy by synchrotron X-ray microtomography and ptychography

Synchrotron X-ray microtomography and ptychography were used to characterize the 3D network structure, morphology and distribution of metal carbides in an as-cast IN713LC Ni superalloy. MC typed carbides were found to distribute mainly on the grain boundary between the matrix γ and γ' phase. The differences in solidification cooling rate had a minor influence on the volume fraction of the MC type carbides, but significantly affected the carbide size, distribution and network morphology. Depending on the local composition of the remaining liquid phase and geometric constraints, the carbides can form either spherical or strip or network morphologies. The research demonstrated clearly the advantage and technical potential of using the two complementary tomography techniques synergistically to characterize non-destructively complex multiple-phase structures in three dimensional space with a spatial resolution of ~30 nm

Imaging Light-Induced Migration of Dislocations in Halide Perovskites with 3D Nanoscale Strain Mapping

In recent years, halide perovskite materials have been used to make high performance solar cell and light-emitting devices. However, material defects still limit device performance and stability. Here, we use synchrotron-based Bragg Coherent Diffraction Imaging to visualise nanoscale strain fields, such as those local to defects, in halide perovskite microcrystals. We find significant strain heterogeneity within MAPbBr$_{3}$ (MA = CH$_{3}$NH$_{3}^{+}$) crystals in spite of their high optoelectronic quality, and identify both $\langle$100$\rangle$ and $\langle$110$\rangle$ edge dislocations through analysis of their local strain fields. By imaging these defects and strain fields in situ under continuous illumination, we uncover dramatic light-induced dislocation migration across hundreds of nanometres. Further, by selectively studying crystals that are damaged by the X-ray beam, we correlate large dislocation densities and increased nanoscale strains with material degradation and substantially altered optoelectronic properties assessed using photoluminescence microscopy measurements. Our results demonstrate the dynamic nature of extended defects and strain in halide perovskites and their direct impact on device performance and operational stability.Comment: Main text and Supplementary Information. Main text: 15 pages, 4 figures. Supplementary Information: 16 pages, 27 figures, 1 tabl

Provenance of uranium particulate contained within Fukushima Daiichi Nuclear Power Plant Unit 1 ejecta material.

Here we report the results of multiple analytical techniques on sub-mm particulate material derived from Unit 1 of the Fukushima Daiichi Nuclear Power Plant to provide a better understanding of the events that occurred and the environmental legacy. Through combined x-ray fluorescence and absorption contrast micro-focused x-ray tomography, entrapped U particulate are observed to exist around the exterior circumference of the highly porous Si-based particle. Further synchrotron radiation analysis of a number of these entrapped particles shows them to exist as UO2-identical to reactor fuel, with confirmation of their nuclear origin shown via mass spectrometry analysis. While unlikely to represent an environmental or health hazard, such assertions would likely change should break-up of the Si-containing bulk particle occur. However, more important to the long-term decommissioning of the reactors at the FDNPP (and environmental clean-upon), is the knowledge that core integrity of reactor Unit 1 was compromised with nuclear material existing outside of the reactors primary containment

Ptychographic X-ray computed tomography at a high-brilliance X-ray source

Ptychographic X-ray computed tomography is a phase-contrast imaging technique capable of retrieving three-dimensional maps of the index of refraction of the imaged volumes with nanometric resolution. Despite its unmatched reach, its application remains prerogative of a limited number of laboratories at synchrotron sources. We present a detailed description of an experimental procedure and a data analysis pipeline which can be both exploited for ptychographic X-ray computed tomography experiments at any high-brilliance X-ray source. These have been validated at the I13-1 Coherence Branchline within the first experiment of its kind to be successfully carried out on a biological sample at Diamond Light Source

Color ptychography with a hyperspectral x-ray camera

A possible improvement on a new method of single acquisition hyperspectral (spectroscopic) ptychographic imaging, making use of a hyperspectral X-ray camera, is presented. Undulator tapering is used at the synchrotron to broaden the energy distribution of the X-ray beam to a suitable level for edge subtraction. The combination of a coherent imaging method such as ptychography with spectroscopy poses difficulties in experimental setup design regarding probe size. The final goal of the experiment, a K-edge subtraction, is not successful, but the technique is nevertheless promising. The capability of resolving the absorption edge applies to a wide range of research areas, such as element specific investigations in biological, materials, and earth sciences. We discuss the problems and their possible solutions

New imaging opportunities at the DIAMOND beamline I13L

The Diamond Beamline I13L is dedicated to micro- and nano- imaging, with two independently operating branchlines. The imaging branch preforms imaging in real space, with In-line phase contrast imaging and grating interferometry at micrometre resolution and full-field transmission microscopy up to 50nm spatial resolution. Highest spatial resolution is achieved on the coherence branchline, where diffraction imaging methods such as Ptychography and Bragg-CDI are performed. The article provides an update about the experimental capabilities at the beamline with an emphasis on the rapidly evolving ptychography capabilities. The latter has evolved to an user-friendly method with non-expert users able to explore their science without any specific a-priory knowledge.</p

Fast X-ray ptychography: towards nanoscale imaging of large volume of brain

X-ray ptychography, a scanning coherent diffraction imaging technique, is one of the most used techniques at synchrotron facilities for high resolution imaging, with applications spanning from life science to nano-electronics. In the recent years there has been a great effort to make the technique faster to enable high throughput nanoscale imaging. Here we apply a fast ptychography scanning method to image in 3D 106μm3 of brain-like phantom at 3 kHz, in a 7 h acquisition with a resolution of 270 nm. We then present the latest advances in fast ptychography by showing 2D images acquired at 110 kHz by combining the fast-acquisition scheme with a high-acquisition rate prototype detector from DECTRIS Ltd. We finally review the experimental outcome and discuss the prospective use of fast ptychography schemes for the investigation of mm3 size samples of brain-like phantom, by extrapolating the current results to the high coherent flux scenario of diffraction limited storage rings