I13-1-Coherence
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Open Access
Abstract: Studies of the structural and functional role of chromosomes in cytogenetics have spanned more than 10 decades. In this work, we take advantage of the coherent X-rays available at the latest synchrotron sources to extract the individual masses of all 46 chromosomes of metaphase human B and T cells using hard X-ray ptychography. We have produced ‘X-ray karyotypes’ of both heavy metal–stained and unstained spreads to determine the gain or loss of genetic material upon low-level X-ray irradiation doses due to radiation damage. The experiments were performed at the I-13 beamline, Diamond Light Source, Didcot, UK, using the phase-sensitive X-ray ptychography method.
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Mar 2021
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I13-1-Coherence
I18-Microfocus Spectroscopy
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Peter
Martin
,
Christopher P.
Jones
,
Stuart
Bartlett
,
Konstantin
Ignatyev
,
Dave
Megson-smith
,
Yukihiko
Sato
,
Silvia
Cipiccia
,
Darren J.
Batey
,
Christoph
Rau
,
Keisuke
Sueki
,
Tatsuya
Ishii
,
Junya
Igarashi
,
Kazuhiko
Ninomiya
,
Atsushi
Shinohara
,
Alison
Rust
,
Thomas B.
Scott
Diamond Proposal Number(s):
[24769, 19881]
Open Access
Abstract: The structural form and elemental distribution of material originating from different Fukushima Daiichi Nuclear Power Plant reactors (Units 1 and 3) is hereby examined to elucidate their contrasting release dynamics and the current in-reactor conditions to influence future decommissioning challenges. Complimentary computed X-ray absorption tomography and X-ray fluorescence data show that the two suites of Si-based material sourced from the different reactor Units have contrasting internal structure and compositional distribution. The known event and condition chronology correlate with the observed internal and external structures of the particulates examined, which suggest that Unit 1 ejecta material sustained a greater degree of melting than that likely derived from reactor Unit 3. In particular, we attribute the near-spherical shape of Unit 1 ejecta and their internal voids to there being sufficient time for surface tension to round these objects before the hot (and so relatively low viscosity) silicate melt cooled to form glass. In contrast, a more complex internal form associated with the sub-mm particulates invoked to originate from Unit 3 suggest a lower peak temperature, over a longer duration. Using volcanic analogues, we consider the structural form of this material and how it relates to its environmental particulate stability and the bulk removal of residual materials from the damaged reactors. We conclude that the brittle and angular Unit 3 particulate are more susceptible to further fragmentation and particulate generation hazard than the round, higher-strength, more homogenous Unit 1 material.
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Dec 2020
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I13-1-Coherence
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Sebastian
Weber
,
Ken L.
Abel
,
Ronny T.
Zimmermann
,
Xiaohui
Huang
,
Jens
Bremer
,
Liisa K.
Rihko-struckmann
,
Darren
Batey
,
Silvia
Cipiccia
,
Juliane
Titus
,
David
Poppitz
,
Christian
Kübel
,
Kai
Sundmacher
,
Roger
Gläser
,
Thomas L.
Sheppard
Diamond Proposal Number(s):
[24079]
Open Access
Abstract: CO2 methanation is often performed on Ni/Al2O3 catalysts, which can suffer from mass transport limitations and, therefore, decreased efficiency. Here we show the application of a hierarchically porous Ni/Al2O3 catalyst for methanation of CO2. The material has a well-defined and connected meso- and macropore structure with a total porosity of 78%. The pore structure was thoroughly studied with conventional methods, i.e., N2 sorption, Hg porosimetry, and He pycnometry, and advanced imaging techniques, i.e., electron tomography and ptychographic X-ray computed tomography. Tomography can quantify the pore system in a manner that is not possible using conventional porosimetry. Macrokinetic simulations were performed based on the measures obtained by porosity analysis. These show the potential benefit of enhanced mass-transfer properties of the hierarchical pore system compared to a pure mesoporous catalyst at industrially relevant conditions. Besides the investigation of the pore system, the catalyst was studied by Rietveld refinement, diffuse reflectance ultraviolet-visible (DRUV/vis) spectroscopy, and H2-temperature programmed reduction (TPR), showing a high reduction temperature required for activation due to structural incorporation of Ni into the transition alumina. The reduced hierarchically porous Ni/Al2O3 catalyst is highly active in CO2 methanation, showing comparable conversion and selectivity for CH4 to an industrial reference catalyst.
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Dec 2020
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I13-1-Coherence
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Ana Katrina C.
Estandarte
,
Jiecheng
Diao
,
Alice
Llewellyn
,
Anmol
Jnawali
,
Thomas M. M.
Heenan
,
Sohrab R.
Daemi
,
Josh J.
Bailey
,
Silvia
Cipiccia
,
Darren
Batey
,
Xiaowen
Shi
,
Christoph
Rau
,
Dan J. L.
Brett
,
Rhodri
Jervis
,
Ian K.
Robinson
,
Paul
Shearing
Diamond Proposal Number(s):
[25852, 25440, 24129, 22373, 22309, 21652]
Abstract: Due to complex degradation mechanisms, disparities between the theoretical and practical capacities of lithium-ion battery cathode materials persist. Specifically, Ni-rich chemistries such as LiNi0.8Mn0.1Co0.1O2 (or NMC811) are one of the most promising choices for automotive applications; however, they continue to suffer severe degradation during operation that is poorly understood, thus challenging to mitigate. Here we use operando Bragg coherent diffraction imaging for 4D analysis of these mechanisms by inspecting the individual crystals within primary particles at various states of charge (SoC). Although some crystals were relatively homogeneous, we consistently observed non-uniform distributions of inter- and intracrystal strain at all measured SoC. Pristine structures may already possess heterogeneities capable of triggering crystal splitting and subsequently particle cracking. During low-voltage charging (2.7–3.5 V), crystal splitting may still occur even during minimal bulk deintercalation activity; and during discharging, rotational effects within parallel domains appear to be the precursor for the nucleation of screw dislocations at the crystal core. Ultimately, this discovery of the central role of crystal grain splitting in the charge/discharge dynamics may have ramifications across length scales that affect macroscopic performance loss during real-world battery operation.
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Dec 2020
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I13-1-Coherence
I13-2-Diamond Manchester Imaging
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Zhiguo
Zhang
,
Jia Chuan
Khong
,
Billy
Koe
,
Shifeng
Luo
,
Shi
Huang
,
Ling
Qin
,
Silvia
Cipiccia
,
Darren
Batey
,
Andrew J.
Bodey
,
Christoph
Rau
,
Yu Lung
Chiu
,
Zhu
Zhang
,
Jean-christophe
Gebelin
,
Nick
Green
,
Jiawei
Mi
Diamond Proposal Number(s):
[9974, 13488, 22525]
Open Access
Abstract: 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.
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Oct 2020
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I13-1-Coherence
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Jiecheng
Diao
,
Xiaowen
Shi
,
Tadesse A.
Assefa
,
Longlong
Wu
,
Ana F.
Suzana
,
Daniel S.
Nunes
,
Darren
Batey
,
Silvia
Cipiccia
,
Christoph
Rau
,
Ross J.
Harder
,
Wonsuk
Cha
,
Ian K.
Robinson
Abstract: In this work, ferroelastic domain walls inside
BaTiO
3
(BTO) tetragonal nanocrystals are distinguished by Bragg peak position and studied with Bragg coherent x-ray diffraction imaging (BCDI). Convergence-related features of the BCDI method for strongly phased objects are reported. A ferroelastic domain wall inside a BTO crystal has been tracked and imaged across the tetragonal-cubic phase transition and proves to be reversible. The linear relationship of relative displacement between two twin domains with temperature is measured and shows a different slope for heating and cooling, while the tetragonality reproduces well over temperature changes in both directions. An edge dislocation is also observed and found to annihilate when heating the crystal close to the phase transition temperature.
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Oct 2020
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I13-1-Coherence
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Maria
Seifert
,
Mareike
Weule
,
Silvia
Cipiccia
,
Veronika
Ludwig
,
Thilo
Michel
,
Paul
Neumayer
,
Max
Schuster
,
Andreas
Wolf
,
Gisela
Anton
,
Stefan
Funk
,
Bernhard
Akstaller
Diamond Proposal Number(s):
[18540]
Open Access
Abstract: For imaging events of extremely short duration, like shock waves or explosions, it is necessary to be able to image the object with a single-shot exposure. A suitable setup is given by a laser-induced X-ray source such as the one that can be found at GSI (Helmholtzzentrum für Schwerionenforschung GmbH) in Darmstadt (Society for Heavy Ion Research), Germany. There, it is possible to direct a pulse from the high-energy laser Petawatt High Energy Laser for Heavy Ion eXperiments (PHELIX) on a tungsten wire to generate a picosecond polychromatic X-ray pulse, called backlighter. For grating-based single-shot phase-contrast imaging of shock waves or exploding wires, it is important to know the weighted mean energy of the X-ray spectrum for choosing a suitable setup. In propagation-based phase-contrast imaging the knowledge of the weighted mean energy is necessary to be able to reconstruct quantitative phase images of unknown objects. Hence, we developed a method to evaluate the weighted mean energy of the X-ray backlighter spectrum using propagation-based phase-contrast images. In a first step wave-field simulations are performed to verify the results. Furthermore, our evaluation is cross-checked with monochromatic synchrotron measurements with known energy at Diamond Light Source (DLS, Didcot, UK) for proof of concepts.
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Jul 2020
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J.-n.
Gruse
,
M. J. V.
Streeter
,
C.
Thornton
,
C.d.
Armstrong
,
C. D.
Baird
,
N.
Bourgeois
,
S.
Cipiccia
,
O. J.
Finlay
,
C. D.
Gregory
,
Y.
Katzir
,
N.c.
Lopes
,
S. P. D.
Mangles
,
Z.
Najmudin
,
D.
Neely
,
L. R.
Pickard
,
K. D.
Potter
,
P. P.
Rajeev
,
D. R.
Rusby
,
C. I. D.
Underwood
,
J.m.
Warnett
,
M.a.
Williams
,
J. C.
Wood
,
C. D.
Murphy
,
C. M.
Brenner
,
D. R.
Symes
Open Access
Abstract: X-rays generated by betatron oscillations of electrons in a laser-driven plasma accelerator were characterised and applied to imaging industrial samples. With a 125 TW laser, a low divergence beam with 7.5
2.6
108 photons mrad−2 per pulse was produced with a synchrotron spectrum with a critical energy of 14.6
1.3 keV. Radiographs were obtained of a metrology test sample, battery electrodes, and a damage site in a composite material. These results demonstrate the suitability of the source for non-destructive evaluation applications. The potential for industrial implementation of plasma accelerators is discussed.
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Jul 2020
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I13-1-Coherence
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Diamond Proposal Number(s):
[21555]
Open Access
Abstract: We present here a new method of performing X-ray edge-subtraction ptychographic imaging by combining multiple harmonics from an undulator synchtrotron source and an energy discriminating photon counting detector. Conventionally, monochromatic far-field X-ray ptychography is used to perform edge subtraction through the use of multiple monochromatic energy scans to obtain spectral information for a variety of applications. Here, we use directly the undulator spectrum from a synchrotron source, selecting two separate harmonics post sample using the Pixirad-1/Pixie-III detector. The result is two monochromatic images, above and below an absorption edge of interest. The proposed method is applied to obtain Au L-edge subtraction imaging of a Au-Ni grid test sample. The Au L-edge subtraction is particularly relevant for the identification of gold nanoparticles for biomedical applications. Switching the energy scan mechanism from a mechanical monochromator to an electronic detector threshold allows for faster spectral data collection with improved stability.
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Apr 2020
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I13-1-Coherence
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Peter G.
Martin
,
Christopher P.
Jones
,
Silvia
Cipiccia
,
Darren
Batey
,
Keith R.
Hallam
,
Yukihiko
Satou
,
Ian
Griffiths
,
Christoph
Rau
,
David A.
Richards
,
Keisuke
Sueki
,
Tatsuya
Ishii
,
Thomas B.
Scott
Diamond Proposal Number(s):
[16702]
Open Access
Abstract: Both the three-dimensional internal structure and elemental distribution of near-field radioactive fallout particulate material released during the March 2011 accident at the Fukushima Daiichi Nuclear Power Plant is analysed using combined high-resolution laboratory and synchrotron radiation x-ray techniques. Results from this study allow for the proposition of the likely formation mechanism of the particles, as well as the potential risks associated with their existence in the environment, and the likely implications for future planned reactor decommissioning. A suite of particles is analyzed from a locality 2 km from the north-western perimeter of the site – north of the primary contaminant plume in an area formerly attributed to being contaminated by fallout from reactor Unit 1. The particles are shown to exhibit significant structural similarities; being amorphous with a textured exterior, and containing inclusions of contrasting compositions, as well as an extensive internal void volume – bimodal in its size distribution. A heterogeneous distribution of the various elemental constituents is observed inside a representative particle, which also exhibited a Fukushima-derived radiocesium (134Cs, 135Cs and 137Cs) signature with negligible natural Cs. We consider the structure and composition of the particle to suggest it formed from materials associated with the reactor Unit 1 building explosion, with debris fragments embedded into the particles surface. Such a high void ratio, comparable to geological pumice, suggests such material formed during a rapid depressurisation and is potentially susceptible to fragmentation through attrition.
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Jan 2020
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