Newly designed double surface bimorph mirror for BL-15A of the photon factory

Igarashi, Noriyuki; Nitani, Hiroaki; Takeichi, Yasuo; Niwa, Yasumasa; Abe, Hitoshi; Kimura, Masao; Mori, Toshiyuki; Nagatani, Yasuko; Kondo, Takashi; Kamijo, Ai; Koyama, Atsushi; Ohta, Hiromasa

doi:10.1063/1.4952893

Cited by 7 publications

(6 citation statements)

References 10 publications

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“…Chemical state mapping 29 was carried out on the basis of X-ray absorption measurements at the synchrotron undulator beamline BL-15A1 33 , 34 of the Photon Factory, IMSS, KEK in Japan. A sinter was embedded in a resin and sliced into specimens with a thickness of 20–30 μm.…”

Section: Methodsmentioning

confidence: 99%

Non-empirical identification of trigger sites in heterogeneous processes using persistent homology

Kimura

Obayashi

Takeichi

et al. 2018

Sci Rep

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Macroscopic phenomena, such as fracture, corrosion, and degradation of materials, are associated with various reactions which progress heterogeneously. Thus, material properties are generally determined not by their averaged characteristics but by specific features in heterogeneity (or ‘trigger sites’) of phases, chemical states, etc., where the key reactions that dictate macroscopic properties initiate and propagate. Therefore, the identification of trigger sites is crucial for controlling macroscopic properties. However, this is a challenging task. Previous studies have attempted to identify trigger sites based on the knowledge of materials science derived from experimental data (‘empirical approach’). However, this approach becomes impractical when little is known about the reaction or when large multi-dimensional datasets, such as those with multiscale heterogeneities in time and/or space, are considered. Here, we introduce a new persistent homology approach for identifying trigger sites and apply it to the heterogeneous reduction of iron ore sinters. Four types of trigger sites, ‘hourglass’-shaped calcium ferrites and ‘island’- shaped iron oxides, were determined to initiate crack formation using only mapping data depicting the heterogeneities of phases and cracks without prior mechanistic information. The identification of these trigger sites can provide a design rule for reducing mechanical degradation during reduction.

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Section: Methodsmentioning

confidence: 99%

Non-empirical identification of trigger sites in heterogeneous processes using persistent homology

Kimura

Obayashi

Takeichi

et al. 2018

Sci Rep

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“…The μ-XRD measurement was conducted at beamline BL-15A1, Photon Factory (Tsukuba, Japan), which was recently developed to be capable of simultaneous XRF-XRD-XAFS mapping. 25 The mirror optics of the beamline provides an intense X-ray beam of ∼10 11 photons/sec with an X-ray beam ∼20 μm in diameter. This station is equipped with an ion chamber for transmission XAFS, a silicon-drift detector (SDD) for XRF, and a two-dimensional pixel array detector (PILATUS 100 k) for XRD measurements.…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Tellurium Distribution and Speciation in Contaminated Soils from Abandoned Mine Tailings: Comparison with Selenium

Qin

Takeichi

Nitani

et al. 2017

Environ. Sci. Technol.

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The distribution and chemical species of tellurium (Te) in contaminated soil were determined by a combination of microfocused X-ray fluorescence (μ-XRF), X-ray diffraction (μ-XRD), and X-ray absorption fine structure (μ-XAFS) techniques. Results showed that Te was present as a mixture of Te(VI) and Te(IV) species, while selenium (Se) was predominantly present in the form of Se(IV) in the soil contaminated by abandoned mine tailings. In the contaminated soil, Fe(III) hydroxides were the host phases for Se(IV), Te(IV), and Te(VI), but Te(IV) could be also retained by illite. The difference in speciation and solubility of Se and Te in soil can result from different structures of surface complexes for Se and Te onto Fe(III) hydroxides. Furthermore, our results suggest that the retention of Te(IV) in soil could be relatively weaker than that of Te(VI) due to structural incorporation of Te(VI) into Fe(III) hydroxides. These findings are of geochemical and environmental significance for better understanding the solubility, mobility, and bioavailability of Te in the surface environment. To the best of our knowledge, this is the first study reporting the speciation and host phases of Te in field soil by the μ-XRF-XRD-XAFS techniques.

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“…The semi-micro XAS and XRF system has been developed at the hard X-ray undulator beamline BL-15A1 of PF [9,10]. The mirror optics of the beamline provide an X-ray beam of ~10 11 photons/sec focused down to ~20 µm.…”

Section: Instrumentationmentioning

confidence: 99%

Development of spectromicroscopes for multiscale observation of heterogeneity in materials at photon factory, IMSS, KEK

Niwa¹,

Takeichi²,

Watanabe³

et al. 2019

AIP Conference Proceedings

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We have developed hard X-ray spectromicroscopes at various scales using synchrotron radiation to elucidate the origin of the function of materials at Photon Factory (PF), Institute of Materials Structure Science (IMSS), High Energy Accelerator Research Organization (KEK) in Japan. One is a 2D scanning X-ray microscope with ~20-µm spatial resolution at BL-15A1 in PF; another is full-field 3D X-ray computed tomography (X-CT) with a resolution down to 30 nm at NW2A in PF-AR. In both techniques, not only morphological images but also X-ray absorption spectra (XAS) at any pixel or voxel of interest can be obtained by changing the X-ray energy. These XAS imaging techniques are useful for understanding the chemical states of specific elements and investigating reaction mechanisms. We have applied these techniques to various materials and elucidated the change of heterogeneity in chemical states which determines macroscopic properties. Application to heterogeneous reduction in iron ore sinters demonstrated clearly the impact of this approach; the multi-scale heterogeneity from 50 nm to 20 µm was shown to be related to trigger sites, which determine the degradation of iron ore sinters during reduction.

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Newly designed double surface bimorph mirror for BL-15A of the photon factory

Cited by 7 publications

References 10 publications

Non-empirical identification of trigger sites in heterogeneous processes using persistent homology

Non-empirical identification of trigger sites in heterogeneous processes using persistent homology

Tellurium Distribution and Speciation in Contaminated Soils from Abandoned Mine Tailings: Comparison with Selenium

Development of spectromicroscopes for multiscale observation of heterogeneity in materials at photon factory, IMSS, KEK

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