Inner structure and inclusions in radiocesium-bearing microparticles emitted in the Fukushima Daiichi Nuclear Power Plant accident

Okumura, Taiga*; Yamaguchi, Noriko*; Dohi, Terumi; Iijima, Kazuki; Kogure, Toshihiro*

Microscopy, 68(3), p.234 - 242, 2019/06

https://doi.org/10.1093/jmicro/dfz004

Radiocesium-bearing microparticles (CsMPs), consisting substantially of silicate glass, were released to the environment during the Fukushima nuclear accident in March 2011. We investigated a total of nine CsMPs using transmission electron microscopy (TEM) and inferred the atmosphere in the reactors during the accident. From elemental mapping using energy-dispersive X-ray spectrometry, Fe and Zn showing radial inhomogeneities were found in the CsMPs, in addition to the Cs that had been previously reported. Four of the CsMPs included submicron crystals, which were identified as chromite, franklinite, acanthite, molybdenite, and hessite. The chromium-containing spinels, chromite and franklinite, indicated the presence of ferrous iron (Fe), suggesting that the inside of the reactors was reductive to some extent. Electron energy-loss spectroscopy also confirmed that the CsMPs did not contain boron, and therefore the atmosphere in which they were formed might be boron-free.

Constituent elements and their distribution in the radioactive Cs-bearing silicate glass microparticles released from Fukushima Nuclear Plant

Kogure, Toshihiro*; Yamaguchi, Noriko*; Segawa, Hiroyo*; Mukai, Hiroki*; Motai, Satoko*; Akiyama, Kotone*; Mitome, Masanori*; Hara, Toru*; Yaita, Tsuyoshi

Microscopy, 65(5), p.451 - 459, 2016/10

https://doi.org/10.1093/jmicro/dfw030

Exciting possibilities of soft X-ray emission spectroscopy as chemical state analysis in EPMA and FESEM

Takahashi, Hideyuki*; Handa, Nobuo*; Murano, Takanori*; Terauchi, Masami*; Koike, Masato; Kawachi, Tetsuya; Imazono, Takashi; Hasegawa, Noboru; Koeda, Masaru*; Nagano, Tetsuya*; et al.

Microscopy and Microanalysis, 20(Suppl.3), p.684 - 685, 2014/08

https://doi.org/10.1017/S1431927614005145

A novel wavelength dispersive soft X-ray emission spectrometer (SXES) having a X-ray energy range of 50-210 eV has been developed. One feature is that the SXES is parallel detection of the signals so that it can be used like a conventional energy dispersive spectrometer. The other is a high energy resolution, which is about 0.2 eV at Al-L comparable to those revealed by XPS and EELS. These features enable us to obtain meaningful information about chemical bonding in various bulk samples. The SXES can detect Li-K emission spectrum. In the case of an anode electrode of a lithium ion battery (LIB), two types of lithium peaks are observed: one lower energy peak at 50 eV and the other higher energy peak at 54 eV. It was found that the former peak corresponds to the amount of charging, whereas the latter corresponds to the metallic state of lithium.

Construction of a SXES spectrometer for a conventional SEM

Terauchi, Masami*; Koshiya, Shogo*; Sato, Futami*; Takahashi, Hideyuki*; Handa, Nobuo*; Murano, Takanori*; Koike, Masato; Imazono, Takashi; Koeda, Masaru*; Nagano, Tetsuya*; et al.

Microscopy and Microanalysis, 19(Suppl.2), p.1278 - 1279, 2013/08

https://doi.org/10.1017/S1431927613008386

We have been developed and tested soft-X-ray emission spectroscopy (SXES) instruments by attaching to TEM and EPMA. The spectrometer has an energy range form 50-4000 eV by using four varied-line-spacing (aberration corrected) gratings. This SXES spectrometer inform us energy states of valence electrons (bonding electrons) form an identified specimen area by electron microscopy, which cannot be obtained by EELS and EDS. This provides not only the probing method for the energy states of valence electrons but also a sensitive tool for elemental and chemical identification. The spectrometer has applied also to a SEM (JEOL JSM-6480LV). As SEM can use a larger probe current and excitation volume of specimen than those of TEM, the detection time is about one order shorter than that of TEM. The energy resolution evaluated at AL-Ledge is 0.16 eV. The spectrum of LaB shows apparent intensity corresponds to B-K Fermi edge, showing chemical state of boron.

A New grating X-ray spectrometer for 2-4 keV enabling a separate observation of In-L and Sn-L emissions of indium tin oxide

Terauchi, Masami*; Takahashi, Hideyuki*; Handa, Nobuo*; Murano, Takanori*; Koike, Masato; Kawachi, Tetsuya; Imazono, Takashi; Hasegawa, Noboru; Koeda, Masaru*; Nagano, Tetsuya*; et al.

Microscopy, 62(3), p.391 - 395, 2013/06

https://doi.org/10.1093/jmicro/dfs129

A new multilayer-coated varied line-spaced grating, JS4000, was fabricated and tested for extending the upper limit of a grating X-ray spectrometer for electron microscopy. This grating was designed for 2-3.8 keV at a grazing incidence angle of 1.35 deg. It was revealed that this new multilayer structure enables us to take soft-X-ray emission spectra continuously from 1.5 keV to 4 keV at the same optical setting. The full-width at half maximum of Te-L (3.8 keV) emission peak was 27 eV. Sn-L (3444 eV) and In-L (3487 eV) peaks, which cannot be resolved by a widely used energy-dispersive X-ray spectrometer.

A Newly developed grating and soft X-ray spectrometer for electron probe microanalyser and transmission electron microscope; An Acquisition of the Li K emission spectrum with high-energy resolution and detection of light elements

Takahashi, Hideyuki*; Handa, Nobuo*; Murano, Takanori*; Terauchi, Masami*; Koike, Masato; Kawachi, Tetsuya; Imazono, Takashi; Hasegawa, Noboru; Koeda, Masaru*; Nagano, Tetsuya*; et al.

Proceedings of Microscopy and Microanalysis 2011 (Internet), 2 Pages, 2011/08

http://www.microscopy.org/MandM/2011/abstracts/LB-1.pdf

Soft X-ray spectroscopy with high-energy resolution gives useful information of the chemical bonding states in compounds. Terauchi et al. recently reported a high-energy resolution of 0.2 eV in the Al-L emission spectrum using the previously developed soft X-ray Emission spectrometer (SXES) with a transmission electron microscope. This spectrometer can design to detect the energy from 60 to 1200 eV. In order to progress this result, we had attempted to enhance the detection energy range. Especially to detect the Li-K emission spectrum, we are developing a spectrometer with newly designed aberration corrected gratings. The newly developed grating JS50XL can cover the X-ray energy range from 50 to 200eV with the high energy resolution. It actually means to detect Li-K (55 eV), Al-L (70 eV), Si-L (100 eV), B-K (180 eV) and high order of C-K (279 eV), N-K (392 eV), O-K (525 eV) and so on. This SXES can be equipped not only with TEM, but also with EPMA. Moreover, we found out that attached EPMA with SXES has another strong feature that the X-ray intensity is in directly proportional to probe current. This feature is very useful for the trace element analysis. In the case of Li-K, Be-K and B-K emissions, the detection limits have been evaluated to be a few tens of ppm. For example trace boron analysis is expected to evaluate the newly developed materials quantitatively. This developed spectrometer is hopeful to observe chemical bonding state and trace element analysis in many kinds of fields. In this presentation we report the results for fundamental and actual samples. This development is conducting as one project of Collaborative Development of Innovative Seeds (Practicability verification stage) by Japan Science and Technology Agency.

Heavy ion irradiation induces autophagy in irradiated C2C12 myoblasts and their bystander cells

Hino, Mizuki*; Hamada, Nobuyuki*; Tajika, Yuki*; Funayama, Tomoo; Morimura, Yoshihiro*; Sakashita, Tetsuya; Yokota, Yuichiro; Fukamoto, Kana*; Muto, Yasuko; Kobayashi, Yasuhiko; et al.

Journal of Electron Microscopy, 59(6), p.495 - 501, 2010/12

https://doi.org/10.1093/jmicro/dfq059

Influence of laser irradiation condition on a femtosecond laser-assisted tomographic atom probe

Nishimura, Akihiko; Nogiwa, Kimihiro; Otobe, Tomohito; Okubo, Tadakatsu*; Hono, Kazuhiro*; Kondo, Keietsu; Yokoyama, Atsushi

Ultramicroscopy, 109(5), p.467 - 471, 2009/04

https://doi.org/10.1016/j.ultramic.2008.11.027

Influence of femtosecond laser pulse condition on the performance of an energy compensated tomographic atom probe (ECOTAP) was investigated. Chirping ratio for laser pulses was controlled by a compressor stage. We have succeeded to get tomographic images of oxide dispersion strengthen steel, which will be used as fast breeder reactors. The ECOTAP successfully observed that the instability of the femtosecond laser pulses make the mass peaks slightly sifted or broadened to higher mass number. To investigate insulator materials, numerical simulation of conductivity increase on diamond has been successfully demonstrated.

Mapping the intake of different elements in vegetal tissues by dual-energy X-ray imaging at Dane synchrotron light source

Reale, L.*; Kaiser, J.*; Reale, A.*; Lai, A.*; Flora, F.*; Balerna, A.*; Cinque, G.-F.*; Fanelli, M.*; Ruggieri, F.*; Faenov, A. Y.; et al.

Microscopy Research and Technique, 71(3), p.179 - 185, 2008/03

https://doi.org/10.1002/jemt.20538

Conformational analysis of the structure of ribosome fit into electron microscopy density maps with normal mode analyses and molecular dynamics simulations

Ishida, Hisashi; Matsumoto, Atsushi; Tsutsumi, Yu*; Yura, Kei

Proceedings of 16th International Microscopy Congress (IMC 2006), P. 242, 2006/09

Supra-biomolecules, which contain numerous proteins and nucleic acids, function when the constituent molecules are assembled. Therefore, it is important to determine not only the 3D structures of the constituent molecules but also the 3D structure of the supra-biomolecule. Although X-ray crystallography can determine the atomic coordinates of biomolecules, it has difficulty in handling supra-biomolecules, because crystals of huge molecules cannot be made with ease. Single particle analysis using an electron microscope (EM) has been used to observe the structure of supra-biomolecules, but the resolution of the EM image has only achieve to the atomic level in a limited situation. Therefore, several attempts have been carried out to determine the 3D structure of supra-biomolecules in atomic resolution by fitting the constituent molecules, determined by X-ray crystallography, into an EM density map. In those attempts, each constituent molecule is usually fit into the EM density map manually, and the constituent molecules may have atomic collisions at their interfaces.