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Machida, Masahiko; Yamada, Susumu; Kim, M.; Tanaka, Satoshi*; Tobita, Yasuhiro*; Iwata, Ayako*; Aoki, Yuto; Aoki, Kazuhisa; Yanagisawa, Kenichi*; Yamaguchi, Takashi; et al.
RIST News, (70), p.3 - 22, 2024/09
Inside the Fukushima Daiichi Nuclear Power Plant (1F), there are many locations with high radiation levels due to contamination by radioactive materials that leaked from the reactor. These pose a significant obstacle to the smooth progress of decommissioning work. To help solve this issue, the Japan Atomic Energy Agency (JAEA), under a subsidy from the Ministry of Economy, Trade, and Industry's decommissioning and contaminated water management project, is conducting research and development on digital technologies to improve the radiation environment inside the decommissioning site. This project, titled "Development of Technology to Improve the Environment Inside Reactor Buildings (Enhancing Digital Technology for Environment and Source Distribution to Reduce Radiation Exposure)," began in April of FY 2023. In this project, the aim is to develop three interconnected systems: FrontEnd, Pro, and BackEnd. The FrontEnd system, based on the previously developed 3D-ADRES-Indoor (prototype) from FY 2021-2022, will be upgraded to a high-speed digital twin technology usable on-site. The Pro system will carry out detailed analysis in rooms such as the new office building at 1F, while the BackEnd system will serve as a database to centrally manage the collected and analyzed data. This report focuses on the FrontEnd system, which will be used on-site. After point cloud measurement, the system will quickly create a 3D mesh model, estimate the radiation source from dose rate measurements, and refine the position and intensity of the estimated source using recalculation techniques (re-observation instructions and re-estimation). The results of verification tests conducted on Unit 5 are also presented. Furthermore, the report briefly discusses the future research and development plans for this project.
Kusumoto, Toshiyuki*; Saruta, Koichi; Naoe, Takashi; Teshigawara, Makoto; Futakawa, Masatoshi; Hasegawa, Kazuo*; Tsuboi, Akihiko
Jikken Rikigaku, 23(4), p.310 - 315, 2023/12
Reducing spatter, i.e., melt droplets flown out of the melt pool, is one of the critical issues when laser cutting is employed as a machining tool for radioactive wastes because the ejected droplets can lead to radioactive contamination with potential human exposure. The spattering phenomena are complicated processes that involve multiple physical phenomena, causing difficulty in the determination of laser parameters to minimize the amount of spatter. Here we observe the spatter ejected from 316L stainless steel plates using a high-speed camera and apply a machine learning technique to these captured images on the basis of three distinctive behaviors appeared at specific time intervals of the process of spattering phenomena: (I) a vapor, (II) a liquid film and breakup into droplets, and (III) a liquid capillary. The numerical model established through the machine learning technique predicts the spattering phenomena with an accuracy of 89% and can be used to determine the laser power and beam diameter that reduce the spatter eruption during laser irradiation.
Araki, Shohei; Gunji, Satoshi; Arakaki, Yu; Murakami, Takahiko; Yoshikawa, Tomoki; Hasegawa, Kenta; Tada, Yuta; Izawa, Kazuhiko; Suyama, Kenya
Proceedings of 4th Reactor Physics Asia Conference (RPHA2023) (Internet), 4 Pages, 2023/10
To conduct integrated thermal power measurements for the performance test of the modified STACY, we re-analyzed the experimental data measured in the solution fuel STACY using the activation method. We validated its feasibility under the limited number of activation detectors. The re-analyzed results of the activation method by using MVP and PHITS with JENDL-4.0 indicated that the effect of the difference of the position between activation detectors was small enough, and the results agreed with that of the fission product analysis within almost 10%. It is conceivable that the activation method could be adopted instead of the fission product analysis.
Misaki, Satoshi*; Miwa, Hiroko*; Ito, Takashi; Yoshida, Takefumi*; Hasegawa, Shingo*; Nakamura, Yukina*; Tokutake, Shunta*; Takabatake, Moe*; Shimomura, Koichiro*; Chun, W.-J.*; et al.
ACS Catalysis, 13(18), p.12281 - 12287, 2023/09
Times Cited Count:6 Percentile:52.70(Chemistry, Physical)Tamatsukuri, Hiromu; Hasegawa, Takumi*; Sagayama, Hajime*; Mizumaki, Masaichiro*; Murakami, Yoichi*; Kajitani, Joe*; Higashinaka, Ryuji*; Matsuda, Tatsuma*; Aoki, Yuji*; Tsutsui, Satoshi*
Physical Review B, 107(2), p.024303_1 - 024303_8, 2023/01
Times Cited Count:1 Percentile:18.74(Materials Science, Multidisciplinary)Hayashida, Takeshi*; Uemura, Yohei*; Kimura, Kenta*; Matsuoka, Satoshi*; Hagihara, Masato; Hirose, Sakyo*; Morioka, Hitoshi*; Hasegawa, Tatsuo*; Kimura, Tsuyoshi*
Physical Review Materials (Internet), 5(12), p.124409_1 - 124409_10, 2021/12
Times Cited Count:27 Percentile:81.47(Materials Science, Multidisciplinary)Yang, Z. H.*; Kubota, Yuki*; Corsi, A.*; Yoshida, Kazuki; Sun, X.-X.*; Li, J. G.*; Kimura, Masaaki*; Michel, N.*; Ogata, Kazuyuki*; Yuan, C. X.*; et al.
Physical Review Letters, 126(8), p.082501_1 - 082501_8, 2021/02
Times Cited Count:55 Percentile:96.38(Physics, Multidisciplinary)A quasifree (,
) experiment was performed to study the structure of the Borromean nucleus
B, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for
and
orbitals, and a surprisingly small percentage of 9(2)% was determined for
. Our finding of such a small
component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in
B. The present work gives the smallest
- or
-orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of
or
orbitals is not a prerequisite for the occurrence of a neutron halo.
Kusumoto, Tamon*; Matsuya, Yusuke; Baba, Kentaro*; Ogawara, Ryo*; Akselrod, M. S.*; Harrison, J.*; Fomenko, V.*; Kai, Takeshi; Ishikawa, Masayori*; Hasegawa, Sumitaka*; et al.
Radiation Measurements, 132, p.106256_1 - 106256_4, 2020/03
Times Cited Count:8 Percentile:58.60(Nuclear Science & Technology)Internal radiation therapy with Cu-64 concentrates energy deposition in tumor cells by virtue of released Auger electrons with low energy. In our previous study, we have attached the solutions at the surface of Fluorescent Nuclear Track Detector (FNTD) and succeeded in measuring the absorbed doses of Auger electrons registered in FNTD. However, because there are several types of radiation emitted from the source, i.e., beta rays, positron etc., the contribution degree of Auger electron to energy concentration remain uncertain. In this study, we quantitatively analyzed the spatial dose distribution in the FNTD based on Monte Carlo simulation with PHITS and GEANT4, and evaluated high dose deposited by Auger electrons. The dose distribution calculated by the PHITS code is exactly equivalent to that by Geant4. Also, the simulations are well agreement with experimental results. If the contribution of Auger electrons is ignored, the significantly high absorbed dose proximal to the source is not properly reduced. These findings demonstrate that Auger electrons work very effectively to kill cancer cells proximal to Cu-64 source while minimizing damage effects on normal cells distal to the source.
Nishikino, Masaharu; Ishino, Masahiko; Ichimaru, Satoshi*; Hatayama, Masatoshi*; Hasegawa, Noboru; Kawachi, Tetsuya
Reza Gakkai Dai-483-Kai Kenkyukai Hokoku; Tanhacho Ryoshi Bimu Hassei To Sono Oyo, p.25 - 28, 2015/12
X-ray ablation has been recently achieved using plasma soft X-ray lasers (SXRLs), laser plasma soft X-rays, and X-ray free electron lasers. In order to study the interactions between picosecond SXRL beams and material and multi-layered structure surfaces were irradiated with SXRL pulse. Following irradiation, the substrate surface was observed using a scanning electron microscope and an atomic force microscope. The surface modifications caused by the SXRL beam were clearly seen. The multi-layered mirror is the important component for the EUV lithography. Then, we have started the damage test of multi-layered structure, and the surface modifications caused by the SXRL pulse irradiations were confirmed.
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
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.
Ishino, Masahiko; Faenov, A.*; Tanaka, Momoko; Pikuz, T.; Tamotsu, Satoshi*; Hasegawa, Noboru; Nishikino, Masaharu; Starikov, S. V.*; Stegailov, V. V.*; Norman, G.*; et al.
X-Ray Lasers 2012; Springer Proceedings in Physics, Vol.147, p.121 - 124, 2014/00
Times Cited Count:0 Percentile:0.00(Engineering, Electrical & Electronic)Terauchi, Masami*; Takahashi, Hideyuki*; Handa, Nobuo*; Murano, Takanori*; Koike, Masato; Kawachi, Tetsuya; Imazono, Takashi; Hasegawa, Noboru; Koeda, Masaru*; Nagano, Tetsuya*; et al.
JAEA-Conf 2013-001, p.77 - 80, 2013/09
We have been developing a soft X-ray emission spectroscopy (SXES) instrument for electron microscopes (TEM, EPMA/SEM) with an extension of detectable energy range to 50-4000 eV. An introduction of valence electron spectroscopy with microscopy will supply fruitful information on bonding electrons, which cannot be obtained by EELS and EDS. For extend the lowest (or highest) detection energy upto 50 eV (or 4000 eV), a new laminar-type varied-line-spacing (VLS) grating, JS50XL, (or JS4000) has designed and manufactured. JS50XL and JS4000 having 1200 and 2400 lines/mm as well as coated by Au and a new multilayer-structure of W/BC for a wide-band energy region of 2000-3800 eV, respectively. Those gratings were installed and tested in a SXES spectrometer attached to a TEM. The extension in lowest detection energy was confirmed by Mg-L emission (JS50XL). The energy resolution was 0.2 eV at Fermi edge of 49.5 eV. It can be also seen a sharp Fermi edge for Li-K emission spectrum of metal-Li. The high energy resolution was confirmed by Te-La emission at 3.8 keV (JS4000). The full width at half maximum of the peak was 27 eV. The detection energy range was successfully extended by using the two new VLS-gratings.
Takahashi, Hideyuki*; Handa, Nobuo*; Murano, Takanori*; Koike, Masato; Kawachi, Tetsuya; Imazono, Takashi; Hasegawa, Noboru; Terauchi, Masami*; Koeda, Masaru*; Nagano, Tetsuya*; et al.
JAEA-Conf 2013-001, p.13 - 15, 2013/09
A very unique high performance soft X-ray emission spectrometer (SXES) has successfully been developed which can be attached not only to transmission electron microscopes (TEMs), but also to scanning electron microscopes (SEMs) as well as electron probe microanalyzers (EPMAs). To extend the analyzed energy ranges, a newly designed laminar-type varied-line-spacing (VLS) grating JS50XL, for a lower energy range, 50-170 eV, and a multilayered VLS grating JS4000, for a higher energy range, 2000-4000 eV, have been developed and installed to this spectrometer. Application software has also been developed for a commercial use of SXES in several fields such as battery materials, steel and alloys, and electron devices. The appearance of this spectrometer attached to EPMA and a few results acquired are shown in the following figures. This development has been conducted as one of the projects of Collaborative Development of Innovative Seeds (Practicability verification stage) by Japan Science and Technology Agency.
Imazono, Takashi; Koike, Masato; Kawachi, Tetsuya; Hasegawa, Noboru; Koeda, Masaru*; Nagano, Tetsuya*; Sasai, Hiroyuki*; Oue, Yuki*; Yonezawa, Zeno*; Kuramoto, Satoshi*; et al.
Proceedings of SPIE, Vol.8848, p.884812_1 - 884812_14, 2013/09
Times Cited Count:9 Percentile:95.57(Optics)We have developed an objective soft X-ray flat-field spectrograph to be able to attach to electron microscopes. This spectrograph has two attractive features. One is that it is designed to cover a wide energy range of 50-4000 eV by using four varied-line-spacing holographic gratings optimized for 50-200 eV, 155-350 eV, 300-2200 eV, and 2000-4000 eV. They can be accommodated in the single spectrograph. The other is a newly invented W/BC multilayer coating covering the 2000-4000 eV range. It can enhance the diffraction efficiency above a practical level of
% at a constant incidence angle in the whole energy range.
Ishino, Masahiko; Faenov, A.*; Tanaka, Momoko; Tamotsu, Satoshi*; Pikuz, T.; Hasegawa, Noboru; Nishikino, Masaharu; Inogamov, N.*; Skobelev, I.*; Fortov, V.*; et al.
Proceedings of SPIE, Vol.8849, p.88490F_1 - 88490F_8, 2013/09
Times Cited Count:2 Percentile:72.13(Optics)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, 19(Suppl.2), p.1258 - 1259, 2013/08
A new wavelength dispersive soft X-ray emission spectrometer (WD-SXES) consisting of newly developed diffraction gratings has been developed for soft X-ray emission spectroscopy. The WD-SXES with two types of diffraction gratings nominally covering an energy range between 50 and 210 eV has been installed to electron probe X-ray microanalyzers, JEOL JXA-8100, for commercial use. The energy resolution of this WD-SXES is nominally 0.3 eV, which is one order of magnitude better than that of conventional WDSs with layered dispersion elements. It is to be noted that the corresponding edge of AlB is shifted to higher energy side by about 1 eV. One of the energy range was selected from 72 to 73.5 eV whereas the other was from 73.5 to 75 eV. The contrast in the former map is reversed in the later map as expected even though the energy difference between two maps is only 1.5 eV. The study confirms the high potential for the characterization especially for chemical state mapping.
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
Times Cited Count:11 Percentile:57.43(Microscopy)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.
Hasegawa, Shin; Takahashi, Shuichi*; Iwase, Hiroki*; Koizumi, Satoshi; Onuma, Masato*; Maekawa, Yasunari
Polymer, 54(12), p.2895 - 2900, 2013/05
Times Cited Count:9 Percentile:27.90(Polymer Science)Radiation-induced graft polymerization of sulfo-containing styrene derivatives into crystalline poly(ether ether ketone) (PEEK) substrates was carried out to prepare thermally and mechanically stable polymer electrolyte membranes based on an aromatic hydrocarbon polymer, so-called "super-engineering plastics". Graft polymerization of the sulfo-containing styrene, ethyl 4-styrenesulfonate (E4S) into PEEK substrates with degrees of crystallinity (DC) of 11 - 26% gradually progressed, achieving a grafting degree of more than 50% after 72 hours, whereas graft polymerization of the substrates with DC above 26% did not proceed. When morphological change in these films were measured by SAXS, PEEK films with DC larger than 26% showed a new peak at d=14 nm, corresponding to lamella structure. Thus, the suppression of graft polymerization of PEEK films with DC above 26% was due to obstruct of monomer diffusion by the formation of the oriented lamella structure.
Imazono, Takashi; Koike, Masato; Hasegawa, Noboru; Koeda, Masaru*; Nagano, Tetsuya*; Sasai, Hiroyuki*; Oue, Yuki*; Yonezawa, Zeno*; Kuramoto, Satoshi*; Terauchi, Masami*; et al.
Journal of Physics; Conference Series, 425(15), p.152008_1 - 152008_4, 2013/03
Times Cited Count:3 Percentile:78.25(Instruments & Instrumentation)We have developed a flat-field spectrograph equipped with a wide-band multilayer grating and prefocusing mirror for the 2-4 keV range. To realize a spectrograph without any mechanical movement, the multilayer has a newly invented layer structure to uniformly enhance the diffraction efficiency (or reflectivity) of the grating (or prefocusing mirror) at a fixed angle of incidence in the whole energy region. The multilayer structure consisting of W and BC layers has been deposited by ion beam sputtering method on a varied-line-spacing laminar-type holographic grating. Also the same multilayer has been done on a spherical substrate. The average diffraction efficiency (or reflectivity) of the multilayer grating (or spherical mirror) is in excess of 3% at 88.65
(or 4% at 88.00
) in the 2.1-3.8 keV range. The throughput of the spectrograph with multilayer optics can be evaluated to be 2-5000 times higher than that with conventional optics coated by a gold layer.
Ishino, Masahiko; Faenov, A. Ya.*; Tanaka, Momoko; Tamotsu, Satoshi*; Hasegawa, Noboru; Nishikino, Masaharu; Pikuz, T.; Kaihori, Takeshi*; Kawachi, Tetsuya
Applied Physics A, 110(1), p.179 - 188, 2013/01
Times Cited Count:26 Percentile:70.00(Materials Science, Multidisciplinary)