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Ito, Takashi; Higemoto, Wataru; Koda, Akihiro*; Nakamura, Jumpei*; Shimomura, Koichiro*
Interactions (Internet), 245(1), p.25_1 - 25_7, 2024/12
Shimomura, Koichiro*; Koda, Akihiro*; Pant, A. D.*; Sunagawa, Hikaru*; Fujimori, Hiroshi*; Umegaki, Izumi*; Nakamura, Jumpei*; Fujihara, Masayoshi; Tampo, Motonobu*; Kawamura, Naritoshi*; et al.
Interactions (Internet), 245(1), p.31_1 - 31_6, 2024/12
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：1 Percentile：46.87(Chemistry, Physical)Lind, T.*; Kalilainen, J.*; Marchetto, C.*; Beck, S.*; Nakamura, Koichi*; Kino, Chiaki*; Maruyama, Yu; Kido, Kentaro; Kim, S. I.*; Lee, Y.*; et al.
Proceedings of 20th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-20) (Internet), p.4796 - 4809, 2023/08
Osawa, Takahito; Nagasawa, Shunsaku*; Ninomiya, Kazuhiko*; Takahashi, Tadayuki*; Nakamura, Tomoki*; Wada, Taiga*; Taniguchi, Akihiro*; Umegaki, Izumi*; Kubo, Kenya*; Terada, Kentaro*; et al.
ACS Earth and Space Chemistry (Internet), 7(4), p.699 - 711, 2023/04
Times Cited Count：4 Percentile：93.95(Chemistry, Multidisciplinary)The concentrations of carbon and other major elements in asteroid samples provide very important information on the birth of life on the Earth and the solar-system evolution. Elemental analysis using muonic X-rays is one of the best analytical methods to determine the elemental composition of solid materials, and notably, is the only method to determine the concentration of light elements in bulk samples in a non-destructive manner. We developed a new analysis system using muonic X-rays to measure the concentrations of carbon and other major elements in precious and expectedly tiny samples recovered from the asteroid Ryugu by spacecraft Hayabusa2. Here we report the development process of the system in 4 stages and their system configurations, The analysis system is composed of a stainless-steel analysis chamber, an acrylic glove box for manipulating asteroid samples in a clean environment, and Ge semiconductor detectors arranged to surround the analysis chamber. The performance of the analysis system, including the background level, which is crucial for the measurement, was greatly improved from the first stage to the later ones. Our feasibility study showed that the latest model of our muonic X-ray analysis system is capable of determining the carbon concentration in Hayabusa2's sample model with an uncertainty of less than 10 percent in a 6-day measurement.
Nakamura, Jumpei*; Kawakita, Yukinobu; Okabe, Hirotaka*; Li, B.*; Shimomura, Koichiro*; Suemasu, Takashi*
Journal of Physics and Chemistry of Solids, 175, p.111199_1 - 111199_8, 2023/04
Times Cited Count：1 Percentile：15.7(Chemistry, Multidisciplinary)Shimomura, Koichiro*; Koda, Akihiro*; Pant, A. D.*; Natori, Hiroaki*; Fujimori, Hiroshi*; Umegaki, Izumi*; Nakamura, Jumpei*; Tampo, Motonobu*; Kawamura, Naritoshi*; Teshima, Natsuki*; et al.
Journal of Physics; Conference Series, 2462, p.012033_1 - 012033_5, 2023/03
Times Cited Count：0 Percentile：0.2(Physics, Applied)
SbKitaori, Aki*; Kanazawa, Naoya*; Kida, Takanori*; Narumi, Yasuo*; Hagiwara, Masayuki*; Kindo, Koichi*; Takeuchi, Tetsuya*; Nakamura, Ai*; Aoki, Dai*; Haga, Yoshinori; et al.
Journal of the Physical Society of Japan, 92(2), p.024702_1 - 024702_6, 2023/02
Times Cited Count：0 Percentile：0(Physics, Multidisciplinary) induced by magnetic fieldKinjo, Katsuki*; Fujibayashi, Hiroki*; Kitagawa, Shunsaku*; Ishida, Kenji*; Tokunaga, Yo; Sakai, Hironori; Kambe, Shinsaku; Nakamura, Ai*; Shimizu, Yusei*; Homma, Yoshiya*; et al.
Physical Review B, 107(6), p.L060502_1 - L060502_5, 2023/02
Times Cited Count：7 Percentile：93.16(Materials Science, Multidisciplinary)Nakamura, Jumpei*; Kawakita, Yukinobu; Shimomura, Koichiro*; Suemasu, Takashi*
Journal of Applied Physics, 130(19), p.195701_1 - 195701_7, 2021/11
Times Cited Count：1 Percentile：7.86(Physics, Applied)
electron paramagnetic resonanceSaio, Tomohide*; Hiramatsu, Soya*; Asada, Mizue*; Nakagawa, Hiroshi; Shimizu, Kazumi*; Kumeta, Hiroyuki*; Nakamura, Toshikazu*; Ishimori, Koichiro*
Biophysical Journal, 120(15), p.2943 - 2951, 2021/08
Times Cited Count：1 Percentile：8.05(Biophysics)A rigid double-arm lanthanide tag was utilized in electron paramagnetic resonance spectroscopy to measure the distance between two specific points on a protein, and conformational states and distribution of a multi-domain protein enzyme MurD was investigated. Although the previous crystallographic and NMR studies have reported the three distinct conformational states of MurD, our data unveiled that the protein exists in much more variety of conformational states in the absence of the ligand. Given the fact that MurD is one of the potent drug target for infectious diseases, the finding in this study will provide important structural basis for drug development.
Sekine, Megumi; Matsuki, Takuya; Suzuki, Satoshi*; Tsutagi, Koichi; Nishida, Naoki; Kitao, Takahiko; Tomikawa, Hirofumi; Nakamura, Hironobu; LaFleur, A.*; Browne, M.*
JAEA-Technology 2019-023, 160 Pages, 2020/03
JAEA-Technology-2019-023.pdf:9.43MB
The International Atomic Energy Agency (IAEA) has proposed in its Research and Development plan (STR-385), the development of technology to enable real-time flow measurement of nuclear material as a part of an advanced approach to effective and efficient safeguards for reprocessing facilities. To address this, Japan Atomic Energy Agency (JAEA) has been tackling development of a new detector to enable monitoring of Pu in solutions with numerous FPs as a joint research program with U.S. DOE to cover whole reprocessing process. In this study, High Active Liquid Waste (HALW) Storage Facility in Tokai Reprocessing Plant was used as the test field. At first, the design information of HALW storage tank and radiation (type and intensity) were investigated to develop a Monte Carlo N-Particle Transport Code (MCNP) model. And then, dose rate distribution outside/ inside of the concrete cell where the HALW tank is located was measured to design new detectors and check MCNP model applicability. Using the newly designed detectors, gamma rays and neutron were continuously measured at the outside/ inside of the concrete cell to assess the radiation characteristics and to optimize detector position. Finally, the applicability for Pu monitoring technology was evaluated based on the simulation results and gamma-ray/neutron measurement results. We have found that there is possibility to monitor the change of Pu amount in solution by combination both of gamma-ray and neutron measurement. The results of this study suggested the applicability and capability of the Pu motoring to enhance safeguards for entire reprocessing facility which handles Pu with FP as a feasibility study. This is final report of this project.
Wang, H.*; Otsu, Hideaki*; Chiga, Nobuyuki*; Kawase, Shoichiro*; Takeuchi, Satoshi*; Sumikama, Toshiyuki*; Koyama, Shumpei*; Sakurai, Hiroyoshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; et al.
Communications Physics (Internet), 2(1), p.78_1 - 78_6, 2019/07
Times Cited Count：8 Percentile：56.2(Physics, Multidisciplinary)Searching for effective pathways for the production of proton- and neutron-rich isotopes through an optimal combination of reaction mechanism and energy is one of the main driving forces behind experimental and theoretical nuclear reaction studies as well as for practical applications in nuclear transmutation of radioactive waste. We report on a study on incomplete fusion induced by deuteron, which contains one proton and one neutron with a weak binding energy and is easily broken up. This reaction study was achieved by measuring directly the cross sections for both proton and deuteron for 
Pd at 50 MeV/u via inverse kinematics technique. The results provide direct experimental evidence for the onset of a cross-section enhancement at high energy, indicating the potential of incomplete fusion induced by loosely-bound nuclei for creating proton-rich isotopes and nuclear transmutation of radioactive waste.
Am neutron capture and total cross sections with ANNRI at J-PARCKimura, Atsushi; Nakamura, Shoji; Terada, Kazushi*; Nakao, Taro*; Mizuyama, Kazuhito*; Iwamoto, Nobuyuki; Iwamoto, Osamu; Harada, Hideo; Katabuchi, Tatsuya*; Igashira, Masayuki*; et al.
Journal of Nuclear Science and Technology, 56(6), p.479 - 492, 2019/06
Times Cited Count：14 Percentile：84.54(Nuclear Science & Technology)Nakamura, Shoji; Terada, Kazushi*; Kimura, Atsushi; Nakao, Taro*; Iwamoto, Osamu; Harada, Hideo; Uehara, Akihiro*; Takamiya, Koichi*; Fujii, Toshiyuki*
Journal of Nuclear Science and Technology, 56(1), p.123 - 129, 2019/01
Times Cited Count：1 Percentile：11.15(Nuclear Science & Technology)Accurate data of 
-ray emission probabilities are frequently needed when one quantitatively determines the amount of isotope by -ray measurements or obtains neutron capture cross-sections using them. Americium-243, one of the most important minor actinides, produces 
Am after neutron capture. The 744-keV -ray decaying from the ground state of Am has a relatively large -ray emission probability c.a. 66%, however, its uncertainty is as large as 29%. The uncertainty of the -ray emission probability leads to a major factor of the systematic uncertainty on determining an amount of isotope, and therefore the -ray emission probability was measured by using an activation method and an examined level structure of Cm. In this study, the emission probability of 744-keV ray was derived as 66.5
1.1%, and its uncertainty was improved from 29% to 2%.
Sekine, Megumi; Matsuki, Takuya; Suzuki, Satoshi*; Tsutagi, Koichi; Tomikawa, Hirofumi; Nakamura, Hironobu; LaFleur, A.*; Browne, M.*
Proceedings of IAEA Symposium on International Safeguards; Building Future Safeguards Capabilities (Internet), 8 Pages, 2018/11
The IAEA has proposed, in its Research and Development plan (STR-385), the development of technology to enable real-time flow measurement of nuclear material as part of an advanced approach to effective and efficient safeguards for reprocessing facilities. To address this, JAEA and JNFL had previously designed and developed a neutron coincidence based non-destructive assay system to monitor Pu in solution directly after a purification process. To enhance this technology for entire reprocessing facilities, as a feasibility study, JAEA has been tackling development of a new detector to enable monitoring of Pu in solutions with numerous fission products (FPs) as a joint research program with the U.S. DOE. In this study, the High Active Liquid Waste (HALW) Storage Facility in Tokai Reprocessing Plant (TRP) was used as the test bed. The design information of the HALW storage tank and radiation (type and intensity) were investigated, to develop a Monte Carlo N-Particle Transport Code (MCNP) model. Then, dose rate distribution inside the concrete cell where the HALW tank is located was measured, to enable design of new detectors and check the integrity of the MCNP model and its applicability. Using the newly-designed detectors, -rays and neutrons could be measured continuously at the outside/inside of the concrete cell, to optimize detector position and the radiation characteristics. The applicability as a Pu-monitoring technology was evaluated, based on the simulation results and -ray/neutron measurement results. We have found that there is a possibility to monitor the change of Pu amount in solution by combination of -ray and neutron measurements. The results of this study suggest a feasibility study into the applicability and capability of Pu monitoring to enhance the entire reprocessing facility handling Pu with FPs. In this paper, a summary of the project will be presented.
Am with ANNRI at J-PARCTerada, Kazushi*; Kimura, Atsushi; Nakao, Taro*; Nakamura, Shoji; Mizuyama, Kazuhito*; Iwamoto, Nobuyuki; Iwamoto, Osamu; Harada, Hideo; Katabuchi, Tatsuya*; Igashira, Masayuki*; et al.
Journal of Nuclear Science and Technology, 55(10), p.1198 - 1211, 2018/10
Times Cited Count：18 Percentile：88.27(Nuclear Science & Technology)Sekine, Megumi; Matsuki, Takuya; Tokoro, Hayate; Tsutagi, Koichi; Kitao, Takahiko; Nakamura, Hironobu; Tomikawa, Hirofumi
Proceedings of INMM 59th Annual Meeting (Internet), 10 Pages, 2018/07
In a reprocessing facility, it is necessary to develop a detector which can measure plutonium (Pu) content in the Pu solutions containing fission products (FP) in order to expand the application of Pu monitoring. In order to establish this technology, JAEA has studied a system measure -rays was utilized since it applicable for Pu monitoring. Ce:GAGG (Ce:Gd
AlGaO
) scintillator detector can measure a wide energy range in a high-dose environment and has reasonable resolution. -ray measurements were performed inside of the concrete cell containing the High Active Liquid Waste tank at the Tokai reprocessing plant. In the spectra, the two significant peaks were measured by the GAGG above 800 keV and were considered to be from Eu-154. There -ray measurements will be combined with previous neutron measurements and both will be compared to MCNP models for future Pu monitoring technology. This presentation will describe the detector selection, the design system, the results of -ray spectral measurements and the applicability for Pu monitoring. This project has been carried out under the support of the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of the Japanese government.
Sekine, Megumi; Matsuki, Takuya; Tokoro, Hayate; Tsutagi, Koichi; Tomikawa, Hirofumi; Nakamura, Hironobu
Nihon Kaku Busshitsu Kanri Gakkai Dai-38-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2018/04
In a reprocessing facility, it is necessary to develop a detector which is measurable plutonium (Pu) amount in the Pu solution containing the Fission Product (FP) in order to expand the application of Pu monitoring. To investigate rays which is applicable for Pu monitoring, Ce:GAGG (Ce: GdAlGaO) scintillator which can measure a wide range of energy at high dose and has high resolution (Target: High Active Liquid Waste (HALW)) was newly designed and developed in deal with aim for Pu quantitativeness. ray measurement was performed to the HALW in the concrete cell using the detector, and it was confirmed that high energy rays (9.5 MeV) could be measured and high energy rays spectra over 3 MeV without deriving from FP at the first time. In this presentation, detector design, results of ray spectra measurement, applicability evaluation to Pu monitoring and the future plan are presented. This project has been carried out under the support of the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of the Japanese government.
Suekuni, Koichiro*; Lee, C. H.*; Tanaka, Hiromi*; Nishibori, Eiji*; Nakamura, Atsushi*; Kasai, Hidetaka*; Mori, Hitoshi*; Usui, Hidetomo*; Ochi, Masayuki*; Hasegawa, Takumi*; et al.
Advanced Materials, 30(13), p.1706230_1 - 1706230_6, 2018/03
Times Cited Count：51 Percentile：89.35(Chemistry, Multidisciplinary)Thermoelectric materials for highly efficient devices must satisfy conflicting requirements of high electrical conductivity and low thermal conductivity. In this paper, we studied the crystal structure and phonon dynamics of tetrahedrites (Cu,Zn)(Sb,As)
S
. The results revealed that the Cu atoms in a planar coordination are rattling, which effectively scatter phonons. These findings provide a new strategy for the development of highly efficient thermoelectric materials with planar coordination.
