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Ichikawa, Tsubasa*; Hakoshima, Hideaki*; Inui, Koji*; Ito, Kosuke*; Matsuda, Ryo*; Mitarai, Kosuke*; Miyamoto, Koichi*; Mizukami, Wataru*; Mizuta, Kaoru*; Mori, Toshio*; et al.
Nature Reviews Physics (Internet), 6(6), p.345 - 347, 2024/06
Times Cited Count:1 Percentile:53.54(Physics, Applied)Okitsu, Takayuki*; Hojo, Tomohiko*; Morooka, Satoshi; Miyamoto, Goro*
Tetsu To Hagane, 110(3), p.260 - 267, 2024/02
Times Cited Count:0 Percentile:0.00(Metallurgy & Metallurgical Engineering)Shizuma, Toshiyuki*; Omer, M.; Hayakawa, Takehito*; Minato, Futoshi*; Matsuba, Shunya*; Miyamoto, Shuji*; Shimizu, Noritaka*; Utsuno, Yutaka
Physical Review C, 109(1), p.014302_1 - 014302_7, 2024/01
Times Cited Count:2 Percentile:74.53(Physics, Nuclear)Omer, M.; Shizuma, Toshiyuki*; Koizumi, Mitsuo; Hajima, Ryoichi*; Hashimoto, Satoshi*; Miyamoto, Shuji*
LASTI Annual Report, 24, p.20 - 22, 2023/12
Barucci, M. A.*; Reess, J.-M.*; Bernardi, P.*; Doressoundiram, A.*; Fornasier, S.*; Le Du, M.*; Iwata, Takahiro*; Nakagawa, Hiromu*; Nakamura, Tomoki*; Andr, Y.*; et al.
Earth, Planets and Space (Internet), 73(1), p.211_1 - 211_28, 2021/12
Times Cited Count:19 Percentile:82.33(Geosciences, Multidisciplinary)The MMX InfraRed Spectrometer (MIRS) is an imaging spectrometer on board of MMX JAXA mission. MIRS is built at LESIA-Paris Observatory in collaboration with four other French laboratories, collaboration and financial support of CNES and close collaboration with JAXA and MELCO. The instrument is designed to fully accomplish MMX's scientific and measurement objectives. MIRS will remotely provide near-infrared spectral maps of Phobos and Deimos containing compositional diagnostic spectral features that will be used to analyze the surface composition and to support the sampling site selection. MIRS will also study Mars atmosphere, in particular to spatial and temporal changes such as clouds, dust and water vapor.
Tomita, Jumpei; Ozawa, Mayumi; Ohara, Yoshiyuki; Miyamoto, Yutaka
KEK Proceedings 2021-2, p.130 - 134, 2021/12
no abstracts in English
Sanada, Yukihisa; Miyamoto, Kenji*; Momma, Hiroyasu*; Miyazaki, Nobuyuki*; Nakasone, Takamasa*; Tahara, Junichiro*; Baba, Shoichiro*; Furuyama, Hiroki*
Marine Technology Society Journal, 55(5), p.222 - 230, 2021/09
Large quantities of volatile radionuclides were released into the atmosphere following the Fukushima Daiichi Nuclear Power Station (FDNPS) accident in March 2011. To evaluate their effect on aquatic organisms and radiocesium behavior in the environment, the monitoring of radioactive cesium in the waterbed soil is important. We developed a dedicated radiation survey device that can both directly measure and collect some sediment samples. A comprehensive test was conducted using this device, which was installed in an unmanned surface vehicle at Fukushima offshore contaminated by radiocesium that resulted from the FDNPS accident. Consequently, the effectiveness of this device was confirmed because the measurement results of the sediment-core sample and in-situ radiation survey results show a good correlation. A successful application of this device in the time of post-nuclear facility accident is expected.
Kasugai, Yoshimi; Sato, Koichi; Takahashi, Kazutoshi*; Miyamoto, Yukihiro; Kai, Tetsuya; Harada, Masahide; Haga, Katsuhiro; Takada, Hiroshi
JPS Conference Proceedings (Internet), 33, p.011144_1 - 011144_6, 2021/03
A spallation neutron source with a mercury target has been in operation at the Materials and Life Science Experimental Facility of J-PARC since 2008. The target vessel made of stainless steel is required to be exchanged periodically due to radiation damage etc. In this presentation, tritium gas release observed in the first series of exchange work in 2011 and the analytical results will be shown.
Shizuma, Toshiyuki*; Minato, Futoshi; Omer, M.*; Hayakawa, Takehito*; Ogaki, Hideaki*; Miyamoto, Shuji*
Physical Review C, 103(2), p.024309_1 - 024309_8, 2021/02
Times Cited Count:5 Percentile:56.17(Physics, Nuclear)Low-lying dipole transitions in Pb were measured via nuclear photon scattering using a quasi-monochromatic, linearly polarized photon beam. The electric () and magnetic () dipole strengths were extracted for excitation energies up to 6.8 MeV. The present (,) results, combined with (,) data from the literature, were used to investigate the and photoabsorption cross sections near the neutron separation energy by comparison with predictions of the particle-vibration coupling on top of the quasi-particle random phase approximation (PVC+QRPA).
Misono, Toshiharu; Tsuruta, Tadahiko; Nakanishi, Takahiro; Sanada, Yukihisa; Shiribiki, Takehiko; Miyamoto, Kenji*; Urabe, Yoshimi*
JAEA-Research 2020-008, 166 Pages, 2020/10
After the accident at TEPCO Fukushima Daiichi Nuclear Power Station (1F), marine monitoring survey on radioactive substances have been conducted with financially supported by the Nuclear Regulatory Agency from FY2019. Results obtain in the project in FY2019 are presented in this report. Based on scientific grounds, the concept necessary for "progress of sea area monitoring" was arranged for the future medium- to long-term investigation of radiocesium concentrations. As basic information of survey frequency revise, a seabed topography and sediment distribution survey was conducted, and an attempt was made to understand the relationship between the seabed topography and the grain size distribution of bottom sediment. A columnar core sample was collected in the coastal area and analyzed for radioactive cesium concentration. In order to understand the dynamics of radioactive cesium contained in suspended matter flowing in from a river, suspended solids was collected using a sediment trap and the concentration of radioactive cesium was measured. We re-analyzed the towed monitoring data that had been implemented since 2013, and tried to improve the accuracy of the radioactive cesium distribution estimation map in the coastal area.
Yada, Ryuichi*; Maenaka, Kazusuke*; Miyamoto, Shuji*; Okada, Go*; Sasakura, Aki*; Ashida, Motoi*; Adachi, Masashi*; Sato, Tatsuhiko; Wang, T.*; Akasaka, Hiroaki*; et al.
Medical Physics, 47(10), p.5235 - 5249, 2020/10
Times Cited Count:8 Percentile:49.75(Radiology, Nuclear Medicine & Medical Imaging)The dosimeter system is capable of real-time, accurate, and precise measurement under stereotactic body radiation therapy (SBRT) conditions. The probe is smaller than a conventional dosimeter, has excellent spatial resolution, and can be valuable in SBRT with a steep dose distribution over a small field. The developed PSP dosimeter system appears to be suitable for in vivo SBRT dosimetry.
Hirahara, Toru*; Otrokov, M. M.*; Sasaki, Taisuke*; Sumida, Kazuki*; Tomohiro, Yuta*; Kusaka, Shotaro*; Okuyama, Yuma*; Ichinokura, Satoru*; Kobayashi, Masaki*; Takeda, Yukiharu; et al.
Nature Communications (Internet), 11, p.4821_1 - 4821_8, 2020/09
Times Cited Count:46 Percentile:92.39(Multidisciplinary Sciences)Yoshikawa, Tomoki*; Antonov, V. N.*; Kono, Takashi*; Kakoki, Masaaki*; Sumida, Kazuki; Miyamoto, Koji*; Takeda, Yukiharu; Saito, Yuji; Goto, Kazuki*; Sakuraba, Yuya*; et al.
Physical Review B, 102(6), p.064428_1 - 064428_7, 2020/08
Times Cited Count:3 Percentile:16.26(Materials Science, Multidisciplinary)Shikin, A. M.*; Estyunin, D. A.*; Klimovskikh, I. I.*; Filnov, S. O.*; Kumar, S.*; Schwier, E. F.*; Miyamoto, Koji*; Okuda, Taichi*; Kimura, Akio*; Kuroda, Kenta*; et al.
Scientific Reports (Internet), 10, p.13226_1 - 13226_13, 2020/08
Times Cited Count:67 Percentile:95.88(Multidisciplinary Sciences)Kono, Takashi*; Kakoki, Masaaki*; Yoshikawa, Tomoki*; Wang, X.*; Sumida, Kazuki*; Miyamoto, Koji*; Muro, Takayuki*; Takeda, Yukiharu; Saito, Yuji; Goto, Kazuki*; et al.
Physical Review B, 100(16), p.165120_1 - 165120_6, 2019/10
Times Cited Count:7 Percentile:33.40(Materials Science, Multidisciplinary)Sanada, Yukihisa; Miyamoto, Kenji*; Ochi, Kotaro; Matsuzaki, Koji*; Ogawa, Toshihiro*; Senga, Yasuhiro*
Kaiyo Riko Gakkai-Shi, 24(2), p.9 - 18, 2018/12
Seven years passed since Fukushima Dai-ichi Nuclear Power Station accident which was caused large amount of radionuclide release to the sea. Elucidation of behavior mechanism of radiocesium in the seabed is required for restarting fishing industry. We developed radiation detection system using the unmanned surface vehicle for in-situ measurement of radiocesium concentration in seabed sediment. This system is able to automatically navigate to measurement point and obtain the radiation data on the bottom sediment. The detector was calibrated by comparing the actual sediment samples. The periodical measurement off-shore the Fukushima Prefecture was performed using developed this system. As these results, distribution of radiocesium concentration was changed due to oceanographic condition. However, radiocesium inventory was tendency to decrease according to radiocesium half-life in measurement area. This system is effective for elucidation of behavior mechanism of radiocesium because it can easily measure the radiocesium concentration in the bottom sediment.
Shizuma, Toshiyuki*; Hayakawa, Takehito*; Daito, Izuru*; Ogaki, Hideaki*; Miyamoto, Shuji*; Minato, Futoshi
Physical Review C, 96(4), p.044316_1 - 044316_10, 2017/10
Times Cited Count:9 Percentile:56.83(Physics, Nuclear)The low-lying dipole strength in Cr was measured in nuclear resonance fluorescence experiments using a quasi-monochromatic, linearly polarized photon beam. The parities of the excited dipole states were determined by the intensity asymmetry of resonantly scattered -rays with respect to the polarization plane of the incident photon beam. The summed magnetic dipole (M1) strength was determined as at excitation energies between 7.5 and 12.1 MeV; the summed electric dipole (E1) strength was obtained as fm. The observed M1 and E1 strengths were compared via random phase approximation calculations using the Skyrme interaction. The effects of 2 particle-2 hole configuration mixing and tensor force on dipole strength distributions were investigated.
Hayakawa, Takehito; Miyamoto, Shuji*; Hajima, Ryoichi; Shizuma, Toshiyuki; Amano, So*; Hashimoto, Satoshi*; Misawa, Tsuyoshi*
Journal of Nuclear Science and Technology, 53(12), p.2064 - 2071, 2016/12
Times Cited Count:8 Percentile:57.38(Nuclear Science & Technology)We have proposed a new selective isotope transmutation method using photonuclear reactions with quasi-monochromatic -ray beams. This method is based on the fact that the particle threshold of a long-lived fission product (LLFP) such as Zr, Pd, or Se is lower than those of stable isotopes of the same chemical element. Therefore, this method has an excellent advantage that LLFPs cannot, in principle, be produced newly even if the target materials include stable isotopes in addition to a LLFP. Laser Compton scattering -ray sources and neutron capture -rays in nuclear reactors are candidates for this method.
Deguchi, Akira*; Umeki, Hiroyuki*; Ueda, Hiroyoshi*; Miyamoto, Yoichi; Shibata, Masahiro; Naito, Morimasa; Tanaka, Toshihiko*
LBNL-1006984 (Internet), p.12_1 - 12_22, 2016/12
The H12 report demonstrated the feasibility of safe and technically reliable geological disposal in 1999. The Government of Japan re-evaluated the geological disposal program in terms of technical feasibility based on state-of-the-art geosciences and implementation process, because more than 10 years have passed from H12 and the Great Earthquake and nuclear accident have increased public concern regarding nuclear issues and natural hazards to cause accidents at nuclear facilities. Following the re-evaluation, the Government concluded further to promote geological disposal program, and thus the Basic Policy for Final Disposal was revised in 2015 including a new approach to siting process with identification of "Scientifically Preferable Areas". NUMO and relevant research organizations such as JAEA have been carrying out R and D activities to increase technical reliability for geological disposal. NUMO has started to develop a generic safety case.
Ashida, Takashi; Ito, Hideaki; Miyamoto, Kazuyuki*; Nakamura, Toshiyuki; Koga, Kazuhiro*; Ohara, Norikazu*; Ino, Hiroichi*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 15(4), p.210 - 222, 2016/12
In the experimental fast reactor Joyo, it was confirmed that the top of the irradiation test sub-assembly of material testing rig named "MARICO-2" had been broken and bent onto the in-vessel storage rack as an obstacle and had damaged the upper core structure (UCS). As the result, for Joyo restart, it was necessary to replace the damaged UCS and to retrieve the bent sub-assembly. This paper describes in-vessel repair techniques performed in the retrieval work of the obstacle inside of the reactor vessel. The devices which were prepared for this work demonstrated expected performance under the environmental conditions of an SFR such as high temperature and radiation dose, and the work was completed in 2014. The successful operation of this retrieval work of the damaged component inside of a reactor vessel will contribute to the development of in-service inspections and repair technics in an SFR.