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Kaneda-Nakashima, Kazuko*; Shirakami, Yoshifumi*; Kadonaga, Yuichiro*; Watabe, Tadashi*; Oe, Kazuhiro*; Yin, X.*; Haba, Hiromitsu*; Shirasaki, Kenji*; Kikunaga, Hidetoshi*; Tsukada, Kazuaki; et al.
International Journal of Molecular Sciences (Internet), 25(2), p.933_1 - 933_14, 2024/01
Times Cited Count：1 Percentile：0.01(Biochemistry & Molecular Biology)Mitsuhara, Masatoshi*; Kurino, Koichi*; Yano, Yasuhide; Otsuka, Satoshi; Toyama, Takeshi*; Onuma, Masato*; Nakashima, Hideharu*
Tetsu To Hagane, 109(3), p.189 - 200, 2023/03
Times Cited Count：0 Percentile：0(Metallurgy & Metallurgical Engineering)Oxide Dispersion Strengthened (ODS) ferritic steel, a candidate material for fast reactor fuel cladding, has low thermal expansion, good thermal conductivity, and excellent resistance to irradiation damage and high temperature strength. The origin of the excellent high-temperature strength lies in the dispersion of fine oxides. In this study, creep tests at 700 or 750
C, which are close to the operating temperatures of fast reactors, and high-temperature tensile tests at 900 to 1350 C, which simulate accident conditions, were conducted on 9Cr ODS ferritic steels, M11 and MP23, and 12Cr ODS ferritic steel, F14, to confirm the growth behavior of oxides. In the M11 and F14 creep test samples, there was little oxide growth or decrease in number density from the initial state, indicating that dispersion strengthening by oxides was effective during deformation. After creep deformation of F14, the development of dislocation substructures such as dislocation walls and subgrain boundaries was hardly observed, and mobile dislocations were homogeneously distributed in the grains. The dislocation density increased with increasing stress during the creep test. In the high-temperature ring tensile tests of MP23 and F14, the strength of both steels decreased at higher temperatures. In MP23, elongation decreased with increasing test temperature from 900 to 1100 C, but increased at 1200 C, decreased drastically at 1250 C, and increased again at 1300 C. In F14, elongation decreased with increasing temperature. It was inferred that the formation of the 
-ferrite phase was responsible for this complex change in mechanical properties of MP23 from 1200 to 1300 C.
through water-soluble Ti complexes as raw material for controlling particle size and distribution of synthesized BaTiO
nanocubesNakashima, Koichi*; Hironaka, Kota*; Ouchi, Kazuma*; Ajioka, Mao*; Kobayashi, Yoshio*; Yoneda, Yasuhiro; Yin, S.*; Kakihana, Masato*; Sekino, Toru*
ACS Omega (Internet), 6(48), p.32517 - 32527, 2021/12
Times Cited Count：5 Percentile：38.19(Chemistry, Multidisciplinary)The BaTiO nanoparticles synthesized by the hydrothermal method is examined by synchrotron X-ray and TEM observation. It was found that the particle size of synthesized BaTiO depends on the particle size of the raw material of TiO. Succeeded in synthesizing 100 nm size BaTiO nanocrystals showing uniform particle size distribution using TiO nanoparticles with optimized particle size. The obtained BaTiO nanocrystal is a tetragonal system of ferroelectric phase. A three-dimensional structure of BaTiO nanoparticles could be obtained by the electron beam tomography.
Okutsu, Kenichi*; Yamashita, Takuma*; Kino, Yasushi*; Nakashima, Ryota*; Miyashita, Konan*; Yasuda, Kazuhiro*; Okada, Shinji*; Sato, Motoyasu*; Oka, Toshitaka; Kawamura, Naritoshi*; et al.
Fusion Engineering and Design, 170, p.112712_1 - 112712_4, 2021/09
Times Cited Count：3 Percentile：45.99(Nuclear Science & Technology)A muonic molecule which consists of two hydrogen isotope nuclei (deuteron (d) or tritium (t)) and a muon decays immediately via nuclear fusion and the muon will be released as a recycling muon, and start to find another hydrogen isotope nucleus. The reaction cycle continues until the muon ends up its lifetime of 2.2 
s. Since the muon does not participate in the nuclear reaction, the reaction is so called a muon catalyzed fusion (CF). The recycling muon has a particular kinetic energy (KE) of the muon molecular orbital when the nuclear reaction occurs. Since the KE is based on the unified atom limit where distance between two nuclei is zero. A precise few-body calculation estimating KE distribution (KED) is also in progress, which could be compared with the experimental results. In the present work, we observed recycling muons after CF reaction.
Yamashita, Takuma*; Okutsu, Kenichi*; Kino, Yasushi*; Nakashima, Ryota*; Miyashita, Konan*; Yasuda, Kazuhiro*; Okada, Shinji*; Sato, Motoyasu*; Oka, Toshitaka; Kawamura, Naritoshi*; et al.
Fusion Engineering and Design, 169, p.112580_1 - 112580_5, 2021/08
Times Cited Count：3 Percentile：45.99(Nuclear Science & Technology)A muon () having 207 times larger mass of electron and the same charge as the electron has been known to catalyze a nuclear fusion between deuteron (d) and triton (t). These two nuclei are bound by and form a muonic hydrogen molecular ion, dt. Due to the short inter-nuclear distance of dt, the nuclear fusion, d +t
+ n + 17.6 MeV, occurs inside the molecule. This reaction is called muon catalyzed fusion (CF). Recently, the interest on CF is renewed from the viewpoint of applications, such as a source of high-resolution muon beam and mono-energetic neutron beam. In this work, we report a time evolution calculation of CF in a two-layered hydrogen isotope target.
nanocubes via precise solvothermal crystal growth and their anomalous surface compositional reconstructionNakashima, Koichi*; Onagi, Kaito*; Kobayashi, Yoshio*; Ishigaki, Toru*; Ishikawa, Yoshihisa*; Yoneda, Yasuhiro; Yin, S.*; Kakihana, Masato*; Sekino, Toru*
ACS Omega (Internet), 6(14), p.9410 - 9425, 2021/04
Times Cited Count：9 Percentile：59.91(Chemistry, Multidisciplinary)We succeeded in synthesizing barium titanate nanocubes by hydrothermal synthesis. When the nanocubes were examined in detail using a scanning electron microscope, pulsed neutrons, and large synchrotron radiation, it was found that a reconstituted layer of titanium oxide was formed on the surface.
Nakamura, Takemi; Sakasai, Kaoru; Nakashima, Hiroshi; Takamiya, Koichi*; Kumada, Hiroaki*
Journal of Radiation Protection and Research, 41(2), p.105 - 109, 2016/06
no abstracts in English
nanocubes by solvothermal synthesisYoneda, Yasuhiro; Kohara, Shinji*; Nakashima, Koichi*; Nagata, Hajime*; Wada, Satoshi*
Japanese Journal of Applied Physics, 54(10S), p.10NC01_1 - 10NC01_6, 2015/10
Times Cited Count：4 Percentile：18.63(Physics, Applied)The atomic-scale structure of KNbO nanopowder synthesized by solvothermal method has been studied using high-energy X-ray diffraction, Rietveld refinement, and the atomic pair-distribution function (PDF) technique. It was found that the local structure of KNbO nanoparticles deviates from the average structure. The local structure was found to be rhombohedral structure though the average structure was tetragonal structure. The rhombohedral distortion of NbO
octahedra was maintained in the annealed sample.
Sukegawa, Atsuhiko; Iida, Hiromasa*; Itoga, Toshio*; Okumura, Keisuke; Kai, Tetsuya; Konno, Chikara; Nakashima, Hiroshi; Nakamura, Takashi*; Ban, Shuichi*; Yashima, Hiroshi*; et al.
Hoshasen Shahei Handobukku; Kisohen, p.299 - 356, 2015/03
no abstracts in English
Tokunaga, Tomonori*; Watanabe, Hideo*; Yoshida, Naoaki*; Nagasaka, Takuya*; Kasada, Ryuta*; Lee, Y.-J.*; Kimura, Akihiko*; Tokitani, Masayuki*; Mitsuhara, Masatoshi*; Hinoki, Tatsuya*; et al.
Journal of Nuclear Materials, 442(1-3), p.S287 - S291, 2013/11
Times Cited Count：11 Percentile：64.2(Materials Science, Multidisciplinary)Imaizumi, Tomomi; Miyauchi, Masaru; Ito, Masayasu; Watahiki, Shunsuke; Nagata, Hiroshi; Hanakawa, Hiroki; Naka, Michihiro; Kawamata, Kazuo; Yamaura, Takayuki; Ide, Hiroshi; et al.
JAEA-Technology 2011-031, 123 Pages, 2012/01
JAEA-Technology-2011-031.pdf:16.08MB
The number of research reactors in the world is decreasing because of their aging. However, the planning to introduce the nuclear power plants is increasing in Asian countries. In these Asian countries, the key issue is the human resource development for operation and management of nuclear power plants after constructed them, and also the necessity of research reactor, which is used for lifetime extension of LWRs, progress of the science and technology, expansion of industry use, human resources training and so on, is increasing. From above backgrounds, the Neutron Irradiation and Testing Reactor Center began to discuss basic concept of a multipurpose low-power research reactor for education and training, etc. This design study is expected to contribute not only to design tool improvement and human resources development in the Neutron Irradiation and Testing Reactor Center but also to maintain and upgrade the technology on research reactors in nuclear power-related companies. This report treats the activities of the working group from July 2010 to June 2011 on the multipurpose low-power research reactor in the Neutron Irradiation and Testing Reactor Center and nuclear power-related companies.
Hoshi, Akiko; Watanabe, Koichi; Fujiwara, Asako; Haraga, Tomoko; Kameo, Yutaka; Nakashima, Mikio; Takebe, Shinichi
Nihon Genshiryoku Gakkai Wabun Rombunshi, 7(3), p.177 - 185, 2008/09
The simple and rapid separation method was developed for actinides in the low-level radioactive waste. Extraction chromatographic columns were used for the separation of U, Np, Pu, Am, and Cm in the solution of the simulated solidified product and the simulated waste solution. In the investigation of separation procedure, it was tried to construct the scheme with the relatively non-corrosive reagents aiming to apply to the routine analysis of the radioactive waste. Recoveries and decontamination factors of actinides in the solution of simulated waste were high enough to determine of actinides in radioactive waste by alpha-spectrometry, mass spectroscopy. The time required of the separation operation was 2-3 hours. The chromatographic method was applied to analysis of actinide in actual waste solution, high recoveries and decontamination factors were obtained, which indicated that the extraction chromatographic separation method would be adopted as a simple and rapid separation method of actinide in waste.
(R: Rare earth)Hieu, N. V.*; Takeuchi, Tetsuya*; Shishido, Hiroaki*; Tonohiro, Chie*; Yamada, Tsutomu*; Nakashima, Hiroshi*; Sugiyama, Kiyohiro*; Settai, Rikio*; Matsuda, Tatsuma; Haga, Yoshinori; et al.
Journal of the Physical Society of Japan, 76(6), p.064702_1 - 064702_16, 2007/06
Times Cited Count：49 Percentile：84.5(Physics, Multidisciplinary)Nakashima, Miho*; Ueda, Taiki*; Shimizu, Katsuya*; Nakashima, Hiroshi*; Thamizhavel, A.*; Tateiwa, Naoyuki; Haga, Yoshinori; Hedo, Masato*; Uwatoko, Yoshiya*; Settai, Rikio*; et al.
Journal of Magnetism and Magnetic Materials, 310(2, Part1), p.e9 - e11, 2007/03
We measured the electrical resistivity and AC-specific heat for a canted ferromagnet CePtAl under pressures using a diamond-anvilpressure cell. With increasing pressure, the magnetic ordering temperature 
increases monotonously, becomes constant above 8 GPa and then starts to decrease steeply in a narrow pressure region from 10.3 to 10.9 GPa, indicating the first-order like phase transition. The similar pressure dependence of was obtained in the AC-specific heat measurement.
Sugiyama, Kiyohiro*; Nakashima, Hiroshi*; Aoki, Dai*; Haga, Yoshinori; Yamamoto, Etsuji; Nakamura, Akio; Homma, Yoshiya*; Shiokawa, Yoshinobu*; Kindo, Koichi*; Hagiwara, Masayuki*; et al.
Journal of the Physical Society of Japan, 75(9), p.094707_1 - 094707_6, 2006/09
Times Cited Count：6 Percentile：41.83(Physics, Multidisciplinary)We have measured the high-field magnetization for a transuranium antiferromagnet NpRhGa with two successive antiferromagnetic transition temperatures of 
= 36 and 
= 32 K and an ordered moment of 0.96 
/Np. For the magnetic field along the easy-axis of the [100] direction of the tetragonal structure, the magnetization indicates a metamagnetic transition at 
= 26 T with a sharp step and saturates above 
=38 T, with 0.43 /Np. On the other hand, the hard-axis magnetization for the [001] direction increases linearly and saturates above =28 T, with 0.44 /Np. These magnetization curves were discussed on the basis of reorientation and reduction of the magnetic moment.
AlOzawa, Akira*; Matsuta, Kensaku*; Nagatomo, Takashi*; Mihara, Mototsugu*; Yamada, Kazunari*; Yamaguchi, Takayuki*; Otsubo, Takashi*; Momota, Sadao*; Izumikawa, Takuji*; Sumikama, Toshiyuki*; et al.
Physical Review C, 74(2), p.021301_1 - 021301_4, 2006/08
Times Cited Count：43 Percentile：89.22(Physics, Nuclear)no abstracts in English
, TbRhIn, DyRhIn, and HoRhInHieu, N. V.*; Shishido, Hiroaki*; Takeuchi, Tetsuya*; Thamizhavel, A.*; Nakashima, Hiroshi*; Sugiyama, Kiyohiro*; Settai, Rikio*; Matsuda, Tatsuma; Haga, Yoshinori; Hagiwara, Masayuki*; et al.
Journal of the Physical Society of Japan, 75(7), p.074708_1 - 074708_6, 2006/07
Times Cited Count：19 Percentile：67.26(Physics, Multidisciplinary)We grew single crystals of NdRhIn, TbRhIn, DyRhIn, and HoRhIn with the tetragonal crystal structure and measured the magnetic susceptibility and magnetization. NdRhIn is an antiferromagnet with a Neel temperature 
= 11.6 K. Below , magnetization reveals two metamagnetic transitions at Hm1 = 70 kOe and Hm2 = 93 kOe for the magnetic field along the [001] direction. The saturation moment of 2.5 
/Nd is in good agreement with the staggered Nd moment determined by the neutron diffraction experiment. These metamagnetic transitions correspond to the change of the magnetic structure. TbRhIn, DyRhIn and HoRhIn are found to be antiferromagnets with = 47.3, 28.1, and 15.8 K, respectively. The magnetization curves of these compounds are also quite similar to those of NdRhIn, revealing two metamagnetic transitions. The magnetic structures in magnetic fields are proposed by considering the exchange interactions based on the crystal structure.
B and GdRhBObiraki, Yoshiko*; Nakashima, Hiroshi*; Galatanu, A.*; Matsuda, Tatsuma; Haga, Yoshinori; Takeuchi, Tetsuya*; Sugiyama, Kiyohiro*; Kindo, Koichi*; Hagiwara, Masayuki*; Settai, Rikio*; et al.
Journal of the Physical Society of Japan, 75(6), p.064702_1 - 064702_8, 2006/06
Times Cited Count：4 Percentile：32.33(Physics, Multidisciplinary)We succeeded in growing single crystals of ferromagnets NdRhB and GdRhB with the hexagonal structure, and measured the electrical resistivity, specific heat, magnetic susceptibility and magnetization. From these measurements, the Curie temperature 
is determined as =10.2 K in NdRhB and TC=93 K in GdRhB. The magnetic moments of about 2.5 in NdRhB and 7.7 in GdRhB are oriented in the basal plane. The crystalline electric field scheme is proposed for NdRhB on the basis of the experimental results of Schottky anomaly in the specific heat and anisotropic susceptibility and magnetization. The Fermi surface in NdRhB is very similar to that in a non-4 f reference compound LaRhB, possessing the quasi-one dimensional electronic character.
NiGeThamizhavel, A.*; Nakashima, Hiroshi*; Obiraki, Yoshiko*; Nakashima, Miho*; Matsuda, Tatsuma; Haga, Yoshinori; Sugiyama, Kiyohiro*; Takeuchi, Tetsuya*; Settai, Rikio*; Hagiwara, Masayuki*; et al.
Journal of the Physical Society of Japan, 74(10), p.2843 - 2848, 2005/10
Times Cited Count：14 Percentile：59.33(Physics, Multidisciplinary)Single crystals of a pressure-induced superconductor CeNiGe have been successfully grown by the flux method. The anisotropic magnetic properties due to the orthorhombic crystal structure have been studied precisely by the electrical resistivity, specific heat, magnetic susceptibility, and high-field magnetization measurements. The results of these measurements confirmed two antiferromagnetic transitions at T
=5.0 K and T
=4.3 K. The electronic specific heat coefficient obtained from the low-temperature specific heat data amounts to 90 mJ/K
mol Ce. The high-field magnetization for H //[100] shows four magnetic transitions at 11.8, 12.9, 17.5 and 23.9 T with a saturation moment of 0.73 /Ce at 1.3 K. We have also performed the crystalline electric field (CEF) analysis on the magnetic susceptibility and magnetization to understand the magnetocrystalline anisotropy, where the splitting energies of two excited doublets in the CEF scheme are estimated to be 140 and 576 K, respectively.
Kameo, Yutaka; Fujiwara, Asako; Watanabe, Koichi; Kono, Nobuaki; Nakashima, Mikio
Nihon Genshiryoku Gakkai Wabun Rombunshi, 4(3), p.187 - 193, 2005/09
no abstracts in English
