Takahashi, Naoki; Yoshinaka, Kazuyuki; Harada, Akio; Yamanaka, Atsushi; Ueno, Takashi; Kurihara, Ryoichi; Suzuki, Soju; Takamatsu, Misao; Maeda, Shigetaka; Iseki, Atsushi; et al.
Nihon Genshiryoku Gakkai Homu Peji (Internet), 64 Pages, 2016/00
no abstracts in English
Sato, Takeshi; Muto, Shigeo; Okuno, Hiroshi; Katagiri, Hiromi; Akiyama, Kiyomitsu; Okamoto, Akiko; Koie, Masahiro; Ikeda, Takeshi; Nemotochi, Toshimasa; Saito, Toru; et al.
JAEA-Review 2013-046, 65 Pages, 2014/02
When a nuclear emergency occurs in Japan, the Japan Atomic Energy Agency (JAEA) has the responsibility of providing technical support to the National government, local governments, police, fire stations and nuclear operators etc., because the JAEA has been designated as the Designated Public Institution under the Basic Act on Disaster Control Measures and the Act on Response to Armed Attack Situations, etc.. The Nuclear Emergency Assistance and Training Center (NEAT) of JAEA provides a comprehensive range of technical support activities to an Off-Site Center in case of a nuclear emergency. Specifically, NEAT gives technical advice and information, dispatches specialists as required, and supplies the National Government and local governments with emergency equipments and materials. NEAT provides various exercise and training courses concerning nuclear disaster prevention to those personnel taking an active part in emergency response organizations at normal times. The tasks of NEAT, with its past experiences as a designated public institution including the responses to TEPCO's Fukushima Accident, have been shifted to technical supports to the national government for strengthening its abilities to emergency responses; the NEAT therefore focused on maintenance and operation of its functions, and strengthening its response abilities in cooperation with the national government. This annual report summarized these activities of JAEA/NEAT in the fiscal year 2012.
Nakamoto, Tadahiro*; Nakamura, Akio; Takeda, Masuo*
Mssbauer Spectroscopy; Applications in Chemistry, Biology, and Nanotechnology, p.95 - 114, 2013/10
Nakamura, Akio; Igawa, Naoki; Okamoto, Yoshihiro; Hinatsu, Yukio*; Wang, J.*; Takahashi, Masashi*; Takeda, Masuo*
Mssbauer Spectroscopy; Applications in Chemistry, Biology, and Nanotechnology, p.71 - 94, 2013/10
Nakamura, Akio; Igawa, Naoki; Okamoto, Yoshihiro; Wang, J.*; Hinatsu, Yukio*; Takahashi, Masashi*; Takeda, Masuo*
Hyperfine Interactions, 217(1-3), p.17 - 26, 2013/04
Mesubaua Bunko Kenkyu, (14), p.8 - 11, 2013/00
I have recently proposed a new defect-crystal-chemistry model for coupled non-Vegardianity and non-random defect structure of so-called defect-fluorite oxides. In this lecture, I would like to give its review, emphasizing the importance of microscopic Mssbauer, EXAFS and NMR local-structure data in combination with XRD lattice parameter data.
Haga, Yoshinori; Homma, Yoshiya*; Aoki, Dai*; Nakajima, Kunihisa; Arai, Yasuo; Matsuda, Tatsuma; Ikeda, Shugo*; Sakai, Hironori; Yamamoto, Etsuji; Nakamura, Akio; et al.
Journal of the Physical Society of Japan, 81(Suppl.B), p.SB007_1 - SB007_4, 2012/12
Nakamura, Toshiyuki*; Matsuda, Yasuhiro*; Her, J.-L.*; Kindo, Koichi*; Michimura, Shinji*; Inami, Toshiya; Mizumaki, Masaichiro*; Kawamura, Naomi*; Suzuki, Motohiro*; Chen, B.*; et al.
Journal of the Physical Society of Japan, 81(11), p.114702_1 - 114702_11, 2012/11
The X-ray absorption and magnetic circular dichroism (MCD) spectra at the Yb L edge were measured in the mixed-valent heavy fermion compound YbAgCu at high magnetic fields and low temperatures. The magnetic-field-temperature (H-T) phase boundary determined by the valence state is in very good agreement with that determined by the magnetization. It is clearly found that the metamagnetism of this compound is due to the field induced valence transition. A distinctive positive peak of the XMCD spectra appears in the vicinity of the white line of the absorption due to Yb state, while no feature is observed in the XMCD spectra corresponding to the Yb state. A small negative XMCD peak was observed at a lower energy and was attributed to the quadrupole trasition from theoretical calcuration, which explains its peculicar magnetic field dependence.
Nakamura, Akio; Imai, Kazutaka*; Igawa, Naoki; Okamoto, Yoshihiro; Yamamoto, Etsuji; Matsukawa, Shiro*; Takahashi, Masashi*
Hyperfine Interactions, 207(1-3), p.67 - 71, 2012/03
Nagao, Keisuke*; Okazaki, Ryuji*; Nakamura, Tomoki*; Miura, Yayoi*; Osawa, Takahito; Bajo, Kenichi*; Matsuda, Shintaro*; Ebihara, Mitsuru*; Ireland, T.*; Kitajima, Fumio*; et al.
Science, 333(6046), p.1128 - 1131, 2011/08
A steroid surface materials record regolith processes and a history of cosmic-ray irradiation. Noble gas isotopes in three rocky grains from Itokawa have been determined. High concentrations of solar He, Ne, and Ar, as high as those in lunar soils, are released at variable temperatures from each sample. The isotopic compositions are essentially identical to those of solar wind but distinguishable in He relative abundance. These noble gas characteristics can be explained by repeated implantation and preferential loss of solar He by removal of weathered He-rich rim on the grain surface through friction among regolith grains on Itokawa. Residence time of regolith materials on Itokawa is alculated to be shorter than 10 Myr, suggesting that regolith materials of small asteroids would escape easily to space.
Haga, Yoshinori; Aoki, Dai*; Homma, Yoshiya*; Matsuda, Tatsuma; Ikeda, Shugo*; Sakai, Hironori; Yamamoto, Etsuji; Nakamura, Akio; Shiokawa, Yoshinobu*; Onuki, Yoshichika
Journal of the Physical Society of Japan, 80(Suppl.A), p.SA109_1 - SA109_3, 2011/07
Solid State Ionics, 181(37-38), p.1631 - 1653, 2010/12
Solid State Ionics, 181(35-36), p.1543 - 1564, 2010/11
Yoshii, Kenji; Hiramitsu, Yusuke*; Okajima, Yuka*; Yoneda, Yasuhiro; Nishihata, Yasuo; Mizuki, Junichiro; Nakamura, Akio; Shimojo, Yutaka; Ishii, Yoshinobu*; Morii, Yukio; et al.
Materials Research Bulletin, 45(11), p.1574 - 1580, 2010/10
Magnetic and dielectric properties of perovskite manganites RSrMnO (R = Gd, Tb and Dy) have been investigated. DC and AC magnetic measurements showed short-range glassy magnetic ordering at Tg about 40 K. Such ordering was observed by neutron diffraction and is ascribable to the size mismatch of R and Sr settled randomly at the same crystallographic site. Dielectric constants for each material were about 1000-10000 between about 50 K and 300 K and showed broad maximums above Tg. Dielectric dispersion showed poor coherency of the motion of polar regions, plausibly because of the size-mismatch effect; both the magnetic and dielectric properties of this system are governed by the randomness at the R/Sr site. The tan and EXAFS data suggest that the dielectric response is rooted in a transfer of the Mn-3d electrons.
Haga, Yoshinori; Homma, Yoshiya*; Aoki, Dai*; Ikeda, Shugo*; Matsuda, Tatsuma; Tateiwa, Naoyuki; Yamamoto, Etsuji; Nakamura, Akio; Nakajima, Kenji; Arai, Yasuo; et al.
IOP Conference Series; Materials Science and Engineering, 9, p.012046_1 - 012046_7, 2010/05
Onuki, Yoshichika; Settai, Rikio*; Honda, Fuminori*; Dung, N. D.*; Ishikura, Tatsuro*; Takeuchi, Tetsuya*; Matsuda, Tatsuma; Tateiwa, Naoyuki; Nakamura, Akio; Yamamoto, Etsuji; et al.
Physica B; Condensed Matter, 405(9), p.2194 - 2199, 2010/05
Ikeda, Shugo*; Sakai, Hironori; Tateiwa, Naoyuki; Matsuda, Tatsuma; Aoki, Dai*; Homma, Yoshiya*; Yamamoto, Etsuji; Nakamura, Akio; Shiokawa, Yoshinobu*; Ota, Yuki*; et al.
Journal of the Physical Society of Japan, 78(11), p.114704_1 - 114704_10, 2009/11
Okane, Tetsuo; Okochi, Takuo*; Inami, Toshiya; Takeda, Yukiharu; Fujimori, Shinichi; Kawamura, Naomi*; Suzuki, Motohiro*; Tsutsui, Satoshi*; Yamagami, Hiroshi; Fujimori, Atsushi; et al.
Physical Review B, 80(10), p.104419_1 - 104419_7, 2009/09
Kambe, Shinsaku; Sakai, Hironori; Tokunaga, Yo; Chudo, Hiroyuki; Yasuoka, Hiroshi; Matsuda, Tatsuma; Haga, Yoshinori; Ikeda, Shugo; Nakamura, Akio; Yamamoto, Etsuji; et al.
Journal of Nuclear Materials, 385(1), p.1 - 3, 2009/03
In 5f-electron systems, exotic magnetism and unconventional superconductivity appear at low temperatures owing to strong electron correlations and orbital degeneracy. For example, we have investigated the unconventional superconducting states of recently synthesized NpPdAl (=5K) and PuRhGa (=9K) in terms of both macroscopic (staticsusceptibility, specific heat, resistivity) and microscopic (NMR) probes. The relation between magnetic fluctuations and unconventional superconductivity in f-electron systems is also discussed. Another exciting topic concerns the series AnO (An; U, Np, Pu, Am). Besides the importance of AnO as a nuclear fuel, the magnetic properties of these compounds at low temperatures are particularly interesting. On the basis of O-NMR studies, multipolar ordered states have been identified in UO (dipolar + quadrupolar ordering) and NpO (quadrupolar + octupolar ordering), in contrast with the non-magnetic ground state of PuO.
Haga, Yoshinori; Aoki, Dai*; Homma, Yoshiya*; Ikeda, Shugo; Matsuda, Tatsuma; Yamamoto, Etsuji; Sakai, Hironori; Tateiwa, Naoyuki; Dung, N. D.*; Nakamura, Akio; et al.
Journal of Alloys and Compounds, 464(1-2), p.47 - 50, 2008/09