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Takechi, Manabu; Matsunaga, Go; Sakurai, Shinji; Sasajima, Tadayuki; Yagyu, Junichi; Hoshi, Ryo*; Kawamata, Yoichi; Kurihara, Kenichi; JT-60SA Team; Nishikawa, T.*; et al.
Fusion Engineering and Design, 96-97, p.985 - 988, 2015/10
Times Cited Count:10 Percentile:64.26(Nuclear Science & Technology)Nishiyama, Tomokazu; Yagyu, Junichi; Nakamura, Shigetoshi; Masaki, Kei; Okano, Fuminori; Sakasai, Akira
Heisei-26-Nendo Hokkaido Daigaku Sogo Gijutsu Kenkyukai Hokokushu (DVD-ROM), 6 Pages, 2014/09
no abstracts in English
Suzuki, Sadaaki; Yagyu, Junichi; Masaki, Kei; Nishiyama, Tomokazu; Nakamura, Shigetoshi; Saeki, Hisashi; Hoshi, Ryo; Sawai, Hiroaki; Hasegawa, Koichi; Arai, Takashi; et al.
NIFS-MEMO-67, p.266 - 271, 2014/02
no abstracts in English
Okano, Fuminori; Masaki, Kei; Yagyu, Junichi; Shibama, Yusuke; Sakasai, Akira; Miyo, Yasuhiko; Kaminaga, Atsushi; Nishiyama, Tomokazu; Suzuki, Sadaaki; Nakamura, Shigetoshi; et al.
JAEA-Technology 2013-032, 32 Pages, 2013/11
Japan Atomic Energy Agency started to construct a fully superconducting tokamak experiment device, JT-60SA, to support the ITER since January, 2013 at the Fusion Research and Development Directorate in Naka, Japan. The JT-60SA will be constructed with enhancing the previous JT-60 infrastructures, in the JT-60 torus hall, where the ex-JT-60 machine was disassembled. The JT-60SA Cryostat Base, for base of the entire tokamak structure, were assembly as first step of this construction. The Cryostat Base (CB, 250 tons) is consists of 7 main made of stainless steel, 12m diameter and 3m height. It was built in the Spain and transported to the Naka site with the seven major parts split, via Hitachi port. The assembly work of these steps, preliminary measurements, sole plate adjustments of its height and flatness, and assembly of the CB. Introduces the concrete result of assembly work and transport of JT-60SA cryostat base.
Kiyanagi, Yoshiaki*; Kino, Koichi*; Furusaka, Michihiro*; Hiraga, Fujio*; Kamiyama, Takashi*; Kato, Kiyoshi*; Igashira, Masayuki*; Katabuchi, Tatsuya*; Mizumoto, Motoharu*; Oshima, Masumi; et al.
Journal of the Korean Physical Society, 59(2), p.1781 - 1784, 2011/08
Times Cited Count:13 Percentile:62.11(Physics, Multidisciplinary)The project of the comprehensive nuclear data research for the development of the advanced reactor systems had been executed successfully by eight organizations from 2005 to 2009. In this project, we constructed the pulsed neutron beamline that was aimed to obtain neutron capture cross-sections of long-lived fission products and minor actinides accurately. The energy spectra, spatial distributions, and pulses of the beam were studied by measurements and simulation calculations, and they were found to be consistent with those of the beamline design. In this paper, we present the overview of the project and the properties of the neutron beam provided by this beam line.
Fukuda, Tatsuo; Baron, A. Q. R.*; Nakamura, Hiroki; Shamoto, Shinichi; Ishikado, Motoyuki; Machida, Masahiko; Uchiyama, Hiroshi*; Iyo, Akira*; Kito, Hijiri*; Mizuki, Junichiro; et al.
Physical Review B, 84(6), p.064504_1 - 064504_13, 2011/08
Times Cited Count:9 Percentile:39.24(Materials Science, Multidisciplinary)Fukuda, Tatsuo; Baron, A. Q. R.*; Nakamura, Hiroki; Shamoto, Shinichi; Ishikado, Motoyuki; Machida, Masahiko; Uchiyama, Hiroshi*; Iyo, Akira*; Kito, Hijiri*; Mizuki, Junichiro; et al.
Journal of the Physical Society of Japan, 80(Suppl.B), p.SB015_1 - SB015_4, 2011/01
Times Cited Count:1 Percentile:11.3(Physics, Multidisciplinary)We have investigated phonons of PrFeAsO using high-resolution inelastic X-ray scattering and calculations. Extensive measurements show that there are some changes in phonon spectra with temperature and/or doping. However, we compare our data with several calculations and find that the experimentally observed changes are much smaller than differences between the experiment. data and the calculations. Agreement is improved if magnetism is included in the calculations. However, still in disagreement even in the parent sample below T. We consider several modifications of the calculations. The best agreement is obtained from modifying the nonmagnetic calculation. by softening only the in-plane nearest-neighbor Fe-As force constant. Fluctuating magnetism may be a partial explanation for the failure of the calculations, but seems incomplete in the face of the similarity of the measured phonon response in all the systems investigated including those known to have static magnetism.
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
Times Cited Count:12 Percentile:37.13(Materials Science, Multidisciplinary)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.
Fukuda, Tatsuo; Baron, A. Q. R.*; Shamoto, Shinichi; Ishikado, Motoyuki; Nakamura, Hiroki; Machida, Masahiko; Uchiyama, Hiroshi*; Tsutsui, Satoshi*; Iyo, Akira*; Kito, Hijiri*; et al.
Journal of the Physical Society of Japan, 77(10), p.103715_1 - 103715_4, 2008/10
Times Cited Count:42 Percentile:83.16(Physics, Multidisciplinary)The lattice dynamics of LaFeAsOF (=0, 0.1) and PrFeAsO (0.1) are investigated using inelastic X-ray scattering. Measurements of powder samples provide an approximation to the phonon DOS, while dispersion is measured from a single crystal of PrFeAsO. A model that agrees reasonably well with all of the data at room temperature is built from results of ab-initio calculations by reducing the strength of the Fe-As bond by 30%.
Hiramitsu, Yusuke*; Yoshii, Kenji; Yoneda, Yasuhiro; Mizuki, Junichiro; Nakamura, Akio; Shimojo, Yutaka; Ishii, Yoshinobu*; Morii, Yukio; Ikeda, Naoshi*
Japanese Journal of Applied Physics, Part 1, 46(10B), p.7171 - 7174, 2007/10
Times Cited Count:16 Percentile:53.11(Physics, Applied)Magnetic and dielectric properties of a perivskite manganite TbCaMnO were investigated. Magnetic measurements showed three characteristic temperatures, originating from charge ordering (300 K), antiferromagnetic ordering (120 K) and a transition to a glassy state (50 K). The coexistence of the charge and antiferromagnetic ordering was consistent with the result of powder neutron diffraction. AC dielectric measurements showed large dielectric constants of about 5000 at around room temperature. A temperature dependence of the dielectric constant changed just below the charge-ordering temperature. From the analysis of tan;, the activation energy for a domain-boundary motion was calculated to be about 0.09 eV. These results strongly suggest that the dielectric properties of this material are governed by the ordering and transfer of the Mn-3d charges.
Kuroda, Yoshikatsu*; Nakajima, Atsushi*; Ogata, Junji*; Nakamura, Junichi*; Asada, Kazuo*; Hayashi, Tetsuya*; Obata, Yuji*
PNC TJ8216 98-006, 499 Pages, 1998/03
no abstracts in English
Hayashi, Hirokazu; *; *; *
Journal of Non-Crystalline Solids, 242(1), p.33 - 39, 1998/00
Times Cited Count:2 Percentile:25.37(Materials Science, Ceramics)no abstracts in English
Saido, Masahiro; Ogiwara, Norio; Shimada, Michiya; Arai, Takashi; Hiratsuka, Hajime; ; Shimizu, Masatsugu; Ninomiya, Hiromasa; Nakamura, Hiroo; *; et al.
Japanese Journal of Applied Physics, 32(7), p.3276 - 3281, 1993/07
Times Cited Count:57 Percentile:90.94(Physics, Applied)no abstracts in English
Sumita, Kenji*; *; Kakuta, Tsunemi; *; *; ; *
Nihon Genshiryoku Gakkai-Shi, 30(10), p.870 - 875, 1988/10
Times Cited Count:0 Percentile:0.02(Nuclear Science & Technology)no abstracts in English
; Sumita, Kenji*; *; *; Kakuta, Tsunemi; *; *
EIM-87-143, p.55 - 62, 1987/00
no abstracts in English
; ; Watanabe, Norio; *; *; *
JAERI-M 83-037, 96 Pages, 1983/03
no abstracts in English
Fukuda, Tatsuo; Baron, A. Q. R.*; Shamoto, Shinichi; Ishikado, Motoyuki; Nakamura, Hiroki; Machida, Masahiko; Uchiyama, Hiroshi*; Tsutsui, Satoshi*; Iyo, Akira*; Kito, Hijiri*; et al.
no journal, ,
We studied the lattice dynamics of powders, LaFeAsOF (=0, 0.1) and PrFeAsO (0.4), and a single crystal, PrFeAsO (0.1), using inelastic X-ray scattering. The third peak in phonon density of states are found to be softened by 5 meV compared with ab-initio calculations. A model that agrees reasonably well with all of the data is built from results of ab-initio calculations by reducing the strength of the Fe-As bond by 30%.
Fukuda, Tatsuo; Baron, A. Q. R.*; Shamoto, Shinichi; Uchiyama, Hiroshi*; Ishikado, Motoyuki; Nakamura, Hiroki; Machida, Masahiko; Mizuki, Junichiro; Arai, Masatoshi; Iyo, Akira*; et al.
no journal, ,
Recently discovered iron-arsenide new superconductor has attracted considerable attraction. Within a few months the transition temperature () exceeded 50 K in some related compounds, and the possible novel physics as well as higher- are expected. At the early stage, calculations of phonon properties appeared and suggested that the superconductivity in these materials are not phonon mediated. However, the experimental verification is crucial. We carried out inelastic X-ray scattering on some powder as well as single samples, and found pronounced softening of the Fe-As modes compared to LDA-based phonon calculations. However, further investigation on single crystals showed the spectra are found to agree much better with calculations of the magnetic parent material, which has orthorhombic symmetry, than those using a tetragonal structure like the real superconducting compounds.
Fukuda, Tatsuo; Baron, A. Q. R.*; Shamoto, Shinichi; Ishikado, Motoyuki; Nakamura, Hiroki; Machida, Masahiko; Uchiyama, Hiroshi*; Iyo, Akira*; Kito, Hijiri*; Mizuki, Junichiro; et al.
no journal, ,
Fukuda, Tatsuo; Baron, A. Q. R.*; Shamoto, Shinichi; Ishikado, Motoyuki; Nakamura, Hiroki; Machida, Masahiko; Uchiyama, Hiroshi*; Iyo, Akira*; Kito, Hijiri*; Mizuki, Junichiro; et al.
no journal, ,