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VAl probed by soft X-ray spectroscopiesNagai, Kodai*; Fujiwara, Hidenori*; Aratani, Hidekazu*; Fujioka, Shuhei*; Yomosa, Hiroshi*; Nakatani, Yasuhiro*; Kiss, Takayuki*; Sekiyama, Akira*; Kuroda, Fumiaki*; Fujii, Hitoshi*; et al.
Physical Review B, 97(3), p.035143_1 - 035143_8, 2018/01
Times Cited Count：22 Percentile：70.74(Materials Science, Multidisciplinary)We have studied the electronic structure of ferrimagnetic MnVAl single crystals by means of soft X-ray absorption spectroscopy (XAS), X-ray absorption magnetic circular dichroism (XMCD), and resonant soft X-ray inelastic scattering (RIXS). We have successfully observed the XMCD signals for all the constituent elements. The Mn L
XAS and XMCD spectra are reproduced by spectral simulations based on density-functional theory, indicating the itinerant character of the Mn 3
states. On the other hand, the V 3 electrons are rather localized since the ionic model can qualitatively explain the V L XAS and XMCD spectra. This picture is consistent with local 
excitations revealed by the V L
RIXS.
Nakajima, Kenji; Kawakita, Yukinobu; Ito, Shinichi*; Abe, Jun*; Aizawa, Kazuya; Aoki, Hiroyuki; Endo, Hitoshi*; Fujita, Masaki*; Funakoshi, Kenichi*; Gong, W.*; et al.
Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12
The neutron instruments suite, installed at the spallation neutron source of the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC), is reviewed. MLF has 23 neutron beam ports and 21 instruments are in operation for user programs or are under commissioning. A unique and challenging instrumental suite in MLF has been realized via combination of a high-performance neutron source, optimized for neutron scattering, and unique instruments using cutting-edge technologies. All instruments are/will serve in world-leading investigations in a broad range of fields, from fundamental physics to industrial applications. In this review, overviews, characteristic features, and typical applications of the individual instruments are mentioned.
Sekine, Yurina; Endo, Hitoshi*; Iwase, Hiroki*; Takeda, Shigeo*; Mukai, Sadaatsu*; Fukazawa, Hiroshi; Littrell, K. C.*; Sasaki, Yoshihiro*; Akiyoshi, Kazunari*
Journal of Physical Chemistry B, 120(46), p.11996 - 12002, 2016/11
Times Cited Count：11 Percentile：29.12(Chemistry, Physical)The detailed structure of a nanogel formed by self-association of cholesterol-bearing pullulans (CHP) was determined by contrast variation small-angle neutron scattering. The decomposition of scattering intensities into partial scattering functions of each CHP nanogel component, i.e., pullulan, cholesterol, and the cross-term between the pullulan and the cholesterol allows us to investigate the internal structure of the nanogel. The effective spherical radius of the skeleton formed by pullulan chains was found to be about 8.1 nm. In the CHP nanogel, there are about 19 cross-linking points where a cross-linking point is formed by aggregation of trimer cholesterol molecules with the spatially inhomogeneous distribution of the mass fractal dimension of 2.6. The average radius of the partial chains can also be determined to be 1.7 nm. As the result, the complex structure of the nanogels is coherently revealed at the nanoscopical level.
Fujimori, Shinichi; Okochi, Takuo*; Kawasaki, Ikuto; Yasui, Akira; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Fujimori, Atsushi; Yamagami, Hiroshi; Haga, Yoshinori; et al.
Journal of the Physical Society of Japan, 81(1), p.014703_1 - 014703_9, 2012/01
Times Cited Count：37 Percentile：81.99(Physics, Multidisciplinary)High-energy-resolution core-level and valence-band photoelectron spectroscopic studies were performed for the heavy Fermion uranium compounds UGe
, UCoGe, URhGe, URuSi, UNiAl
, UPdAl, and UPt as well as typical localized and itinerant uranium compounds to understand the relationship between the uranium valence state and their core-level spectral line shapes. The core-level spectra of UGe, UCoGe, URhGe, URuSi, and UNiAl are rather similar to those of itinerant compounds, suggesting that U 5
electrons in these compounds are well hybridized with ligand states. On the other hand, the core-level spectra of UPdAl and UPt show considerably different spectral line shapes from those of the itinerant compounds, suggesting that U 5 electrons in UPdAl and UPt are less hybridized with ligand states, leading to the correlated nature of U 5 electrons in these compounds.
studied by photoemission and soft X-ray absorption spectroscopiesUtsumi, Yuki*; Sato, Hitoshi*; Kurihara, Hidenao*; Maso, Hiroyuki*; Hiraoka, Koichi*; Kojima, Kenichi*; Tobimatsu, Komei*; Okochi, Takuo*; Fujimori, Shinichi; Takeda, Yukiharu; et al.
Physical Review B, 84(11), p.115143_1 - 115143_7, 2011/09
Times Cited Count：11 Percentile：44.43(Materials Science, Multidisciplinary)We have studied conduction-band (CB) electronic states of a typical valence-transition compound YbInCu by means of temperature-dependent hard X-ray photoemission spectroscopy (HX-PES), soft X-ray absorption spectroscopy (XAS), and soft X-ray photoemission spectroscopy (SX-PES) of the valence band. We have described the valence transition in YbInCu in terms of the charge transfer from the CB to Yb 4 states.
Co
OKobayashi, Masaki*; Ishida, Yukiaki*; Hwang, J. I.*; Osafune, Yoshitaka*; Fujimori, Atsushi*; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Kobayashi, Keisuke*; Saeki, Hiromasa*; et al.
Physical Review B, 81(7), p.075204_1 - 075204_7, 2010/02
Times Cited Count：19 Percentile：61.65(Materials Science, Multidisciplinary)Kobayashi, Masaki*; Song, G.-S.*; Kataoka, Takashi*; Sakamoto, Yuta*; Fujimori, Atsushi; Okochi, Takuo*; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Yamagami, Hiroshi; et al.
Journal of Applied Physics, 105(12), p.122403_1 - 122403_4, 2009/06
Times Cited Count：12 Percentile：44.75(Physics, Applied)Takeda, Tetsuaki*; Ichimiya, Koichi*; Nishio, Hitoshi*; Nakagawa, Shigeaki; Takamatsu, Kuniyoshi
Proceedings of 7th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, Operation and Safety (NUTHOS-7) (CD-ROM), 11 Pages, 2008/10
Safety demonstration tests using the HTTR (High Temperature Engineering Test Reactor) are being performed to verify the inherent safety features and to validate the numerical code for the safety assessment of the VHTR (Very High Temperature Reactor). The partial loss of coolant flow test was performed under the condition of the ATWS (Anticipated Transient without Scram). We are planning to perform the test of loss of coolant flow and stopping the vessel cooling system (VCS). The test of the loss of coolant flow as one of safety demonstration tests is carried out by tripping all gas circulators, and the stopping VCS test is performed continuously after the loss of coolant flow. The objective of this study is to evaluate the temperature distribution of the reactor pressure vessel (RPV) and the VCS during the tests. It is necessary to consider the effect of thermal radiation from the RPV for evaluation of temperature of the VCS and concrete vessel.
O thin films exhibiting photoinduced magnetizationKobayashi, Masaki*; Oki, Yasuhiro*; Takizawa, Masaru*; Song, G. S.*; Fujimori, Atsushi; Takeda, Yukiharu; Terai, Kota*; Okane, Tetsuo; Fujimori, Shinichi; Saito, Yuji; et al.
Applied Physics Letters, 92(8), p.082502_1 - 082502_3, 2008/02
Times Cited Count：12 Percentile：44.45(Physics, Applied)V
O thin filmIshida, Yukiaki*; Hwang, J. I.*; Kobayashi, Masaki*; Takeda, Yukiharu; Mamiya, Kazutoshi*; Okamoto, Jun*; Fujimori, Shinichi; Okane, Tetsuo; Terai, Kota*; Saito, Yuji; et al.
Applied Physics Letters, 90(2), p.022510_1 - 022510_3, 2007/01
Times Cited Count：23 Percentile：64.06(Physics, Applied)no abstracts in English
CoO by X-ray magnetic circular dichroismKobayashi, Masaki*; Ishida, Yukiaki*; Hwang, J. I.*; Mizokawa, Takashi*; Fujimori, Atsushi*; Mamiya, Kazutoshi*; Okamoto, Jun*; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; et al.
Physical Review B, 72(20), p.201201_1 - 201201_4, 2005/11
Times Cited Count：140 Percentile：96.02(Materials Science, Multidisciplinary)no abstracts in English
Kawata, Tomio; Takeda, Seietsu; ; Kamei, Gento; Makino, Hitoshi
JNC TN1400 2001-017, 50 Pages, 2002/01
JNC-TN1400-2001-017.pdf:5.59MB
no abstracts in English
Ouchi, Nobuo; Kusano, Joichi; Akaoka, Nobuo*; Mizumoto, Motoharu; Inoue, Hitoshi*; Noguchi, Shuichi*; Saito, Kenji*; Takeda, O.*; Murai, T.*; Kijima, Y.*; et al.
KEK Proceedings 99-25, p.33 - 37, 2000/02
no abstracts in English
Ouchi, Nobuo; Mizumoto, Motoharu; Kusano, Joichi; Chishiro, Etsuji; Hasegawa, Kazuo; Akaoka, Nobuo*; Saito, Kenji*; Noguchi, Shuichi*; Kako, Eiji*; Inoue, Hitoshi*; et al.
Proceedings of 20th International Linac Conference (CD-ROM), 1 Pages, 2000/00
no abstracts in English
Kusano, Joichi; Ouchi, Nobuo; Akaoka, Nobuo*; Takeda, O.*; Matsuoka, Masanori*; Saito, Kenji*; Noguchi, Shuichi*; Inoue, Hitoshi*; Mukugi, Ken*; Mizumoto, Motoharu
Proceedings of 25th Linear Accelerator Meeting in Japan, p.317 - 319, 2000/00
no abstracts in English
Kusano, Joichi; Ouchi, Nobuo; Akaoka, Nobuo*; Tomisawa, Tetsuo; Takeuchi, Suehiro; Mizumoto, Motoharu; Noguchi, Shuichi*; Saito, Kenji*; Inoue, Hitoshi*; *; et al.
Proceedings of 23rd Linear Accelerator Meeting in Japan, p.124 - 126, 1998/00
no abstracts in English
Yui, Mikazu; Takeda, Seietsu; Komuro, Kosei*; Makino, Hitoshi; ; ; Ishiguro, Katsuhiko
PNC TN8410 92-166, 174 Pages, 1992/09
None
Takeda, Tetsuaki; Tochio, Daisuke; Inaba, Yoshitomo; Ichimiya, Koichi*; Nishio, Hitoshi*
no journal, ,
Safety demonstration tests using the HTTR (High Temperature Engineering Test Reactor) are being performed to verify the inherent safety features and to validate the numerical code for the safety assessment of the VHTR (Very High Temperature Reactor). The test of loss of coolant flow as one of safety demonstration tests is carried out by tripping of the helium gas circulators. The objective of this study is to evaluate the temperature distribution of the reactor pressure vessel (RPV) and the vessel cooling system (VCS) during the loss of coolant flow. The temperature distribution of the RPV and surrounding concrete structure were obtained using a commercially available analysis code STAR-CD. The effect of thermal radiation from the RPV was evaluated using the analytical and experimental results. It was found that it is important to take account of the effect of thermal radiation in the transient analysis to evaluate the temperature change of the concrete accurately.
Takeda, Tetsuaki; Nishio, Hitoshi*; Ichimiya, Koichi*
no journal, ,
Safety demonstration tests using the HTTR (High Temperature Engineering Test Reactor) are being performed to verify the inherent safety features and to validate the numerical code for the safety assessment of the VHTR (Very High Temperature Reactor). The test of loss of coolant flow as one of safety demonstration tests is carried out by tripping of the helium gas circulators. The objective of this study is to evaluate the temperature distribution of the reactor pressure vessel (RPV) and the vessel cooling system (VCS) during the loss of coolant flow. The temperature distribution of the RPV and surrounding concrete structure were obtained using a commercially available analysis code STAR-CD. The effect of thermal radiation from the RPV was evaluated using the analytical and experimental results. It was found that the RPV and surrounding concrete structure were cooled enough by the VCS in the case of loss of coolant flow.
Takeda, Tetsuaki; Nishio, Hitoshi*; Ichimiya, Koichi*
no journal, ,
Safety demonstration tests using the HTTR (High Temperature Engineering Test Reactor) are being performed to verify the inherent safety features and to validate the numerical code for the safety assessment of the VHTR (Very High Temperature Reactor). The test of loss of coolant flow as one of safety demonstration tests is carried out by tripping of the helium gas circulators. The objective of this study is to evaluate the temperature distribution of the reactor pressure vessel (RPV) and the vessel cooling system (VCS) during the loss of coolant flow. The temperature distribution of the RPV and surrounding concrete structure were obtained using a commercially available analysis code STAR-CD. It is necessary to consider the effect of thermal radiation from the RPV for evaluation of temperature of the VCS and concrete vessel.
