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Fe and 
Co nuclear magnetic resonance studiesSakai, Hironori; Hattori, Taisuke; Tokunaga, Yo; Kambe, Shinsaku; Ueda, Hiroaki*; Tanioku, Yasuaki*; Michioka, Chishiro*; Yoshimura, Kazuyoshi*; Takao, Kenta*; Shimoda, Aiko*; et al.
Physical Review B, 98(6), p.064403_1 - 064403_10, 2018/08
Times Cited Count：10 Percentile：45.99(Materials Science, Multidisciplinary)To specify preferential occupation sites of Co substituents and to clarify charge and spin states of Co ions in (La, Co)-cosubstituted hexagonal magnetoplumbite-type (M-type) Sr ferrite, Fe and Co nuclear magnetic resonance (NMR) spectra are measured under zero and external magnetic fields using powdered and single crystalline specimens. To a considerable degree, the charge compensation between La
and Co
works in the equal (La, Co)-codoped case, where more than half of the Co ions are considered to be present in the minority spin 
sites at the center of the oxygen tetrahedra, with the 
= 3/2 state carrying a small orbital moment owing to spin-orbit interaction. The remaining small number of high-spin Co ( = 3/2, 
= 1) ions with unquenched orbital moments would be distributed to the other octahedral 
, 
, and 
sites.
Imai, Masaki; Michioka, Chishiro*; Ueda, Hiroaki*; Yoshimura, Kazuyoshi*
Physical Review B, 95(5), p.054417_1 - 054414_7, 2017/02
Times Cited Count：2 Percentile：11.52(Materials Science, Multidisciplinary)We took 
P NMR measurements of mainly paramagnetic phase to reveal the itinerant-electron metamagnetic transition, and of its magnetically ordered phase, and characterized their spin fluctuations by estimating the spin fluctuation parameter 
corresponding to the width of the spin fluctuation in the spectrum in frequency space. As 
increases from 0 to 0.5, the in-plane component of decreases proportionally with the metamagnetic transition field. In the antiferromagnetic cT phase, is constant and spin fluctuations show an isotropic character in contrast to their behavior in the paramagnetic ucT phase. These results indicate that the in-plane spin fluctuations due to the quasi-two-dimensional crystal structure play a significant role in the metamagnetic transition of this system.
O
Tomiyasu, Keisuke*; Iwasa, Kazuaki*; Ueda, Hiroaki*; Niitaka, Seiji*; Takagi, Hidenori*; Kawamura, Seiko; Kikuchi, Tatsuya; Inamura, Yasuhiro; Nakajima, Kenji; Yamada, Kazuyoshi*
Physical Review Letters, 113(23), p.236402_1 - 236402_5, 2014/12
Times Cited Count：16 Percentile：68.53(Physics, Multidisciplinary)Spin fluctuations were studied over a wide momentum (
) and energy (
) space in the frustrated 
-electron heavy-fermion metal LiVO by time-of-flight inelastic neutron scattering. We observed the overall 
evolutions near the characteristic 
= 0.6 
peak and found another weak broad magnetic peak around 2.4 . The data are described by a simple response function, a partially delocalized magnetic form factor, and antiferromagnetic short-range spatial correlations, indicating that heavy-fermion formation is attributable to spin-orbit fluctuations with orbital hybridization.
Hiyama, Kazuhisa; Hanawa, Nobuhiro; Kurosawa, Akihiko; Eguchi, Shohei; Hori, Naohiko; Kusunoki, Tsuyoshi; Ueda, Hisao; Shimada, Hiroshi; Kanda, Hiroaki*; Saito, Isamu*
JAEA-Technology 2013-045, 32 Pages, 2014/02
JAEA-Technology-2013-045.pdf:5.83MB
This report summarizes regarding to develop of real-time multifunctional access control system which is able to manage worker's access control and exposure dose at real-time in the reactor building, besides worker's location and worker might be fall down by accident.
Ueda, Yoshio*; Oya, Kaoru*; Ashikawa, Naoko*; Ito, Atsushi*; Ono, Tadayoshi*; Kato, Daiji*; Kawashima, Hisato; Kawamura, Gakushi*; Kenmotsu, Takahiro*; Saito, Seiki*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 88(9), p.484 - 502, 2012/09
no abstracts in English
Matsueda, Hiroaki*; Sota, Shigetoshi*; Toyama, Takami*; Maekawa, Sadamichi
Journal of the Physical Society of Japan, 81(1), p.013701_1 - 013701_4, 2012/01
Times Cited Count：39 Percentile：82.98(Physics, Multidisciplinary)Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Matsuda, Masaaki; Oyama, Kenji*; Yoshii, Shunsuke*; Nojiri, Hiroyuki*; Frings, P.*; Duc, F.*; Vignolle, B.*; Rikken, G. L. J. A.*; Regnault, L.-P.*; Lee, S.-H.*; et al.
Physical Review Letters, 104(4), p.047201_1 - 047201_4, 2010/01
Times Cited Count：28 Percentile：77.3(Physics, Multidisciplinary)Nishihara, Katsunobu*; Sunahara, Atsushi*; Sasaki, Akira; Nunami, Masanori*; Tanuma, Hajime*; Fujioka, Shinsuke*; Shimada, Yoshinori*; Fujima, Kazumi*; Furukawa, Hiroyuki*; Kato, Takako*; et al.
Physics of Plasmas, 15(5), p.056708_1 - 056708_11, 2008/00
Times Cited Count：122 Percentile：97.46(Physics, Fluids & Plasmas)OMatsuda, Masaaki; Ueda, Hiroaki*; Kikkawa, Akiko*; Tanaka, Yoshikazu*; Katsumata, Koichi*; Narumi, Yasuo*; Inami, Toshiya; Ueda, Yutaka*; Lee, S.-H.*
Nature Physics, 3(6), p.397 - 400, 2007/06
Times Cited Count：104 Percentile：93.31(Physics, Multidisciplinary)Cr-CrCr-based spinel compounds ACrO (A=Mg, Zn, Cd, and Hg) are so far the best model systems for a network of corner-sharing tetrahedrons with isotropic nearest-neighbor antiferromagnetic interactions. The systems exhibit novel spin-Peierls phase transitions from cubic spin liquid to non-cubic N
el states at low temperatures. Recent bulk magnetization studies on CdCrO and HgCrO revealed the magnetic field-induced half magnetization plateau states that are stable over a wide range of field. Recent bulk magnetization studies on CdCrO and HgCrO revealed the magnetic field-induced half magnetization plateau states that are stable over a wide range of field.
O
Matsuda, Masaaki; Takeda, Masayasu; Nakamura, Mitsutaka; Kakurai, Kazuhisa; Osawa, Akira*; Leli
vre-Berna, E.*; Chung, J.-H.*; Ueda, Hiroaki*; Takagi, Hidenori*; Lee, S.-H.*
Physical Review B, 75(10), p.104415_1 - 104415_6, 2007/03
Times Cited Count：43 Percentile：81.73(Materials Science, Multidisciplinary)A frustrated spinel CdCrO undergoes a three-dimensional spin-Peierls transition at 
= 7.8 K from a cubic paramagnetic to a tetragonal Nel state. The Nel state has a spiral magnetic structure with a characteristic wave vector of 
when the 
axis elongated. Here we report our spherical neutron polarimetry experiments to investigate the spiral spin structure in detail. Our results indicate that the spins lie in the 
plane perpendicular to the direction of the spiral modulation. We also found that the spiral structure in the plane is elliptical with the -component larger by 
24% than the 
-component, suggesting a strong coupling between the magnetic structure and structural distortion. Unpolarized neutron diffraction under an external magnetic field has also been performed. The magnetic field dependence suggests existence of magnetic anisotropy in the Nel state, which is consistent with our previous inelastic studies.
Okuno, Tomoharu*; Fujioka, Shinsuke*; Nishimura, Hiroaki*; Tao, Y.*; Nagai, Keiji*; Gu, Q.*; Ueda, Nobuyoshi*; Ando, Tsuyoshi*; Nishihara, Katsunobu*; Norimatsu, Takayoshi*; et al.
Applied Physics Letters, 88(16), p.161501_1 - 161501_3, 2006/04
Times Cited Count：64 Percentile：87.58(Physics, Applied)no abstracts in English
O using an X-ray diffraction techniqueInami, Toshiya; Owada, Kenji; Tsubota, Masami; Murata, Yuto*; Matsuda, Yasuhiro*; Nojiri, Hiroyuki*; Ueda, Hiroaki*; Murakami, Yoichi*
Journal of Physics; Conference Series, 51, p.502 - 505, 2006/00
Times Cited Count：16 Percentile：97.58(Physics, Condensed Matter)no abstracts in English
Fujioka, Shinsuke*; Nishimura, Hiroaki*; Nishihara, Katsunobu*; Sasaki, Akira; Sunahara, Atsushi*; Okuno, Tomoharu*; Ueda, Nobuyoshi*; Ando, Tsuyoshi*; Tao, Y.*; Shimada, Yoshinori*; et al.
Physical Review Letters, 95(23), p.235004_1 - 235004_4, 2005/12
Times Cited Count：147 Percentile：95.58(Physics, Multidisciplinary)no abstracts in English
OChung, J.-H.*; Matsuda, Masaaki; Lee, S.-H.*; Kakurai, Kazuhisa; Ueda, Hiroaki*; Sato, Taku*; Takagi, Hidenori*; Hong, K.-P.*; Park, S.*
Physical Review Letters, 95(24), p.247204_1 - 247204_4, 2005/12
Times Cited Count：140 Percentile：95.25(Physics, Multidisciplinary)no abstracts in English
(BO
)Kakurai, Kazuhisa; Nukui, Katsuyuki*; Aso, Naofumi*; Nishi, Masakazu*; Kadowaki, Hiroaki*; Kageyama, Hiroshi*; Ueda, Yutaka*; Regnault, L.-P.*; Cpas, O.*
Progress of Theoretical Physics Supplement, (159), p.22 - 32, 2005/10
no abstracts in English
(BO)Aso, Naofumi*; Kageyama, Hiroshi*; Nukui, Katsuyuki*; Nishi, Masakazu*; Kadowaki, Hiroaki*; Ueda, Yutaka*; Kakurai, Kazuhisa
Journal of the Physical Society of Japan, 74(8), p.2189 - 2192, 2005/08
Times Cited Count：8 Percentile：48.31(Physics, Multidisciplinary)no abstracts in English
Ikeda, Shugo; Matsuda, Tatsuma; Haga, Yoshinori; Yamamoto, Etsuji; Nakashima, Miho*; Kirita, Shingo*; Kobayashi, Tatsuo*; Hedo, Masato*; Uwatoko, Yoshiya*; Yamagami, Hiroshi*; et al.
Journal of the Physical Society of Japan, 74(8), p.2277 - 2281, 2005/08
Times Cited Count：10 Percentile：53.46(Physics, Multidisciplinary)We have succeeded in growing a high-quality single crystal of an antiferromagnet UPdGa by the Ga-flux method with the off-stoichiometric composition of U : Pd : Ga = 1 : 2 : 7.3. The electronic state has been investigated by the de Haas-van Alphen experiment, indicating the similar cylindrical Fermi surfaces as in an antiferromagnet UPtGa. We have also studied the pressure effect by measuring the electrical resistivity. The N
el temperature decreases with increasing pressure and becomes zero at 3.1 GPa. The antiferromagnetic state is changed into the paramagnetic state above 3.1 GPa.
Fukuda, Yuji; Akahane, Yutaka; Aoyama, Makoto; Inoue, Norihiro*; Ueda, Hideki; Nakai, Yoshiki*; Tsuji, Koichi*; Yamakawa, Koichi; Hironaka, Yoichiro*; Kishimura, Hiroaki*; et al.
Applied Physics Letters, 85(21), p.5099 - 5101, 2004/11
Times Cited Count：11 Percentile：42.77(Physics, Applied)We have demonstrated diffraction from Si(111) crystal using X-rays from highly ionized Ar ions produced by laser irradiation with an intensity of 6
10
W/cm
and a pulse duration of 30 fs acting upon micron-sized Ar clusters. The measured total photon flux and line width in the He
line (3.14 keV) were 410
photons/shot/4
sr and 3.7 eV (FWHM), respectively, which is sufficient to utilize as a debris-free light source for time-resolved X-ray diffraction studies.
-process branching at 
W revisedMohr, P.*; Shizuma, Toshiyuki; Ueda, Hiroyasu*; Goko, Shinji*; Makinaga, Ayano*; Hara, Kaoru*; Hayakawa, Takehito; Lui, Y.-W.*; Ogaki, Hideaki*; Utsunomiya, Hiroaki*
Physical Review C, 69(3), p.032801_1 - 032801_4, 2004/03
Times Cited Count：35 Percentile：84.6(Physics, Nuclear)The neutron capture cross section of the unstable s-process branching nucleus W has been derived from experimental data of the inverse 
W(
,n)W photodisintegration taken with monochromatic photon beams from laser Compton scattering. The result of 
mb at 
keV leads to a relatively high effective neutron density in the classical s process of 
. A realistic model for the s process in thermally pulsing AGB stars overestimates the abundance of Os significantly because of the relatively small neutron capture cross section of W.
