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Kihara, Shinji; Amazawa, Hiroya; Sakai, Akihiro; Nakata, Hisakazu; Kugo, Teruhiko; Matsuda, Norihiro; Oizumi, Akito; Sasamoto, Hiroshi; Mitsui, Seiichiro; Miyahara, Kaname
JAEA-Research 2013-033, 320 Pages, 2014/07
JAEA performed decontamination experiments at two test sites that combined a range of buildings and different types of land use, located in Date and Minami Soma municipalities as field pilot projects in order to accumulate knowledge and data for full-scale decontamination activities performed by local governments. In the pilot projects, we established its plan using practical decontamination methods that can be easily implemented, according to decontamination targets (e.g., forests, agricultural land, residential house and roads) at each site. As a result of the decontamination, the average air dose rates were reduced to approximately one half of the values before decontamination.
Matsuda, Yasuhiro*; Her, J.-L.*; Michimura, Shinji*; Inami, Toshiya; Ebihara, Takao*; Amitsuka, Hiroshi*
JPS Conference Proceedings (Internet), 3, p.011044_1 - 011044_6, 2014/06
Synchrotron X-ray absorption spectroscopy of CeRhSi
has been performed in pulsed high magnetic fields of up to 32 T. The Ce valence is slightly larger than 3+ at 5 K and decreases with increasing magnetic above 20 T. The field-induced valence change seems to correspond to the metamagnetic transition in the magnetization process. This phenomena is similar to our previous result on CeRu
Si
and seems to be common in Ce-based heavy fermion compounds.
Matsumura, Takeshi*; Michimura, Shinji*; Inami, Toshiya; Hayashi, Yuya*; Fushiya, Kengo*; Matsuda, Tatsuma*; Higashinaka, Ryuji*; Aoki, Yuji*; Sugawara, Hitoshi*
Physical Review B, 89(16), p.161116_1 - 161116_5, 2014/04
Times Cited Count:15 Percentile:52.66(Materials Science, Multidisciplinary)The antiferromagnetic ordered phase below = 16.5 K and the unresolved intermediate phase between
and
(= 14 K) in SmRu
P
have been studied by resonant and nonresonant X-ray diffraction. In the intermediate phase, nonresonant Thomson scattering with
= (1,0,0) is induced by applying a magnetic field. This phenomena is caused by atomic displacements reflecting the charge order in the
band, as predicted theoretically. Simultaneously, the antiferromagnetic moment of Sm is enhanced along the field direction, which is considered to reflect the staggered ordering of the
-
crystal-field states. The present results show that the orbital-dependent
-
hybridization in association with the nesting instability in the
band gives rise to the unconventional charge order similarly with PrRu
P
and PrFe
P
.
Nakai, Hirohito*; Ebihara, Takao*; Tsutsui, Satoshi*; Mizumaki, Masaichiro*; Kawamura, Naomi*; Michimura, Shinji*; Inami, Toshiya; Nakamura, Toshiyuki*; Kondo, Akihiro*; Kindo, Koichi*; et al.
Journal of the Physical Society of Japan, 82(12), p.124712_1 - 124712_5, 2013/12
Times Cited Count:9 Percentile:52.65(Physics, Multidisciplinary)The temperature and magnetic field dependences of Yb valence were observed in the heavy fermion compoundYbRhSi
by X-ray absorption spectroscopy. The measurements revealed that the Yb valence decreases with decreasing temperature in the range from 200 to 2 K and increases with increasing magnetic field in the range from 0 to 33 T without showing an abrupt change in the Yb valence. The Yb valence is in the range from 2.92 to 2.96 depending on temperature and magnetic field. With respect to the valence being 2.92 at 0 T and 2.93 at 33 T in 2 K, YbRh
Si
is a valence fluctuation compound and does not reach the integer trivalent state at high magnetic field. These results endorse the conventional knowledge that the valence of Yb is very close to the integer value of 3+, decreases with decreasing temperature, and becomes closer to 3+ with increasing magnetic field.
Matsuda, Yasuhiro*; Nakamura, Toshiyuki*; Kuga, Kentaro*; Nakatsuji, Satoru*; Michimura, Shinji*; Inami, Toshiya; Kawamura, Naomi*; Mizumaki, Masaichiro*
Journal of the Korean Physical Society, 62(12), p.1778 - 1781, 2013/06
Times Cited Count:10 Percentile:54.90(Physics, Multidisciplinary)The valence state of Yb ions in - and
-YbAlB
has been investigated by X-ray absorption and emission spectroscopy at temperatures from 2 to 280 K. It is found that the valence gradually increases with increasing temperature toward 3+ and that the characteristic temperature of the valence fluctuations is about 290 K. We also observe a small increase in the Yb valence (
0.002) in
-YbAlB
by a magnetic field of 32 T at 40 K.
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
Times Cited Count:11 Percentile:56.67(Physics, Multidisciplinary)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.
Matsuda, Yasuhiro*; Nakamura, Toshiyuki*; Her, J. L.*; Michimura, Shinji*; Inami, Toshiya; Kindo, Koichi*; Ebihara, Takao*
Physical Review B, 86(4), p.041109_1 - 041109_4, 2012/07
Times Cited Count:9 Percentile:37.03(Materials Science, Multidisciplinary)The valence state of Ce in a typical heavy fermion compound CeRuSi
has been investigated by synchrotron X-ray absorption spectroscopy at 1.8 K in high magnetic fields of up to 40T. The valence was slightly larger than for the pure trivalent state, as expected in heavy fermion compounds, and it decreased toward the trivalent state as the magnetic field was increased. The field-induced valence reduction indicates that the itinerant character of the 4
electrons in CeRu
Si
was suppressed by a strong magnetic field. The suppression was gradual and showed a characteristic magnetic field dependence, which reflects the metamagnetism around
8T.
Matsuda, Yasuhiro*; Nakamura, Toshiyuki*; 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(1), p.015002_1 - 015002_2, 2012/01
Times Cited Count:11 Percentile:56.67(Physics, Multidisciplinary)The valence change of Yb ion in YbAgCu was measured by means of X-ray absorption spectroscopy under high magnetic fields up to 35T. The valence state of Yb in YbAgCu
at 4.8K significantly increases at the metamagnetic transition. The saturation value of
at 55T is evaluated as 2.97 using the relation
at 35T. This value is in good agreement with
for the related compound YbInCu
at high temperatures and the Yb valence in the localized high-field phase. We conclude that the metamagnetic transition in YbAgCu
arises from the valence transition, as theoretically predicted.
Matsuda, Yasuhiro*; Her, J.-L.*; Michimura, Shinji*; Inami, Toshiya; Suzuki, Motohiro*; Kawamura, Naomi*; Mizumaki, Masaichiro*; Kindo, Koichi*; Yamaura, Junichi*; Hiroi, Zenji*
Physical Review B, 84(17), p.174431_1 - 174431_5, 2011/11
Times Cited Count:26 Percentile:68.57(Materials Science, Multidisciplinary)X-ray magnetic circular dichroism (XMCD) at the -edge of Os has been investigated in the antiferromagneticphase of Cd
Os
O
, which exhibits a metal-insulator transition around 227 K. According to the sum rule, the XMCD spectra at 10 and 37 T clearly show that the ratio between the orbital magnetic moment (
) and spinmagnetic moment (
) is
, and that
and
are coupled in parallel (
). These phenomena are unusual in that the expected ground state of Os
(5
) is an orbital singlet in a cubic crystal field, and
and
should be antiparallel for a less than half-filled system in accordance with Hund's third rule. It is likely that the spin-orbit coupling is important for explaining the observed orbital magnetism.
Inami, Toshiya; Michimura, Shinji; Mitsuda, Akihiro*; Wada, Hirofumi*
Physical Review B, 82(19), p.195133_1 - 195133_5, 2010/11
Times Cited Count:11 Percentile:44.94(Materials Science, Multidisciplinary)Two first-order phase transitions of the valence-fluctuating compound EuPtP at =246 K and
=200 K were examined by means of resonant X-ray diffraction at the Eu
absorption edge. Although previous M
ssbauer spectroscopy and preliminary X-ray diffraction experiments have suggested charge ordered states, characteristic energy spectra of the 111 and 11
reflections observed in the present experiment unambiguously indicated that twofold and threefold superstructures of Eu valence exist below
and between
and
, respectively. We also propose a mechanism to explain the charge ordering in EuPtP based on a charge-lattice coupling that alters a Coulomb repulsion.
Kawamura, Hideki*; Ando, Kenichi*; Noda, Masaru*; Tanaka, Tatsuya*; Matsuda, Takeshi*; Fujii, Haruhiko*; Hashimoto, Shuji*; Ueda, Tadashi*; Matsui, Hiroya; Takeuchi, Shinji; et al.
JAEA-Technology 2009-081, 182 Pages, 2010/03
Grouting has practical importance for the reduction of groundwater inflow into excavations during construction of underground facilities. Considering the performance assessment of a radioactive waste repository, the performance of the engineered barrier system could be adversely affected by a high pH plume generated from grout. Therefore, a quantitative estimation of the effectiveness of grouting and grout material is essential. This study has been performed in the Mizunami URL being excavated in crystalline rock as a part of the Project for Grouting Technology Development for the Radioactive Waste Repository funded by METI, Japan. The aims were to evaluate the applicability of existing grouting technology and to develop methodology to determine the distribution of grout and change in hydraulic properties of the grouted rock volume. The target rock is the volume of rock around a planned refuge niche where the pre-excavation grouting was performed at 200-m depth from ground surface. After excavation of the refuge niche, ten boreholes were drilled and different kinds of investigations were carried out during and after drilling. The results were integrated and groundwater flow analysis of pre and post excavation grouting conditions were carried out to estimate quantitatively the effect of pre-excavation grouting. The results suggest that current pre-excavation grouting technology is effective for reduction of groundwater inflow into excavations and that hydraulic conductivity of the surrounding rock can be reduced by more than one order of magnitude.
Kikuchi, Mitsuru; Matsuda, Shinzaburo; Yoshida, Naoaki*; Takase, Yuichi*; Miura, Yukitoshi; Fujita, Takaaki; Matsukawa, Makoto; Tamai, Hiroshi; Sakurai, Shinji; Ikeda, Yoshitaka; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 82(8), p.455 - 469, 2006/08
no abstracts in English
Kurita, Genichi; Bialek, J.*; Tsuda, Takashi; Azumi, Masafumi*; Ishida, Shinichi; Navratil, G. A.*; Sakurai, Shinji; Tamai, Hiroshi; Matsukawa, Makoto; Ozeki, Takahisa; et al.
Nuclear Fusion, 46(2), p.383 - 390, 2006/02
Times Cited Count:9 Percentile:30.44(Physics, Fluids & Plasmas)It is shown that critical beta is decreased by ferromagnetic effect by about 8% for /
2,
and
denoting the permeability of ferromagnetic wall and vacuum, respectively, for tokamak of aspect ratio 3. The existence of the stability window for resistive wall mode opened by both effects of the toroidal plasma rotation and the plasma dissipation, which was not observed for high aspect ratio tokamak, is found for tokamak of aspect ratio 3. The effect of ferromagnetism on them is also investigated. The critical beta analyses of NCT (National Centralized Tokamak) plasma using VALEN code are started with stabilizing plate and vacuum vessel geometry with finite resistivity, and the results for passive effect of stabilizing plate are obtained. The calculations including stabilizing effect of the vacuum-vessel and also active feedback control are also performed for present design of NCT plasma.
Kurita, Genichi; Bialek, J.*; Tsuda, Takashi; Azumi, Masafumi; Ishida, Shinichi; Navratil, G. A.*; Sakurai, Shinji; Tamai, Hiroshi; Matsukawa, Makoto; Ozeki, Takahisa; et al.
IAEA-CN-116/FT/P7-7 (CD-ROM), 8 Pages, 2004/11
The critical beta is shown to be decreased by ferromagnetic effect by about 8 % for m/m02, m and m0 denote the permeability of ferromagnetic wall and vacuum, respectively, for tokamak of aspect ratio 3. The existence of the stability window opened by both effects of the toroidal plasma rotation and the plasma dissipation, which was not observed for high aspect ratio tokamak, is found for tokamak of aspect ratio 3. The effect of ferromagnetism on them is also investigated. The critical beta analyses of NCT (National Centralized Tokamak) plasma using VALEN code are started with stabilizing plate and vacuum vessel geometry with finite resistivity, and the results for passive effect of stabilizing plate are obtained. The calculations including stabilizing effect of the vacuum-vessel and also active feedback control are also performed for present design of NCT plasma.
Hagiwara, Rika*; Matsumoto, Kazuhiko*; Tsuda, Tetsuya*; Ito, Yasuhiko*; Kohara, Shinji*; Suzuya, Kentaro; Matsumoto, Hajime*; Miyazaki, Yoshinori*
Journal of Non-Crystalline Solids, 312-314, p.414 - 418, 2002/10
Times Cited Count:32 Percentile:85.38(Materials Science, Ceramics)The structures of a series of XF2.3HF (X= 1-methylimidazolium (MI), 1-ethyl-3-methylimidazolium (EMI), 1-butyl-3-methylimidazolium (BMI), 1-hexyl-3-methyl-imidazolium (HMI)) room temperature molten salts have been investigated by high-energy synchrotron X-ray diffraction technique. The correlation peaks appeared in the total correlation function are mainly ascribed to intra-molecular correlation of alkylimidazolium cations. However, it is suggested that the peak at around 3.6
is ascribed not only to intra-molecular but also inter-molecular correlation of the cation. The contribution of the latter is also supported by the first sharp diffraction peak of the total structure factor found at almost the same position as that of a Bragg peak in the simulated X-ray diffraction pattern of solid EMIF
HF with a layered structure, corresponding to the layer separation of
Takeji, Satoru; Isayama, Akihiko; Ozeki, Takahisa; Tokuda, Shinji; Ishii, Yasutomo; Oikawa, Toshihiro; Ishida, Shinichi; Kamada, Yutaka; Neyatani, Yuzuru; Yoshino, Ryuji; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.278 - 297, 2002/09
Times Cited Count:7 Percentile:3.03(Nuclear Science & Technology)no abstracts in English
Takeji, Satoru; Tokuda, Shinji; Kurita, Genichi; Suzuki, Takahiro; Isayama, Akihiko; Takechi, Manabu; Oyama, Naoyuki; Fujita, Takaaki; Ide, Shunsuke; Ishida, Shinichi; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 78(5), p.447 - 454, 2002/05
no abstracts in English
Hagiwara, Rika*; Matsumoto, Kazuhiko*; Tsuda, Tetsuya*; Kohara, Shinji*; Suzuya, Kentaro; Ito, Yasuhiko*
Proceedings of 6th International Symposium on Molten Salts Chemistry and Technology (MS6), p.136 - 139, 2001/10
no abstracts in English
Usuda, Shigekazu; Watanabe, Kazuo; Sakurai, Satoshi; Magara, Masaaki; Hanzawa, Yukiko; Esaka, Fumitaka; Miyamoto, Yutaka; Yasuda, Kenichiro; Saito, Yoko; Gunji, Katsubumi*; et al.
KEK Proceedings 2001-14, p.88 - 92, 2001/06
no abstracts in English
Nishimura, Hideo; Magara, Masaaki; Hanzawa, Yukiko; Esaka, Fumitaka; Takahashi, Tsukasa; Gunji, Katsubumi; Miyamoto, Yutaka; Yasuda, Kenichiro; Tsuruta, Yasuhiro; Tsuda, Shinji; et al.
Heisei 11-Nendo Hosho Sochi Semina Koenroku Tekisuto, p.95 - 107, 2000/01
no abstracts in English