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Takeuchi, Ryuji; Mikake, Shinichiro; Ikeda, Koki; Nishio, Kazuhisa*; Kokubu, Yoko; Hanamuro, Takahiro
JAEA-Review 2023-007, 114 Pages, 2023/07
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center has been conducting the Mizunami Underground Research Laboratory (MIU) Project to enhance the reliability of geological disposal technologies through investigations of the deep geological environment in the crystalline rock (granite) at Mizunami City, Gifu Prefecture, central Japan since fiscal year 1996. Backfilling and restoration works in the MIU site have been being conducted based on "the MIU Project from FY2020 onwards" which is defined the way forward of backfilling and restoration works and environmental monitoring investigations in the MIU site, since fiscal year 2020. This report summarizes the outline, process, and achievements of the construction and the safety patrol of the backfilling and restoration works in the MIU site performed from May 16, 2020 to January 16, 2022.
Takeuchi, Ryuji; Nishio, Kazuhisa*; Hanamuro, Takahiro; Kokubu, Yoko
JAEA-Data/Code 2022-010, 110 Pages, 2023/03
The Tono Geoscience Center of Japan Atomic Energy Agency (JAEA) has been conducting the environmental monitoring investigation to confirm the environmental impacts associated with the backfilling of shafts and tunnels at the Mizunami Underground Research Laboratory (MIU). This report summarizes the results of environmental impact investigations conducted as part of the environmental monitoring investigation around the MIU Site from FY2020 to FY2021, which include groundwater level measurement in wells, river flow rate measurement, water analysis of Hazama river, noise and vibration surveys, and soil survey.
MnGe revealed by resonant photoelectron spectroscopyKono, Takashi*; Kakoki, Masaaki*; Yoshikawa, Tomoki*; Wang, X.*; Sumida, Kazuki*; Miyamoto, Koji*; Muro, Takayuki*; Takeda, Yukiharu; Saito, Yuji; Goto, Kazuki*; et al.
Physical Review B, 100(16), p.165120_1 - 165120_6, 2019/10
Times Cited Count:7 Percentile:30.59(Materials Science, Multidisciplinary)Yamada, Kunimi; Hanamuro, Takahiro; Tagami, Takahiro*; Shimada, Koji; Takagi, Hideo*; Yamada, Ryuji*; Umeda, Koji
Journal of Asian Earth Sciences, 45(2), p.17 - 23, 2012/02
Times Cited Count:5 Percentile:12.55(Geosciences, Multidisciplinary)no abstracts in English
Takeda, Yukiharu; Saito, Yuji; Saito, Hiroyuki; Machida, Akihiko; Aoki, Katsutoshi; Yamagami, Hiroshi; Muro, Takayuki*; Kato, Yukako*; Kinoshita, Toyohiko*
Physical Review B, 84(15), p.153102_1 - 153102_4, 2011/10
Times Cited Count:7 Percentile:31.17(Materials Science, Multidisciplinary)We have performed soft X-ray emission spectroscopy (SXES) and soft X-ray absorption spectroscopy (SXAS) experiments on aluminum hydride
-AlH
. The occupied and unoccupied electronic states of the Al 3
partial density of states are obtained experimentally. By comparing the data from Al metal and
-AlH
, a band gap with a few eV is found for
-AlH
. In addition, the occupied states of
-AlH
have a larger spectral intensity than that of Al metal, indicating an increase in the number of electrons with the Al 3
character through Al-H bond formations. The results of a band-structure calculation account for the formation of the energy gap and the increase of the Al 3
electrons qualitatively. This suggests that a covalent-like nature is important to the Al-H bond in
-AlH
.
Kamakura, Nozomu; Takeda, Yukiharu; Saito, Yuji; Yamagami, Hiroshi; Tsubota, Masami*; Paik, B.*; Ichikawa, Takayuki*; Kojima, Yoshitsugu*; Muro, Takayuki*; Kato, Yukako*; et al.
Physical Review B, 83(3), p.033103_1 - 033103_4, 2011/01
Times Cited Count:6 Percentile:27.59(Materials Science, Multidisciplinary)The electronic structure of lithium amide, which is lightweight complex hydride expected as a high-capacity hydrogen storage material, is investigated by N 1
soft X-ray emission spectroscopy (XES) and absorption spectroscopy (XAS). The overall feature of the electronic structure of lithium amide by the XES and XAS is consistent with the band calculation, while the strongly hybridized state with H 1
is located at higher binding energy than the band calculation.


)
O
(
=Cr,Ti)Mo, S.-K.*; Kim, H.-D.*; Denlinger, J. D.*; Allen, J. W.*; Park, J.-H.*; Sekiyama, Akira*; Yamasaki, Atsushi*; Suga, Shigemasa*; Saito, Yuji; Muro, Takayuki*; et al.
Physical Review B, 74(16), p.165101_1 - 165101_12, 2006/10
Times Cited Count:49 Percentile:84.10(Materials Science, Multidisciplinary)We present high-resolution bulk-sensitive photoemission spectra of (V

)
O
(
=Cr,Ti). The measurements were made for the paramagnetic metal (PM), paramagnetic insulator (PI), and antiferromagnetic insulator (AFI) phases of (V

)
O
. In the PM phase, we observe a prominent quasiparticle peak in general agreement with theory, which combines dynamical mean-field theory with the local density approximation. For both the PI and AFI phases, the vanadium 3
parts of the valence spectra are not simple one peak structures. For the PI phase, there is not yet a good theoretical understanding of these structures. Spectra taken in the same phases with different compositions show interesting monotonic changes as the dopant concentration increases, regardless of the dopant species. With increased Cr-doping, the AFI phase gap decreases and the PI phase gap increases.
Sekiguchi, Masato; Takahashi, Masa; Miyauchi, Hideaki; Tachibana, Haruo; Komuro, Yuji*; Nemoto, Kiyoko*; Okawa, Ikuko*; Yoshizawa, Michio
Proceedings of 2nd Asian and Oceanic Congress Radiological Protection (AOCRP-2) (CD-ROM), p.114 - 117, 2006/10
In the Japan Atomic Energy Research Institute (JAERI), which was merged with the Japan Nuclear Cycle Development Institute into the Japan Atomic Energy Agency in 2005, individual monitoring and dose record keeping for radiation workers have been conducted since 1957. This report outlines the statistics of the number of radiation workers and individual doses, such as annual collective doses, annual average doses, the maximum doses and dose distributions, over the past 48 years from 1957 to 2005. Individual doses were increased due to the augment of trouble and maintenance of new experimental facilities in 1960's. The collective doses and annual average doses in 1960's exceeded 1,200 man-mSv and 0.4mSv, respectively, in some years. Then, consecutive dose reduction efforts made the collective dose significantly decrease to less than 400 man-mSv (
1/3 of the highest) and the average dose to
0.04 mSv (
1/10 of the highest). The collective doses in recent years keep almost constant even though radiation works increase in some high-contaminated hot laboratories for the decontamination and maintenance of experimental equipments. It was found from the analysis of cumulative distributions that there was a specific work-group exposed to significantly high dose compared with other workers.
Shiraishi, Akemi; Sekiguchi, Masato; Tachibana, Haruo; Yoshizawa, Michio; Komuro, Yuji*; Nemoto, Kiyoko*; Okawa, Ikuko*
JAEA-Data/Code 2006-014, 36 Pages, 2006/06
In Japan Atomic Energy Research Institute (JAERI), individual monitoring and dose data recording for radiation workers have been conducted since 1957, the next year of which JAERI was established. This report compiles the statistics of individual doses, such as average doses, collective doses, the number of radiation workers and dose distributions, over the past 48 years from 1957 to 2005, when JAERI merged with Japan Nuclear Cycle Development Institute into Japan Atomic Energy Agency. Transition of the statistics showed the history of radiation works in JAERI and many efforts for dose reduction based on the ALARA principle recommended by ICRP. In addition, it was found from the analysis of cumulative distributions that, in recent years, there was a specific work-group exposed to significantly high dose compared with other workers.

Sato, Hitoshi*; Yoshikawa, Kunta*; Hiraoka, Koichi*; Arita, Masashi*; Fujimoto, Koji*; Kojima, Kenichi*; Muro, Takayuki*; Saito, Yuji; Sekiyama, Akira*; Suga, Shigemasa*; et al.
Physical Review B, 69(16), p.165101_1 - 165101_6, 2004/04
Times Cited Count:34 Percentile:77.08(Materials Science, Multidisciplinary)no abstracts in English
A
MnO
(A=Ca,Sr)Kang, J.-S.*; Kim, J. H.*; Sekiyama, Akira*; Kasai, Shuichi*; Suga, Shigemasa*; Han, S. W.*; Kim, K. H.*; Choi, E. J.*; Kimura, Tsuyoshi*; Muro, Takayuki*; et al.
Physical Review B, 68(1), p.012410_1 - 012410_4, 2003/07
Times Cited Count:21 Percentile:67.40(Materials Science, Multidisciplinary)no abstracts in English
O
Mo, S.-K.*; Denlinger, J. D.*; Kim, H.-D.*; Park, J.-H.*; Allen, J. W.*; Sekiyama, Akira*; Yamasaki, Atsushi*; Kadono, Koji*; Suga, Shigemasa*; Saito, Yuji; et al.
Physical Review Letters, 90(18), p.186403_1 - 186403_4, 2003/05
Times Cited Count:144 Percentile:95.35(Physics, Multidisciplinary)no abstracts in English
Hara, Toru*; Shirasawa, Katsutoshi*; Takeuchi, Masao*; Seike, Takamitsu*; Saito, Yuji; Muro, Takayuki*; Kitamura, Hideo*
Nuclear Instruments and Methods in Physics Research A, 498(1-3), p.496 - 502, 2003/02
Times Cited Count:60 Percentile:95.34(Instruments & Instrumentation)no abstracts in English
FeMoO
double perovskites (
=Sr, Ba)Kang, J.-S.*; Kim, J. H.*; Sekiyama, Akira*; Kasai, Shuichi*; Suga, Shigemasa*; Han, S. W.*; Kim, K. H.*; Muro, Takayuki*; Saito, Yuji; Hwang, C.*; et al.
Physical Review B, 66(11), p.113105_1 - 113105_4, 2002/09
Times Cited Count:66 Percentile:89.92(Materials Science, Multidisciplinary)The electronic structures of Sr
FeMoO
(SFMO) and Ba
FeMoO
(BFMO) double perovskites have been investigated using Fe 2p-3d resonant photoemission spectroscopy (PES) and the Cooper minimum in the Mo 4d photoionization cross section. The states close to the Fermi level are found to have a strongly mixed Mo–Fe t
character, indicating that the Fe valence is far from pure 3+. The Fe 2p
x-ray absorption spectroscopy spectra reveal the mixed-valent Fe
–Fe
configurations, and a larger Fe
component for BFMO than for SFMO, suggesting an operative double exchange interaction. The valence-band PES spectra reveal good agreement with the local-spin-density-approximation (LSDA+U) calculation.
(
=Pt, Pd;
=P, As, Sb)Iwasaki, T.*; Sekiyama, Akira*; Yamasaki, Atsushi*; Okazaki, Makoto*; Kadono, Koji*; Utsunomiya, Hiroshi*; Imada, Shin*; Saito, Yuji; Muro, Takayuki*; Matsushita, Tomohiro*; et al.
Physical Review B, 65(19), p.195109_1 - 195109_9, 2002/05
Times Cited Count:24 Percentile:70.94(Materials Science, Multidisciplinary)no abstracts in English
Sn (
=Ti, Zr, and Nb)Yamasaki, Atsushi*; Imada, Shin*; Arai, Ryuji*; Utsunomiya, Hiroshi*; Suga, Shigemasa*; Muro, Takayuki*; Saito, Yuji; Kanomata, Takeshi*; Ishida, Shoji*
Physical Review B, 65(10), p.104410_1 - 104410_6, 2002/03
Times Cited Count:64 Percentile:89.35(Materials Science, Multidisciplinary)The magnetic circular dichroism (MCD) of core-level absorption [x-ray absorption spectroscopy (XAS)] spectra in the soft x-ray region has been measured for the ferromagnetic Heusler alloys Co
TiSn, Co
ZrSn, and Co
NbSn. The many-peak structures which are clearly observed in the Co 2p-3d XAS-MCD spectra cannot be well explained by atomic multiplet calculations but are better explained by the Co 3d unoccupied states predicted by linear muffin-tin orbital atomic sphere approximation band structure calculations. The MCD spectra show an obvious contribution of the orbital angular momentum component to the magnetic moment in these alloys. The ratio between the orbital angular momentum and spin derived from the MCD spectra varies by more than a factor of 2 within these alloys. The mechanism of this variation is discussed in comparison with the band structure calculations.
Miyahara, Tsuneaki*; Ishii, Hiroyoshi*; Takayama, Yasuhiro*; Hirose, Masaaki*; Maruyama, Kenichi*; Obu, Kenji*; Shinoda, Motoki*; Muro, Takayuki*; Saito, Yuji; Matsuda, Tatsuma*; et al.
Journal of the Physical Society of Japan, 70(10), p.2977 - 2981, 2001/10
Times Cited Count:6 Percentile:41.67(Physics, Multidisciplinary)no abstracts in English
Saito, Yuji; Kimura, Hiroaki*; Suzuki, Yoshio*; Nakatani, Takeshi*; Matsushita, Tomohiro*; Muro, Takayuki*; Miyahara, Tsuneaki*; Fujisawa, M.*; Soda, Kazuo*; Ueda, Shigenori*; et al.
Nuclear Instruments and Methods in Physics Research A, 467-468(Part.1), p.553 - 556, 2001/07
Times Cited Count:23 Percentile:81.54(Instruments & Instrumentation)no abstracts in English
TiS
Yamasaki, Atsushi*; Imada, Shin*; Utsunomiya, Hiroshi*; Muro, Takayuki*; Saito, Yuji; Negishi, H.*; Sasaki, M.*; Inoue, M.*; Suga, Shigemasa*
Physica E, 10(1-3), p.387 - 390, 2001/05
Times Cited Count:5 Percentile:31.82(Nanoscience & Nanotechnology)no abstracts in English
Mn
AsUeda, Shigenori*; Imada, Shin*; Muro, Takayuki*; Saito, Yuji; Suga, Shigemasa*; Matsukura, F.*; Ohno, Hideo*
Physica E, 10(1-3), p.210 - 214, 2001/05
Times Cited Count:24 Percentile:73.18(Nanoscience & Nanotechnology)no abstracts in English