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Zn
Kitazawa, Takafumi; Ikeda, Yoichi*; Sakakibara, Toshiro*; Matsuo, Akira*; Shimizu, Yusei*; Tokunaga, Yo; Haga, Yoshinori; Kindo, Koichi*; Nambu, Yusuke*; Ikeuchi, Kazuhiko*; et al.
Physical Review B, 108(8), p.085105_1 - 085105_7, 2023/08
Cu(PO
)SO 
5HO as a model antiferromagnetic spin-1/2 Heisenberg 
- chainFujihara, Masayoshi; Jeschke, H. O.*; Morita, Katsuhiro*; Kuwai, Tomohiko*; Koda, Akihiro*; Okabe, Hirotaka*; Matsuo, Akira*; Kindo, Koichi*; Mitsuda, Setsuo*
Physical Review Materials (Internet), 6(11), p.114408_1 - 114408_8, 2022/11
Times Cited Count：0 Percentile：0(Materials Science, Multidisciplinary)
= 1/2 Heisenberg - chain antiferromagnets have been investigated extensively due to their exotic magnetic states. Here, we report the magnetic behavior of birchite CdCu(PO)SO5HO and its effective spin model. Experimental studies by magnetic susceptibility, magnetization, heat capacity, and 
SR measurements indicate the absence of long-range order down to 0.4 K. Theoretical studies reveal that birchite is a model compound for the - antiferromagnetic chain: the intrachain interactions and are antiferromagnetic and their magnitude is about 100 times larger than the interchain interactions. The magnitude of is two to three times larger than that of , thus the spin gap is expected to be only a few percent of that of . The temperature dependence of the specific heat shows a broad peak at about 1 K (
0.036 ), which suggests the presence of a spin gap.
Fujihara, Masayoshi*; Morita, Katsuhiro*; Mole, R.*; Mitsuda, Setsuo*; Toyama, Takami*; Yano, Shinichiro*; Yu, D.*; Sota, Shigetoshi*; Kuwai, Tomohiko*; Koda, Akihiro*; et al.
Nature Communications (Internet), 11, p.3429_1 - 3429_7, 2020/07
Times Cited Count：37 Percentile：90.63(Multidisciplinary Sciences)Hattori, Koichi*; Hongo, Masaru*; Huang, X.-G.*; Matsuo, Mamoru; Taya, Hidetoshi*
Physics Letters B, 795, p.100 - 106, 2019/08
Times Cited Count：114 Percentile：99.74(Astronomy & Astrophysics)Harii, Kazuya; Seo, Y.-J.*; Tsutsumi, Yasumasa*; Chudo, Hiroyuki; Oyanagi, Koichi*; Matsuo, Mamoru; Shiomi, Yuki*; Ono, Takahito*; Maekawa, Sadamichi; Saito, Eiji
Nature Communications (Internet), 10, p.2616_1 - 2616_5, 2019/06
Times Cited Count：28 Percentile：81.46(Multidisciplinary Sciences)
axisPosp
il, J.*; Haga, Yoshinori; Kohama, Yoshimitsu*; Miyake, Atsushi*; Kambe, Shinsaku; Tateiwa, Naoyuki; Valika, M.*; Proschek, P.*; Prokleka, J.*; Sechovsk
, V.*; et al.
Physical Review B, 98(1), p.014430_1 - 014430_7, 2018/07
Times Cited Count：16 Percentile：61.77(Materials Science, Multidisciplinary)Negi, Tateyuki; Umeda, Koji; Matsuo, Koichi*; Asamori, Koichi; Yokoi, Koichi*; Ohara, Hidefumi*
Butsuri Tansa, 64(2), p.153 - 165, 2011/04
The wide band MT method is recognized as an effective method for identifying deep resistivity structures in the crust. In the method, natural variations in the electric and magnetic fields of the earth are acquired over a wide range of frequencies. World wide, thunderstorm activity produces magnetic fields at frequencies above 1Hz. These natural phenomena create strong MT source signals over the entire frequency spectrum. However, magnetic fields at frequencies below 1Hz activate intermittently, because they are caused by the interaction between solar wind and the magnetosphere and therefore, long recording times are required to obtain usable readings. In noisy regions, the signals may be contaminated by DC train signals and other coherent noise, such as occur in western Japan. When magnetic field data are contaminated by such noise, it is difficult to remove or segregate the contaminated data from the usable data. In the paper, we showed the validity of the new weighted stacking method using survey data contaminated by coherent noise.
Negi, Tateyuki; Umeda, Koji; Matsuo, Koichi*; Asamori, Koichi; Yokoi, Koichi*; Ohara, Hidefumi
Butsuri Tansa, 63(5), p.395 - 408, 2010/10
In the MT-survey, it is important for the reliability evaluation of inversion result to evaluate acquired data quality. We suggested new reliability parameters, "Predict Phase Error (PPE)", "Acquired Curve Roughness (ACR)", "Error Bar Level (EBL)" to evaluate acquired data quality that was depend on the skill and experience of MT surveyor. We examined the relation between noise level and numerically expressed parameters. As a result, extremely high correlation coefficient was recognized between noise level and PPE. PPE was expected available parameter to evaluate the noise level of acquired MT data. We suggested combination of PPE, ACR, and EBL to keep the objectivity and stability for the reliability evaluation.
Nakamura, Takahiro; Sanada, Hiroyuki; Sugita, Yutaka; Teshima, Minoru*; Kishimoto, Munemaru*; Matsuo, Koichi*
JAEA-Research 2008-102, 58 Pages, 2009/03
JAEA-Research-2008-102.pdf:48.97MB
The present document is to report the result of geophysical survey by electric survey around a site proposed for the Horonobe Underground Research Laboratory Project at Horonobe-cho, Hokkaido by the Japan Atomic Energy Agency. This Electric survey using pole-pole array in Horonobe Underground Research Laboratory Area was the second survey. Resistivity distribution near surface was about 20 ohm-m and it become to about 2 ohm-m as the depth increasing. Resistivity distribution was good agreement with existing survey results and existing electrical resistivity log data. By comparing resistivity model with hydrology model, it was confirmed that resistivity reflected the density of salinity. The range and distribution trends of apparent resistivity in this year were similar to the results of last year. It is thought that the data in which reproducibility is high is acquired in this survey. The influence on the underground water flow by construction is not admitted now.
Matsuo, Koichi*; Kishimoto, Munemaru*; Makuuchi, Ayumu*; Teshima, Minoru*; Sanada, Hiroyuki; Niunoya, Sumio*; Matsui, Hiroya
JAEA-Research 2008-071, 44 Pages, 2008/09
JAEA-Research-2008-071.pdf:29.04MB
Correlation between resistivity in rock mass and groundwater quality is shown from the results of investigation such as borings and geophysical exploration. Electrical resistivity survey had been done to understand impact on behavior of groundwater by construction of underground research laboratory. This paper shows distribution of resistivity around underground research laboratory obtained from electrical resistivity survey.
Negi, Tateyuki; Umeda, Koji; Matsuo, Koichi*; Asamori, Koichi
Shadan Hojin Butsuri Tansa Gakkai Dai-117-Kai (Heisei-19-Nendo Shuki) Gakujutsu Koenkai Koen Rombunshu, p.195 - 198, 2007/10
MT survey has been applied to various fields in recent years. It is recognized as effective method to know deep resistivity structure. However, it is difficult to acquire interpretable quality data in highly noisy environments, because natural electromagnetic fields are used in the MT survey. To apply MT survey in such environments, it is important to develop robust stacking method to improve the quality of MT spectrum data. In the last SEGJ conference held in Spring 2007, we have reported effective robust stacking method based on MT reliability index shown in Negi et al (2005). In the fall conference, we report the development of robust smoothing method of MT data to compile with the robust stacking method. As a result of application to poor quality data, it was improved to interpretable quality data in short time. Therefore, it is expected to be effective and practical stacking method for the poor quality data.
Ishii, Eiichi; Yasue, Kenichi; Tanaka, Takenobu*; Tsukui, Rota; Matsuo, Koichi*; Sugiyama, Kazutoshi*; Matsuo, Shigeaki*
Chishitsugaku Zasshi, 112(5), p.301 - 314, 2006/05
Fault zones have significant influences on ground water flow. It is important to understand the characteristics of fault zones for hydrogeological modeling. We investigated the hydrogeological property and the geological structure of the fault in Neogene siliceous sedimentary rocks of northern Hokkaido, using geological mappings, reflection seismic surveys, and audio-frequency magneto telluric surveys. The result of description at a fault outcrop suggests that the Omagari Fault is a fault zone of about 120 m width that consists of mainly damage zone and that is a permeable structure without the strong anisotropy in permeability. In addition, the result of magneto telluric surveys shows high-resistivity zones having a flower structure, and one of the high-resistivity zones corresponds to the position of the Omagari fault inferred from the results of the reflection seismic surveys and of the borehole investigations. These high resistivity zones overlap with the low saline concentration zones, and the overlapping suggests the infiltration of the fresh water from the surface into the deeper part through the Omagari Fault as permeable structures. Based on these results and on study of the hydrogeological property, the geological structure, and petrological characteristics in and around the fault, it seems that the fault is a sinistral oblique-slip fault with eastside uplift sense that is formed after late Pliocene to early Pleistocene, but the possibility of the previous activity needs to research, and that the fault is over-stepping at the surface and is converging in deep underground like a flower structure shape.
Matsuo, Koichi*; Kishimoto, Munemaru*; Negi, Tateyuki*; Teshima, Minoru*
JNC TJ5440 2005-001, 51 Pages, 2005/08
JNC-TJ5440-2005-001.pdf:15.08MB
The present document is to report the results of geophysical survey by electric syrvey around a site proposed for the Horonobe Underground Research Project at Horonobe-cho, Hokkaidou by JNC. Electrical survey using dipole-diple array was carried out at the area of Hokushin in Horonobe-cho near presumued Omagari-fault. Two dimensional resistivity inversion analysis was carried out and the resistivity structure from the surface to 250m below the sea level became clear.
Matsuo, Koichi*; Yokoi, Koichi*; Negi, Tateyuki*; Kasagi, Toshio*; Takahashi, Takeharu*; Teshima, Minoru*
JNC TJ5410 2005-001, 142 Pages, 2005/03
JNC-TJ5410-2005-001.pdf:18.35MB
The present document is to report the result of resistivity monitoring by using MT(Magnetotelluric) method near the site proposed for the Horonobe Underground Research Program at Horonobe-cho, Hokkaido by the Japan Nuclear Cycle Development Institute. The stationary MT observation system, installed near the HDB-1 borehole on November 2002, was moved to a site at the Hokusei-en, 4km west of the first site. This system is monitoring for the depth of underground resistivity. 0bservation data at the Hokusei-en from February 1st 2004 to January 31st 2005 was added in the investigation in 2004 fiscal year. But, data cannot be acquired from July 8th to November 11th of 2004 due to the disconnection trouble of the optical fiber cable for data transfer.The results were as follows
Matsuo, Koichi*; Negi, Tateyuki*; Yokoi, Koichi*; Takahashi, Takeharu*; Teshima, Minoru*
JNC TJ5410 2004-002, 188 Pages, 2004/02
JNC-TJ5410-2004-002.pdf:109.99MB
The present document is to report the results of geophysical survey by electromagnetic method around a site proposed for the Horonobe Underground Research Program at Horonobe-cho, Hokkaido by the Japan Nuclear Cycle Development Institute. Remote-reference AMT(Audio-frequency magnetotelluric) method was carried out at 59 stations over 4 km2 in the area of Hokushin in Horonobe-cho. Two dimensional and three dimensional resistivity inversion analysis was carried out and the resistivity structure from the surface to 1,000m below sea level became clear. The resistivity structure was studied by comparing geological structure presumed from existing geological information. Resistivity contour lines extends NNW-SSE trend in plan of resistivity that is coincident with geological structure. The resistivity distribution was good agreement with existing electrical resistivity log data. At 500m below sea level, the resistivity of South-West part from presumed Omagari-fault was ranges from 1 to 3 ohm-m, and that of North-East part is ranges from 3 to 7 ohm-m.
Kitamura, Koichi; Hayashi, Hirokazu; Morishita, Yoshitsugu; Murakami, Kazuo*; Namba, Haruyuki*; Matsuo, Kiyoshi*
no journal, ,
no abstracts in English
Kitamura, Koichi; Sano, Kazuya; Nakamura, Yasuyuki; Matsushima, Akira; Matsuo, Hidehiko; Ishiyama, Masahiro; Haneda, Takahiro; Tezuka, Masashi
no journal, ,
The decommissioning program of proto-type Advanced Thermal Reactor (ATR) FUGEN has started in 2008 as first decommissioning of the commercial-scale water reactor. It consists of four periods, considering the transportation of spent fuels and the radioactive decrease of highly activated materials. It is expected that the whole program of decommissioning will be completed until 2028.Now, the decommissioning is under the first period, spent fuels and heavy water has been carrying out from FUGEN, and a part of the turbine system with relatively low radioactive contamination has been dismantled. FUGEN has a complicated core structure consisting 224 fuel channels with pressure tubes and calandria tank, etc. and used heavy water as moderator, unlike other light water reactor. So, the dismantling technology of the reactor core and the decontamination technology of tritium in heavy water system, etc. have been studying in order to dismantle them safely. In this presentation, the contents of the decommissioning program and its current status, the studying situation of dismantling technology of reactor core using Abrasive Water Jet (AWJ) which is a candidate of cutting technologies, the examination of tritium decontamination in heavy water system, the study for C-14 penetrated into concrete structure will be presented mainly.
Negi, Tateyuki; Umeda, Koji; Matsuo, Koichi*; Asamori, Koichi; Yokoi, Koichi*
no journal, ,
no abstracts in English
Izumi, Yudai; Matsuo, Koichi*; Fujii, Kentaro; Yokoya, Akinari
no journal, ,
no abstracts in English
Izumi, Yudai; Matsuo, Koichi*; Fujii, Kentaro; Yokoya, Akinari
no journal, ,
