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Journal Articles

Development of borehole fracture column and spatial distribution of fracture systems; Case study at the Grimsel test site (GTS, Switzerland)

Tsuda, Hidenori

Oyo Chishitsu, 55(5), p.216 - 228, 2014/12

Regarding grouting of geological disposal repository, geological research that shows the site specific existent condition and aggregation form of rock fractures reached ca.1000 m underground, which buried high-level radioactive waste, is necessary, by a limited number of rock boring survey in the earlier stage of the site investigation. And this fundamental problem holds the key to the success and failure of modeling, design and construction of grouting. This paper introduces rock fractures boring column by simulant real boring core, and attempted to overview of fractures perspective intervening and outer space of borings based on the cross-sectional representation of fractures. Using fractures column, each fracture's location, orientation, and those morphological combination forming fractures aggregate zone are shown systematically. In addition, the relationships between rock fractures and geological features, rock grading are shown in parallel.

Journal Articles

Development of a grout database for geological disposal of high-level radioactive waste

Tsuda, Hidenori; Walker, C.; Shinkai, Fumiaki*; Kishi, Hirokazu*; Yui, Mikazu

Journal of Nuclear Science and Technology, 49(11), p.1110 - 1113, 2012/11

 Times Cited Count:4 Percentile:31.96(Nuclear Science & Technology)

Journal Articles

Development of grouting technologies for HLW disposal in Japan, 2; In-situ grouting test program and site investigation results at the Grimsel Test Site in Switzerland

Nakanishi, Tatsuro; Tsuda, Hidenori; Abumi, Kensho*; Uyama, Masao*; Onishi, Yuzo*

Proceedings of 7th Asian Rock Mechanics Symposium (ARMS-7) (USB Flash Drive), p.682 - 691, 2012/10

JAEA has been developing grouting materials and technologies with the consideration of long term chemical interaction between the grout material and the rock mass as a natural barrier. This paper describes the in-situ grout injection test program carried out in the fractured granite of the Grimsel Test Site (GTS) in Switzerland, which has been set up to increase knowledge and understanding of the design of grouting in order to reduce the grout penetration area into the rock mass and of the results of the site investigation. The grout injection test project at the GTS has been carried out in several stages. The site investigation results of all six boreholes were then used to determine the best location for the final grout injection test. The staged approach proved to be a good way not only to determine the best location for the grout injection test, but also to focus on the best approach in the next stages by identifying and mitigating possible problems before they occurred.

Journal Articles

Development of grouting technologies for geological disposal of high level waste in Japan, 1; Preliminary study for in-situ grout injection test in crystalline rock mass test site

Nakanishi, Tatsuro; Fujita, Tomoo; Tsuda, Hidenori; Tanaka, Tatsuya*; Uyama, Masao*; Onishi, Yuzo*

Dai-41-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koenshu (CD-ROM), p.71 - 76, 2012/01

Grouting technology is fundamental to the safe and efficient construction of underground facilities for the geological disposal of high level waste in Japan. The Japan Atomic Energy Agency has been developing grouting materials and technologies with consideration to the long term chemical interactions between the grout material and the natural barrier rock mass. An in-situ grout injection test has been carried out at the Grimsel Test Site to optimize grouting design.

Journal Articles

The Project for grouting development for high level radioactive waste repository, 4; Preliminary study for planning of grouting test

Nakanishi, Tatsuro; Kawaguchi, Masanao; Tsuda, Hidenori; Uyama, Masao*; Tanaka, Tatsuya*

Doboku Gakkai Heisei-23-Nendo Zenkoku Taikai Dai-66-Kai Nenji Gakujutsu Koenkai Koen Gaiyoshu (DVD-ROM), p.71 - 72, 2011/09

no abstracts in English

Journal Articles

The Project for grouting development for high level radioactive waste repository, 5; Evaluation of geological structure for fractures network modeling in the crystalline rock site

Abumi, Kensho*; Tanaka, Tatsuya*; Hashimoto, Shuji*; Nakanishi, Tatsuro; Tsuda, Hidenori

Doboku Gakkai Heisei-23-Nendo Zenkoku Taikai Dai-66-Kai Nenji Gakujutsu Koenkai Koen Gaiyoshu (DVD-ROM), p.73 - 74, 2011/09

no abstracts in English

Journal Articles

Frustrated minority spins in GeNi$$_2$$O$$_4$$

Matsuda, Masaaki; Chung, J.-H.*; Park, S.*; Sato, Taku*; Matsuno, Kenichiro*; Katori, Hiroko*; Takagi, Hidenori*; Kakurai, Kazuhisa; Kamazawa, Kazuya*; Tsunoda, Yorihiko*; et al.

Europhysics Letters, 82(3), p.37006_1 - 37006_5, 2008/05

 Times Cited Count:21 Percentile:71.09(Physics, Multidisciplinary)

Recently, two consecutive phase transitions were observed, upon cooling, in an antiferromagnetic spinel GeNi$$_2$$O$$_4$$ at $$T_{N1}=12.1$$ K and $$T_{N2}=11.4$$ K, respectively. Using unpolarized and polarized elastic neutron scattering we show that the two transitions are due to the existence of frustrated minority spins in this compound. Upon cooling, at $$T_{N1}$$ the spins on the $$<$$111$$>$$ kagom$'e$ planes order ferromagnetically in the plane and antiferromagnetically between the planes (phase I), leaving the spins on the $$<$$111$$>$$ triangular planes that separate the kagom$'e$ planes frustrated and disordered. At the lower $$T_{N2}$$, the triangular spins also order in the $$<$$111$$>$$ plane (phase II). We also present a scenario involving exchange interactions that qualitatively explains the origin of the two purely magnetic phase transitions.

Journal Articles

Spiral spin structure in the Heisenberg pyrochlore magnet CdCr$$_2$$O$$_4$$

Matsuda, Masaaki; Takeda, Masayasu; Nakamura, Mitsutaka; Kakurai, Kazuhisa; Osawa, Akira*; Leli$`e$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 CdCr$$_2$$O$$_4$$ undergoes a three-dimensional spin-Peierls transition at $$T_N$$ = 7.8 K from a cubic paramagnetic to a tetragonal N$'e$el state. The N$'e$el state has a spiral magnetic structure with a characteristic wave vector of $$(0,delta,1)$$ when the $$c$$ 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 $$ac$$ plane perpendicular to the direction of the spiral modulation. We also found that the spiral structure in the $$ac$$ plane is elliptical with the $$c$$-component larger by $$sim$$24% than the $$a$$-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 N$'e$el state, which is consistent with our previous inelastic studies.

Journal Articles

Statics and dynamics of incommensurate spin order in a geometrically frustrated antiferromagnet CdCr$$_2$$O$$_4$$

Chung, 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

Journal Articles

Radiation damages of InGaAs photodiodes by high-temperature electron irradiation

Oyama, Hidenori*; Takakura, Kenichiro*; Nakabayashi, Masakazu*; Hirao, Toshio; Onoda, Shinobu; Kamiya, Tomihiro; Simoen, E.*; Claeys, C.*; Kuboyama, Satoshi*; Oka, Katsumi*; et al.

Nuclear Instruments and Methods in Physics Research B, 219-220, p.718 - 721, 2004/06

 Times Cited Count:3 Percentile:24.89(Instruments & Instrumentation)

no abstracts in English

Oral presentation

Detailed magnetic structure of a frustrated spinel CdCr$$_2$$O$$_4$$ studied by polarized neutron techniques

Matsuda, Masaaki; Osawa, Akira*; Takeda, Masayasu; Kakurai, Kazuhisa; Chung, J.-H.*; Lee, S.-H.*; Ueda, Hiroaki*; Takagi, Hidenori*

no journal, , 

CdCr$$_2$$O$$_4$$ has the spinel structure, in which geometrical frustration exists between the Cr$$^{3+}$$ moments located at the corners of the tetrahedron. It shows an incommensurate antiferromagnetic ordering below $$Trm_N$$=7.8K with a characteristic wave vector of $$Q=(0, delta, 1)$$ ($$deltasim0.09$$). We first performed a 1D polarized neutron analysis and determined that the Cr$$^{3+}$$ moments has a planer anisotropy in the $$ac$$ plane, indicating that the magnetic structure is spiral. Finally, the 3D polarized neutron analysis using a CRYOPAD on TAS-1 at JRR-3 determined that the magnetic structure is elliptical spiral in the $$ac$$ plane with ellipsoid slightly elongated along the $$c$$ axis. The origin of the structure will be discussed.

Oral presentation

Analysis of all strand locations in a large superconducting CIC conductor

Sato, Hidenori*; Yagai, Tsuyoshi*; Tsuda, Makoto*; Hamajima, Takataro*; Nunoya, Yoshihiko; Okuno, Kiyoshi

no journal, , 

no abstracts in English

Oral presentation

Spiral structure of a frustrated spinel CdCr$$_2$$O$$_4$$ studied by polarized neutron techniques

Matsuda, Masaaki; Osawa, Akira*; Takeda, Masayasu; Nakamura, Mitsutaka; Leli$`e$vre-Berna, E.*; Kakurai, Kazuhisa; Chung, J.-H.*; Lee, S.-H.*; Ueda, Hiroaki*; Takagi, Hidenori*

no journal, , 

no abstracts in English

Oral presentation

Magnetic Structure of a Frustrated Spinel CdCr$$_{2}$$O$$_{4}$$

Matsuda, Masaaki; Osawa, Akira*; Takeda, Masayasu; Nakamura, Mitsutaka; Kakurai, Kazuhisa; Leli$`e$vre-Berna, E.*; Chung, J.-H.*; Lee, S.-H.*; Ueda, Hiroaki*; Takagi, Hidenori*

no journal, , 

no abstracts in English

Oral presentation

Neutron diffraction study in spinel GeCo$$_2$$O$$_4$$ in magnetic field

Matsuda, Masaaki; Hoshi, Takemichi*; Katori, Hiroko*; Kosaka, Masashi*; Takagi, Hidenori*

no journal, , 

GeCo$$_2$$O$$_4$$ has the spinel structure, in which the Co$$^{2+}$$ moments with $$S$$=3/2 are located at the corners of the tetrahedron. It shows an antiferromagnetic ordering with a characteristic wave vector of $$Q$$=(1/2, 1/2, 1/2) below $$Trm_Nsim$$21 K accompanied by a structural phase transition from cubic to tetragonal symmetry. This compound also exhibits a magnetic phase transition at $$H_csim$$4 T. Magnetic field dependence of some magnetic Bragg peak intensities was measured. For example, the (1/2, 1/2, 1/2) Bragg intensity increases with increasing magnetic field up to 4 T and gradually decreases above 4 T. This characteristic field is consistent with Hc. The field dependence of the intensity probably originates from the combined effects of the redistribution of the magnetic domains and a magnetic phase transition.

Oral presentation

Neutron scattering study of spinel LiCrMnO$$_4$$

Matsuda, Masaaki; Honda, Zentaro*; Katori, Hiroko*; Takagi, Hidenori*

no journal, , 

LiCrMnO$$_4$$ has the spinel structure, in which the Cr$$^{3+}$$ and Mn$$^{4+}$$ moments with $$S$$=3/2 are randomly located at the corners of the tetrahedron. It shows a spin-glass behavior below $$T_gsim$$13 K suggested from the magnetic susceptibility experiments. Our neutron scattering study shows that short-range magnetic correlations with characteristic $$Qsim$$0.6 and 1.6 $AA$^{-1}$$ develop at low temperatures. The correlation with $$Qsim$$1.6 $AA$^{-1}$$ is explained by the antiferromagnetic fluctuations originating from the hexagonal spin clusters, which is proposed in ZnCr$$_2$$O$$_4$$. We plan to perform neutron scattering experiments in magnetic field in the near future.

Oral presentation

Neutron scattering study of spinel Li(Mn$$_{1-x}$$Cr$$_x$$)$$_2$$O$$_4$$

Matsuda, Masaaki; Honda, Zentaro*; Katori, Hiroko*; Takagi, Hidenori*

no journal, , 

LiCrMnO$$_4$$ has the spinel structure, in which the Cr$$^{3+}$$ and Mn$$^{4+}$$ moments with $$S$$=3/2 are randomly located at the corners of the tetrahedron. It shows a spin-glass behavior below $$T_gsim$$13 K suggested from the magnetic susceptibility experiments. Our neutron scattering study shows that short-range magnetic correlations with characteristic $$Qsim$$0.6 and 1.6 $AA$^{-1}$$ develop at low temperatures. The correlation with $$Qsim$$1.6 $AA$^{-1}$$ is explained by the antiferromagnetic fluctuations originating from the hexagonal spin clusters, which is proposed in ZnCr$$_2$$O$$_4$$.

Oral presentation

Neutron scattering study of spinel Li(Mn$$_{1-x}$$Cr$$_x$$)$$_2$$O$$_4$$

Matsuda, Masaaki; Honda, Zentaro*; Katori, Hiroko*; Takagi, Hidenori*

no journal, , 

LiCrMnO$$_4$$ has the spinel structure, in which the Cr$$^{3+}$$ and Mn$$^{4+}$$ moments with $$S$$=3/2 are randomly located at the corners of the tetrahedron. It shows a spin-glass behavior below $$T_gsim$$13 K suggested from the magnetic susceptibility experiments. Our neutron scattering study shows that short-range magnetic correlations with characteristic $$Qsim$$0.6 and 1.6 $AA$^{-1}$$ develop at low temperatures. The correlation with $$Qsim$$1.6 $AA$^{-1}$$ is explained by the antiferromagnetic fluctuations originating from the hexagonal spin clusters, which is proposed in ZnCr$$_2$$O$$_4$$.

Oral presentation

Spin correlations in a frustrated spinel antiferromagnet LiCrMnO$$_4$$

Matsuda, Masaaki; Honda, Zentaro*; Katori, Hiroko*; Takagi, Hidenori*; Ueda, Hiroaki*; Ueda, Yutaka*; Mitamura, Hiroyuki*; Kindo, Koichi*

no journal, , 

Oral presentation

2016 Activity Summary on Simple Calculation Code Review WG for radiation shielding, 1; Survey on code use and development, and WG activity plan

Hirao, Yoshihiro*; Matsuda, Norihiro; Sakamoto, Hiroki*; Kawano, Hidenori*; Onishi, Seiki*; Nobuhara, Fumiyoshi*

no journal, , 

no abstracts in English

20 (Records 1-20 displayed on this page)
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