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Yuguchi, Takashi*; Ito, Daichi*; Yokoyama, Tatsunori; Sakata, Shuhei*; Suzuki, Satoshi*; Ogita, Yasuhiro; Yagi, Koshi*; Imura, Takumi*; Motai, Satoko*; Ono, Takeshi*
Lithos, 440-441, p.107026_1 - 107026_14, 2023/03
Times Cited Count：0 Percentile：0.02(Geochemistry & Geophysics)We propose a new method for elucidating zircon growth in granitic plutons, based on variations in three-dimensional 3D cathodoluminescence (CL) patterns, U-Pb ages, titanium concentration, and Th/U ratios. We focused on the zircon growth processes in the Okueyama granite (OKG) in central Kyushu, Japan, to obtain interpretations of magma chamber processes that result in the formation of granitic plutons. The OKG consists of three lithofacies: biotite granite (BG), hornblende granite (HG), and hornblende granodiorite (HGD). To determine the 3D internal structure and growth pattern of a zircon crystal, we performed CL observations for multi-sections of the samples. Simultaneously, we also determined the zircon U-Pb age and titanium concentration of the center sections of the samples. The 3D distribution of the oscillatory zoning can be used to determine the crystal nucleus. The simultaneous determination of zircon U-Pb ages and Ti concentrations of the granite samples indicates the time-temperature (t-T) history of granitic magma before its solidification. The t-T histories of the BG, HG, and HGD represented similar cooling behaviors within the magma chamber: rapid cooling from the zircon crystallization temperature to the closure temperature of the biotite K-Ar system between 16 Ma and 10 Ma. The variations in the Th/U ratios against temperature also demonstrate a different trend at the boundary of approximately 670 
C. Fractional crystallization in the magma chamber progressed significantly at temperatures above 670 C; below 670 C, crystallization progressed slowly, indicating only minimal changes in the magma composition. The variations in the Th/U ratio against temperature in the BG, HG, and HGD portrayed common tendencies, indicating the same behavior in the progression of fractional crystallization among the three lithofacies, which in turn, represented the same behavior within the entire magma chamber.
Ogawa, Rina; Abe, Daichi*; Sugaya, Toshikatsu; Sakuma, Kota; Saito, Tatsuo; Sakai, Akihiro
JAEA-Technology 2022-008, 46 Pages, 2022/05
JAEA-Technology-2022-008.pdf:3.09MB
Japan Atomic Energy Agency (JAEA) has planned to dispose of the Uranium-bearing waste, whose radioactivity concentration is low, in trench disposal facility. In Japan, uranium is a material to impact on human health, therefore Environmental quality standards for water pollution for uranium has been established, and the standard value is 0.002mg/L. Safety of trench disposal facilities will be assessed that radionuclides contained in the radioactive waste are transferred to the biosphere by seepage water and groundwater. Therefore, JAEA considers that not only dose evaluation but also environmental pollution evaluation is needed as a safety assessment. In this report, we examined whether the concentration of uranium leaching from the trench facility in the aquifer can meet the Environmental quality standards. In addition, parameter study under various conditions of disposal facility were done. Based on the results, conditions and issues of future basic design of trench disposal facility were discussed. The uranium concentration in the aquifer was calculated by the one-dimensional dose evaluation code "GSA-GCL2" for the disposal of LLW. As the result, the uranium concentration in the aquifer significantly changed depending on the conditions of design of disposal facility and so on. However, if the shape and arrangement of the trench facility to groundwater flow direction, the distribution coefficient of uranium of the waste layer, the specification of the impermeable layer and their combination are appropriately designed we consider that the uranium concentration of aquifer can made to adapt the environmental quality standard.
CoGa
filmsKubota, Takahide*; Takano, Daichi*; Kota, Yohei*; Mohanty, S.*; Ito, Keita*; Matsuki, Mitsuhiro*; Hayashida, Masahiro*; Sun, M.*; Takeda, Yukiharu; Saito, Yuji; et al.
Physical Review Materials (Internet), 6(4), p.044405_1 - 044405_12, 2022/04
Times Cited Count：5 Percentile：59.75(Materials Science, Multidisciplinary)Yuguchi, Takashi*; Ishibashi, Kozue*; Sakata, Shuhei*; Yokoyama, Tatsunori; Ito, Daichi*; Ogita, Yasuhiro; Yagi, Koshi*; Ono, Takeshi*
Lithos, 372-373, p.105682_1 - 105682_9, 2020/11
Times Cited Count：3 Percentile：14.2(Geochemistry & Geophysics)Simultaneous determination of zircon U-Pb age and titanium concentration for a single analysis spot gives both the crystallization age and temperature. The crystallization age and temperature pairs in granitic zircons map the time-temperature (
) path of granitic magma before its solidification. In laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis, it is challenging to quantitatively analyse a low level of titanium concentration. This study employed two approaches using a Quadrupole mass spectrometer equipped with a collision/reaction cell (CRC). The methods were applied to zircon samples of the Kurobegawa granite (KRG), the Okueyama granite (OKG), the Toki granite (TKG), and the Tono plutonic complex (TPC) and provided U-Pb ages and titanium concentrations consistent with previous studies. The crystallization ages and temperatures collected from individual analysis spots of zircon samples in the KRG, OKG, TKG, and TPC are plotted in the diagrams and enable us to characterize the rapid cooling paths at thermal conditions of zircon crystallization at the sampling sites.
Hirobe, Daichi*; Sato, Masahiro*; Hagihara, Masato*; Shiomi, Yuki*; Masuda, Takatsugu*; Saito, Eiji
Physical Review Letters, 123(11), p.117202_1 - 117202_7, 2019/09
Times Cited Count：14 Percentile：65.02(Physics, Multidisciplinary)
and CrGeTeIto, Naohiro*; Kikkawa, Takashi*; Barker, J.*; Hirobe, Daichi*; Shiomi, Yuki*; Saito, Eiji
Physical Review B, 100(6), p.060402_1 - 060402_6, 2019/08
Times Cited Count：43 Percentile：88.83(Materials Science, Multidisciplinary)Kameda, Mai*; Hirobe, Daichi*; Daimon, Shunsuke*; Shiomi, Yuki*; Takahashi, Saburo*; Saito, Eiji
Journal of Magnetism and Magnetic Materials, 476, p.459 - 463, 2019/04
Times Cited Count：1 Percentile：4.76(Materials Science, Multidisciplinary)Shiomi, Yuki*; Lustikova, J.*; Watanabe, Shingo*; Hirobe, Daichi*; Takahashi, Saburo*; Saito, Eiji
Nature Physics, 15(1), p.22 - 26, 2018/10
Times Cited Count：17 Percentile：74.55(Physics, Multidisciplinary)Nakajima, Kenji; Kawakita, Yukinobu; Ito, Shinichi*; Abe, Jun*; Aizawa, Kazuya; Aoki, Hiroyuki; Endo, Hitoshi*; Fujita, Masaki*; Funakoshi, Kenichi*; Gong, W.*; et al.
Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12
The neutron instruments suite, installed at the spallation neutron source of the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC), is reviewed. MLF has 23 neutron beam ports and 21 instruments are in operation for user programs or are under commissioning. A unique and challenging instrumental suite in MLF has been realized via combination of a high-performance neutron source, optimized for neutron scattering, and unique instruments using cutting-edge technologies. All instruments are/will serve in world-leading investigations in a broad range of fields, from fundamental physics to industrial applications. In this review, overviews, characteristic features, and typical applications of the individual instruments are mentioned.
Watanabe, Shingo*; Hirobe, Daichi*; Shiomi, Yuki*; Iguchi, Ryo*; Daimon, Shunsuke*; Kameda, Mai*; Takahashi, Saburo*; Saito, Eiji
Scientific Reports (Internet), 7, p.4576_1 - 4576_6, 2017/07
Times Cited Count：6 Percentile：29.59(Multidisciplinary Sciences)Hirobe, Daichi*; Sato, Masahiro*; Kawamata, Takayuki*; Shiomi, Yuki*; Uchida, Kenichi*; Iguchi, Ryo*; Koike, Yoji*; Maekawa, Sadamichi; Saito, Eiji
Nature Physics, 13(1), p.30 - 34, 2017/01
Times Cited Count：99 Percentile：96.76(Physics, Multidisciplinary)Ito, Shinichi*; Yokoo, Tetsuya*; Masuda, Takatsugu*; Yoshizawa, Hideki*; Soda, Minoru*; Ikeda, Yoichi*; Ibuka, Soshi*; Kawana, Daichi*; Sato, Taku*; Nambu, Yusuke*; et al.
JPS Conference Proceedings (Internet), 8, p.034001_1 - 034001_6, 2015/09
Ueyama, Daichi*; Saito, Yuichi; Ishikawa, Norito; Omura, Takahito*; Semboshi, Satoshi*; Hori, Fuminobu*; Iwase, Akihiro*
Nuclear Instruments and Methods in Physics Research B, 351, p.1 - 5, 2015/05
Times Cited Count：6 Percentile：39.96(Instruments & Instrumentation)
OSeOHirobe, Daichi*; Shiomi, Yuki*; Shimada, Yuki*; Oe, Junichiro*; Saito, Eiji
Journal of Applied Physics, 117(5), p.053904_1 - 053904_6, 2015/02
Times Cited Count：9 Percentile：38.07(Physics, Applied)Ueyama, Daichi*; Semboshi, Satoshi*; Saito, Yuichi; Ishikawa, Norito; Nishida, Kenji*; Soneda, Naoki*; Hori, Fuminobu*; Iwase, Akihiro*
Japanese Journal of Applied Physics, 53(5S1), p.05FC04_1 - 05FC04_5, 2014/05
Times Cited Count：9 Percentile：34.69(Physics, Applied)In our previous research, it was found that the hardness of Cu-Ti alloy increased by energetic heavy ion irradiation at room temperature. In the conference, we will show the result of electron beam irradiation on the hardness of Cu-Ti alloys. We used CuTi sheets with the dimension of 10 
10 0.250 mm
. The specimens were irradiated at 473 K and 523 K with 2 MeV electrons. For comparison, we thermally aged some specimens at the same temperatures as that for the irradiation. The electron fluence of 8.0 10
/cm
corresponds to the processing time of about 10 h. As a result, the thermal aging for 10 h increases the hardness by 5 or less, which is much smaller than that by the irradiation (about 20). The hardness of the reverse side of irradiated surface is almost the same as that of the irradiated surface. The present result implies that energetic electron irradiation can be a useful tool for controlling the hardness of the "bulk" Cu-Ti alloy.
Iguchi, Ryo*; Sato, Koji*; Hirobe, Daichi*; Daimon, Shunsuke*; Saito, Eiji
Applied Physics Express, 7(1), p.013003_1 - 013003_4, 2014/01
We investigate a dc rectification effect of magnetization dynamics based on spin Hall magnetoresistance (SMR) in an insulating magnet/metal system on spin pumping measurements. We theoretically find that the rectification effect by SMR has different in-plane magnetization angle dependence from that of the inverse spin Hall effect on the spin pumping. The negligible contribution from the rectification effect is experimentally confirmed in a cavity measurement.
Iguchi, Ryo*; Sato, Koji*; Hirobe, Daichi*; Daimon, Shunsuke*; Saito, Eiji
Applied Physics Express, 7(1), p.013003_1 - 013003_4, 2014/01
Times Cited Count：21 Percentile：65.2(Physics, Applied)
in Al-H systemSaito, Hiroyuki; Okajima, Yuka; Yoneda, Yasuhiro; Machida, Akihiko; Kawana, Daichi; Watanuki, Tetsu; Katayama, Yoshinori; Aoki, Katsutoshi
Journal of Alloys and Compounds, 496(1-2), p.L25 - L28, 2010/04
Times Cited Count：21 Percentile：68.76(Chemistry, Physical)Takizawa, Daichi*; Takagi, Hitoshi*; Makita, Chikako*; Nakajima, Yuka*; Saito, Etsuko*; Oyama, Tatsuya*; Ichikawa, Takeshi*; Kakizaki, Akira*; Sato, Ken*; Mori, Masatomo*; et al.
no journal, ,
no abstracts in English
in the Al-H systemSaito, Hiroyuki; Okajima, Yuka; Yoneda, Yasuhiro; Machida, Akihiko; Kawana, Daichi; Watanuki, Tetsu; Katayama, Yoshinori; Aoki, Katsutoshi
no journal, ,
no abstracts in English
