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Journal Articles

Deuterium content and site occupancy in iron sulfide at high pressure and temperature determined using in situ neutron diffraction measurements

Abeykoon, S.*; Howard, C.*; Dominijanni, S.*; Eberhard, L.*; Kurnosov, A.*; Frost, D. J.*; Boffa Ballaran, T.*; Terasaki, Hidenori*; Sakamaki, Tatsuya*; Suzuki, Akio*; et al.

Journal of Geophysical Research; Solid Earth, 128(9), p.e2023JB026710_1 - e2023JB026710_17, 2023/09

 Times Cited Count:0 Percentile:0.01(Geochemistry & Geophysics)

Small amounts of iron sulphide minerals are found in most rocks from the Earth's mantle and as inclusions trapped in natural diamonds. Hydrogen may dissolve into iron sulphide minerals under high pressures and temperature, but is most likely lost once pressure and temperature are removed. In this study, we determined deuterium contents in iron sulphide, held under high pressure and temperature conditions, using neutron diffraction measurements with 6-ram multi-anvil press at PLANET, J-PARC. Deuterium contents in iron sulphide were measured at high-P, up to 11.4 GPa and high-T to 1300 K in in situ neutron diffraction experiments. The total deuterium content increases with both P and T. The results are used to estimate hydrogen contents of iron sulphide minerals in the deep continental lithospheric mantle, which are found to be in the range 1700-2700 ppm. This corresponds to approximately 2-3 ppm of hydrogen in the bulk mantle.

Journal Articles

Structure of basaltic glass at pressures up to 18 GPa

Ohashi, Tomonori*; Sakamaki, Tatsuya*; Funakoshi, Kenichi*; Hattori, Takanori; Hisano, Naoki*; Abe, Jun*; Suzuki, Akio*

American Mineralogist, 107(3), p.325 - 335, 2022/03

 Times Cited Count:1 Percentile:22.72(Geochemistry & Geophysics)

The basaltic glass structure were investigated to 18 GPa using in situ X-ray and neutron diffraction. The O-O coordination number (CN$$_textrm{OO}$$) starts to rise with maintaining the mean O-O distance (r$$_textrm{OO}$$) above 2-4 GPa, and then CN$$_textrm{OO}$$ stops increasing and r$$_textrm{OO}$$ begins to shrink along with the increase in the Al-O coordination number (CN$$_textrm{AlO}$$) above 9 GPa. This is interpreted by the change in the contraction mechanism from tetrahedral network bending to oxygen packing ratio increase via the CN$$_textrm{AlO}$$ increase. The oxygen packing fraction exceeds the value for dense random packing, suggesting that the oxygen-packing hypothesis cannot account for the pressure-induced structural transformations of silica and silicate glasses. The CN$$_textrm{OO}$$ increase at 2-4 GPa reflects the elastic softening of silicate glass, which may causes anomalous elastic moduli of basaltic glass at $$sim$$ 2 GPa.

Journal Articles

Unified mercury radioactivity monitoring system at J-PARC and its operation experiences

Harada, Masahide; Sekijima, Mitsuaki*; Morikawa, Noriyuki*; Masuda, Shiho; Kinoshita, Hidetaka; Sakai, Kenji; Kai, Tetsuya; Kasugai, Yoshimi; Muto, Giichi*; Suzuki, Akio*; et al.

JPS Conference Proceedings (Internet), 33, p.011099_1 - 011099_6, 2021/03

In MLF at J-PARC, a unified mercury radioactivity monitor (UHAM) is installed to find an indication of failure of the mercury target and loop system by detecting radioactive materials leaked from the system with a $$gamma$$-ray energy analysis with Germanium semi-conductor detectors (Ge detectors). It is composed of three units of sampling port and radiation monitors: (1) HAM for interstitial helium gas layer between the mercury vessel and surrounding water shroud of the mercury target, (2) CAM for atmosphere in the hot cell where the target loop is operated and (3) VAM for helium gas in the helium vessel where the target vessel is installed. Once any leakages of radioactive materials are detected, an alarm signal is issued immediately to the accelerator control system to stop beam operation. Software and hardware have been upgraded yearly. For example, two Ge detectors are used for HAM for redundancy, NaI Scintillation detectors are also used as supplemental for the Ge detector to keep availability of the system for high counting rate event. In April 2015, the UHAM activated when a small water coolant leakage from the water shroud of the mercury target occurred. VAM detected an abnormal increase of the counting rate in the helium vessel. It was also indicated that the measured radioactive nuclides were generated from the activation of the coolant (water) in the water shroud and not from the mercury.

Journal Articles

Report on special sessions in the 49th Annual Meeting of the Japan Health Physics Society

Sakoda, Akihiro; Kataoka, Noriaki*; Ishikawa, Junya*; Ota, Akio*; Suzuki, Tatsuhiko*; Nishiyama, Yuichi*; Hirouchi, Jun; Hokama, Tomonori

Hoken Butsuri, 51(3), p.181 - 186, 2016/09

The 49th annual meeting of the Japan Health Physics Society was held in Hirosaki, Aomori between June 30th and July 1st, 2016. This article gives the report on all of twelve special sessions in this meeting.

Journal Articles

Technical estimation for mass production of highly-concentrated $$^{rm 99m}$$Tc solution from $$^{99}$$Mo to be obtained by ($$n,gamma$$) reaction; A Preliminary study using inactive Re instead of $$^{rm 99m}$$Tc

Tanase, Masakazu*; Fujisaki, Saburo*; Ota, Akio*; Shiina, Takayuki*; Yamabayashi, Hisamichi*; Takeuchi, Nobuhiro*; Tsuchiya, Kunihiko; Kimura, Akihiro; Suzuki, Yoshitaka; Ishida, Takuya; et al.

Radioisotopes, 65(5), p.237 - 245, 2016/05

no abstracts in English

Journal Articles

2016 Professional Engineer (PE) test preparation course "Nuclear and Radiation Technical Disciplines"

Takahashi, Naoki; Yoshinaka, Kazuyuki; Harada, Akio; Yamanaka, Atsushi; Ueno, Takashi; Kurihara, Ryoichi; Suzuki, Soju; Takamatsu, Misao; Maeda, Shigetaka; Iseki, Atsushi; et al.

Nihon Genshiryoku Gakkai Homu Peji (Internet), 64 Pages, 2016/00

no abstracts in English

JAEA Reports

Annual report on the effluent control of low level liquid waste in Nuclear Fuel Cycle Engineering Laboratories FY2014

Watanabe, Hitoshi; Nakano, Masanao; Fujita, Hiroki; Kono, Takahiko; Inoue, Kazumi; Yoshii, Hideki*; Otani, Kazunori*; Hiyama, Yoshinori*; Kikuchi, Masaaki*; Sakauchi, Nobuyuki*; et al.

JAEA-Review 2015-030, 115 Pages, 2015/12

JAEA-Review-2015-030.pdf:25.28MB

Based on the regulations (the safety regulation of Tokai reprocessing plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and bylaw of Ibaraki prefecture), the effluent control of liquid waste discharged from the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency has been performed. This report describes the effluent control results of the liquid waste in the fiscal year 2014. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other nuclear fuel material usage facilities were much lower than the limits authorized by the above regulations.

JAEA Reports

Annual report on the effluent control of low level liquid waste in Nuclear Fuel Cycle Engineering Laboratories FY2013

Watanabe, Hitoshi; Nakano, Masanao; Fujita, Hiroki; Kono, Takahiko; Inoue, Kazumi; Yoshii, Hideki*; Otani, Kazunori*; Hiyama, Yoshinori*; Goto, Ichiro*; Kibe, Satoshi*; et al.

JAEA-Review 2014-040, 115 Pages, 2015/01

JAEA-Review-2014-040.pdf:4.26MB

Based on the regulations (the safety regulation of Tokai reprocessing plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and bylaw of Ibaraki prefecture), the effluent control of liquid waste discharged from the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency has been performed. This report describes the effluent control results of the liquid waste in the fiscal year 2013. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other nuclear fuel material usage facilities were much lower than the limits authorized by the above regulations.

JAEA Reports

Annual report on the effluent control of low level liquid waste in Nuclear Fuel Cycle Engineering Laboratories FY2012

Sumiya, Shuichi; Watanabe, Hitoshi; Miyagawa, Naoto; Nakano, Masanao; Fujita, Hiroki; Kono, Takahiko; Inoue, Kazumi; Yoshii, Hideki; Otani, Kazunori*; Hiyama, Yoshinori*; et al.

JAEA-Review 2013-041, 115 Pages, 2014/01

JAEA-Review-2013-041.pdf:19.01MB

Based on the regulations (the safety regulation of Tokai reprocessing plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, and the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and bylaw of Ibaraki prefecture), this report describes the effluent control results of liquid waste discharged from the JAEA's Nuclear Fuel Cycle Engineering Laboratories in the fiscal year 2012, from 1st April 2012 to 31st March 2013. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other facilities were much lower than the authorized limits of the above regulations.

Journal Articles

Ponded melt at the boundary between the lithosphere and asthenosphere

Sakamaki, Tatsuya*; Suzuki, Akio*; Otani, Eiji*; Terasaki, Hidenori*; Urakawa, Satoru*; Katayama, Yoshinori; Funakoshi, Kenichi*; Wang, Y.*; Hernlund, J. W.*; Ballmer, M. D.*

Nature Geoscience, 6(12), p.1041 - 1044, 2013/12

 Times Cited Count:128 Percentile:96.48(Geosciences, Multidisciplinary)

The bounday between Earth's rigid lighosphere and the underlying, ductile ashenosphere is marked by a distinct siseismic discontinuity. We measure the density, viscosity and structure of basaltic magmas using high-pressure and high-temperature experiments and in situ X-ray analysis under pressure of up to 5.5 GPa. We find that the magmas rapidly become denser with increasing presure and show a viscosity minimum near 4 GPa. Magma mobility determined by the density and viscosity data exhibits a peak at pressures corresponding to depths of 120-150 km, within the asthenosphere. The diminishing mobility of magma in Earth's asthenosphere as the mlets ascend could lead to excessive melt accumulation at depths of 80-100 km, at the lithosphere-asthenosphere boundary. It is concluded that the observed seismic discontinuity at the lithosphere-asthenosphere boundary records this accumulation of melt.

Journal Articles

High-magnetic-field X-ray absorption and magnetic circular dichroism spectroscopy in the mixed-valent compound YbAgCu$$_4$$

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:57.56(Physics, Multidisciplinary)

The X-ray absorption and magnetic circular dichroism (MCD) spectra at the Yb L$$_3$$ edge were measured in the mixed-valent heavy fermion compound YbAgCu$$_4$$ 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$$^{3+}$$ state, while no feature is observed in the XMCD spectra corresponding to the Yb$$^{2+}$$ 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.

Journal Articles

Density measurement of liquid FeS at high pressures using synchrotron X-ray absorption

Nishida, Keisuke*; Otani, Eiji*; Urakawa, Satoru*; Suzuki, Akio*; Sakamaki, Tatsuya*; Terasaki, Hidenori*; Katayama, Yoshinori

American Mineralogist, 96(5-6), p.864 - 868, 2011/05

 Times Cited Count:32 Percentile:69.49(Geochemistry & Geophysics)

The density of liquid iron sulfide (FeS) was measured up to 3.8 GPa and 1800 K using the X-ray absorption method. The compression curve of the liquid FeS can be fitted using the Vinet equation of state. Isothermal bulk modulus and its temperature and pressure derivatives were determined by a non-linear least squares fit. Liquid FeS is more compressible than Fe-rich Fe-S liquid.

Journal Articles

Density of high-Ti basalt magma at high pressure and origin of heterogeneities in the lunar mantle

Sakamaki, Tatsuya*; Otani, Eiji*; Urakawa, Satoru*; Suzuki, Akio*; Katayama, Yoshinori; Zhao, D.*

Earth and Planetary Science Letters, 299(3-4), p.285 - 289, 2010/11

 Times Cited Count:29 Percentile:58.17(Geochemistry & Geophysics)

The density of the Apollo 14 black glass melt, which has the highest TiO$$_{2}$$ content of pristine mare glasses, was measured to 4.8 GPa and 2100 K using an X-ray absorption method. A fit of the pressure-density-temperature data to the high-temperature Birch-Murnaghan equation of state yielded the isothermal bulk modulus, its pressure derivative, and the temperature derivative of the bulk modulus. Implication for heterogeneities in the lunar mantle is discussed.

Journal Articles

Designing PLANET; Neutron beamline for high-pressure material science at J-PARC

Arima, Hiroshi; Hattori, Takanori; Komatsu, Kazuki*; Abe, Jun; Utsumi, Wataru; Kagi, Hiroyuki*; Suzuki, Akio*; Suzuya, Kentaro; Kamiyama, Takashi; Arai, Masatoshi; et al.

Journal of Physics; Conference Series, 215(1), p.012025_1 - 012025_6, 2010/03

The powder diffractometer dedicated to high-pressure experiments (PLANET) is now being constructed on BL11 at the spallation neutron source of J-PARC. PLANET aims to study structures of hydrogen-bearing materials including dense hydrous minerals of the Earth's deep interior, magmas and light element liquids. The instrument will realize diffraction and radiography experiments for powder and liquid/glass samples at high pressures up to 20 GPa and 2000 K. It covers d spacing from 0.2 ${AA}$ to 4.1 ${AA}$ at 90$$^{circ}$$ bank within the first frame.

Journal Articles

Designing PLANET; Neutron beamline for high-pressure material science at J-PARC

Arima, Hiroshi*; Hattori, Takanori; Komatsu, Kazuki*; Abe, Jun; Utsumi, Wataru; Kagi, Hiroyuki*; Suzuki, Akio*; Suzuya, Kentaro; Kamiyama, Takashi*; Arai, Masatoshi; et al.

Journal of Physics; Conference Series, 215(1), p.012025_1 - 012025_6, 2010/03

 Times Cited Count:14 Percentile:96.3(Instruments & Instrumentation)

The powder diffractometer dedicated to high-pressure experiments (PLANET) is now being constructed on BL11 at the spallation neutron source of J-PARC. PLANET aims to study structures of hydrogen-bearing materials including dense hydrous minerals of the Earth's deep interior, magmas and light element liquids. The instrument will realize diffraction and radiography experiments for powder and liquid/glass samples at high pressures up to 20 GPa and 2000 K. It covers $$d$$ spacing from 0.2${AA}$ to 4.1${AA}$ at 90$$^{circ}$$ bank within the first frame. The design and performance of PLANET have been evaluated using Monte Carlo simulations.

Journal Articles

Density of dry peridotite magma at high pressure using an X-ray absorption method

Sakamaki, Tatsuya*; Otani, Eiji*; Urakawa, Satoru*; Suzuki, Akio*; Katayama, Yoshinori

American Mineralogist, 95(1), p.144 - 147, 2010/01

 Times Cited Count:37 Percentile:70.43(Geochemistry & Geophysics)

The density of a peridotite magma was measured up to 2.5 GPa and 2300 K using an X-ray absorption method. The method allowed measurement of the density of a peridotite melt under seven different conditions and clarified the pressure and temperature dependence of the density. A fit of the pressure-density-temperature data to the high-temperature Birch-Murnaghan equation of state yielded the isothermal bulk modulus, $$K_{T0} = 24.0 pm 1.3$$ GPa, its pressure derivative, $$K'_{0} = 7.3 pm 0.8$$, and the derivative of bulk modulus $$(delta K_{T}/delta T)_{P} = -0.0027 pm 0.0017$$ GPa/K at 2100 K. The large bulk modulus and its pressure derivative of the peridotite melt compared with that of basaltic melt is consistent with previous results from sink-float experiments.

Journal Articles

Measurement of hydrous peridotite magma density at high pressure using the X-ray absorption method

Sakamaki, Tatsuya*; Otani, Eiji*; Urakawa, Satoru*; Suzuki, Akio*; Katayama, Yoshinori

Earth and Planetary Science Letters, 287(3-4), p.293 - 297, 2009/10

 Times Cited Count:57 Percentile:78.64(Geochemistry & Geophysics)

The density of hydrous peridotite magma containing 5wt.% H$$_{2}$$O was measured at pressures and temperatures up to 4.3 GPa and 2073 K, respectively, using the X-ray absorption method. A fit of pressure-density-temperature data to the high-temperature Birch-Murnagan equation of state yields isothermal bulk modulus $$K_{T}=8.8pm 1.9$$ GPa, its pressure derivative $$K'=9.9pm 3.6$$ and the temperature derivative of the bulk modulus $$(delta K_{T}/delta T)_{P}=-0.0022 pm 0.0015$$ GPa/K at 1773K. The small bulk modulus of the hydrous peridotite magma compared with that of the dry peridotite magma reflects the effect of water, which is more compressible than the silicate melt.

Journal Articles

Element and orbital-specific observation of two-step magnetic transition in NpNiGa$$_5$$; X-ray magnetic circular dichroism study

Okane, Tetsuo; Okochi, Takuo*; Inami, Toshiya; Takeda, Yukiharu; Fujimori, Shinichi; Kawamura, Naomi*; Suzuki, Motohiro*; Tsutsui, Satoshi*; Yamagami, Hiroshi; Fujimori, Atsushi; et al.

Physical Review B, 80(10), p.104419_1 - 104419_7, 2009/09

 Times Cited Count:6 Percentile:29.51(Materials Science, Multidisciplinary)

Journal Articles

Overview of national centralized tokamak program; Mission, design and strategy to contribute ITER and DEMO

Ninomiya, Hiromasa; Akiba, Masato; Fujii, Tsuneyuki; Fujita, Takaaki; Fujiwara, Masami*; Hamamatsu, Kiyotaka; Hayashi, Nobuhiko; Hosogane, Nobuyuki; Ikeda, Yoshitaka; Inoue, Nobuyuki; et al.

Journal of the Korean Physical Society, 49, p.S428 - S432, 2006/12

To contribute DEMO and ITER, the design to modify the present JT-60U into superconducting coil machine, named National Centralized Tokamak (NCT), is being progressed under nationwide collaborations in Japan. Mission, design and strategy of this NCT program is summarized.

Journal Articles

The Effect of argon and helium glow discharge cleaning on boronized surface in LHD

Kizu, Kaname; Yagyu, Junichi; Ishimoto, Yuki*; Nakano, Tomohide; Tsuzuki, Kazuhiro*; Miya, Naoyuki; Ashikawa, Naoko*; Nishimura, Kiyohiko*; Sagara, Akio*

Annual Report of National Institute for Fusion Science; April 2005 - March 2006, P. 65, 2006/11

no abstracts in English

55 (Records 1-20 displayed on this page)