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Journal Articles

Neutron transmission CB-KID imager using samples placed at room temperature

Ishida, Takekazu*; Vu, TheDang*; Shishido, Hiroaki*; Aizawa, Kazuya; Oku, Takayuki; Oikawa, Kenichi; Harada, Masahide; Kojima, Kenji M*; Miyajima, Shigeyuki*; Koyama, Tomio*; et al.

Journal of Low Temperature Physics, 214(3-4), p.152 - 157, 2024/02

Journal Articles

Orientation mapping of YbSn$$_{3}$$ single crystals based on Bragg-dip analysis using a delay-line superconducting sensor

Shishido, Hiroaki*; Vu, TheDang*; Aizawa, Kazuya; Kojima, Kenji M*; Koyama, Tomio*; Oikawa, Kenichi; Harada, Masahide; Oku, Takayuki; Soyama, Kazuhiko; Miyajima, Shigeyuki*; et al.

Journal of Applied Crystallography, 56(4), p.1108 - 1113, 2023/08

Journal Articles

Anaerobic methane-oxidizing activity in a deep underground borehole dominantly colonized by $$Ca.$$ Methanoperedenaceae

Nishimura, Hiroki*; Kozuka, Mariko*; Fukuda, Akari*; Ishimura, Toyoho*; Amano, Yuki; Beppu, Hikari*; Miyakawa, Kazuya; Suzuki, Yohei*

Environmental Microbiology Reports (Internet), 15(3), p.197 - 205, 2023/06

 Times Cited Count:0 Percentile:0(Environmental Sciences)

The family $$Ca.$$ Methanoperedenaceae archaea mediate anaerobic oxidation of methane (AOM). We newly developed a high-pressure laboratory incubation system and investigated groundwater from 214- and 249-m deep boreholes at Horonobe Underground Research Laboratory, Japan, where the high and low abundances of $$Ca.$$ Methanoperedenaceae archaea have been revealed, respectively. We incubated the samples amended with or without amorphous Fe(III) and $$^{13}$$C-labelled methane at an in-situ pressure of 1.6 MPa. After three to seven-day incubation, AOM activities were not detected from the 249-m sample but from the 214-m sample. The AOM rates were 93.7$$pm$$40.6 and 27.7$$pm$$37.5 nM/day with and without Fe(III) amendment. Suspended particulates were not visible in the 249-m sample on the filter, while they were abundant and contained amorphous Fe(III) and Fe(III)-bearing phyllosilicates in the 214-m sample. This supports the in-situ activity of Fe(III)-dependent AOM in the deep subsurface borehole.

Journal Articles

Tunnel magnetoresistance exceeding 100% in magnetic tunnel junctions using Mn-based tetragonal alloy electrodes with perpendicular magnetic anisotropy

Suzuki, Kazuya; Mizukami, Shigemi*

AIP Advances (Internet), 13(3), p.035225_1 - 035225_6, 2023/03

 Times Cited Count:1 Percentile:59.51(Nanoscience & Nanotechnology)

We studied MgO barrier magnetic tunnel junctions (MTJs) comprising perpendicularly magnetized MnGa and FeCoB electrodes. In those perpendicular ($$p$$-) MTJs, we utilized thin metastable bcc CoMn alloys for an interlayer between MnGa and MgO to enhance the tunnel magnetoresistance (TMR). Moreover, we investigated the effect of a thin Mg interlayer between MnGa and CoMn. Owing to the interlayer engineering, we achieved a TMR ratio over 100%, the highest value observed for $$p$$-MTJs with a tetragonal MnGa electrode. Our study contributes to the further development of spintronic devices using $$p$$-MTJs with various Mn-based tetragonal alloy electrodes.

JAEA Reports

Stepwise renewal of JRR-3 process control computer system

Isaka, Koji; Suwa, Masayuki; Kimura, Kazuya; Suzuki, Makoto; Ikekame, Yoshinori; Nagadomi, Hideki

JAEA-Technology 2021-039, 48 Pages, 2023/02

JAEA-Technology-2021-039.pdf:6.97MB

JRR-3 Process control system is used from the initial criticality (1990) after remodeling JRR- 3 as equipment used for monitoring and control of flow rate, temperature, pressure, water level, etc. of coolant and operation of nuclear reactor equipment, and it became necessary to renew as the aging progressed and spare parts could not be obtained sufficiently. Upon renewal, from the viewpoint of ensuring conservation of the core such as decay heat removal and minimizing the impact on reactor users and minimizing costs, it is important not to stop long-term reactor shutdown we planned to divide it into three stages and make it on a continuous basis. This report summarizes the renewal plan and renewal work divided into three stages.

Journal Articles

Tracing magnetic atom diffusion with annealing at the interface between CoMn alloy and MnGa layer by X-ray magnetic circular dichroism

Okabayashi, Jun*; Suzuki, Kazuya; Mizukami, Shigemi*

Journal of Magnetism and Magnetic Materials, 564, Part2, p.170163_1 - 170163_5, 2022/12

 Times Cited Count:1 Percentile:17.17(Materials Science, Multidisciplinary)

The magnetic atom diffusion at the interface between CoMn alloy and MnGa layer with annealing is studied using X-ray magnetic circular dichroism (XMCD) analysis. We found that the spins in bcc CoMn are coupled parallel to those in perpendicularly magnetized MnGa layer under the as-grown conditions, while the post annealing modulates the interfacial magnetic coupling to antiferromagnetic in Co. The elementspecific hysteresis curves at each absorption edge revealed the large coercive fields in Mn and Co through the exchange coupling with MnGa. After the annealing process, the changes of XMCD spectral line shapes are related to the interfacial reactions promoting the formation of Mn and Co$$_{2}$$MnGa layers, which is deduced from the analysis oftransmission electron microscopy. The interfacial diffusion of Mn atoms modulates the magnetic exchange coupling between Mn and Co sites and reverses the direction of perpendicular magnetization.

Journal Articles

High spatial resolution neutron transmission imaging using a superconducting two-dimensional detector

Shishido, Hiroaki*; Nishimura, Kazuma*; Vu, TheDang*; Aizawa, Kazuya; Kojima, Kenji M*; Koyama, Tomio*; Oikawa, Kenichi; Harada, Masahide; Oku, Takayuki; Soyama, Kazuhiko; et al.

IEEE Transactions on Applied Superconductivity, 31(9), p.2400505_1 - 2400505_5, 2021/12

 Times Cited Count:0 Percentile:0(Engineering, Electrical & Electronic)

In this study, we employed a superconducting detector, current-biased kinetic-inductance detector (CB-KID) for neutron imaging using a pulsed neutron source. We employed the delay-line method, and high spatial resolution imaging with only four reading channels was achieved. We also performed wavelength-resolved neutron imaging by the time-of-flight method. We obtained the neutron transmission images of a Gd-Al alloy sample, inside which single crystals of GdAl$$_{3}$$ were grown, using the delay-line CB-KID. Single crystals were well imaged, in both shapes and distributions, throughout the Al-Gd alloy. We identified Gd nuclei via neutron transmissions that exhibited characteristic suppression above the neutron wavelength of 0.03 nm. In addition, the $$_{155}$$Gd resonance dip, a dip structure of the transmission caused by the nuclear reaction between an isotope and neutrons, was observed even when the number of events was summed over a limited area of 15 $$mu$$m $$times$$ 12 $$mu$$m. Gd selective imaging was performed using the resonance dip of $$_{155}$$Gd, and it showed clear Gd distribution even with a limited neutron wavelength range of 1 pm.

Journal Articles

Practical tests of neutron transmission imaging with a superconducting kinetic-inductance sensor

Vu, TheDang; Shishido, Hiroaki*; Aizawa, Kazuya; Kojima, Kenji M*; Koyama, Tomio*; Oikawa, Kenichi; Harada, Masahide; Oku, Takayuki; Soyama, Kazuhiko; Miyajima, Shigeyuki*; et al.

Nuclear Instruments and Methods in Physics Research A, 1006, p.165411_1 - 165411_8, 2021/08

 Times Cited Count:0 Percentile:0.02(Instruments & Instrumentation)

JAEA Reports

Development of fireproof sheet on glove box panels

Kawasaki, Kohei; Shinada, Kenta; Okamoto, Naritoshi; Kageyama, Tomio; Eda, Takashi; Okazaki, Hiro; Suzuki, Hiromichi; Yamamoto, Kazuya; Otabe, Jun

JAEA-Technology 2020-025, 80 Pages, 2021/03

JAEA-Technology-2020-025.pdf:3.72MB

Plutonium Fuel Production Facility was built in 1988 for the purpose of mainly producing MOX fuel of the prototype fast breeder reactor MONJU, and large glove boxes were installed for handling unsealed nuclear fuel material remotely. The panels of these glove boxes are made of acrylic, except for those installed after December 2013. For fires inside the glove box, automatic fire extinguishing systems using halides have been introduced since the beginning of construction, but for fires outside the glove box, there have been issues with direct measures for acrylic. Therefore, we have developed a fireproof sheet that mitigates the effect of fire outside the glove box on the panels as much as possible. As a result, fire-retardant sheets have been selected and attached to the glove box panels. We conducted a flammability test of the acrylic plate attached with these fireproof sheets and a usage environment influence test of fireproof sheets, and obtained good results. In addition, we set up a working group in the Plutonium Fuel Development Center in view of reducing external exposure during the work of attaching fireproof sheets, in which we discussed and examined the work procedure, and summarized it in the basic procedure manual.

Journal Articles

Homogeneity of neutron transmission imaging over a large sensitive area with a four-channel superconducting detector

Vu, TheDang; Shishido, Hiroaki*; Kojima, Kenji M*; Koyama, Tomio*; Oikawa, Kenichi; Harada, Masahide; Miyajima, Shigeyuki*; Oku, Takayuki; Soyama, Kazuhiko; Aizawa, Kazuya; et al.

Superconductor Science and Technology, 34(1), p.015010_1 - 015010_10, 2021/01

 Times Cited Count:3 Percentile:28.82(Physics, Applied)

Journal Articles

Energy-resolved neutron imaging using a delay line current-biased kinetic-inductance detector

Shishido, Hiroaki*; Nishimura, Kazuma*; Vu, TheDang*; Kojima, Kenji M*; Koyama, Tomio*; Oikawa, Kenichi; Harada, Masahide; Miyajima, Shigeyuki*; Hidaka, Mutsuo*; Oku, Takayuki; et al.

Journal of Physics; Conference Series, 1590, p.012033_1 - 012033_8, 2020/10

Journal Articles

Development and application of a $$^3$$He neutron spin filter at J-PARC

Okudaira, Takuya; Oku, Takayuki; Ino, Takashi*; Hayashida, Hirotoshi*; Kira, Hiroshi*; Sakai, Kenji; Hiroi, Kosuke; Takahashi, Shingo*; Aizawa, Kazuya; Endo, Hitoshi*; et al.

Nuclear Instruments and Methods in Physics Research A, 977, p.164301_1 - 164301_8, 2020/10

 Times Cited Count:9 Percentile:79.84(Instruments & Instrumentation)

Journal Articles

The $$f$$-electron state of the heavy fermion superconductor NpPd$$_5$$Al$$_2$$ and the isostructural family

Metoki, Naoto; Aczel, A. A.*; Aoki, Dai*; Chi, S.*; Fernandez-Baca, J. A.*; Griveau, J.-C.*; Hagihara, Masato*; Hong, T.*; Haga, Yoshinori; Ikeuchi, Kazuhiko*; et al.

JPS Conference Proceedings (Internet), 30, p.011123_1 - 011123_6, 2020/03

Rare earths (4$$f$$) and actinides (5$$f$$) provide variety of interesting states realized with competing interactions between the increasing number of $$f$$ electrons. Since crystal field splitting of many-body $$f$$ electron system is smaller than the bandwidth, (1) high resolution experiments are needed, (2) essentially no clear spectrum with well defined peaks is expected in itinerant Ce and U compounds, and (3) Np and Pu is strictly regulated. Therefore, systematic research on magnetic excitations by neutron scattering experiments of localized compounds and rare earth iso-structural reference is useful. We describe the $$f$$ electron states of heavy electron compounds NpPd$$_5$$Al$$_2$$ and actinide and rare earth based iso-structural family.

Journal Articles

Sequestration and oxidation of Cr(III) by fungal Mn oxides with Mn(II) oxidizing activity

Suzuki, Ryohei*; Tani, Yukinori*; Naito, Hirotaka*; Miyata, Naoyuki*; Tanaka, Kazuya

Catalysts, 10(1), p.44_1 - 44_15, 2020/01

 Times Cited Count:10 Percentile:41.25(Chemistry, Physical)

We prepared biogenic Mn oxides (BMOs) using ${it Acremonium strictum}$ strain KR21-2, and subsequently conducted single or repeated treatment experiments in Cr(NO$$_{3}$$)$$_{3}$$ at pH6.0. Under aerobic conditions, newly formed BMOs exhibited a rapid production of Cr(VI) without a significant release of Mn(II), demonstrating that newly formed BMO mediates a catalytic oxidation of Cr(III) with a self-regeneration step of reduced Mn. In anaerobic solution, newly formed BMOs showed a cessation of Cr(III) oxidation in the early stage of the reaction, and subsequently had a much smaller Cr(VI) production with significant release of reduced Mn(II).

Journal Articles

Energy-resolved neutron imaging with high spatial resolution using a superconducting delay-line kinetic inductance detector

Iizawa, Yuki*; Shishido, Hiroaki*; Nishimura, Kazuma*; Vu, TheDang*; Kojima, Kenji M*; Koyama, Tomio*; Oikawa, Kenichi; Harada, Masahide; Miyajima, Shigeyuki*; Hidaka, Mutsuo*; et al.

Superconductor Science and Technology, 32(12), p.125009_1 - 125009_8, 2019/12

 Times Cited Count:11 Percentile:56.9(Physics, Applied)

Journal Articles

Enhancement of element production by incomplete fusion reaction with weakly bound deuteron

Wang, H.*; Otsu, Hideaki*; Chiga, Nobuyuki*; Kawase, Shoichiro*; Takeuchi, Satoshi*; Sumikama, Toshiyuki*; Koyama, Shumpei*; Sakurai, Hiroyoshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; et al.

Communications Physics (Internet), 2(1), p.78_1 - 78_6, 2019/07

 Times Cited Count:7 Percentile:56.64(Physics, Multidisciplinary)

Searching for effective pathways for the production of proton- and neutron-rich isotopes through an optimal combination of reaction mechanism and energy is one of the main driving forces behind experimental and theoretical nuclear reaction studies as well as for practical applications in nuclear transmutation of radioactive waste. We report on a study on incomplete fusion induced by deuteron, which contains one proton and one neutron with a weak binding energy and is easily broken up. This reaction study was achieved by measuring directly the cross sections for both proton and deuteron for $$^{107}$$Pd at 50 MeV/u via inverse kinematics technique. The results provide direct experimental evidence for the onset of a cross-section enhancement at high energy, indicating the potential of incomplete fusion induced by loosely-bound nuclei for creating proton-rich isotopes and nuclear transmutation of radioactive waste.

Journal Articles

Neutron inelastic scattering study of the $$f$$-electron states in NdPd$$_5$$Al$$_2$$

Metoki, Naoto; Yamauchi, Hiroki; Suzuki, Hiroyuki*; Kitazawa, Hideaki*; Kamazawa, Kazuya*; Ikeuchi, Kazuhiko*; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro

Journal of the Physical Society of Japan, 87(8), p.084708_1 - 084708_7, 2018/08

 Times Cited Count:6 Percentile:46.89(Physics, Multidisciplinary)

Inelastic neutron scattering experiments were carried out in order to study the $$f$$-electron states of NdPd$$_5$$Al$$_2$$The CEF levels at 0K, 35.4K, 88.3K, 101.5K, and 198.8K were clarified from the excitation spectra. The $$Gamma_6$$ ground state contains the orbital with $$J_z=pm9/2$$ as a main component due to a large negative B$$_{20}=-1.4$$K, which is the origin of the strong uniaxial anisotropy. The estimated magnetic moment, the calculated susceptibility, magnetization curve, and specific heat are in good agreement with the experimental data. The existence of a common charge distribution with CePd$$_5$$Al$$_2$$ and PrPd$$_5$$Al$$_2$$. Indicates that a localized character is important even in actinide-based iso-structural compounds as actually observed in UPd$$_5$$Al$$_2$$ and also NpPd$$_5$$Al$$_2$$, in which the valence crossover plays important role for the heavy fermion superconductivity.

Journal Articles

High stereographic resolution texture and residual stress evaluation using time-of-flight neutron diffraction

Xu, P. G.; Harjo, S.; Ojima, Mayumi*; Suzuki, Hiroshi; Ito, Takayoshi*; Gong, W.; Vogel, S. C.*; Inoue, Junya*; Tomota, Yo*; Aizawa, Kazuya; et al.

Journal of Applied Crystallography, 51(3), p.746 - 760, 2018/06

AA2018-0163.pdf:3.0MB

 Times Cited Count:23 Percentile:90.77(Chemistry, Multidisciplinary)

Journal Articles

Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex, 2; Neutron scattering instruments

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.

Journal Articles

Materials and Life Science Experimental Facility at the Japan Proton Accelerator Research Complex, 3; Neutron devices and computational and sample environments

Sakasai, Kaoru; Sato, Setsuo*; Seya, Tomohiro*; Nakamura, Tatsuya; To, Kentaro; Yamagishi, Hideshi*; Soyama, Kazuhiko; Yamazaki, Dai; Maruyama, Ryuji; Oku, Takayuki; et al.

Quantum Beam Science (Internet), 1(2), p.10_1 - 10_35, 2017/09

Neutron devices such as neutron detectors, optical devices including supermirror devices and $$^{3}$$He neutron spin filters, and choppers are successfully developed and installed at the Materials Life Science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC), Tokai, Japan. Four software components of MLF computational environment, instrument control, data acquisition, data analysis, and a database, have been developed and equipped at MLF. MLF also provides a wide variety of sample environment options including high and low temperatures, high magnetic fields, and high pressures. This paper describes the current status of neutron devices, computational and sample environments at MLF.

237 (Records 1-20 displayed on this page)