Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 109

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Transverse asymmetry of individual $$gamma$$ rays in the $$^{139}$$La($$overrightarrow{n},gamma$$)$$^{140}$$La reaction

Okuizumi, Mao*; Auton, C. J.*; Endo, Shunsuke; Fujioka, Hiroyuki*; Hirota, Katsuya*; Ino, Takashi*; Ishizaki, Kohei*; Kimura, Atsushi; Kitaguchi, Masaaki*; Koga, Jun*; et al.

Physical Review C, 111(3), p.034611_1 - 034611_6, 2025/03

 Times Cited Count:0 Percentile:0.00(Physics, Nuclear)

Journal Articles

Growth processes of zircon crystals in a granitic magma chamber, variation in U-Pb age, titanium concentration, and Th/U in relation to internal texture

Yuguchi, Takashi*; Endo, Kyoka*; Suzuki, Satoshi*; Ogita, Yasuhiro; Sakata, Shuhei*; Yokoyama, Tatsunori; Imura, Takumi*; Ono, Takeshi*; Sasao, Eiji

Lithos, 494-495, p.107909_1 - 107909_14, 2025/02

 Times Cited Count:0 Percentile:0.00(Geochemistry & Geophysics)

This study described the growth characteristics of zircon crystals in the Kuki granite from the Kitakami Mountains in northeastern Japan as the key for elucidating granitic magma chamber processes. Using two approaches, analyses based on multiple sections of separated zircon crystals and thin-section-based zircon crystal analyses, we determined the characteristics of the 3D internal structure of the crystals, variations in U-Pb age, Ti concentrations, and Th/U in relation to crystal texture, and the crystallization sequence between zircon crystals and other minerals within the magma chamber. The textures, which occupy a large proportion of zircon, comprise low luminescence homogeneous cores (LLCs) and oscillatory zoning (OZ). The 3D distribution of the zircon internal structure can be classified into three types: Type 1 zircon comprising LLCs and the surrounding OZ and Types 2 and 3 zircon crystals composed entirely of OZ from the cores to the rims and characterized by brightness and darkness cores, respectively. LLC and OZ grew at temperatures from approximately 900 to 800$$^{circ}$$C and 850 to 700$$^{circ}$$C, respectively, and LLC has a higher Th/U than that of OZ, indicating that fractional crystallization progression as the magma chamber cooled resulted in the transition from LLC to OZ. In the progression of fractional crystallization, the diffusion rate deceleration with decreasing magma temperatures triggered the transition from interfacial reaction-controlled growth producing LLC to diffusion-controlled growth producing OZ. In the thin-section analysis, zircon crystals which contained in different minerals are characterized by different Th/U values. The variation in Th/U and the crystallization temperature of zircon crystals considering the surrounding minerals can be used to elucidate the differentiation and mineral crystallization in magma chamber processes over a wide range of temperature conditions.

Journal Articles

Circular polarization measurement for individual gamma rays in capture reactions with intense pulsed neutrons

Endo, Shunsuke; Abe, Ryota*; Fujioka, Hiroyuki*; Ino, Takashi*; Iwamoto, Osamu; Iwamoto, Nobuyuki; Kawamura, Shiori*; Kimura, Atsushi; Kitaguchi, Masaaki*; Kobayashi, Ryuju*; et al.

European Physical Journal A, 60(8), p.166_1 - 166_10, 2024/08

 Times Cited Count:2 Percentile:74.11(Physics, Nuclear)

Journal Articles

High sensitivity of a future search for effects of $$P$$-odd/$$T$$-odd interactions on the 0.75 eV $$p$$-wave resonance in $$overrightarrow{n}$$+$$^{139}overrightarrow{textrm{La}}$$ forward transmission determined using a pulsed neutron beam

Nakabe, Rintaro*; Auton, C. J.*; Endo, Shunsuke; Fujioka, Hiroyuki*; Gudkov, V.*; Hirota, Katsuya*; Ide, Ikuo*; Ino, Takashi*; Ishikado, Motoyuki*; Kambara, Wataru*; et al.

Physical Review C, 109(4), p.L041602_1 - L041602_4, 2024/04

 Times Cited Count:1 Percentile:18.90(Physics, Nuclear)

Journal Articles

Spin dependence in the $$p$$-wave resonance of $$^{139}$$$overrightarrow{textrm{La}}$+$overrightarrow{n}$

Okudaira, Takuya*; Nakabe, Rintaro*; Auton, C. J.*; Endo, Shunsuke; Fujioka, Hiroyuki*; Gudkov, V.*; Ide, Ikuo*; Ino, Takashi*; Ishikado, Motoyuki*; Kambara, Wataru*; et al.

Physical Review C, 109(4), p.044606_1 - 044606_9, 2024/04

 Times Cited Count:2 Percentile:74.11(Physics, Nuclear)

Journal Articles

Petrography and geochronology of the Kuki granite, Kitakami mountains, northeastern Japan; Shallow crustal intrusion and emplacement processes of granitic magma

Suzuki, Satoshi*; Yuguchi, Takashi*; Ishiguro, Keito*; Endo, Kyoka*; Kato, Asuka*; Yokoyama, Kosuke*; Ogita, Yasuhiro; Yokoyama, Tatsunori; Sakata, Shuhei*; Ono, Takeshi*; et al.

Journal of Mineralogical and Petrological Sciences (Internet), 119(1), p.230807_1 - 230807_18, 2024/02

 Times Cited Count:1 Percentile:45.39(Mineralogy)

Understanding the crustal evolutionary dynamics of island arc-trench systems requires a thorough evaluation of magma chamber processes, and especially of shallow crustal granitic magma intrusion and emplacement processes. To address this, we studied the petrography and geochronology of the Kuki granite, Kitakami Mountains, northeast Japan, as an example of a non-adakitic granite at the magmatic flare-up stage. Granitic borehole samples reflect vertical variation within a magma chamber. Whole-rock chemical composition and mode data reveal a vertical transition from felsic to mafic composition with increasing depth, potentially due to gravitational fractionation of crystals in the magma chamber. The pressure and temperature history of the Kuki granite indicates no change in the magma depth with cooling from 800 to 730$$^{circ}$$C, and geobarometric calculations indicate the emplacement of magma at a depth of approximately10 km. Simultaneous determination of the zircon U Pb age, Ti concentration, and Th/U yields 1) the time temperature history of granitic magma before its solidification, and 2) the correlation between temperature and Th/U in the magma. The magma chamber cooled from ca. 900 to 700$$^{circ}$$C at approximately 125 Ma. The change in Th/U with temperature indicates greater fractional crystallization in the magma chamber at temperatures above 800$$^{circ}$$C than below 800$$^{circ}$$C. Samples from different depth exhibit common tendencies in terms of the relationship between Th/U and temperature, indicating the same system of fractional crystallization throughout the cooling magma chamber.

Journal Articles

Iron-induced association between selenium and humic substances in groundwater from deep sedimentary formations

Terashima, Motoki; Endo, Takashi*; Kimuro, Shingo; Beppu, Hikari*; Nemoto, Kazuaki*; Amano, Yuki

Journal of Nuclear Science and Technology, 60(4), p.374 - 384, 2023/04

 Times Cited Count:4 Percentile:28.39(Nuclear Science & Technology)

JAEA Reports

Analysis of the radioactivity concentrations in radioactive waste generated from JPDR Facility

Tobita, Minoru*; Haraga, Tomoko; Endo, Tsubasa*; Omori, Hiroyuki*; Mitsukai, Akina; Aono, Ryuji; Ueno, Takashi; Ishimori, Kenichiro; Kameo, Yutaka

JAEA-Data/Code 2021-013, 30 Pages, 2021/12

JAEA-Data-Code-2021-013.pdf:1.47MB

Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal field. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes until the beginning of disposal. In order to contribute to this work, we collected and analyzed concrete samples generated from JPDR facility. In this report, we summarized the radioactivity concentrations of 21 radionuclides ($$^{3}$$H, $$^{14}$$C, $$^{36}$$Cl, $$^{41}$$Ca, $$^{60}$$Co, $$^{63}$$Ni, $$^{90}$$Sr, $$^{94}$$Nb, $$^{rm 108m}$$Ag, $$^{137}$$Cs, $$^{152}$$Eu, $$^{154}$$Eu, $$^{rm 166m}$$Ho, $$^{234}$$U, $$^{238}$$U, $$^{238}$$Pu, $$^{239}$$Pu, $$^{240}$$Pu, $$^{241}$$Am, $$^{243}$$Am, $$^{244}$$Cm) which were obtained from radiochemical analysis of the samples in fiscal year 2018-2019.

Journal Articles

Development of evaluation method for diffusion and filtration behavior of colloid in compacted bentonites using dendrimers

Endo, Takashi*; Tachi, Yukio; Ishidera, Takamitsu; Terashima, Motoki

Nihon Genshiryoku Gakkai Wabun Rombunshi, 20(1), p.9 - 22, 2021/03

Evaluation method of colloid diffusion and filtration in compacted bentonites was developed using dendrimers. Diffusion and filtration behavior of PAMAM dendrimers with the size of 5.7$$sim$$7.2nm was investigated by the through-diffusion experiment in bentonite compacted to 0.8 Mg/m$$^{3}$$ and saturated with 0.005$$sim$$0.5mol/L NaCl. Effective diffusivities (De) and filtration ratios (Rf) of dendrimers were determined from the breakthrough curves and the depth profiles in compacted bentonite, respectively. The De values of negatively charged dendrimer increased when porewater salinity increased and dendrimer size decreased as influenced by anion exclusion effect in negatively charged clay surfaces. The Rf values increased when porewater salinity decreased and dendrimer size increased, demonstrating significant fractions of dendrimer were filtered by narrow pores in complex pore networks. These trends consistent with the previous studies emphasize the validity of the evaluation method using dendrimer.

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:21 Percentile:88.75(Instruments & Instrumentation)

Journal Articles

Transverse asymmetry of $$gamma$$ rays from neutron-induced compound states of $$^{140}$$La

Yamamoto, Tomoki*; Okudaira, Takuya; Endo, Shunsuke; Fujioka, Hiroyuki*; Hirota, Katsuya*; Ino, Takashi*; Ishizaki, Kohei*; Kimura, Atsushi; Kitaguchi, Masaaki*; Koga, Jun*; et al.

Physical Review C, 101(6), p.064624_1 - 064624_8, 2020/06

 Times Cited Count:18 Percentile:84.46(Physics, Nuclear)

Journal Articles

Determination of humic substances in deep groundwater from sedimentary formations by the carbon concentration-based DAX-8 resin isolation technique

Terashima, Motoki; Endo, Takashi*; Miyakawa, Kazuya

Journal of Nuclear Science and Technology, 57(4), p.380 - 387, 2020/04

 Times Cited Count:2 Percentile:17.25(Nuclear Science & Technology)

Journal Articles

Measurement of the angular distribution of $$gamma$$-rays after neutron capture by $$^{139}$$La for a T-violation search

Okudaira, Takuya; Shimizu, Hirohiko*; Kitaguchi, Masaaki*; Hirota, Katsuya*; Haddock, C. C.*; Ito, Ikuya*; Yamamoto, Tomoki*; Endo, Shunsuke*; Ishizaki, Kohei*; Sato, Takumi*; et al.

EPJ Web of Conferences, 219, p.09001_1 - 09001_6, 2019/12

Parity violating effects enhanced by up to 10$$^6$$ times have been observed in several neutron induced compound nuclei. There is a theoretical prediction that time reversal (T) violating effects can also be enhanced in these nuclei implying that T-violation can be searched for by making very sensitive measurements. However, the enhancement factor has not yet been measured in all nuclei. The angular distribution of the (n,$$gamma$$) reaction was measured with $$^{139}$$La by using a germanium detector assembly at J-PARC, and the enhancement factor was obtained. From the result, the measurement time to achieve the most sensitive T-violation search was estimated as 1.4 days, and a 40% polarized $$^{139}$$La target and a 70% polarized $$^3$$He spin filter whose thickness is 70 atm$$cdot$$cm are needed. Therefore high quality $$^3$$He spin filter is developed in JAEA. The measurement result of the (n,$$gamma$$) reaction at J-PARC and the development status of the $$^3$$He spin filter will be presented.

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

A Stencil framework to realize large-scale computations beyond device memory capacity on GPU supercomputers

Shimokawabe, Takashi*; Endo, Toshio*; Onodera, Naoyuki; Aoki, Takayuki*

Proceedings of 2017 IEEE International Conference on Cluster Computing (IEEE Cluster 2017) (Internet), p.525 - 529, 2017/09

Stencil-based applications such as CFD have succeeded in obtaining high performance on GPU supercomputers. The problem sizes of these applications are limited by the GPU device memory capacity, which is typically smaller than the host memory. On GPU supercomputers, a locality improvement technique using temporal blocking method with memory swapping between host and device enables large computation beyond the device memory capacity. Our high-productivity stencil framework automatically applies temporal blocking to boundary exchange required for stencil computation and supports automatic memory swapping provided by a MPI/CUDA wrapper library. The framework-based application for the airflow in an urban city maintains 80% performance even with the twice larger than the GPU memory capacity and have demonstrated good weak scalability on the TSUBAME 2.5 supercomputer.

Journal Articles

Gamma radiation resistance of spin Seebeck devices

Yagmur, A.*; Uchida, Kenichi*; Ihara, Kazuki*; Ioka, Ikuo; Kikkawa, Takashi*; Ono, Madoka*; Endo, Junichi*; Kashiwagi, Kimiaki*; Nakashima, Tetsuya*; Kirihara, Akihiro*; et al.

Applied Physics Letters, 109(24), p.243902_1 - 243902_4, 2016/12

 Times Cited Count:3 Percentile:13.39(Physics, Applied)

Thermoelectric devices based on the spin Seebeck effect (SSE) were irradiated with gamma ($$gamma$$) rays with the total dose of around 3$$times$$10$$^{5}$$ Gy in order to investigate the $$gamma$$-radiation resistance of the devices. To demonstrate this, Pt/Ni$$_{0.2}$$Zn$$_{0.3}$$Fe$$_{2.5}$$O$$_{4}$$/Glass and Pt/Bi$$_{0.1}$$Y$$_{2.9}$$Fe$$_{5}$$O$$_{12}$$/Gd$$_{3}$$Ga$$_{5}$$O$$_{12}$$ SSE devices were used. We confirmed that the thermoelectric, magnetic, and structural properties of the SSE devices are not affected by the $$gamma$$-ray irradiation. This result demonstrates that SSE devices are applicable to thermoelectric generation even in high radiation environments.

Journal Articles

Small-angle neutron scattering study of specific interaction and coordination structure formed by mono-acetyl-substituted dibenzo-20-crown-6-ether and cesium ions

Motokawa, Ryuhei; Kobayashi, Toru; Endo, Hitoshi*; Ikeda, Takashi; Yaita, Tsuyoshi; Suzuki, Shinichi; Narita, Hirokazu*; Akutsu, Kazuhiro*; Heller, W. T.*

Journal of Nuclear Science and Technology, 53(8), p.1205 - 1211, 2016/08

 Times Cited Count:1 Percentile:9.49(Nuclear Science & Technology)

Journal Articles

22A beam production of the uniform negative ions in the JT-60 negative ion source

Yoshida, Masafumi; Hanada, Masaya; Kojima, Atsushi; Kashiwagi, Mieko; Grisham, L. R.*; Hatayama, Akiyoshi*; Shibata, Takanori*; Yamamoto, Takashi*; Akino, Noboru; Endo, Yasuei; et al.

Fusion Engineering and Design, 96-97, p.616 - 619, 2015/10

 Times Cited Count:13 Percentile:69.44(Nuclear Science & Technology)

In JT-60 Super Advanced for the fusion experiment, 22A, 100s negative ions are designed to be extracted from the world largest ion extraction area of 450 mm $$times$$ 1100 mm. One of the key issues for producing such as high current beams is to improve non-uniform production of the negative ions. In order to improve the uniformity of the negative ions, a tent-shaped magnetic filter has newly been developed and tested for JT-60SA negative ion source. The original tent-shaped filter significantly improved the logitudunal uniformity of the extracted H$$^{-}$$ ion beams. The logitudinal uniform areas within a $$pm$$10 deviation of the beam intensity were improved from 45% to 70% of the ion extraction area. However, this improvement degrades a horizontal uniformity. For this, the uniform areas was no more than 55% of the total ion extraction area. In order to improve the horizontal uniformity, the filter strength has been reduced from 660 Gasus$$cdot$$cm to 400 Gasus$$cdot$$cm. This reduction improved the horizontal uniform area from 75% to 90% without degrading the logitudinal uniformity. This resulted in the improvement of the uniform area from 45% of the total ion extraction areas. This improvement of the uniform area leads to the production of a 22A H$$^{-}$$ ion beam from 450 mm $$times$$ 1100 mm with a small amount increase of electron current of 10%. The obtained beam current fulfills the requirement for JT-60SA.

JAEA Reports

Evaluation of irradiation behavior on oxide dispersion strengthened (ODS) steel claddings irradiated in Joyo/CMIR-6

Yano, Yasuhide; Otsuka, Satoshi; Yamashita, Shinichiro; Ogawa, Ryuichiro; Sekine, Manabu; Endo, Toshiaki; Yamagata, Ichiro; Sekio, Yoshihiro; Tanno, Takashi; Uwaba, Tomoyuki; et al.

JAEA-Research 2013-030, 57 Pages, 2013/11

JAEA-Research-2013-030.pdf:48.2MB

It is necessary to develop the fast reactor core materials, which can achieve high-burnup operation improving safety and economical performance. Ferritic steels are expected to be good candidate core materials to achieve this objective because of their excellent void swelling resistance. Therefore, oxide dispersion strengthened (ODS) ferritic steel and 11Cr-ferritic/martensitic steel (PNC-FMS) have been respectively developed for cladding and wrapper tube materials in Japan Atomic Energy Agency. In this study, the effects of fast neutron irradiation on mechanical properties and microstructure of 9Cr-and 12Cr-ODS steel claddings for fast reactor were investigated. Specimens were irradiated in the experimental fast reactor Joyo using the CMIR-6 at temperatures between 420 and 835$$^{circ}$$C to fast neutron doses ranging from 16 to 33 dpa. The post-irradiation ring tensile tests were carried out at irradiation temperatures.

Journal Articles

Origin of non-uniformity of the source plasmas in JT-60 negative ion source

Yoshida, Masafumi; Hanada, Masaya; Kojima, Atsushi; Inoue, Takashi; Kashiwagi, Mieko; Grisham, L. R.*; Akino, Noboru; Endo, Yasuei; Komata, Masao; Mogaki, Kazuhiko; et al.

Plasma and Fusion Research (Internet), 8(Sp.1), p.2405146_1 - 2405146_4, 2013/11

Distributions of H$$^{0}$$ and H$$^{+}$$ in the source plasmas produced at the end-plugs of JT-60 negative ions source were measured by Langmuir probes and emission spectroscopy in order to experimentally investigate the cause of lower density of the negative ions extracted from end-plugs in the source. Densities of H$$^{0}$$ and H$$^{+}$$ in end-plugs of the plasma grid in the source were compared with those in the center regions. As a result, lower density of the negative ion at the edge was caused by lower beam optics due to lower and higher density of the H$$^{0}$$ and H$$^{+}$$.

109 (Records 1-20 displayed on this page)