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Iwamoto, Osamu; Iwamoto, Nobuyuki; Kunieda, Satoshi; Minato, Futoshi; Nakayama, Shinsuke; Abe, Yutaka*; Tsubakihara, Kosuke*; Okumura, Shin*; Ishizuka, Chikako*; Yoshida, Tadashi*; et al.
Journal of Nuclear Science and Technology, 60(1), p.1 - 60, 2023/01
Times Cited Count:75 Percentile:99.99(Nuclear Science & Technology)Ohshima, Hiroyuki; Morishita, Masaki*; Aizawa, Kosuke; Ando, Masanori; Ashida, Takashi; Chikazawa, Yoshitaka; Doda, Norihiro; Enuma, Yasuhiro; Ezure, Toshiki; Fukano, Yoshitaka; et al.
Sodium-cooled Fast Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.3, 631 Pages, 2022/07
This book is a collection of the past experience of design, construction, and operation of two reactors, the latest knowledge and technology for SFR designs, and the future prospects of SFR development in Japan. It is intended to provide the perspective and the relevant knowledge to enable readers to become more familiar with SFR technology.
Toyoda, Satoshi*; Yamamoto, Tomoki*; Yoshimura, Masashi*; Sumida, Hirosuke*; Mineoi, Susumu*; Machida, Masatake*; Yoshigoe, Akitaka; Suzuki, Satoru*; Yokoyama, Kazushi*; Ohashi, Yuji*; et al.
Vacuum and Surface Science, 64(2), p.86 - 91, 2021/02
We have developed measurement and analysis techniques in X-ray photoelectron spectroscopy. To begin with, time-division depth profiles of gate stacked film interfaces have been achieved by NAP-HARPES (Near Ambient Pressure Hard X-ray Angle-Resolved Photo Emission Spectroscopy) data. We then have promoted our methods to quickly perform peak fittings and depth profiling from time-division ARPES data, which enables us to realize 4D-XPS analysis. It is found that the traditional maximum entropy method (MEM) combined with Jackknife averaging of sparse modeling in NAP-HARPES data is effective to perform dynamic measurement of depth profiles with high precision.
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 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,) reaction was measured with 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 La target and a 70% polarized He spin filter whose thickness is 70 atmcm are needed. Therefore high quality He spin filter is developed in JAEA. The measurement result of the (n,) reaction at J-PARC and the development status of the He spin filter will be presented.
Strasser, P.*; Abe, Mitsushi*; Aoki, Masaharu*; Choi, S.*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; et al.
EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01
Times Cited Count:13 Percentile:98.93(Quantum Science & Technology)Ueno, Yasuhiro*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; Ito, Takashi; Iwasaki, Masahiko*; et al.
Hyperfine Interactions, 238(1), p.14_1 - 14_6, 2017/11
Times Cited Count:3 Percentile:86.37(Physics, Atomic, Molecular & Chemical)Strasser, P.*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; Ito, Takashi; Iwasaki, Masahiko*; et al.
Hyperfine Interactions, 237(1), p.124_1 - 124_9, 2016/12
Times Cited Count:7 Percentile:90.97(Physics, Atomic, Molecular & Chemical)Iguchi, Masahide; Morimoto, Masaaki; Chida, Yutaka*; Hemmi, Tsutomu; Nakajima, Hideo; Nakahira, Masataka; Koizumi, Norikiyo; Yamamoto, Akio*; Miyake, Takashi*; Sawa, Naoki*
IEEE Transactions on Applied Superconductivity, 24(3), p.3801004_1 - 3801004_4, 2014/06
Times Cited Count:6 Percentile:35.56(Engineering, Electrical & Electronic)no abstracts in English
Tokuhisa, Atsushi*; Arai, Junya*; Jochi, Yasumasa*; Ono, Yoshiyuki*; Kameyama, Toyohisa*; Yamamoto, Keiji*; Hatanaka, Masayuki*; Gerofi, B.*; Shimada, Akio*; Kurokawa, Motoyoshi*; et al.
Journal of Synchrotron Radiation, 20(6), p.899 - 904, 2013/11
Times Cited Count:5 Percentile:29.09(Instruments & Instrumentation)Nakanishi, Chika; Sato, Takeshi; Sato, Sohei; Nagai, Haruyasu; Kakefuda, Toyokazu; Katata, Genki; Tsuzuki, Katsunori; Ikeda, Takeshi; Okuno, Hiroshi; Yamamoto, Kazuya; et al.
JAEA-Technology 2013-030, 105 Pages, 2013/10
North Korea carried out the third nuclear test in February 2013. Due to the request of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Nuclear Emergency Assistance and Training Center (NEAT) and Nuclear Science and Engineering Directorate (NSED) of JAEA predicted the atmospheric dispersion of radionuclide by WSPEEDI-II for the purpose of contributing to the environmental monitoring plan. From February 12 to 22, they provided daily reports on the prediction to the MEXT and the Ministry of Defense. MEXT has published these reports on the website. Since April 2012, NEAT and NSED had prepared to predict by the framework for the prediction around the clock during 10months until February 2013. This report described this experience and pointed issues out on this system.
Kataoka, Takahiro*; Sakoda, Akihiro*; Yoshimoto, Masaaki*; Toyota, Teruaki*; Yamamoto, Yuki*; Ishimori, Yuu; Hanamoto, Katsumi*; Kawabe, Atsushi*; Mitsunobu, Fumihiro*; Yamaoka, Kiyonori*
Radiation Safety Management, 10(1), p.1 - 7, 2011/12
We examined the effect of continuous radon inhalation on acute alcohol-induced oxidative damage of mouse liver and brain. Assay of antioxidative functions indicated that lipid peroxide levels in both the liver and brain of the alcohol-treated mice were significantly higher than those of the saline-treated mice. However, the lipid peroxide level in the liver, but not in the brain, of alcohol-treated mice was significantly decreased by radon inhalation whereas that in the brain of saline-treated mice, but not in the liver of saline-treated mice, was significantly increased by radon inhalation. These findings suggest that radon inhalation inhibits alcohol-induced oxidative damage of liver due to activation of antioxidative functions and that radon inhalation exert only a week effect on the brains in comparing with the livers. They further suggest that alcohol administration protects against oxidative damage of the brain that is induced by radon inhalation.
Kashiwagi, Mieko; Taniguchi, Masaki; Kojima, Atsushi; Dairaku, Masayuki; Hanada, Masaya; Hemsworth, R. S.*; Mizuno, Takatoshi*; Takemoto, Jumpei; Tanaka, Masanobu*; Tanaka, Yutaka*; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
At JAEA, a multi-aperture multi-grid accelerator has been developed for the ITER neutral beam system. A target is H ion beam acceleration of 0.5 A (200 A/m) at 1 MeV. In real accelerators, it was found that the voltage holding was about a half of that obtained in an ideal small electrode. After applying necessary gap length and radii of edges of grid supports to lower local electric field concentrations, the accelerator succeeded in sustaining 1 MV for 4000 s. As a result, beam parameters were increased to 879 keV, 0.36 A (157 A/m) at perveance matched condition from 796 kV, 0.32 A (140 A/m) reported in FEC2008. In the beam acceleration, the beamlet deflections due to magnetic field and space charge repulsion caused direct interceptions, that resulted in limitations in the beam energy and current. Compensation of these beamlet deflections has been tested applying aperture offset and field shaping plate, which were examined in a three-dimensional beam analysis.
Matsuda, Tatsuma; Dung, N. D.*; Haga, Yoshinori; Ikeda, Shugo*; Yamamoto, Etsuji; Ishikura, Tatsuro*; Endo, Toyoaki*; Takeuchi, Tetsuya*; Settai, Rikio*; Onuki, Yoshichika
Physica Status Solidi (B), 247(3), p.757 - 759, 2010/03
Times Cited Count:3 Percentile:12.09(Physics, Condensed Matter)We succeeded in growing high-quality single crystals of a heavy electron compound YbCuSi. The electronic specific heat coefficient is determined to be 150 mJ/Kmol, which is consistent with the value of the electrical resistivity from Kadowaki-Woods relation. We succeeded in observing the de Haas-van Alphen (dHvA) oscillations. The dHvA frequencies and large cyclotron effective masses in YbCuSi are highly different from those in a non-4 reference compound YCuSi. From these dHvA results, the heavy electron state of YbCuSi is characterized by the large contribution of 4-electrons to the volume of the Fermi surface and also to the strong enhancement of effective mass caused by the spin fluctuations.
Sanada, Hiroyuki; Matsui, Hiroya; Ogawa, Toyokazu*; Kinomura, Koji*; Aoki, Tomoyuki*; Yamamoto, Takuya*
JAEA-Research 2009-050, 57 Pages, 2010/01
It is important to understand EDZ in assessing performance of repository and designing of plug. It is known that it remains possible that the large-scale EDZ is generated due to strain localization from boring investigations and tunnel excavation analyses and rock properties changes with increase of depth. Excavation analysis of vertical shaft in sedimentary rock taken into account strain softening, depth variation of rock properties and the actual construction procedure had been done in order to understand EDZ of Horonobe URL. The large-scale EDZ due to strain localization was generated around the border between Koetoi formation and Wakkanai formation. From result obtained from excavation analysis, scale of EDZ obtained from excavation analysis is from 60 cm to 120 cm. And it was estimated that seismic velocity changed by 20 percent, elastic modulus changed by 30 percent and hydraulic conductivity changed by 0.1 m/s order.
Ogawa, Toyokazu*; Kinomura, Koji*; Aoki, Tomoyuki*; Yamamoto, Takuya*; Sanada, Hiroyuki; Matsui, Hiroya
Dai-12-Kai Iwa No Rikigaku Kokunai Shimpojiumu Koen Rombunshu (CD-ROM), p.933 - 940, 2008/09
Japan Atomic Energy Agency is planning to conduct researches into geological disposal of high-level radioactive wastes in the Horonobe site located in Hokkaido, Japan. As part of the underground research facilities, two 500m-long vertical shafts have been constructed in tertiary sedimentary rocks since 2005. The surrounding rocks are known to exhibit strain-softening characteristics, necessitating appropriate modelling in the stability analysis. In addition the rocks physical properties often vary with depth. This study shows the results of three-dimensional numerical analysis of the ventilation shaft, taking the construction sequence and the variation of rock properties with depth into consideration.
Nguyen, D.; Matsuda, Tatsuma; Ikeda, Shugo*; Yamamoto, Etsuji; Haga, Yoshinori; Takeda, Yuji*; Endo, Toyoaki*; Doi, Yusuke*; Settai, Rikio*; Harima, Hisatomo*; et al.
Journal of the Physical Society of Japan, 77(9), p.094702_1 - 094702_6, 2008/09
Times Cited Count:15 Percentile:64.33(Physics, Multidisciplinary)We have succeeded in growing a high-quality single crystal of a non-4 reference compound YCuSi for a heavy-fermion superconductor CeCuSi, and observed the de Haas-van Alphen (dHvA) oscillation. The detected dHvA branches in YCuSi indicate that the Fermi surfaces are multiply connected, and the dHvA frequencies are in the range from 9 to 2 Oe. These dHvA branches are found to be well explained by the results of energy band calculations. The corresponding cyclotron masses are light, ranging from 0.4 to 1.5 , and are consistent with the electronic specific heat coefficient of 2.2 mJ/Kmol.
Mori, Michiaki; Yogo, Akifumi; Kiriyama, Hiromitsu; Nishiuchi, Mamiko; Ogura, Koichi; Orimo, Satoshi; Ma, J.*; Sagisaka, Akito; Kanazawa, Shuhei; Kondo, Shuji; et al.
IEEE Transactions on Plasma Science, 36(4), p.1872 - 1877, 2008/08
Times Cited Count:7 Percentile:28.39(Physics, Fluids & Plasmas)A dependence of cut-off proton kinetic energy on laser prepulse duration has been observed. ASE pedestal duration is controlled by a fast electro-optic pulse slicer where the risetime is estimated to be 130 ps. We demonstrate a new correlated spectral technique for determining this risetime using a stretched, frequency chirped pulse.
Yoshimoto, Masahiro; Ueno, Tomoaki; Togashi, Tomohito; Toyokawa, Ryoji; Takeda, Osamu; Watanabe, Masao; Yamazaki, Yoshio; Yamamoto, Kazami; Kamiya, Junichiro; Takayanagi, Tomohiro; et al.
IEEE Transactions on Applied Superconductivity, 18(2), p.301 - 305, 2008/06
Times Cited Count:1 Percentile:12.87(Engineering, Electrical & Electronic)Nguyen, D.; Matsuda, Tatsuma; Haga, Yoshinori; Ikeda, Shugo*; Yamamoto, Etsuji; Endo, Toyoaki*; Settai, Rikio*; Harima, Hisatomo*; Onuki, Yoshichika
Journal of the Physical Society of Japan, 77(6), p.064708_1 - 064708_6, 2008/06
Times Cited Count:1 Percentile:11.65(Physics, Multidisciplinary)We succeeded in growing a single crystal of a layered compound LuRhGa with an YCoGa-type orthorhombic crystal structure by the Ga-flux method. The lattice, positional, and thermal parameters were determined by single-crystal X-ray diffraction measurement. We also measured the electrical resistivity, specific heat, and de Haas-van Alphen (dHvA) effect. The detected dHvA branches were well explained by the results of full potential LAPW energy band calculations. The electronic state was found to be quasi-two-dimensional, indicating nearly cylindrical Fermi surfaces along the [001] direction.
Hayashi, Naoki; Hiroki, Seiji; Saeki, Riuji; Toyokawa, Ryoji; Yamamoto, Kazami; Yoshimoto, Masahiro; Arakawa, Dai*; Hiramatsu, Shigenori*; Lee, S.*; Sato, Kenichiro*; et al.
Proceedings of 11th European Particle Accelerator Conference (EPAC '08) (CD-ROM), p.1125 - 1127, 2008/06
A 3-GeV Rapid-Cycling Synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC) has been commissioned recently. During its beam commissioning, various beam diagnostic instrumentation has been used. The multi-wire profile monitor (MWPM) is used to establish injection and H0 dump line. The electron catcher confirms that the beam hits a charge exchange carbon foil and the specified current monitor limits the beam current to the H0 dump. Single pass BPMs and ionization profile monitors (IPM) help to check the one pass orbit without circulation of the beam. The beam position monitor (BPM) can measure both COD and turn-by-turn position. Tune monitor system consists of exciter and its own BPM. The exciter shakes the beam and coherent oscillation. Dedicated BPMs, Fast CT (FCT) and Wall Current Monitor (WCM) are used for RF feedback or feedfoward control. It will describe the performance of each instruments and how they are contributed to the successful beam commissioning.