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Hosomi, Kenji; Ma, Y.*; Ajimura, Shuhei*; Aoki, Kanae*; Dairaku, Seishi*; Fu, Y.*; Fujioka, Hiroyuki*; Futatsukawa, Kenta*; Imoto, Wataru*; Kakiguchi, Yutaka*; et al.
Progress of Theoretical and Experimental Physics (Internet), 2015(8), p.081D01_1 - 081D01_8, 2015/08
Times Cited Count:14 Percentile:66.59(Physics, Multidisciplinary)Level structure of the C hypernucleus was precisely determined by means of -ray spectroscopy. We identified four -ray transitions via the C reaction using a germanium detector array, Hyperball2. The spacing of the ground-state doublet was measured to be (stat) (syst)keV from the direct transition. Excitation energies of the and states were measured to be , keV and , keV, respectively. The obtained level energies provide definitive references for the reaction spectroscopy of hypernuclei.
Akino, Noboru; Endo, Yasuei; Hanada, Masaya; Kawai, Mikito*; Kazawa, Minoru; Kikuchi, Katsumi*; Kojima, Atsushi; Komata, Masao; Mogaki, Kazuhiko; Nemoto, Shuji; et al.
JAEA-Technology 2014-042, 73 Pages, 2015/02
According to the project plan of JT-60 Super Advanced that is implemented as an international project between Japan and Europe, the neutral beam (NB) injectors have been disassembled. The disassembly of the NB injectors started in November, 2009 and finished in January, 2012 without any serious problems as scheduled. This reports the disassembly activities of the NB injectors.
Agui, Akane; Mizumaki, Masaichiro*; Kuroda, Tomoko*; Kawai, Masahiro*; Nagata, Tomoko*; Ikeda, Naoshi*; Uozumi, Takayuki*
Journal of Electron Spectroscopy and Related Phenomena, 197, p.13 - 16, 2014/12
Times Cited Count:4 Percentile:24.74(Spectroscopy)In this paper, we report on the study of the temperature dependence of Fe L-edge X-ray absorption spectra (XAS) of LuFeO. In the charge ordered state the valence of Fe is in Fe and Fe. And the Fe L-edge XAS spectra have double peak structure which is attributed the Fe and Fe state. In high temperature, the double peak structure becomes indistinct because the thermal excited state overlaps while the Fe valence keeping the integer number.
Ikeda, Yoshitaka; Hanada, Masaya; Kamada, Masaki; Kobayashi, Kaoru; Umeda, Naotaka; Akino, Noboru; Ebisawa, Noboru; Inoue, Takashi; Honda, Atsushi; Kawai, Mikito; et al.
IEEE Transactions on Plasma Science, 36(4), p.1519 - 1529, 2008/08
Times Cited Count:12 Percentile:41.25(Physics, Fluids & Plasmas)The JT-60SA N-NBI system is required to inject 10 MW for 100 s at 500 keV. Three key issues should be solved for the JT-60SA N-NBI ion source. One is to improve the voltage holding capability. Recent R&D tests suggested that the accelerator with a large area of grids may need a high margin in the design of electric field and a long time for conditioning. The second issue is to reduce the grid power loading. It was found that some beamlets were strongly deflected due to beamlet-beamlet interaction and strike on the grounded grid. The grids are to be designed by taking account of beamlet-beamlet interaction in three-dimensional simulation. Third is to maintain the D- production for 100 s. A simple cooling structure is proposed for the active cooled plasma grid, where a key is the temperature gradient on the plasma grid for uniform D- production. The modified N-NBI ion source will start on JT-60SA in 2015.
Kawai, Masayoshi*; Furusaka, Michihiro; Li, J.-F.*; Kawasaki, Akira*; Yamamura, Tsutomu*; Mehmood, M.*; Kurishita, Hiroaki*; Kikuchi, Kenji; Takenaka, Nobuyuki*; Kiyanagi, Yoshiaki*; et al.
Proceedings of ICANS-XVI, Volume 3, p.1087 - 1096, 2003/07
In order to establish the technique fabricating a thin target slab with a real size, thin tantalum-clad tungsten slab with a hole for a thermocouple was fabricated with the high-precision machinery techniques and the HIP'ing method. The ultrasonic diagnostic showed that tantalum and tungsten bond was perfect. The HIP optimum condition was certified by means of the small punch test as already reported. The electrolytic coating technique in a molten salt was developed to make a thinner tantalum cladding on a tungsten target with a complicated shape, in order to reduce radioactivity from tantalum in an irradiated target.
Kawai, Masayoshi*; Li, J.*; Watanabe, Ryuzo*; Kurishita, Hiroaki*; Kikuchi, Kenji; Igarashi, Tadashi*; Kato, Masahiro*
Dai-23-Kai Nihon Netsu Bussei Shimpojiumu Koen Rombunshu, p.313 - 315, 2002/11
The objective of the present study is to develop the stainless-steel-bonded tungsten alloys by powder metallurgy processes. Commercially available tungsten powders and stainless steel (SUS304L) powder were used as the raw materials and mixed by ball milling at the ratios of 97mass% W -3% SUS and 93mass% W -7mass% SUS. Powder compacts were formed by die pressing and cold isostatic pressing (CIP), then sintered mainly in vacuum at the temperatures above the melting point of the stainless steel phase. Some samples were fabricated by glass-encapsulated hot isostatic pressing (HIPing) at lower temperatures. The microstructural observation was made by scanning electron microscopy (SEM). The thermal properties of the produced alloy and various tungsten materials supplied from Allied Material Corp. was measured with the laser-frash method. It was found that stable liquid-phase-sintered microstructures were not easily formed in the tungsten-stainless steel system. The electron probe microanalysis (EPMA) revealed that tungsten was considerably dissolved in the stainless steel phase during sintering. Therefore, thermal conductivity of the W/7 mass% SUS alloy was 22.8-53.5 W/m/K that was very lower than theoretical value calculated from those of pure tungsten and stainless steel. Its temperature dependence is resembled to that of stainless steel, i.e., thermal conductivity increased with the specimen temperature as like stainless steel. The diffusivity of pure tungsten is compared with those of tungsten alloys.
Kuriyama, Masaaki; Akino, Noboru; Ebisawa, Noboru; Honda, Atsushi; Ito, Takao; Kawai, Mikito; Mogaki, Kazuhiko; Oga, Tokumichi; Ohara, Hiroshi; Umeda, Naotaka; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.424 - 434, 2002/09
Times Cited Count:15 Percentile:67.86(Nuclear Science & Technology)no abstracts in English
Kuriyama, Masaaki; Akino, Noboru; Ebisawa, Noboru; Grisham, L. R.*; Honda, Atsushi; Ito, Takao; Kawai, Mikito; Kazawa, Minoru; Mogaki, Kazuhiko; Ohara, Yoshihiro; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.410 - 423, 2002/09
Times Cited Count:49 Percentile:93.12(Nuclear Science & Technology)no abstracts in English
Kawai, Mikito; Akino, Noboru; Ebisawa, Noboru; Honda, Atsushi; Ito, Takao; Kazawa, Minoru; Kuriyama, Masaaki; Mogaki, Kazuhiko; Oga, Tokumichi; Ohara, Hiroshi; et al.
JAERI-Tech 2001-073, 98 Pages, 2001/11
The world's first negative-ion based neutral beam injector(N-NBI) system has been developed for studies of non-inductive current drive and plasma core heating with high energy neutral beam injection in higher density plasma. Construction of the N-NBI system for JT-60U was completed in March 1996. The system is composed of a beamline with two ion souces, a set of ion source power supllies, control system and auxiliary sub-system such as cooling water, refrigeration and vaccum system. In July 2001, deuterium neutral beam injection of 400keV and 5.8MW into JT-60U plasma was achieved. In order to increase both beam power and energy we have to go on more improvement of the N-NBI.
Komata, Masao; Hanada, Masaya; Akino, Noboru; Kazawa, Minoru; Ozeki, Masahiro; Kawai, Mikito*; Otsuki, Shinichi*
no journal, ,
no abstracts in English
Agui, Akane; Kawai, Masahiro*; Nagata, Tomoko*; Mizumaki, Masaichiro*; Izumi, Yudai*; Ikeda, Naoshi*
no journal, ,
no abstracts in English
Agui, Akane; Kawai, Masahiro*; Nagata, Tomoko*; Mizumaki, Masaichiro*; Ikeda, Naoshi*
no journal, ,
We have measured the resonant Fe L2,3 emission spectra of LuFeO. The charge order temperature is Tco = 320 K and the and arrange alternately in the charge ordered phase. We found that the spectrum at T Tco could not be explained only by the simple sum of spectra from the and sites. We assumed that when an Fe 2p state was excited, the electron transited not only to the on-state Fe 3d state but also to the neighboring Fe 3d state. This intermediate interference made the new spectra shape.
Agui, Akane; Mizumaki, Masaichiro*; Nagata, Tomoko*; Kawai, Masahiro*; Ikeda, Naoshi*
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no abstracts in English