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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.
Arai, Kenji*; Umezawa, Shigemitsu*; Oikawa, Hirohide*; Onuki, Akira*; Nakamura, Hideo; Nishi, Yoshihisa*; Fujii, Tadashi*
Nihon Genshiryoku Gakkai-Shi ATOMO
, 58(3), p.161 - 166, 2016/03
no abstracts in English
Sukegawa, Atsuhiko; Miya, Naoyuki; Oikawa, Akira
Proceedings of 19th International Conference on Nuclear Engineering (ICONE-19) (CD-ROM), 8 Pages, 2011/10
The radioactivities on the materials of JT-60U fusion device, which decommissioning is underway toward the upgraded superconducting tokamak machine, have been evaluated by calculation and measurements on the specimens of the structure materials and the components. In the induced activities on those materials, the highest activation on the material was stainless steel. The essential nuclide was 
Co in the stainless steels. The stainless steel 316 of about 35 tons constitutes the base of interiorities as a first wall on the vacuum vessel in JT-60U. For the management of radioactive materials, the evaluation for the steels with the activated nuclides is important. The activated structure materials are kept in the controlled area in the JT-60 facilities, according to the criteria for handling activated materials by the defined domestic government.
Nishiyama, Tomokazu; Okano, Fuminori; Miyo, Yasuhiko; Kubo, Hirotaka; Miya, Naoyuki; Oikawa, Akira; Sasajima, Tadayuki; Sakasai, Akira
Heisei-22-Nendo Kumamoto Daigaku Sogo Gijutsu Kenkyukai Hokokushu (CD-ROM), 5 Pages, 2011/03
no abstracts in English
Oikawa, Masataka; Yonetani, Yoshiteru
Biophysical Journal, 98(12), p.2974 - 2983, 2010/06
Times Cited Count：9 Percentile：23.53(Biophysics)Sukegawa, Atsuhiko; Oikawa, Akira; Miya, Naoyuki; Fujita, Takaaki
Proceedings of 15th International Conference on Nuclear Engineering (ICONE-15) (CD-ROM), 6 Pages, 2007/04
The low level waste of JT-60U fusion device has been estimated by a regulatory clearance. The JT-60U consists of the heating devices such as neutral beam injectors and radio frequency systems, the main devices including the vacuum vessel and the coils, and the diagnostic devices in the torus hall. Those structure materials of the JT-60U device include copper, stainless steels, carbon steel, high manganese steel, inconel 625, ferritic steel, and lead. The gross weight of the device is about 6,400 tons. Radiation transport calculations are performed using 1D code ANISN. In the activation calculations, ACT-4 was employed. The stainless steels of about 50 tons are used for the base of the first wall on the vacuum vessel in JT-60U. For the low level waste management, the evaluation for the steels with the activated nuclides is important. IAEA RS-G-1.7 is applied to the clearance level for the structures of the activated materials. The activated level of the material with Co takes about 45 years until less than the clearance level.
Sakasai, Akira; Ishida, Shinichi; Matsukawa, Makoto; Akino, Noboru; Ando, Toshinari*; Arai, Takashi; Ezato, Koichiro; Hamada, Kazuya; Ichige, Hisashi; Isono, Takaaki; et al.
Nuclear Fusion, 44(2), p.329 - 334, 2004/02
no abstracts in English
Sakasai, Akira; Ishida, Shinichi; Matsukawa, Makoto; Akino, Noboru; Ando, Toshinari*; Arai, Takashi; Ezato, Koichiro; Hamada, Kazuya; Ichige, Hisashi; Isono, Takaaki; et al.
Nuclear Fusion, 44(2), p.329 - 334, 2004/02
Times Cited Count：7 Percentile：22.95(Physics, Fluids & Plasmas)no abstracts in English
Morioka, Atsuhiko; Sakasai, Akira; Masaki, Kei; Ishida, Shinichi; Miya, Naoyuki; Matsukawa, Makoto; Kaminaga, Atsushi; Oikawa, Akira
Fusion Engineering and Design, 63-64, p.115 - 120, 2002/12
Times Cited Count：11 Percentile：58.11(Nuclear Science & Technology)no abstracts in English
Oikawa, Akira; Miya, Naoyuki
Purazuma, Kaku Yugo Gakkai-Shi, 78(12), p.1308 - 1312, 2002/12
Tritium experience over decade in DD operation of JT-60 is summarized.Effluent of tritium in vacuum exhaust through the stack to environment always remains a level below detectable levels. Tritium concentration of drain is also below the limit of regurations of the local agreement amd the law. For a scheduled maintenance work of the in-vessel components, following an annual deuterium plasma discharge campaign, a 4-week no-deuterium plasma discharge campaign and the succeeded ventilation by room air allow to reduce tritium concentration on the surface of in-vessel components. A cooperative endeavour is underway for analysis of tritium behavior in JT-60.
Harada, Satoshi*; Tamakawa, Yoshiharu*; Ishii, Keizo*; Tanaka, Akira*; Sato, Takahiro; Matsuyama, Shigeo*; Yamazaki, Hiromichi*; Kamiya, Tomihiro; Sakai, Takuro; Arakawa, Kazuo; et al.
Nuclear Instruments and Methods in Physics Research B, 189(1-4), p.437 - 442, 2002/04
Times Cited Count：1 Percentile：12.5(Instruments & Instrumentation)To study the interactions between the induction of radiation-induced apoptosis and trace elements kinetics, human leukemia cells were irradiated in vitro by Co 
rays, after which the cells were evaluated for the detection of apoptosis and trace element imaging was carried out. The frequency of apoptosis was obtained by microscopic assay using TUNEL staining. The trace element distribution in the cell was determined by micro-PIXE. In the early phase of apoptosis, the maximum level of Fe accumulation was observed in the cell stroma. In the mid to end phase, Fe accumulation was diminished, and instead, Ca accumulation increased and Zn decreased in the nucleus. There appear to be two steps for the development of apoptosis: (1) the signaling from cell stroma to nucleus by Fe or an Fe-containing enzyme; and (2) the degeneration of the nucleus by Ca-dependent enzyme, and release of Zn from digested nucleus. Those strong accumulations may be new markers for apoptosis.
Sakai, Takuro; Kamiya, Tomihiro; Oikawa, Masakazu*; Sato, Takahiro; Tanaka, Akira*; Ishii, Keizo*
Nuclear Instruments and Methods in Physics Research B, 190(1-4), p.271 - 275, 2001/09
Times Cited Count：66 Percentile：95.98(Instruments & Instrumentation)no abstracts in English
Ninomiya, Hiromasa; Kamada, Yutaka; Miya, Naoyuki; *; *; Oikawa, Akira; Sakasai, Akira; Takahashi, Yoshikazu; Takizuka, Tomonori; ; et al.
15th IEEE/NPSS Symp. on Fusion Engineering,Vol. 1, 0, p.374 - 377, 1993/00
no abstracts in English
Miya, Naoyuki; ; *; Nakamura, Hiroo; Ushigusa, Kenkichi; Oikawa, Akira; Nishitani, Takeo; ; *; Nakagawa, S.*; et al.
Fusion Engineering and Design, 23, p.351 - 358, 1993/00
Times Cited Count：1 Percentile：17.88(Nuclear Science & Technology)no abstracts in English
Miya, Naoyuki; *; Ushigusa, Kenkichi; Oikawa, Akira; Imai, Tsuyoshi; ; Nishitani, Takeo; Matsuzaki, Yoshimi; Kuriyama, Masaaki;
JAERI-M 92-140, 156 Pages, 1992/09
no abstracts in English
Kikuchi, Mitsuru; Seki, Yasushi; Oikawa, Akira; Ando, Toshinari; Ohara, Yoshihiro; Nishio, Satoshi; Seki, Masahiro; Takizuka, Tomonori; Tani, Keiji; Ozeki, Takahisa; et al.
Fusion Engineering and Design, 18, p.195 - 202, 1991/00
Times Cited Count：8 Percentile：66.05(Nuclear Science & Technology)no abstracts in English
Oikawa, Akira
Fusion Technology, 17, p.232 - 235, 1990/03
no abstracts in English
; ; Oikawa, Akira; Miya, Naoyuki; ; Ozeki, Takahisa; ; Kunieda, Shunsuke; ;
Fusion Engineering and Design, 5, p.9 - 25, 1987/00
Times Cited Count：4 Percentile：44.92(Nuclear Science & Technology)no abstracts in English
Oikawa, Akira; Nakamura, Hirofumi; Kaminaga, Atsushi; Masaki, Kei; Yamazaki, Takeshi*; Tanabe, Tetsuo*
no journal, ,
During DD plasma discharges, tritium produced by the discharges are accumulated on in-vessel components including a carbon based first wall. A few week of detritiation campaign with no-deuterium plasma discharges take place before the scheduled maintenance work on JT-60U. It is recently found that a longer pulse and higher power electron cyclotron resonance heating(ECRH) with deuterium on JT-60U also provides effectively detritiation of the plasma facing components, simultaneously improving confinement and supressing neutron yield. This approach could help control tritium inventory under plasma discharges on fusion devices. The enhanced radiation power is expected to cause the particle recycling and resultantly enhanced detritiation. The higher plasma current with higher electron density with the longer pulse of ECR power injection enhances the detritiation capability.
Morioka, Atsuhiko; Oikawa, Akira; Miya, Naoyuki
no journal, ,
no abstracts in English
