Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Oikawa, Kenichi; Kiyanagi, Yoshiaki*; Sato, Hirotaka*; Omae, Kazuma*; Pham, A.*; Watanabe, Kenichi*; Matsumoto, Yoshihiro*; Shinohara, Takenao; Kai, Tetsuya; Harjo, S.; et al.
Materials Research Proceedings, Vol.15, p.207 - 213, 2020/02
B conversion layerMiyajima, Shigeyuki*; Shishido, Hiroaki*; Narukami, Yoshito*; Yoshioka, Naohito*; Fujimaki, Akira*; Hidaka, Mutsuo*; Oikawa, Kenichi; Harada, Masahide; Oku, Takayuki; Arai, Masatoshi*; et al.
Nuclear Instruments and Methods in Physics Research A, 842, p.71 - 75, 2017/01
Times Cited Count：13 Percentile：78.05(Instruments & Instrumentation)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
Nakamura, Hideo; Arai, Kenji*; Oikawa, Hirohide*; Fujii, Tadashi*; Umezawa, Shigemitsu*; Abe, Yutaka*; Sugimoto, Jun*; Koshizuka, Seiichi*; Yamaguchi, Akira*
Proceedings of 16th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-16) (USB Flash Drive), p.5353 - 5366, 2015/08
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
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.
Endo, Kiyoshi*; Shibata, Yasushi*; Yoshida, Fumiyo*; Nakai, Kei*; Yamamoto, Tetsuya*; Matsumura, Akira*; Ishii, Keizo*; Sakai, Takuro; Sato, Takahiro; Oikawa, Masakazu*; et al.
Proceedings of 11th World Congress on Neutron Capture Therapy (ISNCT-11) (CD-ROM), 2 Pages, 2004/10
Micro PIXE, which is installed in a single end accelerator in JAERI, was used for quantitative analysis of boron and gadolinium distribution in a cell level. The micro beam of 1 
m diameter is possible to observe the distribution. In the adjustment procedure of the sample, first is a fix of mylar film by using a glass ring and a bite ring of 2cm diameter. Next the 9L cells were scattered on the washed film, and is cultivated on 37
C in medium until they form the mono-layer. After the Gd-BOPTA was added, it incubates for the 24-72 hour on 37C. The film is washed in the THAM liquid, and is directly put on liquid nitrogen. A vacuum drying for 24 hours is conducted in order to fix a film on holder. It is important to uniformly fix the cell in distribution analysis in the cell using Micro PIXE. In recent result, it became possible that the distribution of P, S, Gd, etc. was analyzed. But we could not distinguish whether K and Gd exist in the cell or whether it exists around the cell. It was indicated that these elements was leaked by the reason of cell breaking or other on the cytoplasm.
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.
Fukuda, Takeshi; Oikawa, Toshihiro; Takeji, Satoru; Isayama, Akihiko; Kawano, Yasunori; Neyatani, Yuzuru; Nagashima, Akira; Nishitani, Takeo; Konoshima, Shigeru; Tamai, Hiroshi; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.357 - 367, 2002/09
Times Cited Count：7 Percentile：44.35(Nuclear Science & Technology)no abstracts in English
Kamada, Yutaka; Fujita, Takaaki; Ishida, Shinichi; Kikuchi, Mitsuru; Ide, Shunsuke; Takizuka, Tomonori; Shirai, Hiroshi; Koide, Yoshihiko; Fukuda, Takeshi; Hosogane, Nobuyuki; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.185 - 254, 2002/09
Times Cited Count：34 Percentile：48.48(Nuclear Science & Technology)With the main aim of providing physics basis for ITER and the steady-state tokamak reactors, JT-60/JT-60U has been developing and optimizing the operational concepts, and extending the discharge regimes toward sustainment of high integrated performance in the reactor relevant parameter regime. In addition to achievement of the equivalent break-even condition (QDTeq up to 1.25) and a high fusion triple product = 1.5E21 m-3skeV, JT-60U has demonstrated the integrated performance of high confinement, high beta-N, full non-inductive current drive with a large fraction of bootstrap current in the reversed magnetic shear and in the high-beta-p ELMy H mode plasmas characterized by both internal and edge transport barriers. The key factors in optimizing these plasmas are profile and shape controls. As represented by discovery of various Internal Transport Barriers, JT-60/JT-60U has been emphasizing freedom and restriction of profiles in various confinement modes. JT-60U has demonstrated applicability of these high confinement modes to ITER and also clarified remaining issues.
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.
Isei, Nobuaki; Isayama, Akihiko; Ishida, Shinichi; Sato, Masayasu; Oikawa, Toshihiro; Fukuda, Takeshi; Nagashima, Akira; Iwama, Naofumi*; JT-60 Team
Fusion Engineering and Design, 53(1-4), p.213 - 220, 2001/11
Times Cited Count：16 Percentile：73.21(Nuclear Science & Technology)no abstracts in English
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
Takenaga, Hidenobu; Nagashima, Keisuke; Sakasai, Akira; Asakura, Nobuyuki; Shimizu, Katsuhiro; Kubo, Hirotaka; Higashijima, Satoru; Oikawa, Toshihiro; Shirai, Hiroshi; Fujita, Takaaki; et al.
Nuclear Fusion, 39(11Y), p.1917 - 1928, 1999/11
Times Cited Count：22 Percentile：57.71(Physics, Fluids & Plasmas)no abstracts in English
Takenaga, Hidenobu; Sakasai, Akira; Koide, Yoshihiko; Sakamoto, Yoshiteru; Kubo, Hirotaka; Higashijima, Satoru; Oikawa, Toshihiro; Shirai, Hiroshi; Fujita, Takaaki; Kamada, Yutaka
Purazuma, Kaku Yugo Gakkai-Shi, 75(8), p.952 - 966, 1999/00
no abstracts in English
Takenaga, Hidenobu; Nagashima, Keisuke; Sakasai, Akira; Asakura, Nobuyuki; Shimizu, Katsuhiro; Kubo, Hirotaka; Higashijima, Satoru; Oikawa, Toshihiro; Fujita, Takaaki; Kamada, Yutaka; et al.
Fusion Energy 1998, Vol.2, p.749 - 752, 1998/10
no abstracts in English
