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Kamiya, Junichiro; Takano, Kazuhiro; Yuza, Hiromu*; Wada, Kaoru
Proceedings of 12th International Particle Accelerator Conference (IPAC 21) (Internet), p.3471 - 3474, 2021/08
The NEG coating, which has been developed in CERN, is a revolutionary technique that can make a beam pipe act as a vacuum pump by coating the getter materials with the ability to adsorb/absorb gas molecules on the beam pipe surface. The NEG materials are alloys of titanium, zirconium, and vanadium. Titanium is one of the getter materials. In high-power beam accelerators, titanium has been used as the beam pipe chamber material due to its low radioactivation characteristics. The ordinal titanium surface has no getter function because it is covered with titanium-oxide film. The new technique, which removes the titanium-oxide surface by the sputtering and makes the titanium vacuum chamber itself the vacuum pump like NEG coated chamber, has been developed. After sputtering the inner surface of the titanium chamber, we obtained clear evidence that shows the chamber acts as a vacuum pump. We have also tried to make a titanium chamber with a getter function only by baking. Dependence of the getter characteristics on the baking temperature will also be reported.
Nakamura, Hirofumi; Higashijima, Satoru
Shinku, 49(2), p.62 - 68, 2006/02
no abstracts in English
Ioki, Kimihiro*; Elio, F.*; Maruyama, So; Morimoto, Masaaki*; Rozov, V.*; Tivey, R.*; Utin, Y.*
Fusion Engineering and Design, 74(1-4), p.185 - 190, 2005/11
Times Cited Count：5 Percentile：35.8(Nuclear Science & Technology)The ITER project has started preparation of Procurement Specification Documents for the vacuum vessel (VV). The design of the VV and FW/Blanket has progressed in many aspects, such as an double curvature pressing instead of facet shape welding for inner and outer shells in the upper and lower inboard regions to improve the fabrication and NDT process. The plasma facing surface of the FW has been defined to avoid protruding the leading edges, especially in the inboard area. Separate FW panels are supported with a central beam, and selection of a race-track shape cross-section for the central beam provides a more robust structure against halo current EM loads and also leads to a new cooling configuration in the shield block, where the pressure drop is significantly reduced to 
0.05 MPa. A UT R&D program is also going on to achieve acceptable S/N ratio for small-angle launching waves (20-30 deg.) to a weld. Hydraulic testing has been performed to demonstrate natural convection cooling in the transient condition.
Yagisawa, Hiroshi; Arai, Takashi; Goto, Yoshitaka*
Heisei-16-Nendo Osaka Daigaku Sogo Gijutsu Kenkyukai Hokokushu (CD-ROM), 4 Pages, 2005/03
no abstracts in English
Sukegawa, Kota*; Kishimoto, Maki; Kado, Masataka
JAERI-Tech 2004-077, 21 Pages, 2005/01
JAERI-Tech-2004-077.pdf:4.17MB
no abstracts in English
analyses with ferromagnetic and plasma rotation effects and wall geometry for a high steady state tokamakKurita, Genichi; Bialek, J.*; Tsuda, Takashi; Azumi, Masafumi; Ishida, Shinichi; Navratil, G. A.*; Sakurai, Shinji; Tamai, Hiroshi; Matsukawa, Makoto; Ozeki, Takahisa; et al.
IAEA-CN-116/FT/P7-7 (CD-ROM), 8 Pages, 2004/11
The critical beta is shown to be decreased by ferromagnetic effect by about 8 % for m/m02, m and m0 denote the permeability of ferromagnetic wall and vacuum, respectively, for tokamak of aspect ratio 3. The existence of the stability window opened by both effects of the toroidal plasma rotation and the plasma dissipation, which was not observed for high aspect ratio tokamak, is found for tokamak of aspect ratio 3. The effect of ferromagnetism on them is also investigated. The critical beta analyses of NCT (National Centralized Tokamak) plasma using VALEN code are started with stabilizing plate and vacuum vessel geometry with finite resistivity, and the results for passive effect of stabilizing plate are obtained. The calculations including stabilizing effect of the vacuum-vessel and also active feedback control are also performed for present design of NCT plasma.
Ioki, Kimihiro*; Akiba, Masato; Barabaschi, P.*; Barabash, V.*; Chiocchio, S.*; Daenner, W.*; Elio, F.*; Enoeda, Mikio; Ezato, Koichiro; Federici, G.*; et al.
Journal of Nuclear Materials, 329-333(1), p.31 - 38, 2004/08
Times Cited Count：14 Percentile：66.09(Materials Science, Multidisciplinary)The preparation of the procurement specifications is being progressed for key components. Progress has been made in the preparation of the procurement specifications for key nuclear components of ITER. Detailed design of the vacuum vessel (VV) and in-vessel components is being performed to consider fabrication methods and non-destructive tests (NDT). R&D activities are being carried out on vacuum vessel UT inspection with waves launched at an angle of 20 or 30 degree, on flow distribution tests of a two-channel model, on fabrication and testing of FW mockups and panels, on the blanket flexible support as a complete system including the housing, on the blanket co-axial pipe connection with guard vacuum for leak detection, and on divertor vertical target prototypes. The results give confidence in the validity of the design and identify possibilities of attractive alternate fabrication methods.
Tamai, Hiroshi; Matsukawa, Makoto; Kurita, Genichi; Hayashi, Nobuhiko; Urata, Kazuhiro*; Miura, Yushi; Kizu, Kaname; Tsuchiya, Katsuhiko; Morioka, Atsuhiko; Kudo, Yusuke; et al.
Plasma Science and Technology, 6(1), p.2141 - 2150, 2004/02
Times Cited Count：2 Percentile：6.49(Physics, Fluids & Plasmas)The dominant issue for the the modification program of JT-60 (JT-60SC) is to demonstrate the steady state reactor relevant plasma operation. Physics design on plasma parameters, operation scenarios, and the plasma control method are investigated for the achievement of high-. Engineering design and the R&D on the superconducting magnet coils, radiation shield, and vacuum vessel are performed. Recent progress in such physics and technology developments is presented.
Kurihara, Ryoichi; Watanabe, Kenichi*; Konishi, Satoshi
JAERI-Review 2003-020, 37 Pages, 2003/07
JAERI-Review-2003-020.pdf:2.08MB
no abstracts in English
Ioki, Kimihiro*; Barabaschi, P.*; Barabash, V.*; Chiocchio, S.*; Daenner, W.*; Elio, F.*; Enoeda, Mikio; Gervash, A.*; Ibbott, C.*; Jones, L.*; et al.
Nuclear Fusion, 43(4), p.268 - 273, 2003/04
Times Cited Count：21 Percentile：54.59(Physics, Fluids & Plasmas)Although the basic concept of the vacuum vessel (VV) and in-vessel components of the ITER design has stayed the same, there have been several detailed design improvements resulting from efforts to raise reliability, to improve maintainability and to save money. One of the most important achievements in the VV R&D has been demonstration of the necessary fabrication and assembly tolerances. Recently the deformation due to cutting of the port extension was measured and it was shown that the deformation is small and acceptable. Further development of advanced methods of cutting, welding and NDT on a thick plate have been continued in order to refine manufacturing and improve cost and technical performance. With regard to the related FW/blanket and divertor designs, the R&D has resulted in the development of suitable technologies. Prototypes of the FW panel, the blanket shield block and the divertor components have been successfully fabricated.
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
Saito, Shigeru; Fukaya, Kiyoshi*; Ishiyama, Shintaro; Amezawa, Hiroo; Yonekawa, Minoru; Takada, Fumiki; Kato, Yoshiaki; Takeda, Takashi; Takahashi, Hiroyuki*; Nakahira, Masataka
Journal of Nuclear Materials, 307-311(Part2), p.1573 - 1577, 2002/12
Times Cited Count：2 Percentile：17.03(Materials Science, Multidisciplinary)no abstracts in English
Omori, Junji*; Kitamura, Kazunori*; Araki, Masanori; Oono, Isamu*; Shoji, Teruaki
JAERI-Tech 2002-053, 86 Pages, 2002/07
JAERI-Tech-2002-053.pdf:3.81MB
no abstracts in English
Takase, Kazuyuki; Akimoto, Hajime
Nuclear Fusion, 41(12), p.1873 - 1883, 2001/12
Times Cited Count：6 Percentile：21.45(Physics, Fluids & Plasmas)no abstracts in English
Onozuka, Masanori*; Ioki, Kimihiro*; Sannazzaro, G.*; Utin, Y.*; Yoshimura, Hideto*
Fusion Engineering and Design, 58-59, p.857 - 861, 2001/11
Times Cited Count：15 Percentile：71.2(Nuclear Science & Technology)no abstracts in English
Nishi, Hiroshi; Eto, Motokuni; Tachibana, Katsumi; Koizumi, Koichi; Nakahira, Masataka; Takahashi, Hiroyuki*
Fusion Engineering and Design, 58-59, p.869 - 873, 2001/11
Times Cited Count：2 Percentile：19.66(Nuclear Science & Technology)no abstracts in English
Urata, Kazuhiro*; Suzuki, Yutaka*; Kudo, F.*; Kimura, Haruyuki; Miura, Yukitoshi; Yamamoto, Masahiro
Fusion Engineering and Design, 56-57, p.849 - 853, 2001/10
Times Cited Count：4 Percentile：33.39(Nuclear Science & Technology)no abstracts in English
Onozuka, Masanori*; Alfile, J. P.*; Aubert, P.*; Dagenais, J.-F.*; Grebennikov, D.*; Ioki, Kimihiro*; Jones, L.*; Koizumi, Koichi; Krylov, V.*; Maslakowski, J.*; et al.
Fusion Engineering and Design, 55(4), p.397 - 410, 2001/09
Times Cited Count：25 Percentile：84.32(Nuclear Science & Technology)Development of welding, cutting and non-destructive testing (NDT) techniques, and development of remotized systems, have been conducted for on-site manufacturing and maintenance of the thick wall structure of the ITER vacuum vessel (VV). Conventional techniques, including TIG (tungsten inert gas) welding, plasma cutting and ultrasonic inspection, have been improved and optimized for the application to thick austenitic stainless steel plates. In addition, advanced methods have been investigated including reduced-pressure electron-beam and multi-pass NdYAG (neodymium-doped yttrium aluminum garnet) laser welding, NdYAG laser cutting, and EMAT (electro-magnetic acoustic transducer) inspection to improve cost and technical performance. Two types of remotized systems with different payloads have been investigated and one of them has been fabricated and demonstrated in field joint welding, cutting, and NDT tests on test mockups and full-scale ITER VV sector models. The progress and results of this development to date provide a high level of confidence that the manufacturing and maintenance of the ITER VV is feasible.
Nishi, Hiroshi; Eto, Motokuni; Tachibana, Katsumi; Nakahira, Masataka
Transactions of 16th International Conference on Structural Mechanics in Reactor Technology (SMiRT-16) (CD-ROM), 8 Pages, 2001/08
Fatigue test of the weldments was performed to investigate their fatigue behavior and the effect of the incomplete penetrations on the fatigue strength. Fatigue crack propagation test of their weld metals was also carried out using CT specimen. By calculating stress intensity factors of the weldments contained the incomplete penetrations and cracks using FEM analysis, the fatigue crack propagation rates of weldments were evaluated and compared those of their weld metals. Fatigue life of the weldments was evaluated based on fracture mechanics to discuss the effect of incomplete penetrations on the fatigue strength. As the results, the incomplete penetration behaved as a crack and most of total fatigue life for the weldment was crack propagation life. The crack propagation rates of weldment were in accordance with those of the weld metals. The fatigue strength of the weldment was considerably lower than that of smoothed specimen. The incomplete penetrations affected greatly the fatigue strength of the weldments even if the depth of incomplete penetrations was small.
Kurihara, Ryoichi; Ajima, Toshio*; Ueda, Shuzo; Seki, Yasushi
Journal of Nuclear Science and Technology, 38(7), p.571 - 576, 2001/07
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)no abstracts in English
