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Takahashi, Masakazu*; Masuo, Hiroshige*; Takano, Katsutoshi; Koizumi, Norikiyo
Proceedings of 11th International Conference on Hot Isostatic Pressing (HIP 2014), 4 Pages, 2014/06
As part of the research and development of Tokamak-type nuclear fusion reactors, super electromagnetic coils are required to control the plasma reaction. The structure that supports the plasmas chamber is maintained at cryogenic temperatures in liquid helium and thus must be able to withstand the extremes of this type of environment. The most promising material for this support is, SUS316LNH and at present, the only fabrication method being employed is traditional machining from solid materials. This creates a large amount of waste material with extremely long fabrication time, due to the large size of the support at 13 m in height and 8 m in width. Therefore, it is thought that by combining machining with the HIP diffusion bonding process, both waste and fabrication time can be reduced. Although this method is still under development, it is believed that a reduction of about 50% in wasted material and an about 40% in machining time can be achieved.
Takano, Katsutoshi; Koizumi, Norikiyo; Masuo, Hiroshige*; Natsume, Yoshihisa*
Yosetsu Gakkai Rombunshu (Internet), 32(1), p.8 - 14, 2014/03
The authors performed trial manufacture of the RP segments using a diffusion bonding method, namely Hot Isostatic Pressing (HIP). As a result of trials, it was clarified that even when HIPping is applied, the mechanical characteristic of base metal is not deteriorated. The machining period can be reduced by half compared with the traditional manufacturing method. On the other hand, mechanical strength at 4 K is degraded due to weak bonding, that is no grain growth through joint, by HIPping. However, additional test indicates promising possibility of much better joint by higher temperature and joint surface treated HIPpings. These results justified that RP segment manufacturing is not only possible, but it is a technically valid manufacturing method that satisfies all requirements.
Sakurai, Shinji; Higashijima, Satoru; Hayashi, Takao; Shibama, Yusuke; Masuo, Hiroshige*; Ozaki, Hidetsugu; Sakasai, Akira; Shibanuma, Kiyoshi
Fusion Engineering and Design, 85(10-12), p.2187 - 2191, 2010/08
Times Cited Count：10 Percentile：57.61(Nuclear Science & Technology)JT-60SA tokamak project has just started construction phase under both the Japanese domestic program and the Japan-EU international program "ITER Broader Approach". All of plasma facing components (PFC) shall be actively cooled due to high power long pulse plasma heating. Lower single null closed divertor with vertical target (VT) will be installed at the start of experiment phase. Each divertor module covers a 10-degree sector in toroidal direction. PFCs such as VTs, baffles and dome shall be assembled on a divertor cassette, which provides integrated coolant pipe connection to coolant headers in the VV. Static structural analysis for dead weight, coolant pressure and EM loads shows that displacement and stress of the divertor module are generally small but a part of support structure of PFC requires improvement.
Sakurai, Shinji; Higashijima, Satoru; Shibama, Yusuke; Hayashi, Takao; Ozaki, Hidetsugu; Masaki, Kei; Masuo, Hiroshige*; Shibanuma, Kiyoshi; Sakasai, Akira; JT-60SA Team
no journal, ,
Heat removal for heat flux of 15MW/m
and compatibility with remote handling maintenance are required for the lower divertor in JT-60SA. Vertical divertor targets and a private dome with V-shaped corner similar to ITER are applied to reduce heat flux by radiation enhancement. The lower divertor consists from 36 divertor cassettes with toroidal width of 10 degree for transporting through large horizontal port of vacuum vessel (VV). Each cassette is fixed on the three supports at bottom of VV. The cassette has coolant pipe connections to the coolant pipe headers in VV. The pipe connection can be cut and welded by remote handling tools. Although bolted CFC tiles on water cooled copper alloy heatsinks will be adopted for most part of divertor targets in the initial operation phase, brazed CFC monoblock targets will be applied partially. The bolted CFC targets will be replaced to CFC monoblock targets in accordance with increment of plasma heating power.
Masuo, Hiroshige*; Uno, Tsuyoshi*; Takano, Katsutoshi; Hamada, Kazuya; Koizumi, Norikiyo; Nakajima, Hideo
no journal, ,
Two pairs of SUS316LNH block samples were prepared, surface treatment was performed on the two bonded surfaces. With the surface treatment, the crystal growth was encouraged by the diffusion of surface treatment material atom as the crystal grain grew across the interface. As shown in result of 77 K charpy impact test, Test piece that gave surface treatment B HIPed under 1,300 
C, 118 MPa, and four h holding time provided the largest impact value recorded 120 J/cm at very low temperature. Material yield for the SUS316LNH structure model was calculated taking into account premachining before bonding, and by comparing the machining from bonded structure and from solid material. It was succeeded to reduce the using material mass in half accomplished by component assembly and HIP bonding.
Takano, Katsutoshi; Koizumi, Norikiyo; Masuo, Hiroshige*; Natsume, Yoshihisa*
no journal, ,
no abstracts in English
