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Wakui, Takashi; Ishii, Hideaki*; Naoe, Takashi; Kogawa, Hiroyuki; Haga, Katsuhiro; Wakai, Eiichi; Takada, Hiroshi; Futakawa, Masatoshi
Materials Transactions, 60(6), p.1026 - 1033, 2019/06
Times Cited Count：3 Percentile：14.31(Materials Science, Multidisciplinary)The mercury target has large size as 1.3
1.32.5 m
. In view of reducing the amount of wastes, we studied the structure so that the fore part could be separated. The flange is required to have high seal performance less than 110
Pa m/s. Invar with low thermal expansion is a candidate. Due to its low stiffness, however, the flange may deform when it is fastened by bolts. Practically invar is reinforced with stainless steel where all interface between them has to be bonded completely with the HIP bonding. In this study, we made specimens at four temperatures and conducted tensile tests. The specimen bonded at 973 K had little diffusion layer, and so fractured at the interface. The tensile strength reduced with increasing the temperature, and the reduced amount was about 10% at 1473 K. The analyzed residual stresses near the interface increased by 50% at maximum. Then, we concluded that the optimum temperature was 1173 K.
Kaji, Daiya*; Morimoto, Koji*; Wakabayashi, Yasuo*; Takeyama, Mirei*; Yamaki, Sayaka*; Tanaka, Kengo*; Haba, Hiromitsu*; Huang, M.*; Murakami, Masashi*; Kanaya, Jumpei*; et al.
JPS Conference Proceedings (Internet), 6, p.030107_1 - 030107_4, 2015/06
Performance of the new gas-filled recoil ion separator GARIS-II was investigated using asymmetric 
Ne-induced fusion reactions. The use of He-H
mixture gas for the gas-filled magnet significantly reduced background scattered particles detected at the focal-plane Si detector, and increased a transmission of the asymmetric reaction products. A target-identification system was newly installed for efficient measurements of excitation functions without changing beam energy nor target.
C and 1500C and measurements of lifetime and photoluminescenceKlahold, W. M.*; Devaty, R. P.*; Choyke, W. J.*; Kawahara, Kotaro*; Kimoto, Tsunenobu*; Oshima, Takeshi
Materials Science Forum, 778-780, p.273 - 276, 2014/02
Inoue, Takashi; Kashiwagi, Mieko; Taniguchi, Masaki; Dairaku, Masayuki; Hanada, Masaya; Watanabe, Kazuhiro; Sakamoto, Keishi
Nuclear Fusion, 46(6), p.S379 - S385, 2006/06
Times Cited Count：36 Percentile：73.86(Physics, Fluids & Plasmas)The JAERI MeV accelerator has been designed extrapolating vacuum insulation design guidelines (the clump theory and Paschen law) to Mega Volt and long vacuum gap. Reduction of electric field concentration at triple junction by a large stress ring was effective to prevent flashover along insulator surface. By the vacuum insulation technology above, the accelerator sustained 1 MV for 8,500 s continuously. Strong enhancement of negative ion surface production has been attained by stopping vacuum leaks due to SF
permeation through Viton O rings and a damage of port by backstream ions, followed by increase of the H
ion current density without saturation. Operating the KAMABOKO source with high power arc discharge (
40 kW), H ion beams of 146 A/m
(total ion current: 0.2 A) have been obtained stably at the beam energy of 836 keV (pulse length: 
0.2 s). Bremsstrahlung generation in the accelerator is also estimated from EGS4 analysis, and then discussion on the breakdown possibility follows.
Nakamura, Hirofumi; Hayashi, Takumi; Kobayashi, Kazuhiro; Nishi, Masataka
Fusion Science and Technology, 48(1), p.452 - 455, 2005/07
Times Cited Count：2 Percentile：17.10(Nuclear Science & Technology)Tritium behavior released in ITER hot cell has been investigated numerically. Tritium behavior was evaluated by a combined analytical methods of a tritium transport analysis with the one dimensional diffusion model in the multi-layer wall (concrete and epoxy paint) and a tritium concentration analysis with the complete mixing model by the ventilation in the hot cell under the simulated hot cell operational conditions. As the results, tritium concentration in the hot cell volume decreases rapidly from 300 DAC (Derived Air Concentration) less than 1 DAC in several days after removing the tritium release source. Tritium inventory in the wall is estimated to be about 0.1 PBq for 20 years operation. On the other hand, Tritium permeation through the epoxy painted concrete wall will be negligible. Finally, as to the effect of epoxy paint on the tritium permeation and inventory, it is found that the epoxy paint can reduce tritium inventory by about two orders of magnitude relative to bare concrete wall.
Nakamura, Hiroo; Riccardi, B.*; Loginov, N.*; Ara, Kuniaki*; Burgazzi, L.*; Cevolani, S.*; Dell'Ocro, G.*; Fazio, C.*; Giusti, D.*; Horiike, Hiroshi*; et al.
Journal of Nuclear Materials, 329-333(1), p.202 - 207, 2004/08
Times Cited Count：14 Percentile：64.92(Materials Science, Multidisciplinary)International Fusion Materials Irradiation Facility (IFMIF), being developed by EU, JA, RF and US, is a deuteron-lithium (Li) reaction neutron source for fusion materials testing. In the end of 2002, 3 year Key Element technology Phase (KEP) to reduce the key technology risk factors has been completed. This paper describes these KEP tasks results. To evaluate Li flow characteristics, a water and Li flow experiments have been done. To develop Li purification system, evaluation of nitrogen and tritium gettering materials have been done. Conceptual design of remote handling and basic experiment have been donde. In addition, safety analysis and diganostics design have been done. In the presentation, the latest design and future prospects will be also summarized.
Akiba, Masato; Ishitsuka, Etsuo; Enoeda, Mikio; Nishitani, Takeo; Konishi, Satoshi
Purazuma, Kaku Yugo Gakkai-Shi, 79(9), p.929 - 934, 2003/09
no abstracts in English
range for International Fusion Materials Irradiation Facility (IFMIF)Nakamura, Hiroo; Ida, Mizuho*; Nakamura, Hideo; Takeuchi, Hiroshi; IFMIF International Team
Fusion Engineering and Design, 65(3), p.467 - 474, 2003/04
Times Cited Count：4 Percentile：31.06(Nuclear Science & Technology)IFMIF is an accelerator-based neutron source for development of fusion materials. The Li target system consists of a target assembly, a Li purification system and various diagnostics. An intense deuterium beam power up to 10 MW in a footprint of 205 cm corresponds to ultra high heat flux up to 1 GW/m. To handle such an ultra high heat flux, the high-speed liquid Li flow with a velocity of 20 m/s and a concave flow configuration are necessary. According to thermal-hydraulic analysis, an induced centrifugal force (160 G) under the concave back wall of a radius of 25 cm is sufficient for IFMIF operation. To confirm the hydraulic characteristics of Li flow, water jet experiment has been done. Moreover, validation experiment in Li loop is planned. In addition, to control tritium and impurities such as C, N, O below permissible levels, a cold trap and two hot traps are used. These technologies have similarities in plasma facing components in fusion reactor. In presentation, the IFMIF Li target technology and its application of to the plasma facing component will be discussed.
Yoshida, Kiyoshi; Takigami, Hiroyuki*; Kubo, Hiroatsu*
Teion Kogaku, 36(11), p.617 - 625, 2001/11
no abstracts in English
Yoshida, Kiyoshi; Takigami, Hiroyuki*; Kubo, Hiroatsu*
Cryogenics, 41(8), p.583 - 594, 2001/08
Times Cited Count：8 Percentile：37.13(Thermodynamics)no abstracts in English
C-carbon fiber composite ceramics as plasma facing materials in nuclear fusion reactor, 3; Heat resistance evaluation by electron beam irradiation and by in situ plasma discharge in JT-60Jimbo, Ryutaro*; Saido, Masahiro; Nakamura, Kazuyuki; Akiba, Masato; ; Dairaku, Masayuki; ; ; ;
Journal of the Ceramic Society of Japan, International Edition, 105, p.1179 - 1187, 1997/00
no abstracts in English
Yamagiwa, Mitsuru; Koga, J. K.; Ishida, Shinichi
Proc. of 24th European Physical Society Conf. on Controlled Fusion and Plasma Physics, 21A, p.517 - 520, 1997/00
no abstracts in English
plasmasYamagiwa, Mitsuru
Plasma Physics and Controlled Fusion, 34(5), p.715 - 723, 1992/00
no abstracts in English
Hot Atom Chemistry, p.501 - 511, 1984/00
no abstracts in English
; Konishi, Satoshi; Naruse, Yuji
Nucl.Technol./Fusion, 3, p.471 - 484, 1983/00
no abstracts in English
Li(n, 
)T reaction in lithium oxide; Tanaka, Kichizo;
Journal of Inorganic and Nuclear Chemistry, 40(3), p.363 - 367, 1978/03
Times Cited Count：42no abstracts in English
Wakui, Takashi; Naoe, Takashi; Kogawa, Hiroyuki; Haga, Katsuhiro; Wakai, Eiichi; Takada, Hiroshi; Futakawa, Masatoshi
no journal, ,
The mercury target vessel has large size as 1.31.32.5 m. In view of reducing the amount of wastes, we have studied the structure so that the fore part could be separated. The flange is required to have high seal performance less than 110 Pam/s. Invar with low thermal expansion is a candidate. Due to its low stiffness, however, the flange may deform when it is fastened by bolts. Practically invar is reinforced with stainless steel where all interface between them has to be bonded completely with the HIP bonding. In this study, we made specimens at four temperatures of 973, 1173, 1373 and 1473 K and conducted tensile tests. The specimen bonded at 973 K had little diffusion layer, and so fractured at the interface. The tensile strength reduced with increasing the temperature, and the reduced amount was about 10 % at 1473 K. The analyzed residual stresses near the interface increased by 50 % at maximum. Then, we concluded that the optimum temperature was 1173 K.
