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Goniche, M.*; Kazarian, F.*; Bibet, P.*; Maebara, Sunao; Seki, Masami; Ikeda, Yoshitaka; Imai, Tsuyoshi*
Journal of Vacuum Science and Technology A, 23(1), p.55 - 65, 2005/01
Times Cited Count：2 Percentile：9.36(Materials Science, Coatings & Films)Outgassing rates have been measured for long duration (100-4700 seconds) of RF transmission at high power density (50-200 MW/m
) for waveguides made of OFHC copper, dispersoid copper, copper-coated carbon fiber composite and copper-coated graphite. The measurements were performed on multi-waveguide(2 to 8)mockups, using a test bed facility equipped with a 3.7 GHz klystron. The effect on the outgassing rate of waveguide surface temperature and of initial wall gas loading('conditioning'), is examined. It is concluded that an outgassing rate of 1
10
Pam
s
m
and 510 Pamsm at 300
C and 400C respectively, can be expected for the tested material. Based on these measurement results, it is further concluded that no additional pumping will be needed for the LHRF antenna proposed for ITER.
Sogabe, Toshiaki; Ishihara, Masahiro; Baba, Shinichi; Tachibana, Yukio; Yamaji, Masatoshi*; Iyoku, Tatsuo; Hoshiya, Taiji*
Materials Science Research International, 9(3), p.235 - 241, 2003/09
2D-C/C composite is one of the promising materials as a next-generation core material in gas-cooled reactors. Effect of air-oxidation on the thermal diffusivity up to 1673K of the 2D-C/C composite was investigated. The C/C composite specimens for measurement of thermal diffusivity were oxidized from 1 to 11 percent weight loss in air at 823K. Thermal diffusivity at room temperature declined 10
20 percent for parallel to lamina direction and 59 percent for that of perpendicular within 11 percent weight loss by oxidation. Thermal diffusivity tended to decrease gradually as the increase of oxidation loss in parallel to lamina, however, it decreased in the beginning of oxidation pretty much and not so changed by further oxidation loss in perpendicular to lamina. Change in thermal conductivity under oxidation condition was also estimated.
Baba, Shinichi; Ishihara, Masahiro; Minakawa, Nobuaki; Suzuki, Junichi
Proceedings of International Conference on Advanced Technology in Experimental Mechanics 2003 (ATEM '03) (CD-ROM), 4 Pages, 2003/09
The aim of the present paper is to clarify the residual stress occuring in the c/c composite to improve the manufacturing process. The residual stress was measured by a neutron diffraction method using the RESA in the JRR-3M of JAERI in this study. As a results of the residual stress measurment, it was found that the residual stress of the ring type c/c composite is the comporessive stress, and the macroscopic residual strain/stress is absorbed mainly microstructural change such as pore shape change.
Baba, Shinichi; Ishihara, Masahiro; Sozawa, Shizuo; Sekino, Hajime
JAERI-Data/Code 2003-003, 394 Pages, 2003/03
JAERI-Data-Code-2003-003.pdf:13.63MB
The research on the radiation damage mechanism of heat resistant ceramic composite materials is one of the research subjects of the innovative basic research in the field of high temperature engineering, using the High Temperature engineering Test Reactor (HTTR). Three series of irradiation tests on the heat resistant ceramic composite materials, first to third irradiation test program, were carried out using the Japan Material Testing Reactor (JMTR). This is a summary report on the the first irradiation test program; irradiation induced dimensional change, thermal expansion coefficient, X-ray diffraction and 
-ray spectrum are reported.
Lavrentiev, V.; Abe, Hiroaki; Yamamoto, Shunya; Naramoto, Hiroshi; Narumi, Kazumasa
Surface and Interface Analysis, 35(1), p.36 - 39, 2003/01
Times Cited Count：8 Percentile：22.86(Chemistry, Physical)no abstracts in English
Sogabe, Toshiaki; Ishihara, Masahiro; Baba, Shinichi; Kojima, Takao; Tachibana, Yukio; Iyoku, Tatsuo; Hoshiya, Taiji; Hiraoka, Toshiharu*; Yamaji, Masatoshi*
JAERI-Research 2002-026, 22 Pages, 2002/11
JAERI-Research-2002-026.pdf:2.41MB
Carbon Fiber Reinforced Carbon-carbon Composites, C/C composites, have been developed and extensively studied their characteristics. C/C composites are considered to be promising materials for the application of a control rod in the next high performance high temperature gas-cooled reactors. In the present paper, details of the development of the candidate C/C composite are described. In the course of the development of the material, especially, feasibility of the production, stableness of the supply and cost are much taken into consideration. As the physical properties of the material, high mechanical strength such as tensile and bending, high fracture strain and fracture toughness and low dimensional change by neutron irradiation have to be met. The developed 2D-C/C composite consists of plain-weave PAN-based carbon fiber cloth and pitch derived matrix. Also, high purification up to the level of nuclear grade was successfully attained in the composite.
Masaki, Kei; Taniguchi, Masaki; Miyo, Yasuhiko; Sakurai, Shinji; Sato, Kazuyoshi; Ezato, Koichiro; Tamai, Hiroshi; Sakasai, Akira; Matsukawa, Makoto; Ishida, Shinichi; et al.
Fusion Engineering and Design, 61-62, p.171 - 176, 2002/11
Times Cited Count：19 Percentile：75.01(Nuclear Science & Technology)A flat carbon fiber composite tile mock-up with screw tubes, which have helical fins like a nut, was fabricated aiming at further improvement of the heat removal performance of the cost-effectively manufactured divertor target for JT-60SC (modified JT-60 as a superconducting coil tokamak). The heat removal performance of the mock-up was successfully demonstrated on the JAERI Electron Beam Irradiation Stand. The estimated heat transfer coefficient of the screw tube at the non-boiling region was roughly 3 times higher than that of the smooth tube. This corresponds to 1.5 times that of the swirl tube. A heat cycle test of 10 MW/m2 showed that the mock-up with the screw tubes could withstand for 1400 cycles. These results indicate that the divertor target plate with the flat carbon fiber composite tile and the screw tube can be a promising candidate for the JT-60SC divertor target.
Eto, Motokuni; Ishii, Toshimitsu; Inagaki, Terumi*; Okamoto, Yoshizo*
Carbon, 40(3), p.285 - 294, 2002/03
Times Cited Count：9 Percentile：37.07(Chemistry, Physical)no abstracts in English
Ishihara, Masahiro; Kojima, Takao; Hoshiya, Taiji
Proceedings of International Conference on Carbon in 2002 (Carbon2002) (CD-ROM), 6 Pages, 2002/00
Bending failure of two-dimensional C/C composite was studied by both experimental and analytical approaches. In the experiment, a bending test and observation of failure surfaces were performed. From the surface observation, three kinds of fundamental fracture modes were observed; these were tensile, compressive and shear fracture modes. In the analysis, the risk-based statistical fracture theory, so-called the competing risk theory was applied to clarify the bending failure taking account of the competition of these fracture modes. Parameters used in the theory on these fundamental fracture modes were determined by additional experiments, and the theory was applied to the bending failure prediction. As a result of this study, it is concluded that the bending failure was well predicted by the theory, and that the theory would be possible to predict the strength under stress gradient condition. Furthermore, a new strength prediction method combined with FEM code, which is applicable to arbitrary shaped structures with stress gradient, was proposed in this paper.
Oshima, Akihiro; Udagawa, Akira; Morita, Yosuke
Radiation Physics and Chemistry, 60(4-5), p.467 - 471, 2001/03
Times Cited Count：12 Percentile：64.97(Chemistry, Physical)Plain-woven carbon fber-filled polytetrafluoroethylene (PTFE)composites were fabricated by radiation-crosslinking under selective conditions.High mechanical and frictional properties are found in the composite materials compared with crosslinked PTFE without fiber.The composite materials with optional shapes,which are laminated after electron beam (EB) crosslinking treatment of each mono-layer could also be fabricated.
Oshima, Akihiro; Udagawa, Akira; Morita, Yosuke
Radiation Physics and Chemistry, 60(1-2), p.95 - 100, 2001/01
Times Cited Count：8 Percentile：52.55(Chemistry, Physical)no abstracts in English
Oshima, Akihiro; Udagawa, Akira; Morita, Yosuke
Proceedings of International Symposium on Prospect for Application of Radiation towards the 21st Century, p.83 - 84, 2000/00
no abstracts in English
*; Udagawa, Akira; Morita, Yosuke
Conference Proceeding RadTech Asia'99, p.507 - 512, 1999/08
no abstracts in English
Oku, Tatsuo*; Kurumada, A.*; Nakata, M.*; Takeda, K.*; Kawamata, K.*; Arai, Taketoshi; Ishihara, Masahiro
Proceedings of 24th Biennial Conference on Carbon (CARBON '99), p.574 - 575, 1999/07
no abstracts in English
; *; Araki, Masanori; Nakamura, Kazuyuki; Akiba, Masato
Journal of Nuclear Materials, 258-263, p.318 - 322, 1998/00
Times Cited Count：8 Percentile：57.41(Materials Science, Multidisciplinary)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
Araki, Masanori; Nakamura, Kazuyuki; ; Akiba, Masato; *; *; *
Fusion Technology 1996, 0, p.359 - 362, 1996/00
no abstracts in English
Sato, Kazuyoshi; Akiba, Masato; Araki, Masanori; ; ; I.Smid*; A.Cardella*; R.Duwe*; E.D.Pietro*
JAERI-M 93-058, 22 Pages, 1993/03
no abstracts in English
Ando, Toshiro; Takatsu, Hideyuki; Nakamura, Hiroo; Yamamoto, Masahiro; ; Arai, Takashi; Kaminaga, Atsushi; ; Horiike, Hiroshi; Shimizu, Masatsugu; et al.
Kaku Yugo Kenkyu, 65(SPECIAL ISSUE), p.27 - 49, 1991/03
no abstracts in English
Eto, Motokuni; Fukaya, Kiyoshi; Ando, Toshiro; Takatsu, Hideyuki; Seki, Masahiro
Twentieth Biennial Conf. on Carbon, p.640 - 641, 1991/00
no abstracts in English
