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Tanabe, Tetsuo*; Sugiyama, Kazuyoshi*; Shibahara, Takahiro*; Hirohata, Yuko*; Yoshida, Masafumi; Masaki, Kei; Sato, Masayasu
Journal of Nuclear Materials, 390-391, p.705 - 708, 2009/06
Times Cited Count：8 Percentile：49.29(Materials Science, Multidisciplinary)no abstracts in English
Masaki, Kei; Tanabe, Tetsuo*; Hirohata, Yuko*; Oya, Yasuhisa*; Shibahara, Takahiro*; Hayashi, Takao; Sugiyama, Kazuyoshi*; Arai, Takashi; Okuno, Kenji*; Miya, Naoyuki
Nuclear Fusion, 47(11), p.1577 - 1582, 2007/11
Times Cited Count：14 Percentile：44.94(Physics, Fluids & Plasmas)In JT-60U, erosion/deposition analyses for the plasma facing wall have shown that deposition was dominant at the inner-middle first wall and the inner divertor, whereas erosion dominant at the upper first wall and the outer divertor. Assuming toroidal symmetry in the erosion and deposition patterns, the net carbon erosion and deposition in the divertor area were estimated to be 0.34 kg and 0.55 kg, respectively. In a whole, the increment of carbon in the divertor region was 0.21 kg, which should be originated from the first wall. The hydrogen concentration in the thick deposition layer of the inner divertor was 0.02 in (H+D)/C. In the plasma-shadowed area underneath the divertor region at around 420 K, re-deposited layers of 2 
m-thick were found with high hydrogen concentration of 0.8 in (H+D)/C. The carbon deposition rate in the plasma-shadowed area, however, was 8
10
atoms/s, which was one order smaller than that (610
atoms/s) on the wall surface.
Oya, Yasuhisa*; Hirohata, Yuko*; Nakahata, Toshihiko*; Suda, Taichi*; Yoshida, Masashi*; Arai, Takashi; Masaki, Kei; Okuno, Kenji*; Tanabe, Tetsuo*
Fusion Science and Technology, 52(3), p.554 - 558, 2007/10
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)To investigate retention characteristics of hydrogen isotopes in the first wall tiles of JT-60U, surface morphology, erosion/deposition profiles and hydrogen isotope retentions were examined by SEM, XPS, TDS and SIMS. It was found that poloidal deuterium retention profile was rather uniform, while the thermal desorption behavior of deuterium was quite different depending on the locations of the tiles. Deuterium retained in the upper first wall, where was covered by thick boron layers with high concentration of B, was desorbed at lower temperature than that in the lower area covered by carbon layers with much less B content. D/H ratio in the first wall tiles was appreciably higher than that observed in the divertor tiles, suggesting the injection of high energy deuteron originating from NBI into the first wall. In addition, the lower temperature of the first wall compared to that of the divertor tiles would prohibit desorption of the implanted deuterium and/or its replacement by subsequent D or H impingement.
Hirohata, Yuko*; Tanabe, Tetsuo*; Oya, Yasuhisa*; Okuno, Kenji*; Masaki, Kei; Miya, Naoyuki; JT-60U Team
Journal of Nuclear Materials, 363-365, p.854 - 861, 2007/06
Times Cited Count：11 Percentile：60.92(Materials Science, Multidisciplinary)no abstracts in English
Masaki, Kei; Tanabe, Tetsuo*; Hirohata, Yuko*; Oya, Yasuhisa*; Shibahara, Takahiro*; Hayashi, Takao; Sugiyama, Kazuyoshi*; Arai, Takashi; Okuno, Kenji*; Miya, Naoyuki
Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 8 Pages, 2007/03
Evaluation of fuel inventory and its retention process are critical issues for a next-step fusion device, especially with carbon-based wall. In order to resolve the issues, the hydrogen retention and carbon deposition analyses for the plasma facing surfaces and plasma-shadowed area of JT-60U have been performed. In JT-60U, erosion/deposition analyses for the plasma facing wall have shown that deposition was dominant at the inner-middle first wall and the inner divertor, whereas erosion dominant at the upper first wall and the outer divertor. Assuming toroidal symmetry in the erosion and deposition patterns, the net carbon erosion and deposition in the divertor area were estimated to be 0.34 kg and 0.55 kg, respectively. In a whole, the increment of carbon in the divertor region was 0.21 kg, which should be originated from the first wall. The hydrogen concentration in the thick deposition layer of the inner divertor was 
0.02 in (H+D)/C. In the plasma-shadowed area underneath the divertor region at around 420 K, re-deposited layers of 2m-thick were found with high hydrogen concentration of 0.8 in (H+D)/C. The carbon deposition rate in the plasma-shadowed area, however, was 810 atoms/s, which was one order smaller than that (610 atoms/s) on the wall surface.
Tsuzuki, Kazuhiro; Kamiya, Kensaku; Shinohara, Koji; Bakhtiari, M.*; Ogawa, Hiroaki; Kurita, Genichi; Takechi, Manabu; Kasai, Satoshi; Sato, Masayasu; Kawashima, Hisato; et al.
Nuclear Fusion, 46(11), p.966 - 971, 2006/11
Times Cited Count：16 Percentile：48.1(Physics, Fluids & Plasmas)no abstracts in English
Shibahara, Takahiro*; Tanabe, Tetsuo*; Hirohata, Yuko*; Oya, Yasuhisa*; Oyaizu, Makoto*; Yoshikawa, Akira*; Onishi, Yoshihiro*; Arai, Takashi; Masaki, Kei; Okuno, Kenji*; et al.
Journal of Nuclear Materials, 357(1-3), p.115 - 125, 2006/10
Times Cited Count：20 Percentile：78.69(Materials Science, Multidisciplinary)no abstracts in English
Tsuzuki, Kazuhiro*; Kimura, Haruyuki; Kusama, Yoshinori; Sato, Masayasu; Kawashima, Hisato; Kamiya, Kensaku; Shinohara, Koji; Ogawa, Hiroaki; Uehara, Kazuya; Kurita, Genichi; et al.
Fusion Science and Technology, 49(2), p.197 - 208, 2006/02
Times Cited Count：11 Percentile：60.07(Nuclear Science & Technology)no abstracts in English
Yamaguchi, Y.*; *; Hino, Tomoaki*; Masaki, Kei; Saido, Masahiro; Ando, Toshiro; D.G.Whyte*; C.Wong*
Journal of Nuclear Materials, 266-269, p.1257 - 1260, 1999/00
Times Cited Count：20 Percentile：79.69(Materials Science, Multidisciplinary)no abstracts in English
*; *; *; Hino, Tomoaki*; Ogiwara, Norio; Yagyu, Junichi; Saido, Masahiro
Vacuum, 53(1-2), p.309 - 312, 1999/00
Times Cited Count：3 Percentile：18.85(Materials Science, Multidisciplinary)no abstracts in English
Hirohata, Yuko*; Tanabe, Tetsuo*; Sugiyama, Kazuyoshi*; Shibahara, Takahiro*; Oya, Yasuhisa*; Oyaizu, Makoto*; Yoshikawa, Akira*; Okuno, Kenji*; Masaki, Kei; Arai, Takashi; et al.
no journal, ,
no abstracts in English
Hirohata, Yuko*; Tanabe, Tetsuo*; Oya, Yasuhisa*; Shibahara, Takahiro*; Sugiyama, Kazuyoshi*; Oyaizu, Makoto*; Yoshikawa, Akira*; Yoshida, Masashi*; Arai, Takashi; Masaki, Kei; et al.
no journal, ,
no abstracts in English
Hirohata, Yuko*; Tanabe, Tetsuo*; Oya, Yasuhisa*; Shibahara, Takahiro*; Sugiyama, Kazuyoshi*; Oyaizu, Makoto*; Yoshikawa, Akira*; Yoshida, Masashi*; Arai, Takashi; Masaki, Kei; et al.
no journal, ,
no abstracts in English
Hirohata, Yuko*; Tanabe, Tetsuo*; Oya, Yasuhisa*; Arai, Takashi; Masaki, Kei; Okuno, Kenji*; Sugiyama, Kazuyoshi*; Oyaizu, Makoto*; Yoshikawa, Akira*; Yoshida, Masashi*
no journal, ,
no abstracts in English
