Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Kamiya, Kensaku; Kawashima, Hisato; Ido, Takeshi*; Oyama, Naoyuki; Bakhtiari, M.*; Kasai, Satoshi; Kusama, Yoshinori; Miura, Yukitoshi; Ogawa, Hiroaki; Tsuzuki, Kazuhiro; et al.
Nuclear Fusion, 46(2), p.272 - 276, 2006/02
Times Cited Count：3 Percentile：10.71(Physics, Fluids & Plasmas)An attractive operational regime without any large ELMs, namely High Recycling Steady (HRS) H-mode, was found on JFT-2M during Y2000 campaign after boronization. Recent experiments have concentrated on the studies of the access conditions for the HRS regime, in terms of the pedestal parameters. The HRS regime was more likely at higher edge density and lower edge temperature, which corresponds to the normalized electron collisionality of 1 in the plasma edge region.
Seki, Masami; Moriyama, Shinichi; Shinozaki, Shinichi; Hasegawa, Koichi; Hiranai, Shinichi; Yokokura, Kenji; Shimono, Mitsugu; Terakado, Masayuki; Fujii, Tsuneyuki
Fusion Engineering and Design, 74(1-4), p.273 - 277, 2005/11
Times Cited Count：3 Percentile：24.17(Nuclear Science & Technology)no abstracts in English
Kawashima, Hisato; Uehara, Kazuya; Nishino, Nobuhiro*; Kamiya, Kensaku; Tsuzuki, Kazuhiro; Bakhtiari, M.; Nagashima, Yoshihiko*; Ogawa, Hiroaki; Hoshino, Katsumichi; Suzuki, Sadaaki; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 80(11), p.907 - 908, 2004/11
A comparison of divertor heat load between ELMy and "High Recycling Steady" (HRS) H-mode was carried out by fast measurements of the two dimensional 
emission, and the divertor electron temperature and ion saturation current on JFT-2M. They brought an attractive feature of HRS H-mode that the heat load was reduced to the level on time average that for ELMy H-mode, being able to avoid the severe heat load during pulsed ELM event. It was also indicated that the HRS H-mode was dominated by an enhancement of particle transport, whereas both heat and particle transport increased abruptly at ELM event.
Oyama, Naoyuki; Asakura, Nobuyuki; Chankin, A. V.; Oikawa, Toshihiro; Sugihara, Masayoshi; Takenaga, Hidenobu; Itami, Kiyoshi; Miura, Yukitoshi; Kamada, Yutaka; Shinohara, Koji; et al.
Nuclear Fusion, 44(5), p.582 - 592, 2004/05
Times Cited Count：46 Percentile：80.18(Physics, Fluids & Plasmas)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：31.59(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 20
5 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.
-drift, current, and kinetic effects on divertor plasma profiles during ELMsRognlien, T. D.*; Shimada, Michiya
Journal of Nuclear Materials, 313-316, p.1000 - 1004, 2003/03
Times Cited Count：8 Percentile：49.8(Materials Science, Multidisciplinary)Edge Localized Mode (ELM) heat load on material surfaces is a key issue for burning-plasma tokamak experiments, e.g., ITER or FIRE. When a hot and dense plasma is injected to open field lines near the midplane at an ELM event, there will be a pressure imbalance along the field line, because ion motion is slow. Therefore an electric field will develop along the field line(an extended presheath). Due to the rotational transform, the parallel electric field becomes a poloidal electric field. The field Ep generates an . Therefore, as the injected plasma flows toward the divertor surface to deposit its energy, it experiences a radial shift 1cm. As the target plate is usually inclined to reduce the heat load, a radial shift of 1 cm is appreciable. For ITER, this would correspond to 3 cm on the target. As different portions of the hot ion plasma feel different electric field, the heat flux should also spread radially. A detailed assessment of these cross-field drift effects is given for an ITER-sized device using time-dependent simulations with the 2D UEDGE transport code.
Higashijima, Satoru; Asakura, Nobuyuki; Kubo, Hirotaka; Miura, Yukitoshi; Nakano, Tomohide; Konoshima, Shigeru; Itami, Kiyoshi; Sakurai, Shinji; Takenaga, Hidenobu; Tamai, Hiroshi; et al.
Journal of Nuclear Materials, 313-316, p.1123 - 1130, 2003/03
Times Cited Count：18 Percentile：74.33(Materials Science, Multidisciplinary)Reduction of steady-state heat load in the divertor and transient one by ELMs is a crucial issue for tokamak fusion devices. High radiation loss power is necessary for the heat load reduction, and the conventional gas puffing can increase the density and the radiation loss power, but it degrades the confinement. Core plasma with high confinement should be maintained simultaneously. Impurity seeding is a secure way to enhance the radiation loss power. In JT-60U, heat load is successfully reduced by Ar injection with keeping a high confinement in ELMy H-mode plasmas. In this paper, heat load reduction, radiation enhancement, and change of ELM activity are discussed.
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：74.68(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.
Seki, Masami; Ikeda, Yoshitaka; Maebara, Sunao; Moriyama, Shinichi; Naito, Osamu; Anno, Katsuto; Hiranai, Shinichi; Shimono, Mitsugu; Shinozaki, Shinichi; Terakado, Masayuki; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.452 - 466, 2002/09
Times Cited Count：14 Percentile：65.5(Nuclear Science & Technology)no abstracts in English
Yamamoto, Takumi; Umeda, Naotaka; Kuriyama, Masaaki; Lei, G.*; Grisham, L. R.*; Kawai, Mikito; Oga, Tokumichi; JT-60 NBI-Team
Journal of Plasma and Fusion Research SERIES, Vol.5, p.474 - 477, 2002/00
The performance of a 500keV negative-ion based neutral beam injection system for the JT-60U has been enhanced significantly. By improving the beam divergence, 10-second operation of beam injection has been attained. Small peaks were observed in the beam profile measured at the near field. These peaks are clearly resulted from the deflection of the beamlets due to an unwanted electric field. Correction of the deflection reduced the heat load on the limiter at the injection port by more than 50%. The Doppler shifted spectrum from the negative ion beam was measured, and then indicated that electron stripping of the negative ion beam occurs primarily inside the extraction grid, as expected from theoretical consideration. The electron stripping contributed to half of the heat load on the grounded grid.
Yamazaki, H.*; Yabashi, Makina*; Tamasaku, Kenji*; Yoneda, Yasuhiro; Goto, Shunji*; Mochizuki, Tetsuro*; Ishikawa, Tetsuya*
Nuclear Instruments and Methods in Physics Research A, 467-468(Part1), p.643 - 646, 2001/07
Times Cited Count：7 Percentile：48.66(Instruments & Instrumentation)no abstracts in English
Fujiwara, Yukio; Hanada, Masaya; Miyamoto, Kenji; Okumura, Yoshikazu; ; Watanabe, Kazuhiro
JAERI-Tech 99-052, 52 Pages, 1999/07
no abstracts in English
Kuriyama, Masaaki; Akino, Noboru; Ebisawa, Noboru; Grisham, L. R.*; Hikida, Shigenori*; Honda, Atsushi; Ito, Takao; Kawai, Mikito; Kazawa, Minoru; Kusaka, Makoto*; et al.
Proceedings of the 18th IEEE/NPSS Symposium on Fusion Engineering (SOFE '99), p.133 - 136, 1999/00
no abstracts in English
Araki, Masanori; D.L.Youchison*; Akiba, Masato; R.D.Watson*; Sato, Kazuyoshi;
Journal of Nuclear Materials, 233-237(PT.A), p.632 - 637, 1996/00
Times Cited Count：5 Percentile：45.07(Materials Science, Multidisciplinary)no abstracts in English
Nakamura, Kazuyuki; Akiba, Masato; Araki, Masanori; Dairaku, Masayuki; Sato, Kazuyoshi; ; ; J.Linke*; R.Duwe*; H.Bolt*; et al.
Journal of Nuclear Materials, 233-237(PT.A), p.730 - 735, 1996/00
Times Cited Count：7 Percentile：54.39(Materials Science, Multidisciplinary)no abstracts in English
Naito, Osamu; Ikeda, Yoshitaka; Seki, Masami; Ide, Shunsuke; Kondoh, Takashi; Ushigusa, Kenkichi
Journal of Nuclear Materials, 220-222, p.425 - 428, 1995/04
Times Cited Count：2 Percentile：28.04(Materials Science, Multidisciplinary)Heat loads on a lower hybrid wave launcher as well as on the first wall during high power auxiliary heating and their origin are investigated. It is found that the heat load on the launcher is moderate during injection of lower hybrid wave into a ohmic plasma. However, it is significantly enhanced by the existence of high energy banana-trapped particles and localized near the equatorial plane. In JT-60U, lower hybrid wave can be coupled to the plasma at a launcher-plasma distance of ~ 20 cm without any significant heat load on the launcher grill. Nevertheless, the heat load due to banana-orbit particles may impose a constraint on the position of a launcher.
Araki, Masanori; Akiba, Masato; Dairaku, Masayuki; *; Ise, Hideo*; Seki, Masahiro; ;
Journal of Nuclear Science and Technology, 29(9), p.901 - 908, 1992/09
no abstracts in English
ion sourceOkumura, Yoshikazu; Hanada, Masaya; Inoue, Takashi; Mizuno, Makoto; Ohara, Yoshihiro; Suzuki, Yasuo*; Tanaka, Hideki*; Tanaka, M.*; Watanabe, Kazuhiro
Review of Scientific Instruments, 63(4), p.2708 - 2710, 1992/04
Times Cited Count：24 Percentile：86.57(Instruments & Instrumentation)no abstracts in English
Sugimoto, Makoto; Kato, Takashi; Kawano, Katsumi; Hiyama, Tadao; *; *; *; *; *; Okuno, Kiyoshi; et al.
Teion Kogaku, 27(3), p.239 - 244, 1992/00
no abstracts in English
Ikeda, Yoshitaka; Imai, Tsuyoshi; Ushigusa, Kenkichi; Naito, Osamu; Seki, Masami; *; Nemoto, Masahiro; Kubo, Hirotaka
Journal of Nuclear Materials, 176-177, p.306 - 310, 1990/00
Times Cited Count：2 Percentile：31.33(Materials Science, Multidisciplinary)no abstracts in English
