Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Fukui, Toshiki*; Maki, Takashi*; Miura, Nobuyuki; Tsukada, Takeshi*
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 23(2), p.169 - 173, 2016/12
The basic research programs for the next generation vitrification technology, which are commissioned project from Ministry of Economy, Trade and Industry of Japan, have been implemented from 2014 until 2018 for developing the advanced vitrification technology of low level wastes and high level liquid wastes.
Ishizawa, Akihiro*; Idomura, Yasuhiro; Imadera, Kenji*; Kasuya, Naohiro*; Kanno, Ryutaro*; Satake, Shinsuke*; Tatsuno, Tomoya*; Nakata, Motoki*; Nunami, Masanori*; Maeyama, Shinya*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 92(3), p.157 - 210, 2016/03
The high-performance computer system Helios which is located at The Computational Simulation Centre (CSC) in The International Fusion Energy Research Centre (IFERC) started its operation in January 2012 under the Broader Approach (BA) agreement between Japan and the EU. The Helios system has been used for magnetised fusion related simulation studies in the EU and Japan and has kept high average usage rate. As a result, the Helios system has contributed to many research products in a wide range of research areas from core plasma physics to reactor material and reactor engineering. This project review gives a short catalogue of domestic simulation research projects. First, we outline the IFERC-CSC project. After that, shown are objectives of the research projects, numerical schemes used in simulation codes, obtained results and necessary computations in future.
Hwang, J.-G.*; Kim, E.-S.*; Miyajima, Tsukasa*; Honda, Yosuke*; Harada, Kentaro*; Shimada, Miho*; Takai, Ryota*; Kume, Tatsuya*; Nagahashi, Shinya*; Obina, Takashi*; et al.
Nuclear Instruments and Methods in Physics Research A, 753, p.97 - 104, 2014/07
Times Cited Count:7 Percentile:48.01(Instruments & Instrumentation)Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Sakanaka, Shogo*; Ago, Tomonori*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; Harada, Kentaro*; Hiramatsu, Shigenori*; Honda, Toru*; et al.
Proceedings of 11th European Particle Accelerator Conference (EPAC '08) (CD-ROM), p.205 - 207, 2008/06
Future synchrotron light sources based on the energy-recovery linacs (ERLs) are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. Our Japanese collaboration team is making efforts for realizing an ERL-based hard X-ray source. We report recent progress in our R&D efforts.
Fujita, Takaaki; Tamai, Hiroshi; Matsukawa, Makoto; Kurita, Genichi; Bialek, J.*; Aiba, Nobuyuki; Tsuchiya, Katsuhiko; Sakurai, Shinji; Suzuki, Yutaka; Hamamatsu, Kiyotaka; et al.
Nuclear Fusion, 47(11), p.1512 - 1523, 2007/11
Times Cited Count:24 Percentile:63.05(Physics, Fluids & Plasmas)Design of modification of JT-60U, JT-60SA, has been optimized in viewpoint of plasma control, and operation regimes have been evaluated. Upper and lower divertors with different geometry are prepared for flexibility of plasma shape control. The beam lines of negative-ion NBI are shifted downward for off-axis current drive, in order to obtain a weak/reversed shear plasma. The feedback control coils along the port hole in the stabilizing plate are found effective to suppress the resistive wall mode (RWM) and sustain high close to the ideal wall limit. The regime of full current drive operation has been extended with upgraded heating and current drive power. Full current drive operation for 100 s with reactor-relevant high values of normalized beta and bootstrap current fraction ( = 2.4 MA, = 4.4, = 0.70, / = 0.86, H = 1.3) is expected in a highly-shaped low-aspect-ratio configuration ( = 2.65). High , high-density ELMy H-mode is also expected.
Yamada, Hiroshi*; Takenaga, Hidenobu; Suzuki, Takahiro; Fujita, Takaaki; Takizuka, Tomonori; Kamada, Yutaka; Asakura, Nobuyuki; Tsuda, Takashi; Takechi, Manabu; Matsunaga, Go; et al.
Nuclear Fusion, 47(11), p.1418 - 1424, 2007/11
Times Cited Count:1 Percentile:3.47(Physics, Fluids & Plasmas)High densities exceeding the Greenwald limit by a factor of 1.7 have been obtained in discharges with high internal inductances of as high as 2.8 in JT-60U L-mode plasmas. The internal inductance, which is an index of the edge magnetic shear, is controlled by ramping down the plasma current. In addition to the extension of the operational regime, confinement performance remains as good as an H89PL factor of 1.5 even above the Greenwald limit. While the earlier work of a high study has indicated that core confinement improvement, the additional improvement of the tolerance against the high density is turned out to be correlated with high edge temperature. The normalized density when the detachment characterized by the decrease in a D signal at the divertor occurs is even higher in the case with no disruption than the case with a disruption. These comparisons have indicated that the improvement in thermal and particle transport does exist in the periphery and the edge in the high plasmas, and mitigation of the density limit is observed coincidently. Although the high discharge studied here lies outside of the usual parameter space for a steady-state operation of tokamak, demonstration of a stable discharge with good confinement beyond the Greenwald limit suggest the magnetic shear at the edge is one key parameter to uncover physical element of the operational density limit.
Yamada, Hiroshi*; Takenaga, Hidenobu; Suzuki, Takahiro; Fujita, Takaaki; Takizuka, Tomonori; Kamada, Yutaka; Asakura, Nobuyuki; Tsuda, Takashi; Takechi, Manabu; Matsunaga, Go; et al.
Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 8 Pages, 2007/03
no abstracts in English
Ninomiya, Hiromasa; Akiba, Masato; Fujii, Tsuneyuki; Fujita, Takaaki; Fujiwara, Masami*; Hamamatsu, Kiyotaka; Hayashi, Nobuhiko; Hosogane, Nobuyuki; Ikeda, Yoshitaka; Inoue, Nobuyuki; et al.
Journal of the Korean Physical Society, 49, p.S428 - S432, 2006/12
To contribute DEMO and ITER, the design to modify the present JT-60U into superconducting coil machine, named National Centralized Tokamak (NCT), is being progressed under nationwide collaborations in Japan. Mission, design and strategy of this NCT program is summarized.
Nakano, Tomohide; Asakura, Nobuyuki; Takenaga, Hidenobu; Kubo, Hirotaka; Miura, Yukitoshi; Shimizu, Katsuhiro; Konoshima, Shigeru; Masaki, Kei; Higashijima, Satoru; JT-60 Team
Nuclear Fusion, 46(5), p.626 - 634, 2006/05
Times Cited Count:21 Percentile:57.01(Physics, Fluids & Plasmas)In order to understand plasma-wall interactions in a long time scale, the discharge pulse length has been extended from 15 s to 65 s, with the NB-heating duration extended to 30 s. Nearly-saturation of the divertor plates was observed in the latter half of long pulse ELMy H-mode discharges. Particle sink into the divertor plates gradually decreased, and subsequently, wall-pumping efficiency became zero. This wall saturation resulted in a rise of the main plasma density without any auxiliary particle supply besides NB with divertor-pumping. Even when the total injected energy reached up to 350 MJ in a discharge, neither sudden increase of carbon generation such as carbon bloom nor increase of the dilution of the main plasma was observed.
Kikuchi, Mitsuru; Tamai, Hiroshi; Matsukawa, Makoto; Fujita, Takaaki; Takase, Yuichi*; Sakurai, Shinji; Kizu, Kaname; Tsuchiya, Katsuhiko; Kurita, Genichi; Morioka, Atsuhiko; et al.
Nuclear Fusion, 46(3), p.S29 - S38, 2006/03
Times Cited Count:13 Percentile:41.56(Physics, Fluids & Plasmas)The National Centralized Tokamak (NCT) facility program is a domestic research program for advanced tokamak research to succeed JT-60U incorporating Japanese university accomplishments. The mission of NCT is to establish high beta steady-state operation for DEMO and to contribute to ITER. The machine flexibility and mobility is pursued in aspect ratio and shape controllability, feedback control of resistive wall modes, wide current and pressure profile control capability for the demonstration of the high-b steady state.
Tsuchiya, Katsuhiko; Akiba, Masato; Azechi, Hiroshi*; Fujii, Tsuneyuki; Fujita, Takaaki; Fujiwara, Masami*; Hamamatsu, Kiyotaka; Hashizume, Hidetoshi*; Hayashi, Nobuhiko; Horiike, Hiroshi*; et al.
Fusion Engineering and Design, 81(8-14), p.1599 - 1605, 2006/02
Times Cited Count:1 Percentile:9.91(Nuclear Science & Technology)no abstracts in English
Oyama, Naoyuki; Urano, Hajime; Yoshida, Maiko; Takenaga, Hidenobu; Shinohara, Koji; Sakurai, Shinji; Masaki, Kei; Kamiya, Kensaku; Isayama, Akihiko; Suzuki, Takahiro; et al.
Europhysics Conference Abstracts (CD-ROM), 30I, 4 Pages, 2006/00
no abstracts in English
Tamai, Hiroshi; Akiba, Masato; Azechi, Hiroshi*; Fujita, Takaaki; Hamamatsu, Kiyotaka; Hashizume, Hidetoshi*; Hayashi, Nobuhiko; Horiike, Hiroshi*; Hosogane, Nobuyuki; Ichimura, Makoto*; et al.
Nuclear Fusion, 45(12), p.1676 - 1683, 2005/12
Times Cited Count:15 Percentile:45.37(Physics, Fluids & Plasmas)Design studies are shown on the National Centralized Tokamak facility. The machine design is carried out to investigate the capability for the flexibility in aspect ratio and shape controllability for the demonstration of the high-beta steady state operation with nation-wide collaboration, in parallel with ITER towards DEMO. Two designs are proposed and assessed with respect to the physics requirements such as confinement, stability, current drive, divertor, and energetic particle confinement. The operation range in the aspect ratio and the plasma shape is widely enhanced in consistent with the sufficient divertor pumping. Evaluations of the plasma performance towards the determination of machine design are presented.
Takenaga, Hidenobu; Asakura, Nobuyuki; Kubo, Hirotaka; Higashijima, Satoru; Konoshima, Shigeru; Nakano, Tomohide; Oyama, Naoyuki; Porter, G. D.*; Rognlien, T. D.*; Rensink, M. E.*; et al.
Nuclear Fusion, 45(12), p.1618 - 1627, 2005/12
Times Cited Count:19 Percentile:53.12(Physics, Fluids & Plasmas)no abstracts in English
Takenaga, Hidenobu; Asakura, Nobuyuki; Higashijima, Satoru; Nakano, Tomohide; Kubo, Hirotaka; Konoshima, Shigeru; Oyama, Naoyuki; Isayama, Akihiko; Ide, Shunsuke; Fujita, Takaaki; et al.
Journal of Nuclear Materials, 337-339, p.802 - 807, 2005/03
Times Cited Count:14 Percentile:67.69(Materials Science, Multidisciplinary)no abstracts in English
Takenaga, Hidenobu; Asakura, Nobuyuki; Kubo, Hirotaka; Higashijima, Satoru; Konoshima, Shigeru; Nakano, Tomohide; Oyama, Naoyuki; Porter, G. D.*; Rognlien, T. D.*; Rensink, M. E.*; et al.
Proceedings of 20th IAEA Fusion Energy Conference (FEC 2004) (CD-ROM), 8 Pages, 2004/11
no abstracts in English
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:80.03(Physics, Fluids & Plasmas)no abstracts in English
Tamai, Hiroshi; Matsukawa, Makoto; Kurita, Genichi; Hayashi, Nobuhiko; Urata, Kazuhiro*; Miura, Yushi; Kizu, Kaname; Tsuchiya, Katsuhiko; Morioka, Atsuhiko; Kudo, Yusuke; et al.
Plasma Science and Technology, 6(1), p.2141 - 2150, 2004/02
Times Cited Count:2 Percentile:6.49(Physics, Fluids & Plasmas)The dominant issue for the the modification program of JT-60 (JT-60SC) is to demonstrate the steady state reactor relevant plasma operation. Physics design on plasma parameters, operation scenarios, and the plasma control method are investigated for the achievement of high-. Engineering design and the R&D on the superconducting magnet coils, radiation shield, and vacuum vessel are performed. Recent progress in such physics and technology developments is presented.
Oyama, Naoyuki; Miura, Yukitoshi; Chankin, A. V.; Takenaga, Hidenobu; Asakura, Nobuyuki; Kamada, Yutaka; Oikawa, Toshihiro; Shinohara, Koji; Takeji, Satoru
Nuclear Fusion, 43(10), p.1250 - 1257, 2003/10
Times Cited Count:16 Percentile:46.39(Physics, Fluids & Plasmas)no abstracts in English