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Shinohara, Koji; Kurki-Suonio, T.*; Spong, D.*; Asunta, O.*; Tani, Keiji*; Strumberger, E.*; Briguglio, S.*; G
nter, S.*; Koskela, T.*; Kramer, G.*; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
Sn conductors for ITER Toroidal Field coilsTakahashi, Yoshikazu; Isono, Takaaki; Hamada, Kazuya; Nunoya, Yoshihiko; Nabara, Yoshihiro; Matsui, Kunihiro; Hemmi, Tsutomu; Kawano, Katsumi; Koizumi, Norikiyo; Oshikiri, Masayuki; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
Japan Atomic Energy Agency is procuring the NbSn superconductors for Toroidal Field (TF) coils under the ITER project. Because manufacturing amount of NbSn strands is quite large compared with the past experience and required superconducting performance is higher than that of the model coils which have been fabricated and tested in the ITER-EDA, quality control technique is very important for the manufacture of the strands. Sophisticated control technique is also required for the jacketing, in order to fabricate the conductors with the precise outer diameter and without leakage at welding part. Cu dummy conductor with full length (760 m) has been fabricated successfully and all jacketing technology was confirmed through this fabrication. The fabrication of the NbSn conductor for TF coils will start in March 2010.
Kojima, Atsushi; Hanada, Masaya; Tanaka, Yutaka*; Kawai, Mikito*; Akino, Noboru; Kazawa, Minoru; Komata, Masao; Mogaki, Kazuhiko; Usui, Katsutomi; Sasaki, Shunichi; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
Hydrogen negative ion beams of 490keV, 3A and 510 keV, 1A have been successfully produced in the JT-60 negative ion source with three acceleration stages. These successful productions of the high-energy beams at high current have been achieved by overcoming the most critical issue, i.e., a poor voltage holding of the large negative ion sources with the grids of 
2 m
for JT-60SA and ITER. To improve voltage holding capability, the breakdown voltages for the large grids was examined for the first time. It was found that a vacuum insulation distance for the large grids was 6-7 times longer than that for the small-area grid (0.02 m). From this result, the gap lengths between the grids were tuned in the JT-60 negative ion source. The modification of the ion source also realized a significant stabilization of voltage holding and a short conditioning time. These results suggest a practical use of the large negative ion sources in JT-60 SA and ITER.
Mayoral, M.-L.*; Bobkov, V.*; Colas, L.*; Goniche, M.*; Hosea, J.*; Kwak, J. G.*; Pinsker, R.*; Moriyama, Shinichi; Wukitch, S.*; Baity, F. W.*; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 11 Pages, 2011/03
For any given ICRF antenna design for ITER, the maximum achievable power strongly depends on the density profiles in the SOL. It has been suggested that gas injection can be used to modify the SOL profiles and thus minimize the sensitivity of the ICRF coupling to variations in the density at the edge of the confined plasma. Recently joint experiments coordinated by the ITPA were performed to characterize further this method. An increase in SOL density during gas injection led to improved coupling for all tokamaks in this multi-machine comparison. The effectiveness of using gas injection over a wide range of conditions, as a tool to tailor the edge density in front of the ICRF antennas, is documented for different gas inlet location and plasma configurations. In addition, any deleterious effects on the confinement and interaction with the antenna near-field are not investigated.
Murakami, Masanori*; Park, J. M.*; Giruzzi, G.*; Garcia, J.*; Bonoli, P.*; Budny, R. V.*; Doyle, E. J.*; Fukuyama, Atsushi*; Hayashi, Nobuhiko; Honda, Mitsuru; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
Honda, Mitsuru; Takizuka, Tomonori; Tobita, Kenji; Matsunaga, Go; Fukuyama, Atsushi*; Ozeki, Takahisa
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
Wakasa, Arimitsu*; Fukuyama, Atsushi*; Murakami, Sadayoshi*; Miki, Masayuki*; Yokoyama, Masayuki*; Sato, Masahiko*; Toda, Shinichiro*; Funaba, Hisamichi*; Tanaka, Kenji*; Ida, Katsumi*; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
Imbeaux, F.*; Basiuk, V.*; Budny, R.*; Casper, T.*; Citrin, J.*; Fereira, J.*; Fukuyama, Atsushi*; Garcia, J.*; Gribov, Y. V.*; Hayashi, Nobuhiko; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
Bae, Y. S.*; Park, Y. M.*; Kim, J. S.*; Han, W. S.*; Kwak, S. W.*; Chang, Y. B.*; Park, H. T.*; Song, N. H.*; Chang, D. H.*; Jeong, S. H.*; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 9 Pages, 2011/03
The neutral beam injection (NBI) system is designed to provide the ion heating and current drive for the high performance operation and long pulse operation of the Korean Superconducting Tokamak Advanced Research (KSTAR). The KSTAR NBI consists of two beam lines. Each beam line contains three ion sources of which one ion source has been designed to deliver more than 2.5 MW of deuterium neutral beam power with maximum 120-keV beam energy. Consequently, the final goal of the KSTAR NBI system aims to inject more than 14 MW of deuterium beam power with the two beam lines. According to the planned NBI system, the first NBI system is to demonstrate the beam injection from one ion source into the KSTAR tokamak plasma in 2010 campaign including the system commissioning of each components and subsystems. In this paper, the construction and the commissioning of the first NBI system with one ion source is presented.
Yang, H. L.*; Kim, Y. S.*; Park, Y. M.*; Bae, Y. S.*; Kim, H. K.*; Kim, K. M.*; Lee, K. S.*; Kim, H. T.*; Bang, E. N.*; Joung, M.*; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
Because the 2010 operation of Korea Superconducting Tokamak Advanced Research (KSTAR) mainly aims to achieve strongly elongated and diverted plasma, all the necessary hardware systems to provide an essential circumstance for the plasma shaping were newly installed and upgraded in 2010. In this paper, general configuration of the upgraded systems described earlier will be outlined. Moreover, several key performances and test results of the systems will be also reported in summary.
Shiraishi, Junya; Tokuda, Shinji*
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
no abstracts in English
Hoshino, Kazuo; Toma, Mitsunori*; Shimizu, Katsuhiro; Nakano, Tomohide; Hatayama, Akiyoshi*; Takizuka, Tomonori
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 6 Pages, 2011/03
The transport of high-Z impurity in a toroidally rotating tokamak plasma is investigated analytically and numerically. It is shown that the inward pinch is driven by the atomic processes in co- and ctr- rotating plasmas. This inward pinch is enhanced by the radial electric field. It is derived that the negative and positive radial electric fields cause the inward pinch and the outward movement (unpinch) of the high-Z impurity, respectively, under the influence of Coulomb collisions with the rotating background plasma. In the ctr-rotation case, the inward pinch becomes significant with increasing toroidal rotation velocity, because the directions of the both pinches are inward. On the other hand, in the co-rotation case, these pinches have opposite directions. Therefore, the unpinch due to the positive radial electric field is decreased by the inward pinch due to the atomic processes. These tendencies are consistent with the tungsten accumulation observed in the JT-60U.
B flow on gyrokineticsMiyato, Naoaki; Scott, B. D.*; Tokuda, Shinji*; Yagi, Masatoshi
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
Based on the phase space Lagrangian Lie-transform perturbation method and the field theory, a reduced kinetic model with large EB flow beyond the standard ordering (
) is constructed by modifying the guiding-centre phase space trans-formation. The model can be regarded as a natural extension of the standard model without flow since the symplectic part of the Lagrangian is the same as the standard one formally. Some aspects of the model are revealed and effects of the flow are discussed in course of comparison with the standard model. The push-forward representation of general particle fluid moment is presented in the subsonic flow case. In sonic flow case, corrections to the reduced quasi-neutrality condition due to the EB flow are found by variational derivation of the push-forward representation of particle density.
plasmasMatsunaga, Go; Aiba, Nobuyuki; Shinohara, Koji; Sakamoto, Yoshiteru; Takechi, Manabu; Suzuki, Takahiro; Asakura, Nobuyuki; Isayama, Akihiko; Oyama, Naoyuki; Yoshida, Maiko; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
Hayashi, Nobuhiko; Parail, V.*; Koechl, F.*; Aiba, Nobuyuki; Takizuka, Tomonori; Wiesen, S.*; Lang, P.*; Oyama, Naoyuki; Ozeki, Takahisa; JET-EFDA Contributors*
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
Tobari, Hiroyuki; Inoue, Takashi; Hanada, Masaya; Dairaku, Masayuki; Watanabe, Kazuhiro; Umeda, Naotaka; Taniguchi, Masaki; Kashiwagi, Mieko; Yamanaka, Haruhiko; Takemoto, Jumpei; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
High voltage (HV) bushing in the ITER NBI is one of critical components, which acts as a feedthrough for electric power and cooling water from the -1 MV power supply in SF
gas to beam source inside vacuum. JAEA has overcome a longstanding issue on manufacturing of a large bore ceramic ring with 1.56 m in diameter as the insulator of the five-stage HV bushing. Joining method of the ceramic and metal flange with thick Kovar plate to form vacuum boundary was also developed. By assembling components, a full-size mockup bushing simulating one stage of the HV bushing was successfully manufactured. In the voltage holding test, the high voltage of 240 kV including the margin of 20 % of a rated voltage was sustained for 3600 s without breakdown, and the voltage holding capability required in ITER was successfully verified.
Idomura, Yasuhiro; Jolliet, S.; Yoshida, Maiko; Urano, Hajime
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
An impact of the toroidal rotation and the safety factor q on the ion temperature gradient driven (ITG) turbulence is studied using a global gyrokinetic toroidal full-f five dimensional Euleriancode GT5D. In the rotation scan numerical experiments, the radial electric field Er profile is changed depending on the toroidal rotation. Although local transport levels are affected by the Er profile, global transport properties are not changed, when the magnitudes of its shearing rate are in similar levels on average. In the q scan numerical experiments, turbulent transport is significantly enhanced at higher q. It is found that the stabilizing effect of Er shear on liner ITG modes becomes less effective at higher q. Both the ion heat transport and the non-diffusive momentum transport are enhanced. The former leads to lower ion temperature gradient, while the latter produces larger inward momentum flux and co-current spontaneous rotation in the plasma core.
n EigenmodesLesur, M.*; Idomura, Yasuhiro; Shinohara, Koji; Garbet, X.*
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
Alfvn Eigenmodes (AEs) with frequency sweeping (chirping AEs) are analyzed based on the so-called Berk-Breizman (BB) model. Kinetic parameter regimes with chirping nonlinear solutions are delimited, and a new quasi-periodic chirping regime is found, where the quasi-period of chirping events depends on the linear growth rate. Fundamental kinetic parameters such as the linear drive and the external damping rate are estimated by fitting nonlinear chirping characteristics between the experiment and the BB model. This approach is applied to Toroidicity-induced AEs on JT-60U, which suggests the existence of modes far from marginal stability. Two collision models are considered, and it is shown that dynamical friction and velocity-space diffusion are essential to reproduce nonlinear features observed in experiments. The results are validated by recovering measured growth and decay of perturbation amplitude, and by estimating collision frequencies from experimental equilibrium data.
Peeters, A. G.*; Angioni, C.*; Bortolon, A.*; Camenen, Y.*; Casson, F. J.*; Dubal, B.*; Fiederspiel, L.*; Hornsby, W. A.*; Idomura, Yasuhiro; Kluy, N.*; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 13 Pages, 2011/03
Labit, B.*; Pochelon, A.*; Rancic, M.*; Piras, F.*; Bencze, A.*; Bottino, A.*; Brunner, S.*; Camenen, Y.*; Chattopadhyay, P. K.*; Coda, S.*; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
