Disassembly of the NBI system on JT-60U for JT-60 SA

Akino, Noboru; Endo, Yasuei; Hanada, Masaya; Kawai, Mikito*; Kazawa, Minoru; Kikuchi, Katsumi*; Kojima, Atsushi; Komata, Masao; Mogaki, Kazuhiko; Nemoto, Shuji; et al.

JAEA-Technology 2014-042, 73 Pages, 2015/02

JAEA-Technology-2014-042.pdf:15.1MB

According to the project plan of JT-60 Super Advanced that is implemented as an international project between Japan and Europe, the neutral beam (NB) injectors have been disassembled. The disassembly of the NB injectors started in November, 2009 and finished in January, 2012 without any serious problems as scheduled. This reports the disassembly activities of the NB injectors.

Demonstration of 500 keV beam acceleration on JT-60 negative-ion-based neutral beam injector

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

http://www-naweb.iaea.org/napc/physics/FEC/FEC2010/html/node294.htm#62473

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.

Procurement of NbSn superconducting conductors in ITER

Nabara, Yoshihiro; Isono, Takaaki; Nunoya, Yoshihiko; Koizumi, Norikiyo; Hamada, Kazuya; Matsui, Kunihiro; Hemmi, Tsutomu; Kawano, Katsumi; Uno, Yasuhiro*; Seki, Shuichi*; et al.

Journal of Plasma and Fusion Research SERIES, Vol.9, p.270 - 275, 2010/08

http://www.jspf.or.jp/JPFRS/PDF/Vol9/jpfrs2010_09-270.pdf

Update of control system for auxiliary pumping and primary water cooling facilities in JT-60 NBI

Kikuchi, Katsumi; Akino, Noboru; Ebisawa, Noboru; Ikeda, Yoshitaka; Seki, Norikazu*; Takenouchi, Tadashi; Tanai, Yutaka

JAEA-Technology 2008-034, 25 Pages, 2008/04

JAEA-Technology-2008-034.pdf:3.7MB

The control system for auxiliary pumping facility and primary water cooling facility in JT-60 NBI was updated. To realize the cost reduction, the control system with many input and outputs of 2000 was updated by JAEA itself using commercial Programmable Logic Controllers (PLC's). JAEA also made software with 3600 ladder lines by JAEA itself based on commercial basic programs. In addition to the simple replacement of the hardware and software, the function of remote operation has been newly added. At present, the auxiliary pumping facility and the primary water cooling facility have been stably operated without troubles. The remote operation enables to collect the detailed information on the trouble more easily, resulting in a quick countermeasure for the trouble.

Extended steady-state and high-beta regimes of net-current free heliotron plasmas in the large helical device

Motojima, Osamu*; Yamada, Hiroshi*; Komori, Akio*; Oyabu, Nobuyoshi*; Kaneko, Osamu*; Kawahata, Kazuo*; Mito, Toshiyuki*; Muto, Takashi*; Ida, Katsumi*; Imagawa, Shinsaku*; et al.

Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 12 Pages, 2007/03

http://www-naweb.iaea.org/napc/physics/FEC/FEC2006/html/node31.htm#5947

The performance of net-current free Heliotron plasmas has been developed by findings of innovative operational scenarios in conjunction with an upgrade of the heating power and the pumping/fueling capability in the Large Helical Device (LHD). Consequently, the operational regime has been extended, in particular, with regard to high density, long pulse length and high beta. Diversified studies in LHD have elucidated the advantages of net-current free heliotron plasmas. In particular, an Internal Diffusion Barrier (IDB) by combination of efficient pumping of the local island divertor function and core fueling by pellet injection has realized a super dense core as high as 510m, which stimulates an attractive super dense core reactor. Achievements of a volume averaged beta of 4.5 % and a discharge duration of 54-min. with a total input energy of 1.6 GJ (490 kW in average) are also highlighted. The progress of LHD experiments in these two years is overviewed with highlighting IDB, high and long pulse.

Application of react-and-wind method to D-shaped test coil using the 20 kA NbAl conductor developed for JT-60SC

Kizu, Kaname; Miura, Yushi; Tsuchiya, Katsuhiko; Koizumi, Norikiyo; Matsui, Kunihiro; Ando, Toshinari*; Hamada, Kazuya; Hara, Eiji*; Imahashi, Koichi*; Ishida, Shinichi; et al.

IEEE Transactions on Applied Superconductivity, 14(2), p.1535 - 1538, 2004/06

https://doi.org/10.1109/TASC.2004.830691

no abstracts in English

Development of the NbAl D-shaped coil fabricated by react-and-wind method for JT-60 superconducting Tokamak

Kizu, Kaname; Miura, Yushi; Tsuchiya, Katsuhiko; Koizumi, Norikiyo; Matsui, Kunihiro; Ando, Toshinari*; Hamada, Kazuya; Hara, Eiji*; Imahashi, Koichi*; Ishida, Shinichi; et al.

Proceedings of 6th European Conference on Applied Superconductivity (EUCAS 2003), p.400 - 407, 2003/00

Toroidal field coils (TFC) of the JT-60SC consist of 18 D-shape coils. The maximum magnetic field is 7.4 T at an operational current of 19.4 kA. An advanced NbAl superconductor was developed for the TFC conductor material in JAERI. The NbAl has lower strain sensitivity on superconducting performances, and allows us to fabricate the TFC by react-and-wind (R&W) method that makes that the coil fabrication with high reliability becomes easier and the fabrication cost becomes lower. To demonstrate the coil fabrication by R&W method, a two-turn D-shape coil was developed. The D-shape coil was tested at 4.3-4.4K and 7-12T. Measured critical current (Ic) was 30 kA at 7.3 T and 4.4 K. Using the measured conductor and strand Ic values, the strain of the conductor was estimated to be -0.6%. The Ic-B-T characteristic expected by an empirical equation substituting this strain shows that the required temperature margin for TFC is satisfied. Thus, the R&W method was demonstrated to be the applicable fabrication method of the TFC.

First test results for the ITER central solenoid model coil

Kato, Takashi; Tsuji, Hiroshi; Ando, Toshinari; Takahashi, Yoshikazu; Nakajima, Hideo; Sugimoto, Makoto; Isono, Takaaki; Koizumi, Norikiyo; Kawano, Katsumi; Oshikiri, Masayuki*; et al.

Fusion Engineering and Design, 56-57, p.59 - 70, 2001/10

https://doi.org/10.1016/S0920-3796(01)00235-6

no abstracts in English

Beam performance of negative-ion based NBI system for JT-60

Ito, Takao; Akino, Noboru; Ebisawa, Noboru; Grisham, L. R.*; Honda, Atsushi; Hu, L.*; Kawai, Mikito; Kazawa, Minoru; Kuriyama, Masaaki; Kusaka, Makoto*; et al.

Fusion Engineering and Design, 51-52, p.1039 - 1047, 2000/11

https://doi.org/10.1016/S0920-3796(00)00438-5

no abstracts in English

Development of 46-kA NbSn conductor joint for ITER model coils

Takahashi, Yoshikazu; Nunoya, Yoshihiko; Nishijima, Gen; Koizumi, Norikiyo; Matsui, Kunihiro; Ando, Toshinari; Hiyama, Tadao; Nakajima, Hideo; Kato, Takashi; Isono, Takaaki; et al.

IEEE Transactions on Applied Superconductivity, 10(1), p.580 - 583, 2000/03

https://doi.org/10.1109/77.828301

no abstracts in English