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Sueoka, Michiharu
Heisei-25-Nendo Kaku Yugo Kagaku Kenkyusho Gijutsu Kenkyukai Hokokusho (CD-ROM), p.251 - 258, 2014/02
no abstracts in English
Nakamura, Kazuo*; Jiang, Y.*; Liu, X.*; Mitarai, Osamu*; Kurihara, Kenichi; Kawamata, Yoichi; Sueoka, Michiharu; Hasegawa, Makoto*; Tokunaga, Kazutoshi*; Zushi, Hideki*; et al.
Fusion Engineering and Design, 86(6-8), p.1080 - 1084, 2011/10
Times Cited Count：4 Percentile：32.59(Nuclear Science & Technology)Sakata, Shinya; Yamaguchi, Taiji; Sugimura, Toru; Kominato, Toshiharu; Kawamata, Yoichi; Totsuka, Toshiyuki; Sato, Minoru; Sueoka, Michiharu; Naito, Osamu
Fusion Science and Technology, 60(2), p.496 - 500, 2011/08
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)For a steady state operation of JT-60SA, a plasma feedback control using various diagnostic sensor signals plays an essential role. To realize this, Real Time Diagnostic Signals acquisition System, RTDS, which utilizes PC-based real-time OS "INtime", has been under consideration toward JT-60SA project. Moreover, long-time experiments more than 100 seconds will be planned in JT-60SA project. Therefore, real time monitoring will be required as an essential function that displays acquired diagnostic signals on real time during long-time experiment. This function will be also realized by utilizing RTDS.
Kawamata, Yoichi; Sugimura, Toru; Yamaguchi, Taiji; Sueoka, Michiharu; Sakata, Shinya; Totsuka, Toshiyuki; Sato, Minoru; Kominato, Toshiharu; Naito, Osamu
Fusion Science and Technology, 60(2), p.491 - 495, 2011/08
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Sueoka, Michiharu; Sakamoto, Kensaku; Shigemori, Yuji*
Heisei-22-Nendo Kumamoto Daigaku Sogo Gijutsu Kenkyukai Hokokushu (CD-ROM), 6 Pages, 2011/03
no abstracts in English
Yoshida, Maiko; Sakamoto, Yoshiteru; Sueoka, Michiharu; Kawamata, Yoichi; Oyama, Naoyuki; Suzuki, Takahiro; Kamada, Yutaka; JT-60 Team
Fusion Engineering and Design, 84(12), p.2206 - 2213, 2009/12
Times Cited Count：17 Percentile：72.88(Nuclear Science & Technology)A fast charge exchange recombination spectroscopy (CXRS) system has been developed for the real-time measurement and feedback control of ion temperature (
) profile and toroidal rotation velocity (
) in JT-60U. In order to control and in real-time, the charge exchange recombination spectroscopy with high time resolution, the real-time processor system, and the real-time control system have been developed. Utilizing this system, real-time control of the gradient has been demonstrated with neutral beams at high beta plasmas. The strength of the internal transport barrier is controlled. Moreover, the real-time control of has been demonstrated from counter (anti parallel to the plasma current, 
) to co (parallel to the ) direction.
Suzuki, Takahiro; Oyama, Naoyuki; Isayama, Akihiko; Sakamoto, Yoshiteru; Fujita, Takaaki; Ide, Shunsuke; Kamada, Yutaka; Naito, Osamu; Sueoka, Michiharu; Moriyama, Shinichi; et al.
Nuclear Fusion, 49(8), p.085003_1 - 085003_8, 2009/08
Times Cited Count：8 Percentile：30.72(Physics, Fluids & Plasmas)Fully non-inductive discharge having a relaxed current profile and high bootstrap current fraction f
=0.5 has been realized in the high-
ELMy H-mode discharge with weak magnetic-shear having q
=5.8, qmin=2.1, and q(0)=2.4, where qmin and q(0) are the safety factor q at the minimum and the plasma center, respectively. The rest of the plasma current is externally driven by neutral beams (NBs) and lower-hybrid (LH) waves. The safety factor profile evaluated by the motional Stark effect (MSE) diagnostic is kept unchanged during 0.7 s at the end of the full current drive (CD) sustainment for 2 s (1.5 times the current relaxation time 
). The loop voltage profile is spatially uniform at 0 V at the end of the sustainment. This demonstration shows, for the first time, that the steady sustainment of ful-CD plasma is possible at high f=0.5 and reasonably low q=5.8 regime and is stably controlled by appropriate external current drivers. On the other hand, when the combination of bootstrap current and externally driven current does not match to the steady current profile, slight change in the current profile due to current relaxation resulted in appearance of magnetohydrodynamic (MHD) instability, e.g. neo-classical tearing mode (NTM), in a high beta plasma. This discharge clarifies importance of the demonstration of steady current profile developed here. These discharges contribute to the ITER steady-state operation scenario development.
Sakata, Shinya; Kiyono, Kimihiro; Sato, Minoru; Kominato, Toshiharu; Sueoka, Michiharu; Hosoyama, Hiroki; Kawamata, Yoichi
Fusion Engineering and Design, 84(7-11), p.1680 - 1683, 2009/06
Times Cited Count：1 Percentile：10.22(Nuclear Science & Technology)no abstracts in English
Kurihara, Kenichi; Kawamata, Yoichi; Sueoka, Michiharu; Wang, F.*; Nakamura, Kazuo*; Mitarai, Osamu*; Sato, Konosuke*; Zushi, Hideki*; Hanada, Kazuaki*; Sakamoto, Mizuki*; et al.
Kyushu Daigaku Oyo Rikigaku Kenkyujo RIAM Foramu 2008 Koen Yoshi, p.66 - 69, 2008/06
no abstracts in English
Sueoka, Michiharu; Totsuka, Toshiyuki; Kawamata, Yoichi; Kurihara, Kenichi; Seki, Akiyuki
Fusion Engineering and Design, 83(2-3), p.283 - 286, 2008/04
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)For safety and efficient operation of a fusion device, appropriate information should be provided to the personnel related to experiment. In order to realize this, we have newly developed highlight screens displaying the plasma movie, the status of discharge sequence, the discharge schedule, the present status of trouble, etc., with the large (65 inch) monitor TV in front of the central consoles. These highlight screens are automatically switched according to the timing signal of JT-60 discharge sequence and/or the operator's request. We call this system the supervisory discharge operation monitoring system. This report deals with the technical details of this system including the plasma movie database system and the discharge information management system.
Kawamata, Yoichi; Naito, Osamu; Kiyono, Kimihiro; Itami, Kiyoshi; Totsuka, Toshiyuki; Akasaka, Hiromi; Sueoka, Michiharu; Sato, Tomoki; Oshima, Takayuki; Sakata, Shinya; et al.
Fusion Engineering and Design, 83(2-3), p.198 - 201, 2008/04
Times Cited Count：3 Percentile：23.55(Nuclear Science & Technology)The design activity of JT-60SA (JT-60 Super Advanced) which is remodeled to a superconducting tokamak device has been starting under the JA-EU collaborative ITER-BA project. For the JT-60SA control system, the existing system should be reused as much as possible from the viewpoint of cost-effectiveness. We have just begun to discuss the configuration of the advanced Supervisory Control System (SVCS) including the following systems: (1) ultimately flexible real-time control system, (2) precise timing system enough to clarify cause and effect, and (3) safety shutdown control system. In this report, we present the design study of the JT-60SA SVCS with focusing on these systems.
Suzuki, Takahiro; Ide, Shunsuke; Oikawa, Toshihiro; Fujita, Takaaki; Ishikawa, Masao; Seki, Masami; Matsunaga, Go; Hatae, Takaki; Naito, Osamu; Hamamatsu, Kiyotaka; et al.
Nuclear Fusion, 48(4), p.045002_1 - 045002_9, 2008/04
Times Cited Count：39 Percentile：80.89(Physics, Fluids & Plasmas)Aiming at optimization of current profile in high-b plasmas for higher confinement and stability, a real-time control system of the minimum of the safety factor (
) using the off-axis current drive has been developed. The off-axis current drive can raise safety factor in the center and help to avoid instability that limits performance of the plasma. The system controls injection power of lower-hybrid (LH) waves, and hence, its off-axis driven current in order to control 
. The real-time control of is demonstrated in a high- plasma, where follows the temporally changing reference 
from 1.3 to 1.7. Applying the control to another high- discharge (
=1.7, =1.5) with 
=2/1 neo-classical tearing mode (NTM), was raised above 2 and the NTM was suppressed. The stored energy increased by 16% with the NTM suppressed, since the resonant rational surface was eliminated. For the future use for current profile control, current density profile for off-axis neutral beam current drive (NBCD) is for the first time measured, using motional Stark effect (MSE) diagnostic. Spatially localized NBCD profile was clearly observed at the normalized 
of about 0.6-0.8. The location was also confirmed by multi-chordal neutron emission profile measurement. The total amount of the measured beam driven current was consistent with the theoretical calculation using the ACCOME code. The CD location in the calculation was inward-shifted than the measurement.
Sueoka, Michiharu; Kawamata, Yoichi; Kurihara, Kenichi; Seki, Akiyuki
JAEA-Technology 2008-021, 23 Pages, 2008/03
JAEA-Technology-2008-021.pdf:10.47MB
A plasma movie is generally expected as one of the most efficient methods to know what plasma discharge has been conducted in the experiment. The JT-60 plasma movie is composed of video camera picture looking at a plasma, computer graphics (CG) picture, and magnetic probe signal as a sound channel. In order to use this movie efficiently, we have developed a new system having the following functions: (a) To store a plasma movie in the movie database system automatically combined with the plasma shape CG and the sound according to a discharge sequence. (b) To make a plasma movie is available (downloadable) for experiment data analyses at the Web-site. Especially, this system aimed at minimizing the development cost, and it tried to develop the real-time plasma shape visualization system (RVS) without any operating system (OS) customized for real-time use. As a result, this system succeeded in working under Windows XP. This report deals with the technical details of the plasma movie database system and the real-time plasma shape visualization system.
Takenaga, Hidenobu; Kubo, Hirotaka; Sueoka, Michiharu; Kawamata, Yoichi; Yoshida, Maiko; Kobayashi, Shinji*; Sakamoto, Yoshiteru; Iio, Shunji*; Shimomura, Koji*; Ichige, Hisashi; et al.
Nuclear Fusion, 48(3), p.035011_1 - 035011_6, 2008/03
Times Cited Count：3 Percentile：13.2(Physics, Fluids & Plasmas)A burning plasma simulation scheme has been developed with consideration for temperature dependence of the DT fusion reaction rate in JT-60U. The heating power for the simulation of alpha particle heating was calculated using real-time measurements of density and ion temperature. Response of a simulated fusion gain to the density was investigated in this scheme with constant heating power for the simulation of external heating, in order to understand burn controllability by the fuel density in a fusion reactor. When temperature dependence of the fusion reaction rate was assumed as square of ion temperature, density dependence of the simulated fusion gain stronger than square of density was observed. Transport analysis using a 1.5 dimension transport code indicated that the strong density dependence is induced due to both change in a confinement improvement factor and change in a pressure profile.
Isayama, Akihiko; Suzuki, Takahiro; Hayashi, Nobuhiko; Ide, Shunsuke; Hamamatsu, Kiyotaka; Fujita, Takaaki; Hosoyama, Hiroki; Kamada, Yutaka; Nagasaki, Kazunobu*; Oyama, Naoyuki; et al.
AIP Conference Proceedings 933, p.229 - 236, 2007/10
no abstracts in English
Sueoka, Michiharu; Kawamata, Yoichi; Kurihara, Kenichi; Seki, Akiyuki
Fusion Engineering and Design, 82(5-14), p.1008 - 1014, 2007/10
Times Cited Count：2 Percentile：18.73(Nuclear Science & Technology)A plasma movie is generally expected as one of the most efficient methods to know what plasma discharge has been conducted in the experiment. On this motivation we have developed and operated a real-time plasma shape visualization system over ten years. The current plasma movie is composed of (1) video camera picture looking at a plasma, (2) computer graphic (CG) picture, and (3) magnetic probe signal as a sound channel. In order to use this movie efficiently, we have developed a new plasma movie database system, where a plasma movie is available (downloadable) for experiment data analyses at the Web-site. This new system and its future prospects will be discussed in detals from a technological point of view.
Shimomura, Koji*; Takenaga, Hidenobu; Tsutsui, Hiroaki*; Mimata, Hideyuki*; Iio, Shunji*; Miura, Yukitoshi; Tani, Keiji; Kubo, Hirotaka; Sakamoto, Yoshiteru; Hiratsuka, Hajime; et al.
Fusion Engineering and Design, 82(5-14), p.953 - 960, 2007/10
Times Cited Count：3 Percentile：25.51(Nuclear Science & Technology)no abstracts in English
Suzuki, Takahiro; Ide, Shunsuke; Oikawa, Toshihiro; Fujita, Takaaki; Ishikawa, Masao*; Seki, Masami; Matsunaga, Go; Takechi, Manabu; Naito, Osamu; Hamamatsu, Kiyotaka; et al.
Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 8 Pages, 2007/03
For the first time, we have measured the current density profile for off-axis neutral beam current drive (NBCD), using motional Stark effect (MSE) diagnostic. A spatially localized NBCD profile was clearly observed at 
. The location was also confirmed by neutron emission profile measurement. The total amount of the driven current (0.15MA) was consistent with the decrease in the surface loop voltage. The off-axis current drive can raise safety factor (q) in the center and help to avoid instability that limits performance of the plasma. We have developed a real-time control system of the minimum q (qmin), using the off-axis current drive. Injection power of lower hybrid (LH) waves, and hence, its off-axis driven current controls qmin. In a high plasma (
, 
), the system was adopted to control qmin. With the control, qmin was raised and MHD fluctuations were suppressed. The stored energy increased by 16% with the MHD fluctuations suppressed.
Yonekawa, Izuru; Sueoka, Michiharu; Hosoyama, Hiroki*; Kawamata, Yoichi; Suzuki, Takahiro; Kurihara, Kenichi
Fusion Engineering and Design, 81(15-17), p.1897 - 1903, 2006/07
Times Cited Count：2 Percentile：17.18(Nuclear Science & Technology)Recent years, plasma current profile (j-profile) control has been newly proposed to avoid instabilities in the high normalized-beta plasma. In particular, for the real-time profile feedback control, the control period should be roughly less than several tens of ms, including data communication among relating systems. In order to minimize data transfer time,the profile data being a function of time and position is required to decrease its data size for efficient data handling. A profile data,defined as 3-dimension time series data (q,R,Z,t), was reduced by introducing normalized minor radius rho in place of (R,Z). Data handling for profile control will be presented with their technical issues, together with computing hardware engineering.
Kurihara, Kenichi; Yonekawa, Izuru; Kawamata, Yoichi; Sueoka, Michiharu; Hosoyama, Hiroki*; Sakata, Shinya; Oshima, Takayuki; Sato, Minoru; Kiyono, Kimihiro; Ozeki, Takahisa
Fusion Engineering and Design, 81(15-17), p.1729 - 1734, 2006/07
Times Cited Count：13 Percentile：65.83(Nuclear Science & Technology)A large tokamak fusion device JT-60 is expected to explore more advanced tokamak discharge scenario towards the ITER and a future power reactor. We believe the following experimental issues are expected to be solved in JT-60. To clarify how to keep a steady-state plasma with high performance, and how to avoid plasma instabilities almost completely. By stimulus of this motivation, several essential development and modifications of plasma control and data acquisition systems have been performed in JT-60. In this report, we discuss the developments to improve the JT-60 plasma control and data acquisition systems. In addition, a future plasma control and data acquisition systems leading to a standard design for a power reactor is envisaged on the basis of the 20-year plasma operation experiences.
