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Novello, L.*; Cara, P.*; Coletti, A.*; Gaio, E.*; Maistrello, A.*; Matsukawa, Makoto; Philipps, G.*; Tomarchio, V.*; Yamauchi, Kunihito
IEEE Transactions on Applied Superconductivity, 26(2), p.4700507_1 - 4700507_7, 2016/03
Times Cited Count：6 Percentile：35.42(Engineering, Electrical & Electronic)Kudo, Yusuke; Sawai, Tomotsugu; Sakurai, Shinji; Masaki, Kei; Suzuki, Yutaka; Sasajima, Tadayuki; Hayashi, Takao; Takahashi, Ryukichi*; Honda, Masao; Jitsukawa, Shiro; et al.
Journal of the Korean Physical Society, 49(96), p.S297 - S301, 2006/12
Installation of ferritic steel tiles was proposed in JT-60U to reduce the toroidal magnetic field ripple and to improve the fast ion loss, which degrades heating efficiency and increases heat load on plasma facing component under large volume plasma operations. We selected a 8Cr-2W-0.2V ferritic steel with the cost-effectiveness, in which concentration limits of activation elements in F82H were relaxed because of the less number of neutron generations from deuterium operations on JT-60U. The fabricated ferritic steel has clear tempered martensitic microstructure, and sufficient magnetic and mechanical properties. The saturated magnetization was estimated to 1.7 Tesla at 573 K, lower than expected, but effectiveness in JT-60U was confirmed by numerical analyses. To research the effect of material conditions, such as microstructure and heat treatment, on saturated magnetization of the ferritic steel based on 8-9Cr is important for the future fusion reactors which will be planned to install the ferritic steel as the in-vessel components.
Urano, Hajime; Kamiya, Kensaku; Koide, Yoshihiko; Takizuka, Tomonori; Oyama, Naoyuki; Kamada, Yutaka; JT-60 Team
Plasma Physics and Controlled Fusion, 48(5A), p.A193 - A199, 2006/05
Times Cited Count：10 Percentile：35.74(Physics, Fluids & Plasmas)The characteristics of the H-mode pedestal structure were investigated by conducting the power scans for a variation of the toroidal momentum sources at different toroidal field ripple in JT-60U. It was found that the pedestal pressure is increased by reduced loss power of fast ions, independently of toroidal rotation. However, the energy confinement is improved with the CO-directed toroidal momentum source at H-mode plasmas with small ripple loss.
Hamada, Kazuya; Nakajima, Hideo; Takano, Katsutoshi*; Kudo, Yusuke; Tsutsumi, Fumiaki*; Okuno, Kiyoshi; Jong, C.*
Fusion Engineering and Design, 75-79, p.87 - 91, 2005/11
Times Cited Count：8 Percentile：50.83(Nuclear Science & Technology)no abstracts in English
test results of a D-shaped Nb
Al CICC coil fabricated with a react-and-wind process for the National Centralized TokamakAndo, Toshinari*; Kizu, Kaname; Miura, Yushi*; Tsuchiya, Katsuhiko; Matsukawa, Makoto; Tamai, Hiroshi; Ishida, Shinichi; Koizumi, Norikiyo; Okuno, Kiyoshi
Fusion Engineering and Design, 75-79, p.99 - 103, 2005/11
Times Cited Count：1 Percentile：10.9(Nuclear Science & Technology)no abstracts in English
Chankin, A. V.
Physics of Plasmas, 11(4), p.1484 - 1492, 2004/04
Times Cited Count：9 Percentile：30.39(Physics, Fluids & Plasmas)no abstracts in English
Urata, Kazuhiro*; Shinohara, Koji; Suzuki, Masanobu*; Kamata, Isao*
JAERI-Data/Code 2004-007, 45 Pages, 2004/03
JAERI-Data-Code-2004-007.pdf:5.63MB
As the toroidal magnetic field generated by discrete TF coils involves magnetic field ripple, the fast ion loss is induced to damage vacuum vessel in tokamaks. An idea of ripple compensation using ferromagnetic is proposed. Since low activation ferritic steel have low activation and thermal conduction properties, the ferritic steel is planned to install in tokamak reactors. Installation of ferritic steel plates with toroidal symmetry is effective to compensate ripple, however in the actual devices it is difficult for interference with other components. Besides the first wall shapes are often asymmetric. So it is better to treat toroidal asymmetry to evaluate the ripple induced loss in the actual devices. For the purpose, magnetic field calculation code considering ferritic steel; FEMAG(FErrite generating MAGnetic field)has been speeded up. On the basis of this magnetic field data, OFMC (Orbit Following Monte Carlo) has been upgraded to treat toroidal asymmetry. The use of FEMAG/OFMC, applications to the JFT-2M experiments, and the national centralized tokamak facility are reported.
Shimada, Katsuhiro; Omori, Yoshikazu; Furukawa, Hiroshi*; Terakado, Tsunehisa; Matsukawa, Makoto; Kurihara, Kenichi
Proceedings of International Conference on Electrical Engineering 2004 (ICEE 2004), p.777 - 781, 2004/00
We developed a new coil current control system for a power supply that consists of a synchronous generator and diode rectifiers. Test results are reported for the toroidal field coil power supply of JT-60, a world-class tokamak-type fusion device. This coil current control system has been designed to improve the control flexibility of the plasma discharge, and to introduce new functions. A state feedback control method is adopted to control coil current. Limit functions for the generator field current, the generator output voltage, and the toroidal field coil voltage have been added to the original coil current control system. Moreover, the abnormal state detection function of a coil is implemented for safety. The developed new intelligent control system has been tested and its performance was confirmed.
Al conductor for toroidal field coilsKoizumi, Norikiyo; Ando, Toshinari*; Nakajima, Hideo; Matsui, Kunihiro; Sugimoto, Makoto; Takahashi, Yoshikazu; Okuno, Kiyoshi; Kizu, Kaname; Miura, Yushi; Tsuchiya, Katsuhiko; et al.
Proceedings of 20th IEEE/NPSS Symposium on Fusion Engineering (SOFE 2003), p.419 - 422, 2003/10
NbSn cConductors have already been developed for the TF coils operating at 13 T. However, the critical current of NbSn degrades due to a strain, and the amount of degradation becomes larger when the magnetic field increases, which set a limit of the NbSn application to a large coil at around 13 T. NbAl is considered, therefore, to be a next generation superconductor, since the critical current of NbAl is superior to that of NbSn and less sensitive against strains. JAERI has been developing NbAl conductor since 80s. As the first step, mass production technique of NbAl strands was established. In the second step, coil fabrication technique was developed and could successfully be charged to the nominal point of 13 T and 46 kA. From these advantages, JAERI is also promoting R&D activities to develop NbAl TF coils for JT-60SC. The prototype NbAl conductor has already been made. A D-shaped coil was fabricated and successfully tested. These activities constitute the basic approaches to develop TF coils whose operating field is expected to be around 16 T.
Ishii, Yasutomo; Azumi, Masafumi; Kishimoto, Yasuaki
Physics of Plasmas, 10(9), p.3512 - 3520, 2003/09
Times Cited Count：9 Percentile：29.72(Physics, Fluids & Plasmas)no abstracts in English
Al conductor to be applied to a fusion reactor and its application to a large superconducting coilKoizumi, Norikiyo; Okuno, Kiyoshi; Nakajima, Hideo; Ando, Toshinari*; Tsuji, Hiroshi
Teion Kogaku, 38(8), p.391 - 398, 2003/08
no abstracts in English
Al insertKoizumi, Norikiyo; Nunoya, Yoshihiko; Takayasu, Makoto*; Sugimoto, Makoto; Nabara, Yoshihiro; Oshikiri, Masayuki*; CS Model Coil Test Group
Teion Kogaku, 38(8), p.399 - 409, 2003/08
A NbAl insert was developed to demonstrate the applicability of a NbAl conductor and wind-and-react method to a TF coil of a fusion reactor by artificially applying 0.4% bending strain to the conductor after its heat treatment. The critical current test results show that the effective strains applied to the strands is almost zero. Then, the validity of the react-and-wind method was demonstrated. In addition, while an unexpected strain, which was proportional to electromagnetic force, was observed in the same scale NbSn conductor, such strain did not exist in the NbAl conductor. This shows a NbAl conductor is suitable to the application to large magnets, such as the TF coil. Furthermore, the effect of the current transfer among the strands on the critical current evaluation is studied by developing a numerical analysis code, KORO. The results figure out that the critical current of a large cable-in-conduit conductor can be easily evaluated assuming the uniform current distribution if the conductance among the strands is 10E5 S/m or less.
Al D-shaped coil fabricated by react-and-wind method for JT-60 superconducting TokamakKizu, 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.
Al cable-in-conduit conductorKoizumi, Norikiyo; Takahashi, Yoshikazu; Nunoya, Yoshihiko; Matsui, Kunihiro; Ando, Toshinari; Tsuji, Hiroshi; Okuno, Kiyoshi; Azuma, Katsunori*; Fuchs, A.*; Bruzzone, P.*; et al.
Cryogenics, 42(11), p.675 - 690, 2002/11
Times Cited Count：23 Percentile：65.65(Thermodynamics)In the framework of ITER-EDA, a 13 T – 46 kA NbAl conductor with stainless steel jacket has been developed to demonstrate applicability of an NbAl conductor with react-and-wind technique to ITER-TF coils. The critical current performances of the NbAl conductors were studied to verify that the conductor achieves the expected performance and 0.4% bending strain does not originate degradation. The critical currents were measured at the background magnetic fields of 7, 9, 10 and 11 T at the temperatures from 6 to 9 K. The expected critical currents is calculated using the developed model and the calculation results indicate that the experimental results showed good agreement with the expected critical currents. Accordingly, we can conclude that the fabrication process of this conductor was appropriate and the applicability of the react-and-wind technique was demonstrated.
Sugimoto, Makoto; Nakajima, Hideo; Kato, Takashi; Okuno, Kiyoshi; Tsuji, Hiroshi; Rodin, I.*; Egorov, S. A.*
Teion Kogaku, 37(10), p.513 - 522, 2002/10
The Central Solenoid (CS) model coil programme has been carrying out since 1992 as a back born project in International Thermonuclear Experimental Reactor (ITER) Engineering Design Activity (EDA). The CS model coil programme has a plan to develop the toroidal fieled (TF) insert to demonstrate the conductor performance of ITER real TF coils under 13 T of magnetic flux density. The fabrication of TF insert was completed on May 2001 by D.V.Efremov Scientific Research Institute for Electrophysical Apparatus(Efremov institute) at St. Petersburg, Russia. Experiments including the cooldown and warmup were completed November 2001 at JAERI Naka. TF insert was achieved to charge up to 13T with 46kA without training under the back up magnetic field by the CS model coil.
Hamada, Kazuya; Koizumi, Norikiyo
Purazuma, Kaku Yugo Gakkai-Shi, 78(7), p.616 - 624, 2002/07
In the Tokamak type fusion reactor design, a forced flow superconducting coil is applied from the viewpoint to high magnetic field, high withstand voltage performance and large electromagnetic force. In the forced flow magnets, it is well known that various electromagnetic phenomena are occurred by zero resistance and diamagnetic effect of superconductor and complicated structure of cable in conduit conductor (CICC). In the R&D of CICC, the study of hysteresis losses and coupling losses CICC have a lot of progress. For example, using the optimization of filament arrangement in superconducting strand and control of contact resistance of strand, ITER model coil project have a large achievement.
W.Liu*; Miura, Yukitoshi; JFT-2M Group
Purazuma, Kaku Yugo Gakkai-Shi, 74(7), p.753 - 757, 1998/07
no abstracts in English
Sato, Satoshi; Takatsu, Hideyuki; *; Seki, Yasushi
J. Fusion Eng. Des., 30(3), p.1076 - 1080, 1996/12
no abstracts in English
J.R.Miller*; L.Bottura*; Koizumi, Koichi; A.Kostenko*; J.Minervini*; N.Mitchell*; Tada, Eisuke; Yoshida, Kiyoshi
IAEA-CN-53/F-3-7, 7 Pages, 1990/00
no abstracts in English
Nishi, Masataka; Takahashi, Yoshikazu; Isono, Takaaki; *; Yoshida, Kiyoshi; Koizumi, Koichi; Tada, Eisuke; Tsuji, Hiroshi; Okuno, Kiyoshi; Ando, Toshinari; et al.
Proc. of IEEE 13th Symp. on Fusion Engineering,Vol. 1, p.780 - 783, 1990/00
no abstracts in English
