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Murakami, Haruyuki; Kizu, Kaname; Ichige, Toshikatsu; Furukawa, Masato; Natsume, Kyohei; Tsuchiya, Katsuhiko; Kamiya, Koji; Koide, Yoshihiko; Yoshida, Kiyoshi; Obana, Tetsuhiro*; et al.
IEEE Transactions on Applied Superconductivity, 25(3), p.4201305_1 - 4201305_5, 2015/06
Times Cited Count：6 Percentile：34.26(Engineering, Electrical & Electronic)JT-60U magnet system will be upgraded to the superconducting coils in the JT-60SA programme of the Broader Approach activities. Terminal joint of Central Solenoid (CS) is wrap type Nb
Sn-NbTi joint used for connecting CS (NbSn) and current feeder (NbTi). The terminal joints are placed at the top and the bottom of the CS systems. CS modules located at middle position of CS system need the lead extension from the modules to the terminal joint. The joint resistance measurement of terminal joint was performed in the test facility of National Institute for Fusion Science. The joint resistance was evaluated by the operating current and the voltage between both ends of the terminal joint part. Test results met the requirement of JT-60SA magnet system. The structural analysis of the lead extension and its support structure was conducted to confirm the support design. In this paper, the results of resistance test of joint and the structural analysis results of lead extension are reported.
Hamada, Kazuya; Nakajima, Hideo; Kawano, Katsumi; Takano, Katsutoshi*; Tsutsumi, Fumiaki*; Seki, Shuichi*; Okuno, Kiyoshi; Fujitsuna, Nobuyuki*; Mizoguchi, Mitsuru*
IEEE Transactions on Applied Superconductivity, 16(2), p.787 - 790, 2006/06
Times Cited Count：6 Percentile：37.33(Engineering, Electrical & Electronic)no abstracts in English
Takahashi, Yoshikazu; Yoshida, Kiyoshi; Nabara, Yoshihiro; Edaya, Masahiro*; Mitchell, N.*
IEEE Transactions on Applied Superconductivity, 16(2), p.783 - 786, 2006/06
Times Cited Count：9 Percentile：46.66(Engineering, Electrical & Electronic)To investigate the conductor behavior during a quench, quench tests of Center Solenoid (CS) insert coils were carried out with various initial conditions in DC and pulse modes. The conductor has very similar configuration and parameters. The inductive heater, attached at the center of the length, initiated an artificial quench in DC mode. A quench has also occurred during the pulse operation with the ramping rate of 0.4-2 T/s. Simulations of electric, thermal and hydraulic behaviors of the conductor during the quench tests in both modes were carried out by using the thermohydraulic simulation code. The experimental results were compared with the simulation and good agreement was obtained. These results are described and the implication for quench detection in ITER is discussed in this paper. The voltage tap method will be used for the quench detection for the CS, and the sensitivity of the detection and the maximum temperature of the conductor during a quench are described. It is shown that the detection system could be designed with high enough detection sensitivity.
Takahashi, Yoshikazu; Yoshida, Kiyoshi; Mitchell, N.*
IEEE Transactions on Applied Superconductivity, 15(2), p.1395 - 1398, 2005/06
Times Cited Count：8 Percentile：43.7(Engineering, Electrical & Electronic)The quench detection is important and necessary for the coil protection. The voltage tape method and the flow meter method are both considered for the ITER Central Solenoid (CS). The voltage tap method is primary due to its quick response. The CS consists of six pancake wound modules, which are operated with individual operating current patterns in ac mode. The induced voltage in the windings must be compensated to detect the voltage due to any normal transition during pulse operation. We have investigated the optimum configuration for pick-up coils (PC) for compensation. The results of simulations show that the compensated voltages are very low (70 mV) compared with the inductive voltage and adequate normal voltage sensitivity is obtained. The hot spot temperature in the CS during the operation was estimated from the simulation and the experimental data of the CSMC quench. The hot spot temperature estimated is about 144 K, lower than the ITER design criterion (150 K). It is shown that the detection system using the PCs could be designed with a high enough detection sensitivity.
Takahashi, Yoshikazu; Yoshida, Kiyoshi; Mitchell, N.*; Bessette, D.*; Nunoya, Yoshihiko; Matsui, Kunihiro; Koizumi, Norikiyo; Isono, Takaaki; Okuno, Kiyoshi
IEEE Transactions on Applied Superconductivity, 14(2), p.1410 - 1413, 2004/06
Times Cited Count：10 Percentile：48.21(Engineering, Electrical & Electronic)Cable-in-conduit conductors that consist of about 1,000 NbSn strands with an outer diameter of about 0.8mm, have been designed for the TF and CS coils of the ITER. The rated current of these coils is 40 -68kA. Two joint types (Butt and Lap) were developed during the CS Model Coil project. The performance of these joints was evaluated during the operating tests and the satisfied results were obtained. The joints of the TF coils are located outside of the winding in a region where the magnetic field is about 2.1T, a very low value as compared to the maximum field of 11.8T at the winding. The CS joints are located at the coil outer diameter and embedded within the winding pack due to the lack of the space. The maximum fields at the CS joint and winding are 3.5 and 13T, respectively. For the TF coils and the CS, the joints are cooled in series with the conductor at the outlet. The maximum temperature increase due to the joule heating in the joints is set at 0.15K to limit the heat load on the refrigerator. It is shown that both joint types are applicable to the ITER coils.
Sn coil (CS insert)Inaguchi, Takashi*; Hasegawa, Mitsuru*; Koizumi, Norikiyo; Isono, Takaaki; Hamada, Kazuya; Sugimoto, Makoto; Takahashi, Yoshikazu
Cryogenics, 44(2), p.121 - 130, 2004/02
Times Cited Count：6 Percentile：27.83(Thermodynamics)In order to analyze the quench characteristic of a cable-in-conduit (CIC) conductor that has a sub-cooling channel at the center of conductor cross section, an axisymmetrical two-dimensional calculation model was developed. The test and calculation results of the CS insert were compared regarding the pressure drop and the behavior of the total voltage, temperature and normal zone propagation in the quench. They show good agreement. Therefore, the effectiveness of the calculation model is verified. It was also found that there is coolant convection between the central channel and bundle region even in a steady state. This makes the pressure drop in the central channel larger than that in a cylindrical pipe which has a smooth surface. In addition, it was found that the higher temperature of the coolant flowing through the central channel heats the coolant and the cable in the bundle region. It can be said that the hot coolant flowing through the central channel accelerates normal zone propagation.
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
Times Cited Count：17 Percentile：74.85(Nuclear Science & Technology)no abstracts in English
Ando, Toshinari; Tsuji, Hiroshi
Teion Kogaku, 36(6), p.309 - 314, 2001/06
no abstracts in English
Ninomiya, Akira*; Arai, Kazuaki*; Takano, Katsutoshi*; Nakajima, Hideo; Michael, P.*; Martovetsky, N.*; Takahashi, Yoshikazu; Kato, Takashi; Ishigooka, Takeshi*; Kaiho, Katsuyuki*; et al.
Teion Kogaku, 36(6), p.344 - 353, 2001/06
no abstracts in English
Tsuji, Hiroshi; Okuno, Kiyoshi*; Thome, R.*; Salpietro, E.*; Egorov, S. A.*; Martovetsky, N.*; Ricci, M.*; Zanino, R.*; Zahn, G.*; Martinez, A.*; et al.
Nuclear Fusion, 41(5), p.645 - 651, 2001/05
Times Cited Count：57 Percentile：83.02(Physics, Fluids & Plasmas)no abstracts in English
Tsuji, Hiroshi; Team for the ITER CS Model Coil Experiment
Heisei-12-Nendo Denki Gakkai Genshiryoku Kenkyu Shiryo (NE-00-2), p.7 - 12, 2000/09
no abstracts in English
Ando, Toshinari; Hiyama, Tadao; Takahashi, Yoshikazu; Nakajima, Hideo; Kato, Takashi; Isono, Takaaki; Sugimoto, Makoto; Kawano, Katsumi; Koizumi, Norikiyo; Nunoya, Yoshihiko; et al.
IEEE Transactions on Applied Superconductivity, 10(1), p.568 - 571, 2000/03
Times Cited Count：10 Percentile：53.54(Engineering, Electrical & Electronic)no abstracts in English
Takahashi, Yoshikazu
Denki Gakkai Chodendo Oyo Denryoku Kiki, Rinia Doraibu Godo Kenkyukai Shiryo, p.27 - 32, 2000/01
no abstracts in English
Ando, Toshinari; Hiyama, Tadao; Takahashi, Yoshikazu; Nakajima, Hideo; Kato, Takashi; Sugimoto, Makoto; Isono, Takaaki; Kawano, Katsumi; Koizumi, Norikiyo; Hamada, Kazuya; et al.
IEEE Transactions on Applied Superconductivity, 9(2), p.628 - 631, 1999/06
Times Cited Count：8 Percentile：51.51(Engineering, Electrical & Electronic)no abstracts in English
Sn conductor and central solenoid model coils for ITERTakahashi, Yoshikazu; Ando, Toshinari; Hiyama, Tadao; Nakajima, Hideo; Kato, Takashi; Sugimoto, Makoto; Isono, Takaaki; Oshikiri, Masayuki*; Kawano, Katsumi; Koizumi, Norikiyo; et al.
Fusion Engineering and Design, 41(1-4), p.271 - 275, 1998/09
Times Cited Count：4 Percentile：38.68(Nuclear Science & Technology)no abstracts in English
Yoshida, Kiyoshi; Nishi, Masataka; Tsuji, Hiroshi; Sasaki, Takashi*; Yasukawa, Yukio*; Tsukamoto, Hideo*; *; *; *; Hasegawa, Mitsuru*
Nihon Genshiryoku Gakkai-Shi, 37(10), p.938 - 947, 1995/00
Times Cited Count：2 Percentile：28.12(Nuclear Science & Technology)no abstracts in English
