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Obana, Tetsuhiro*; Murakami, Haruyuki; Takahata, Kazuya*; Hamaguchi, Shinji*; Chikaraishi, Hirotaka*; Mito, Toshiyuki*; Imagawa, Shinsaku*; Kizu, Kaname; Natsume, Kyohei; Yoshida, Kiyoshi
Physica C, 518, p.96 - 100, 2015/11
Times Cited Count:7 Percentile:30.35(Physics, Applied)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:32.81(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 NbSn-NbTi joint used for connecting CS (Nb
Sn) 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.
Obana, Tetsuhiro*; Takahata, Kazuya*; Hamaguchi, Shinji*; Chikaraishi, Hirotaka*; Mito, Toshiyuki*; Imagawa, Shinsaku*; Kizu, Kaname; Murakami, Haruyuki; Natsume, Kyohei; Yoshida, Kiyoshi
Fusion Engineering and Design, 90, p.55 - 61, 2015/01
Times Cited Count:2 Percentile:16.28(Nuclear Science & Technology)In the cold test of the JT-60SA CS model coil made by NbSn CIC conductor, magnetic fields were measured using Hall sensors. While holding coil current of 20 kA, the magnetic fields were varying slightly with several long time constants. The range of the time constant was from 17 sec to 571 sec, which was much longer than the time constant derived from the measurement using the short straight sample. To validate the measurements, the magnetic fields of the model coil were calculated using the calculation model representing the positions of Nb
Sn strands inside the CIC conductor. The calculations were in good agreement with the measurements. Consequently, the validity of magnetic field measurements was confirmed.
Murakami, Haruyuki; Kizu, Kaname; Tsuchiya, Katsuhiko; Koide, Yoshihiko; Yoshida, Kiyoshi; Obana, Tetsuhiro*; Takahata, Kazuya*; Hamaguchi, Shinji*; Chikaraishi, Hirotaka*; Natsume, Kyohei*; et al.
IEEE Transactions on Applied Superconductivity, 24(3), p.4200205_1 - 4200205_5, 2014/06
Times Cited Count:25 Percentile:72.35(Engineering, Electrical & Electronic)Central Solenoid (CS) of JT-60SA are designed with the NbSn cable in conduit conductor. CS model coil (CSMC) was manufactured by using the real manufacturing jigs and procedure to validate the CS manufacturing processes before starting mass production. The dimensions of the CSMC are the same as real quad-pancake. The cold test of the CSMC was performed and the test results satisfied the design requirements. These results indicate that the manufacturing processes of the JT-60SA CS has been established. In this paper, the development and the validation of the CS manufacturing processes are described.
Matsukawa, Makoto; Tobita, Kenji; Chikaraishi, Hirotaka*; Sagara, Akio*; Norimatsu, Takayoshi*
Purazuma, Kaku Yugo Gakkai-Shi, 80(7), p.559 - 562, 2004/07
Final purpose of the fusion energy development is to utilize the produced fusion power mainly as electric power for the easiness of transmission and conversion. In spite of the type of fusion power plant, large circulating electric power should exist in the plant for the plasma heating, current drive. This paper describes the electric power flow in the nuclear fusion power plants to be built as the DEMO reactor beyond ITER. Here, the necessity of the local energy storage and high efficient converter will be also discussed.
Ide, Shunsuke; Okada, Hiroyuki*; Hirano, Yoichi*; Todo, Yasushi*; Norimatsu, Takayoshi*; Chikaraishi, Hirotaka*
Purazuma, Kaku Yugo Gakkai-Shi, 79(1), p.65 - 69, 2003/01
no abstracts in English
Obana, Tetsuhiro*; Takahata, Kazuya*; Hamaguchi, Shinji*; Chikaraishi, Hirotaka*; Imagawa, Shinsaku*; Mito, Toshiyuki*; Kizu, Kaname; Murakami, Haruyuki; Natsume, Kyohei; Yoshida, Kiyoshi
no journal, ,
The central solenoid (CS) of JT-60SA is composed of 4 modules consisting of a quad-pancake and 6 octa-pancakes. In order to verify the process for the coil manufacturing and the fabrication jigs, the CS model coil was developed. The model coil is composed of one quad-pancake. The cold test of the model coil was conducted at the Nation Institute for Fusion Science (NIFS) test facility. The critical current, joint resistance, and pressure drop of the model coil were measured in the cold test. In addition, self-magnetic field of the model coil was measured using Hall sensors. The magnetic fields were varying slightly while holding coil current of 20 kA. The range of the time constant was from 17 sec to 571 sec, which was much longer than the time constant derived from the measurement using the short straight sample.
Kajitani, Hideki; Hemmi, Tsutomu; Matsui, Kunihiro; Yamane, Minoru; Koizumi, Norikiyo; Obana, Tetsuhiro*; Hamaguchi, Shinji*; Takata, Suguru*; Chikaraishi, Hirotaka*; Natsume, Kyohei*; et al.
no journal, ,
Two double pancake coils of ITER TF coil are electrically connected at the joint. To evaluate the ITER TF joint performance, the joint test sample, which consists of two TF conductors and has full size joint part, was fabricated. The joint sample was tested using NIFS test facility under the condition of current of 68kA and external field of 2T. As a result, the joint resistance could be 1nohm, which is sufficiently small. In this presentation, detail of the test result is reported.
Saura, Keisuke*; Obana, Tetsuhiro*; Takata, Suguru*; Natsume, Kyohei*; Hamaguchi, Shinji*; Chikaraishi, Hirotaka*; Takahata, Kazuya*; Imagawa, Shinsaku*; Kajitani, Hideki; Hemmi, Tsutomu; et al.
no journal, ,
The full size joint test of ITER TF coil was performed using NIFS test facility. Because of transport current of 68kA, which is high current never experienced before, the reduction of cupper busbar heating was needed. Therefore, high temperature superconducting (HTS) busbar (Bi2212 fabricated by Sumitomo Electric Co.,Ltd) was installed in parallel with cupper busbar. In the test, current of HIS busbar was measured using rogowski coil and it was observed that the current of 20 kA could be distributed to HTS busbar. Therefore, the cupper busbar heating could be reducted to about 60% compared with the case of no HTS busbar.
Murakami, Haruyuki; Kizu, Kaname; Kamiya, Koji; Tsuchiya, Katsuhiko; Koide, Yoshihiko; Yoshida, Kiyoshi; Obana, Tetsuhiro*; Takahata, Kazuya*; Hamaguchi, Shinji*; Chikaraishi, Hirotaka*; et al.
no journal, ,
no abstracts in English
Murakami, Haruyuki; Kizu, Kaname; Natsume, Kyohei; Tsuchiya, Katsuhiko; Koide, Yoshihiko; Yoshida, Kiyoshi; Obana, Tetsuhiro*; Takahata, Kazuya*; Hamaguchi, Shinji*; Chikaraishi, Hirotaka*; et al.
no journal, ,
no abstracts in English
Murakami, Haruyuki; Natsume, Kyohei; Kizu, Kaname; Tsuchiya, Katsuhiko; Koide, Yoshihiko; Yoshida, Kiyoshi; Obana, Tetsuhiro*; Takahata, Kazuya*; Hamaguchi, Shinji*; Chikaraishi, Hirotaka*; et al.
no journal, ,
no abstracts in English