Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Natsume, Kyohei; Murakami, Haruyuki; Kizu, Kaname; Yoshida, Kiyoshi; Koide, Yoshihiko
IOP Conference Series; Materials Science and Engineering, 101(1), p.012113_1 - 012113_8, 2015/12
Times Cited Count：2 Percentile：65.6(Thermodynamics)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：27.97(Physics, Applied)Kizu, Kaname; Murakami, Haruyuki; Natsume, Kyohei; Tsuchiya, Katsuhiko; Koide, Yoshihiko; Yoshida, Kiyoshi; Obana, Tetsuhiro*; Hamaguchi, Shinji*; Takahata, Kazuya*
Fusion Engineering and Design, 98-99, p.1094 - 1097, 2015/10
Times Cited Count：6 Percentile：45.92(Nuclear Science & Technology)Current feeder and Coil Terminal Box (CTB) for the superconducting magnets for JT-60SA were designed. Copper busbar from power supply is connected to the High Temperature Superconductor Current Lead (HTS CL), which is installed on the vacuum vessel called CTB. The superconducting current feeder is connected to the cold end of HTS CL, and is led to main cryostat for magnets. Trial manufacturing of crank shaped feeder to reduce the thermal stress was performed. The small tool which can connect soldering joint with vertical direction was developed. Insulation materials made by manufacturing condition showed sufficient shear stress. Since the all manufacturing process concerned was confirmed, the production of current feeder and CTB can be started.
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.
Nakamura, Kazuya*; Yamamoto, Yusuke*; Suzuki, K.*; Takao, Tomoaki*; Murakami, Haruyuki; Natsume, Kyohei; Yoshida, Kiyoshi
IEEE Transactions on Applied Superconductivity, 25(3), p.4200704_1 - 4200704_4, 2015/06
Times Cited Count：0 Percentile：0(Engineering, Electrical & Electronic)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：17.57(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 NbSn strands inside the CIC conductor. The calculations were in good agreement with the measurements. Consequently, the validity of magnetic field measurements was confirmed.
Sn cable-in-conduit conductorsObana, Tetsuhiro*; Takahata, Kazuya*; Hamaguchi, Shinji*; Natsume, Kyohei*; Imagawa, Shinsaku*; Mito, Toshiyuki*; Kizu, Kaname; Murakami, Haruyuki; Yoshida, Kiyoshi
Plasma and Fusion Research (Internet), 9(Sp.2), p.3405122_1 - 3405122_4, 2014/07
To evaluate the fabrication technology of the butt joint composed of NbSn CIC conductors, joint resistance and quench current were measured using a sample developed for the JT-60SA CS coil. The measurements indicate that the butt joint fulfilled the design requirements. To simulate the characteristics of the butt joint, one dimensional numerical model simplifying the butt joint configuration was developed. Using the model, joint resistance and quench current of the butt joint were calculated. The calculations were in good agreement with the measurements. As a result, the model will be valid for the simulation of the butt joint.
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：72.88(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.
Takao, Tomoaki*; Kawahara, Yuzuru*; Nakamura, Kazuya*; Yamamoto, Yusuke*; Yagai, Tsuyoshi*; Murakami, Haruyuki; Yoshida, Kiyoshi; Natsume, Kyohei*; Hamaguchi, Shinji*; Obana, Tetsuhiro*; et al.
IEEE Transactions on Applied Superconductivity, 24(3), p.4800804_1 - 4800804_4, 2014/06
Times Cited Count：3 Percentile：21.9(Engineering, Electrical & Electronic)no abstracts in English
Murakami, Haruyuki; Kizu, Kaname; Tsuchiya, Katsuhiko; Koide, Yoshihiko; Yoshida, Kiyoshi; Obana, Tetsuhiro*; Takahata, Kazuya*; Hamaguchi, Shinji*; Natsume, Kyohei*; Imagawa, Shinsaku*; et al.
no journal, ,
no abstracts in English
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
Kawahara, Yuzuru*; Yamamoto, Yusuke*; Nakamura, Kazuya*; Takao, Tomoaki*; Yagai, Tsuyoshi*; Murakami, Haruyuki; Yoshida, Kiyoshi; Natsume, Kyohei*; Hamaguchi, Shinji*; Obana, Tetsuhiro*; 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
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.
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
Kizu, Kaname; Murakami, Haruyuki; Natsume, Kyohei; Tsuchiya, Katsuhiko; Koide, Yoshihiko; Yoshida, Kiyoshi; Obana, Tetsuhiro*; Hamaguchi, Shinji*; Takahata, Kazuya*
no journal, ,
The current feeding system for superconducting magnets of JT-60SA were designed. Key components concerned were developed and tested. Trial manufacturing of crank shaped feeder to reduce the thermal stress showed the max. dimensional error of 3 mm. The compact tool to connect the feeder joint with solder vertically was developed. The joint resistance of feeder joint sample was 2n 
within the requirement of 
5n. Feeder insulation samples showed sufficient shear strength. Since all the manufacturing processes concerned were confirmed, the production of CTBs and feeders can be started.
Yoshida, Kiyoshi; Kizu, Kaname; Tsuchiya, Katsuhiko; Murakami, Haruyuki; Honda, Atsushi; Kashiwa, Yoshitoshi; Koide, Yoshihiko; Usui, Katsutomi; Natsume, Kyohei
no journal, ,
The upgrade of the JT-60U magnet system to the superconducting coils (JT-60SA) is progressing as a satellite facility for ITER by both parties of Japanese government and European commission (EU) in the Broader Approach agreement. Three equilibrium field coils were installed in the cryostat base before assembly of plasma vacuum vessel. This report shows the Manufacturing and assembly status of superconducting magnet components for the JT-60SA.
Natsume, Kyohei; Murakami, Haruyuki; Yanagi, Shunki; Kizu, Kaname; Yoshida, Kiyoshi
no journal, ,
Valve Boxes (VBs) and Coil Terminal Boxes (CTBs) will be fabricated as magnet shared components and be installed on the cryostat of JT-60SA. VB is for distributing cryogens to superconducting magnets, cryopumps, and thermal shields. CTB includes the interface between high temperature superconducting current leads and power supply bus bars. In this presentation, attachment methods of thermal sensors on the cryogen pipes in vacuum VB or CTB are described. An Experiment to measure the helium in the pipe has been conducted using the two different attachment methods. The experimental results are compared and estimated by considering measurement accuracy and productivity.
