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Tamatsukuri, Hiromu; Murakami, Yoichi*; Kuramoto, Yoshio*; Sagayama, Hajime*; Matsuura, Masato*; Kawakita, Yukinobu; Matsuishi, Satoru*; Washio, Yasuhito*; Inoshita, Takeshi*; Hamada, Noriaki*; et al.
Physical Review B, 102(22), p.224406_1 - 224406_5, 2020/12
Times Cited Count:7 Percentile:53.71(Materials Science, Multidisciplinary)Nabara, Yoshihiro; Suwa, Tomone; Takahashi, Yoshikazu; Hemmi, Tsutomu; Kajitani, Hideki; Ozeki, Hidemasa; Sakurai, Takeru; Iguchi, Masahide; Nunoya, Yoshihiko; Isono, Takaaki; et al.
IEEE Transactions on Applied Superconductivity, 25(3), p.4200305_1 - 4200305_5, 2015/06
Times Cited Count:0 Percentile:0(Engineering, Electrical & Electronic)Nabara, Yoshihiro; Hemmi, Tsutomu; Kajitani, Hideki; Ozeki, Hidemasa; Suwa, Tomone; Iguchi, Masahide; Nunoya, Yoshihiko; Isono, Takaaki; Matsui, Kunihiro; Koizumi, Norikiyo; et al.
IEEE Transactions on Applied Superconductivity, 24(3), p.6000605_1 - 6000605_5, 2014/06
Times Cited Count:7 Percentile:40.75(Engineering, Electrical & Electronic)no abstracts in English
Takahashi, Yoshikazu; Nabara, Yoshihiro; Ozeki, Hidemasa; Hemmi, Tsutomu; Nunoya, Yoshihiko; Isono, Takaaki; Matsui, Kunihiro; Kawano, Katsumi; Oshikiri, Masayuki; Uno, Yasuhiro; et al.
IEEE Transactions on Applied Superconductivity, 24(3), p.4802404_1 - 4802404_4, 2014/06
Times Cited Count:23 Percentile:73.15(Engineering, Electrical & Electronic)Japan Atomic Energy Agency (JAEA) is procuring all amounts of NbSn conductors for Central Solenoid (CS) in the ITER project. Before start of mass-productions, the conductor should be tested to confirm superconducting performance in the SULTAN facility, Switzerland. The original design of cabling twist pitches is 45-85-145-250-450 mm, called normal twist pitch (NTP). The test results of the conductors with NTP was that current shearing temperature (Tcs) is decreasing due to electro-magnetic (EM) load cycles. On the other hand, the results of the conductors with short twist pitches (STP) of 25-45-80-150-450 mm show that the Tcs is stabilized during EM load cyclic tests. Because the conductors with STP have smaller void fraction, higher compaction ratio during cabling is required and possibility of damage on strands increases. The technology for the cables with STP was developed in Japanese cabling suppliers. The several key technologies will be described in this paper.
Takahashi, Yoshikazu; Nabara, Yoshihiro; Hemmi, Tsutomu; Nunoya, Yoshihiko; Isono, Takaaki; Hamada, Kazuya; Matsui, Kunihiro; Kawano, Katsumi; Koizumi, Norikiyo; Oshikiri, Masayuki; et al.
IEEE Transactions on Applied Superconductivity, 23(3), p.4801504_1 - 4801504_4, 2013/06
Times Cited Count:11 Percentile:51.71(Engineering, Electrical & Electronic)Japan Atomic Energy Agency (JAEA) is the first to start the mass production of the TF conductors in March 2010 among the 6 parties who are procuring TF conductors in the ITER project. The height and width of the TF coils are 14 m and 9 m, respectively. The conductor is cable-in-conduit conductor (CICC) with a central spiral. A circular multistage superconducting cable is inserted into a circular stainless steel jacket with a thickness of 2 mm. A total of 900 NbSn strands and 522 copper strands are cabled around the central spiral and the cable is inserted into a round-in-round stainless steel jacket. It was observed that the cabling pitch of the destructive sample is longer than the original pitch at cabling. The JAEA carried out the tensile tests of the cable and the measurement of the cable rotation during the insertion to investigate the cause of the elongation. The cause of elongation was clarified and the results will be described in this paper.
Takahashi, Yoshikazu; Isono, Takaaki; Hamada, Kazuya; Nunoya, Yoshihiko; Nabara, Yoshihiro; Matsui, Kunihiro; Hemmi, Tsutomu; Kawano, Katsumi; Koizumi, Norikiyo; Oshikiri, Masayuki; et al.
IEEE Transactions on Applied Superconductivity, 22(3), p.4801904_1 - 4801904_4, 2012/06
Times Cited Count:7 Percentile:42.1(Engineering, Electrical & Electronic)Japan Atomic Energy Agency is the first to start the mass production of the TF conductors in Phase IV in March 2010 among the 6 parties who are procuring TF conductors in the ITER project. The conductor is cable-in-conduit conductor with a central spiral. A total of 900 NbSn strands and 522 copper strands are cabled around the central spiral and then wrapped with stainless steel tape whose thickness is 0.1 mm. Approximately 60 tons of Nb
Sn strands were manufactured by the two suppliers in December 2010. This amount corresponds to approximately 55% of the total contribution from Japan. Approximately 30% of the total contribution from Japan was completed as of February 2011. JAEA is manufacturing one conductor per month under a contract with two Japanese companies for strands, one company for cabling and one company for jacketing. This paper summarizes the technical developments including a high-level quality assurance. This progress is a significant step in the construction of the ITER machine.
Miyatake, Takayuki*; Murakami, Yukinobu*; Kurahashi, Hidefumi*; Hayashi, Seiji*; Zaitsu, Kyoji*; Seeber, B.*; Mondonico, G.*; Nabara, Yoshihiro
IEEE Transactions on Applied Superconductivity, 22(3), p.4805005_1 - 4805005_5, 2012/06
Times Cited Count:7 Percentile:42.1(Engineering, Electrical & Electronic)In order to develop bronze processed NbSn strands for ITER TF and CS coils, the influences of various parameters of Nb
Sn strands such as filament diameter, barrier materials, barrier thickness, heat treatment pattern and Ti addition on critical current (
) vs. axial strain
characteristics were investigated. The change of theses parameters brought significant changes to superconducting properties involving
and n-value at zero applied strain. In spite of different strand parameters, the strain dependency of normalized
was almost the same, except for Ti-addition affecting the critical field
. Based on the results, bronze processed Nb
Sn strands with non-Cu critical current density more than 1,100 A/mm
at 12T, 4.2K have been successfully developed for the CS coil.
Nabara, Yoshihiro; Nunoya, Yoshihiko; Isono, Takaaki; Hamada, Kazuya; Uno, Yasuhiro; Takahashi, Yoshikazu; Nakajima, Hideo; Tsuzuku, Seiji*; Tagawa, Kohei*; Miyashita, Katsumi*; et al.
Teion Kogaku, 47(3), p.140 - 146, 2012/03
no abstracts in English
Hamada, Kazuya; Nunoya, Yoshihiko; Takahashi, Yoshikazu; Isono, Takaaki; Nabara, Yoshihiro; Hemmi, Tsutomu; Matsui, Kunihiro; Kawano, Katsumi; Ebisawa, Noboru; Oshikiri, Masayuki; et al.
no journal, ,
The ITER Central Solenoid (CS) conductor is composed of 576 NbSn superconducting strands and 288 Cu strands assembled together into a multistage cable and protected by a circle-in-square jacket with the outer dimension of 49 mm
49 mm. In R&D to prepare for the ITER CS conductor manufacturing, full size conductor performance test and jacket welding test and mechanical tests have been performed. In the presentation, the R&D activities are presented, showing that as a result of this R&D, the CS conductor manufacturing technologies have been confirmed to start the procurement of the CS conductor.
Takahashi, Yoshikazu; Nabara, Yoshihiro; Hemmi, Tsutomu; Nunoya, Yoshihiko; Isono, Takaaki; Oshikiri, Masayuki; Tsutsumi, Fumiaki; Uno, Yasuhiro; Hamada, Kazuya; Shibutani, Kazuyuki*; et al.
no journal, ,
In the ITER project, Japan Atomic Energy Agency (JAEA) is the first to start the mass production of the TF conductors in March 2010 among the 6 parties who are procuring TF conductors in the ITER project. The height and width of the TF coils are 14 m and 9 m, respectively. The conductor is cable-in-conduit conductor (CICC) with a central spiral. A circular multistage superconducting cable is inserted into a circular stainless steel jacket with a thickness of 2 mm. A total of 900 NbSn strands and 522 copper strands are cabled around the central spiral and the cable is inserted into a round-in-round stainless steel jacket. It was observed that the cabling pitch of the destructive sample is longer than the original pitch at cabling. The JAEA carried out the tensile tests of the cable and the measurement of the cable rotation during the insertion to investigate the cause of the elongation. The cause of elongation was clarified and the results will be described in this paper.
Nunoya, Yoshihiko; Takahashi, Yoshikazu; Nabara, Yoshihiro; Tsutsumi, Fumiaki; Oshikiri, Masayuki; Uno, Yasuhiro; Shibutani, Kazuyuki*; Ishibashi, Tatsuji*; Watanabe, Kazuaki*; Sugimoto, Masahiro*; et al.
no journal, ,
no abstracts in English
Takahashi, Yoshikazu; Nabara, Yoshihiro; Ozeki, Hidemasa; Hemmi, Tsutomu; Nunoya, Yoshihiko; Isono, Takaaki; Oshikiri, Masayuki; Tsutsumi, Fumiaki; Uno, Yasuhiro; Shibutani, Kazuyuki*; et al.
no journal, ,
Japan Atomic Energy Agency (JAEA) is procuring all amounts of NbSn conductors for Central Solenoid (CS) in the ITER project. Before start of mass-productions, the conductor should be tested to confirm superconducting performance in the SULTAN facility, Switzerland. The original design of cabling twist pitches is 45-85-145-250-450 mm, called normal twist pitch (NTP). The test results of the conductors with NTP was that current shearing temperature (Tcs) is decreasing due to electro-magnetic (EM) load cycles. On the other hand, the results of the conductors with short twist pitches (STP) of 25-45-80-150-450 show that the Tcs is stabilized during EM load cyclic tests. Because the conductors with STP have smaller void fraction, higher compaction ratio during cabling is required and possibility of damage on strands increases. The technology for the cables with STP was developed in Japanese cabling suppliers. The several key technologies will be described in this paper.
Suwa, Tomone; Nabara, Yoshihiro; Nunoya, Yoshihiko; Takahashi, Yoshikazu; Oshikiri, Masayuki; Tsutsumi, Fumiaki; Shibutani, Kazuyuki*; Murakami, Yukinobu*; Miyashita, Katsumi*; Sim, K.-H.*; et al.
no journal, ,
no abstracts in English
Tamatsukuri, Hiromu; Murakami, Yoichi*; Kuramoto, Yoshio*; Sagayama, Hajime*; Matsuura, Masato*; Kawakita, Yukinobu; Matsuishi, Satoru*; Washio, Yasuhito*; Inoshita, Takeshi*; Hamada, Noriaki*; et al.
no journal, ,
no abstracts in English