The Experts below are selected from a list of 390 Experts worldwide ranked by ideXlab platform

Satoshi Awaji - One of the best experts on this subject based on the ideXlab platform.

  • Upgraded Cryogen-Free 20 T Superconducting Magnet
    IEEE Transactions on Applied Superconductivity, 2014
    Co-Authors: Satoshi Hanai, Satoshi Awaji, Kazuo Watanabe, Takahiro Tsuchihashi, Yuji Minemoto, Shigeru Ioka, Hiroki Oguro
    Abstract:

    We have constructed an 18 T superconducting magnet conductively cooled by a GM/JT (Gifford-McMahon/Joule-Thomson) cryocooler. A double-pancake stacked insert coil using Ag-sheathed Bi2Sr2Ca2Cu3O10 (Bi2223) tape with Stainless Steel Reinforcement has generated 2.5 T in a 15.5 T outer LTS coil. After we constructed the cryogen-free 18 T superconducting magnet (18 T-CSM), Bi2223 tape conductors have been improved in both critical current and strength. The critical current of the conductor doubled and a tape conductor with copper alloy Reinforcement which has a strength of 250 MPa at 77 K was developed. So we developed a new Bi2223 insert coil for the cryogen-free superconducting magnet which can generate 4.5 T in a 15.5 T outer LTS coil by exchanging the insert coil. The new 20 T cryogen-free superconducting magnet (20 T-CSM) can generate constant magnetic fields up to 20 T in a 52-mm room-temperature bore.

  • Rutherford flat cable composed of CuNb-reinforced Nb3Sn strands
    AIP Conference Proceedings, 2014
    Co-Authors: K. Watanabe, M. Sugimoto, Hiroki Oguro, Satoshi Awaji, Hiroaki Kumakura, Haruo Tsubouchi
    Abstract:

    A Rutherford flat cable that is applicable for operational currents up to 1000 A at 13-14 T was developed using a bronze-processed high-strength Nb3Sn strand with CuNb Reinforcement (CuNb/Nb3Sn). The critical current for a 0.8- mm diameter CuNb/Nb3Sn strand is 98 A at 14 T and 4.2 K in the residual strain state. A test coil using the CuNb/Nb3Sn Rutherford flat cable composed of 16 CuNb-reinforced Nb3Sn strands was fabricated. We measured the critical current properties of the Rutherford test coil and obtained an excellent critical current of 1840 A at 14 T and 4.2 K. By using the strain gauges attached onto the Stainless-Steel Reinforcement tape that was co-wounded with the Rutherford flat cable, it was found that a 300-MPa hoop stress at 4.2 K was applied to the CuNb/Nb3Sn strand. This implies that the critical current for a CuNb/Nb3Sn strand is enhanced to be 115 A at 14 T and 4.2 K through the stress-strain effect of the critical current at 300 MPa. [ABSTRACT FROM AUTHOR]

  • Wide Variety of Experiments Using a Cryogen-Free 27.5 T Hybrid Magnet and a Cryogen-Free 18.1 T Superconducting Magnet
    Journal of Low Temperature Physics, 2013
    Co-Authors: K. Watanabe, Satoshi Awaji, Hiroki Oguro
    Abstract:

    A cryogen-free hybrid magnet without liquid helium for operation, generating 27.5 T in a 32 mm room temperature bore of an 8 MW water-cooled resistive insert magnet in an 8.5 T background field of a cryogen-free superconducting outsert magnet, is being operated for basic research at low temperatures down to 17 mK in combination with a dilution refrigerator. In addition, we are developing functional materials using a differential thermal analysis DTA at high temperatures up to 1473 K in high fields up to 27 T. This cryogen-free hybrid magnet will be upgraded to generate 29 T by improving the outer superconducting magnet. A cryogen-free 18.1 T superconducting magnet with a 52 mm room temperature experimental bore, consisting of a Bi_2Sr_2Ca_2Cu_3O_10 (Bi2223) insert coil, has been developed using a GM-JT cryocooler. Recently, bronze-tape-laminated Bi2223 has revealed excellent irreversible stress tolerance of 250 MPa at 77 K. In addition, the critical current properties for recent Bi2223 tapes are largely improved from 200 to 400 A/cm-width at 77 K in a self-field. Therefore, the Stainless Steel Reinforcement tape incorporated for the previous Bi2223 insert coil is no longer needed for a new Bi2223 one. A new Bi2223 insert coil with almost the same size as the existing insert coil can generate two times higher fields at the elevated operation current from 162 to 191 A. An upgraded cryogen-free superconducting magnet can offer a long-term experiment at the constant magnetic field of 20 T for an in-field heat-treatment investigation.

  • strain measurements by neutron diffraction on nb3sn cable with Stainless Steel Reinforcement strands
    Superconductor Science and Technology, 2012
    Co-Authors: K Takahashi, Hiroki Oguro, Satoshi Awaji, K. Watanabe, Stefanus Harjo, Kazuya Aizawa
    Abstract:

    Internal lattice strains under a tensile load for a seven-strand cable consisting of three pre-bent CuNb/Nb3Sn and four Stainless Steel strands were measured by neutron diffraction at room temperature in order to investigate the improvement of mechanical properties of Nb3Sn strands. Stress–lattice strain curves of Nb3Sn and Stainless Steel strands were obtained, and the effective stress for a Nb3Sn strand was estimated by considering the load sharing of a Stainless strand. It was found that the Reinforcement with Stainless Steel strands is an effective way to reduce an applied electromagnetic tensile load for Nb3Sn strands for superconducting magnet application.

  • Research and Development for Upgrading a Cryogen-Free 18 T Superconducting Magnet
    IEEE Transactions on Applied Superconductivity, 2012
    Co-Authors: Kotaro Marukawa, Satoshi Awaji, Kazuo Watanabe, Satoshi Hanai, Hiroshi Miyazaki, Hiroki Oguro
    Abstract:

    We have studied for upgrading an 18 T super-conducting magnet conductively cooled by a GM/JT cryocooler at Tohoku University in Japan to a 23 T superconducting magnet. In order to upgrade the cryogen-free high field superconducting magnet up to 23 T, an YBa2Cu3O7(Y123) coated conductor insert is intended for replacing the insert using tape BiSr2Ca2Cu3O10(Bi2223) with Stainless Steel Reinforcement tape. We have produced double pancake coils with almost the same size as a double pancake coil for the Bi2223 insert, and have investigated the performance of the coils. And the design of the double pancake coil was reviewed from the result of the R&D coils.

Hiroki Oguro - One of the best experts on this subject based on the ideXlab platform.

  • Rutherford flat cable composed of CuNb-reinforced Nb3Sn strands
    AIP Conference Proceedings, 2014
    Co-Authors: K. Watanabe, M. Sugimoto, Hiroki Oguro, Satoshi Awaji, Hiroaki Kumakura, Haruo Tsubouchi
    Abstract:

    A Rutherford flat cable that is applicable for operational currents up to 1000 A at 13-14 T was developed using a bronze-processed high-strength Nb3Sn strand with CuNb Reinforcement (CuNb/Nb3Sn). The critical current for a 0.8- mm diameter CuNb/Nb3Sn strand is 98 A at 14 T and 4.2 K in the residual strain state. A test coil using the CuNb/Nb3Sn Rutherford flat cable composed of 16 CuNb-reinforced Nb3Sn strands was fabricated. We measured the critical current properties of the Rutherford test coil and obtained an excellent critical current of 1840 A at 14 T and 4.2 K. By using the strain gauges attached onto the Stainless-Steel Reinforcement tape that was co-wounded with the Rutherford flat cable, it was found that a 300-MPa hoop stress at 4.2 K was applied to the CuNb/Nb3Sn strand. This implies that the critical current for a CuNb/Nb3Sn strand is enhanced to be 115 A at 14 T and 4.2 K through the stress-strain effect of the critical current at 300 MPa. [ABSTRACT FROM AUTHOR]

  • Upgraded Cryogen-Free 20 T Superconducting Magnet
    IEEE Transactions on Applied Superconductivity, 2014
    Co-Authors: Satoshi Hanai, Satoshi Awaji, Kazuo Watanabe, Takahiro Tsuchihashi, Yuji Minemoto, Shigeru Ioka, Hiroki Oguro
    Abstract:

    We have constructed an 18 T superconducting magnet conductively cooled by a GM/JT (Gifford-McMahon/Joule-Thomson) cryocooler. A double-pancake stacked insert coil using Ag-sheathed Bi2Sr2Ca2Cu3O10 (Bi2223) tape with Stainless Steel Reinforcement has generated 2.5 T in a 15.5 T outer LTS coil. After we constructed the cryogen-free 18 T superconducting magnet (18 T-CSM), Bi2223 tape conductors have been improved in both critical current and strength. The critical current of the conductor doubled and a tape conductor with copper alloy Reinforcement which has a strength of 250 MPa at 77 K was developed. So we developed a new Bi2223 insert coil for the cryogen-free superconducting magnet which can generate 4.5 T in a 15.5 T outer LTS coil by exchanging the insert coil. The new 20 T cryogen-free superconducting magnet (20 T-CSM) can generate constant magnetic fields up to 20 T in a 52-mm room-temperature bore.

  • Wide Variety of Experiments Using a Cryogen-Free 27.5 T Hybrid Magnet and a Cryogen-Free 18.1 T Superconducting Magnet
    Journal of Low Temperature Physics, 2013
    Co-Authors: K. Watanabe, Satoshi Awaji, Hiroki Oguro
    Abstract:

    A cryogen-free hybrid magnet without liquid helium for operation, generating 27.5 T in a 32 mm room temperature bore of an 8 MW water-cooled resistive insert magnet in an 8.5 T background field of a cryogen-free superconducting outsert magnet, is being operated for basic research at low temperatures down to 17 mK in combination with a dilution refrigerator. In addition, we are developing functional materials using a differential thermal analysis DTA at high temperatures up to 1473 K in high fields up to 27 T. This cryogen-free hybrid magnet will be upgraded to generate 29 T by improving the outer superconducting magnet. A cryogen-free 18.1 T superconducting magnet with a 52 mm room temperature experimental bore, consisting of a Bi_2Sr_2Ca_2Cu_3O_10 (Bi2223) insert coil, has been developed using a GM-JT cryocooler. Recently, bronze-tape-laminated Bi2223 has revealed excellent irreversible stress tolerance of 250 MPa at 77 K. In addition, the critical current properties for recent Bi2223 tapes are largely improved from 200 to 400 A/cm-width at 77 K in a self-field. Therefore, the Stainless Steel Reinforcement tape incorporated for the previous Bi2223 insert coil is no longer needed for a new Bi2223 one. A new Bi2223 insert coil with almost the same size as the existing insert coil can generate two times higher fields at the elevated operation current from 162 to 191 A. An upgraded cryogen-free superconducting magnet can offer a long-term experiment at the constant magnetic field of 20 T for an in-field heat-treatment investigation.

  • strain measurements by neutron diffraction on nb3sn cable with Stainless Steel Reinforcement strands
    Superconductor Science and Technology, 2012
    Co-Authors: K Takahashi, Hiroki Oguro, Satoshi Awaji, K. Watanabe, Stefanus Harjo, Kazuya Aizawa
    Abstract:

    Internal lattice strains under a tensile load for a seven-strand cable consisting of three pre-bent CuNb/Nb3Sn and four Stainless Steel strands were measured by neutron diffraction at room temperature in order to investigate the improvement of mechanical properties of Nb3Sn strands. Stress–lattice strain curves of Nb3Sn and Stainless Steel strands were obtained, and the effective stress for a Nb3Sn strand was estimated by considering the load sharing of a Stainless strand. It was found that the Reinforcement with Stainless Steel strands is an effective way to reduce an applied electromagnetic tensile load for Nb3Sn strands for superconducting magnet application.

  • Research and Development for Upgrading a Cryogen-Free 18 T Superconducting Magnet
    IEEE Transactions on Applied Superconductivity, 2012
    Co-Authors: Kotaro Marukawa, Satoshi Awaji, Kazuo Watanabe, Satoshi Hanai, Hiroshi Miyazaki, Hiroki Oguro
    Abstract:

    We have studied for upgrading an 18 T super-conducting magnet conductively cooled by a GM/JT cryocooler at Tohoku University in Japan to a 23 T superconducting magnet. In order to upgrade the cryogen-free high field superconducting magnet up to 23 T, an YBa2Cu3O7(Y123) coated conductor insert is intended for replacing the insert using tape BiSr2Ca2Cu3O10(Bi2223) with Stainless Steel Reinforcement tape. We have produced double pancake coils with almost the same size as a double pancake coil for the Bi2223 insert, and have investigated the performance of the coils. And the design of the double pancake coil was reviewed from the result of the R&D coils.

K. Watanabe - One of the best experts on this subject based on the ideXlab platform.

  • Rutherford flat cable composed of CuNb-reinforced Nb3Sn strands
    AIP Conference Proceedings, 2014
    Co-Authors: K. Watanabe, M. Sugimoto, Hiroki Oguro, Satoshi Awaji, Hiroaki Kumakura, Haruo Tsubouchi
    Abstract:

    A Rutherford flat cable that is applicable for operational currents up to 1000 A at 13-14 T was developed using a bronze-processed high-strength Nb3Sn strand with CuNb Reinforcement (CuNb/Nb3Sn). The critical current for a 0.8- mm diameter CuNb/Nb3Sn strand is 98 A at 14 T and 4.2 K in the residual strain state. A test coil using the CuNb/Nb3Sn Rutherford flat cable composed of 16 CuNb-reinforced Nb3Sn strands was fabricated. We measured the critical current properties of the Rutherford test coil and obtained an excellent critical current of 1840 A at 14 T and 4.2 K. By using the strain gauges attached onto the Stainless-Steel Reinforcement tape that was co-wounded with the Rutherford flat cable, it was found that a 300-MPa hoop stress at 4.2 K was applied to the CuNb/Nb3Sn strand. This implies that the critical current for a CuNb/Nb3Sn strand is enhanced to be 115 A at 14 T and 4.2 K through the stress-strain effect of the critical current at 300 MPa. [ABSTRACT FROM AUTHOR]

  • Wide Variety of Experiments Using a Cryogen-Free 27.5 T Hybrid Magnet and a Cryogen-Free 18.1 T Superconducting Magnet
    Journal of Low Temperature Physics, 2013
    Co-Authors: K. Watanabe, Satoshi Awaji, Hiroki Oguro
    Abstract:

    A cryogen-free hybrid magnet without liquid helium for operation, generating 27.5 T in a 32 mm room temperature bore of an 8 MW water-cooled resistive insert magnet in an 8.5 T background field of a cryogen-free superconducting outsert magnet, is being operated for basic research at low temperatures down to 17 mK in combination with a dilution refrigerator. In addition, we are developing functional materials using a differential thermal analysis DTA at high temperatures up to 1473 K in high fields up to 27 T. This cryogen-free hybrid magnet will be upgraded to generate 29 T by improving the outer superconducting magnet. A cryogen-free 18.1 T superconducting magnet with a 52 mm room temperature experimental bore, consisting of a Bi_2Sr_2Ca_2Cu_3O_10 (Bi2223) insert coil, has been developed using a GM-JT cryocooler. Recently, bronze-tape-laminated Bi2223 has revealed excellent irreversible stress tolerance of 250 MPa at 77 K. In addition, the critical current properties for recent Bi2223 tapes are largely improved from 200 to 400 A/cm-width at 77 K in a self-field. Therefore, the Stainless Steel Reinforcement tape incorporated for the previous Bi2223 insert coil is no longer needed for a new Bi2223 one. A new Bi2223 insert coil with almost the same size as the existing insert coil can generate two times higher fields at the elevated operation current from 162 to 191 A. An upgraded cryogen-free superconducting magnet can offer a long-term experiment at the constant magnetic field of 20 T for an in-field heat-treatment investigation.

  • strain measurements by neutron diffraction on nb3sn cable with Stainless Steel Reinforcement strands
    Superconductor Science and Technology, 2012
    Co-Authors: K Takahashi, Hiroki Oguro, Satoshi Awaji, K. Watanabe, Stefanus Harjo, Kazuya Aizawa
    Abstract:

    Internal lattice strains under a tensile load for a seven-strand cable consisting of three pre-bent CuNb/Nb3Sn and four Stainless Steel strands were measured by neutron diffraction at room temperature in order to investigate the improvement of mechanical properties of Nb3Sn strands. Stress–lattice strain curves of Nb3Sn and Stainless Steel strands were obtained, and the effective stress for a Nb3Sn strand was estimated by considering the load sharing of a Stainless strand. It was found that the Reinforcement with Stainless Steel strands is an effective way to reduce an applied electromagnetic tensile load for Nb3Sn strands for superconducting magnet application.

  • Cryogen-Free 23 T Superconducting Magnet Employing an YBa_2Cu_3O_7 Coated Conductor Insert
    Journal of Superconductivity and Novel Magnetism, 2011
    Co-Authors: K. Watanabe, Satoshi Awaji, G. Nishijima, Satoshi Hanai
    Abstract:

    We have successfully constructed an 18.1 T superconducting magnet conductively cooled by a GM/JT cryocooler. The double-pancake insert using Ag-sheathed Bi_2Sr_2Ca_2Cu_3O_10 (Bi2223) tape with Stainless Steel Reinforcement tape generated 2.5 T in a 15.6 T background magnet. In order to develop a cryogen-free high-field superconducting magnet producing over 20 T, an YBa_2Cu_3O_7 (Y123) coated conductor insert is intended for upgrading the cryogen-free 18 T superconducting magnet. The Bi2223 insert, whose size is 176 mm outer diameter, 90 mm inner diameter, and 252 mm coil height, is now excited at 162 A operation current, and will be replaced by a new Y123 insert. We have already confirmed excellent mechanical properties of 1000 MPa hoop stress tolerance for Y123 coated conductor tape with Hastelloy substrate. This means that we no longer need Stainless Steel Reinforcement for the insert. As a result, an Y123 insert with almost the same size as the Bi2223 insert is designed to generate 7.5 T at 187 A, because the number of turns can be improved extremely. A cryogen-free 23 T superconducting magnet can sufficiently be developed for a long-term experiment at a constant high magnetic field.

  • Cryogen-Free 23 T Superconducting Magnet Employing an YBa2Cu3O7 Coated Conductor Insert
    Journal of Superconductivity and Novel Magnetism, 2010
    Co-Authors: K. Watanabe, Satoshi Awaji, Nishijima, Satoshi Hanai
    Abstract:

    We have successfully constructed an 18.1 T superconducting magnet conductively cooled by a GM/JT cryocooler. The double-pancake insert using Ag-sheathed Bi2Sr2Ca2Cu3O10 (Bi2223) tape with Stainless Steel Reinforcement tape generated 2.5 T in a 15.6 T background magnet. In order to develop a cryogen-free high-field superconducting magnet producing over 20 T, an YBa2Cu3O7 (Y123) coated conductor insert is intended for upgrading the cryogen-free 18 T superconducting magnet. The Bi2223 insert, whose size is 176 mm outer diameter, 90 mm inner diameter, and 252 mm coil height, is now excited at 162 A operation current, and will be replaced by a new Y123 insert. We have already confirmed excellent mechanical properties of 1000 MPa hoop stress tolerance for Y123 coated conductor tape with Hastelloy substrate. This means that we no longer need Stainless Steel Reinforcement for the insert. As a result, an Y123 insert with almost the same size as the Bi2223 insert is designed to generate 7.5 T at 187 A, because the number of turns can be improved extremely. A cryogen-free 23 T superconducting magnet can sufficiently be developed for a long-term experiment at a constant high magnetic field.

Kazuo Watanabe - One of the best experts on this subject based on the ideXlab platform.

  • Upgraded Cryogen-Free 20 T Superconducting Magnet
    IEEE Transactions on Applied Superconductivity, 2014
    Co-Authors: Satoshi Hanai, Satoshi Awaji, Kazuo Watanabe, Takahiro Tsuchihashi, Yuji Minemoto, Shigeru Ioka, Hiroki Oguro
    Abstract:

    We have constructed an 18 T superconducting magnet conductively cooled by a GM/JT (Gifford-McMahon/Joule-Thomson) cryocooler. A double-pancake stacked insert coil using Ag-sheathed Bi2Sr2Ca2Cu3O10 (Bi2223) tape with Stainless Steel Reinforcement has generated 2.5 T in a 15.5 T outer LTS coil. After we constructed the cryogen-free 18 T superconducting magnet (18 T-CSM), Bi2223 tape conductors have been improved in both critical current and strength. The critical current of the conductor doubled and a tape conductor with copper alloy Reinforcement which has a strength of 250 MPa at 77 K was developed. So we developed a new Bi2223 insert coil for the cryogen-free superconducting magnet which can generate 4.5 T in a 15.5 T outer LTS coil by exchanging the insert coil. The new 20 T cryogen-free superconducting magnet (20 T-CSM) can generate constant magnetic fields up to 20 T in a 52-mm room-temperature bore.

  • Research and Development for Upgrading a Cryogen-Free 18 T Superconducting Magnet
    IEEE Transactions on Applied Superconductivity, 2012
    Co-Authors: Kotaro Marukawa, Satoshi Awaji, Kazuo Watanabe, Satoshi Hanai, Hiroshi Miyazaki, Hiroki Oguro
    Abstract:

    We have studied for upgrading an 18 T super-conducting magnet conductively cooled by a GM/JT cryocooler at Tohoku University in Japan to a 23 T superconducting magnet. In order to upgrade the cryogen-free high field superconducting magnet up to 23 T, an YBa2Cu3O7(Y123) coated conductor insert is intended for replacing the insert using tape BiSr2Ca2Cu3O10(Bi2223) with Stainless Steel Reinforcement tape. We have produced double pancake coils with almost the same size as a double pancake coil for the Bi2223 insert, and have investigated the performance of the coils. And the design of the double pancake coil was reviewed from the result of the R&D coils.

  • Cryogen-Free 23 T Superconducting Magnet with a 7.5 T YBa2Cu3O7 Insert Coil
    Applied Physics Express, 2009
    Co-Authors: Kazuo Watanabe, Satoshi Awaji, Nishijima, Satoshi Hanai
    Abstract:

    In order to develop a cryogen-free high-field superconducting magnet generating over 20 T, a YBa2Cu3O7 (Y123)-coated conductor insert coil is used to enhance a cryogen-free 18 T superconducting magnet. The Y123 tape does not require Stainless Steel Reinforcement. The Y123 insert coil, which is almost the same size as the current Bi2Sr2Ca2Cu3O10 (Bi2223) insert coil, is designed to generate 7.5 T at 187 A. It is able to achieve this since without Stainless Steel Reinforcement the number of turns can be greatly increased. A cryogen-free superconducting magnet can achieve a static magnetic field of 23 T, which is higher than that generated by practical superconducting magnets using liquid helium.

  • Development of Pre-Bent High-Strength ${\rm Nb}_{3}{\rm Sn}$ Cable With Stainless-Steel Reinforcement Strands
    IEEE Transactions on Applied Superconductivity, 2009
    Co-Authors: Gen Nishijima, Haruo Tsubouchi, Hiroki Oguro, Satoshi Awaji, Kazuo Watanabe
    Abstract:

    A 7-strand Nb3Sn superconducting cable, which consists of three pre-bent CuNb/Nb3Sn strands, three Stainless-Steel (SS) strands, and a center SS strand, was fabricated. 2.5 turns of the cable was wound on a 262-mm diameter GFRP bobbin A triplet consisting of three pre-bent CuNb/Nb3Sn strands was also tested for comparison. The Reinforcement effect of Stainless-Steel strands in a cable was investigated to develop a high-strength large-current superconducting cable. The hoop stress test result indicated that the Stainless-Steel reinforced CuNb/Nb3Sn cable showed better performance than the CuNb/Nb3Sn triplet under the hoop stress, because the Stainless-Steel strands reduced the hoop stress on Nb3Sn strands. Furthermore, the solder impregnation of the cable, which made the seven strands a monolithic conductor, improved its performance.

Haruo Tsubouchi - One of the best experts on this subject based on the ideXlab platform.

  • Rutherford flat cable composed of CuNb-reinforced Nb3Sn strands
    AIP Conference Proceedings, 2014
    Co-Authors: K. Watanabe, M. Sugimoto, Hiroki Oguro, Satoshi Awaji, Hiroaki Kumakura, Haruo Tsubouchi
    Abstract:

    A Rutherford flat cable that is applicable for operational currents up to 1000 A at 13-14 T was developed using a bronze-processed high-strength Nb3Sn strand with CuNb Reinforcement (CuNb/Nb3Sn). The critical current for a 0.8- mm diameter CuNb/Nb3Sn strand is 98 A at 14 T and 4.2 K in the residual strain state. A test coil using the CuNb/Nb3Sn Rutherford flat cable composed of 16 CuNb-reinforced Nb3Sn strands was fabricated. We measured the critical current properties of the Rutherford test coil and obtained an excellent critical current of 1840 A at 14 T and 4.2 K. By using the strain gauges attached onto the Stainless-Steel Reinforcement tape that was co-wounded with the Rutherford flat cable, it was found that a 300-MPa hoop stress at 4.2 K was applied to the CuNb/Nb3Sn strand. This implies that the critical current for a CuNb/Nb3Sn strand is enhanced to be 115 A at 14 T and 4.2 K through the stress-strain effect of the critical current at 300 MPa. [ABSTRACT FROM AUTHOR]

  • development of pre bent high strength rm nb _ 3 rm sn cable with Stainless Steel Reinforcement strands
    IEEE Transactions on Applied Superconductivity, 2009
    Co-Authors: G. Nishijima, Haruo Tsubouchi, Hiroki Oguro, Satoshi Awaji, K. Watanabe
    Abstract:

    A 7-strand Nb3Sn superconducting cable, which consists of three pre-bent CuNb/Nb3Sn strands, three Stainless-Steel (SS) strands, and a center SS strand, was fabricated. 2.5 turns of the cable was wound on a 262-mm diameter GFRP bobbin A triplet consisting of three pre-bent CuNb/Nb3Sn strands was also tested for comparison. The Reinforcement effect of Stainless-Steel strands in a cable was investigated to develop a high-strength large-current superconducting cable. The hoop stress test result indicated that the Stainless-Steel reinforced CuNb/Nb3Sn cable showed better performance than the CuNb/Nb3Sn triplet under the hoop stress, because the Stainless-Steel strands reduced the hoop stress on Nb3Sn strands. Furthermore, the solder impregnation of the cable, which made the seven strands a monolithic conductor, improved its performance.

  • Development of Pre-Bent High-Strength ${\rm Nb}_{3}{\rm Sn}$ Cable With Stainless-Steel Reinforcement Strands
    IEEE Transactions on Applied Superconductivity, 2009
    Co-Authors: Gen Nishijima, Haruo Tsubouchi, Hiroki Oguro, Satoshi Awaji, Kazuo Watanabe
    Abstract:

    A 7-strand Nb3Sn superconducting cable, which consists of three pre-bent CuNb/Nb3Sn strands, three Stainless-Steel (SS) strands, and a center SS strand, was fabricated. 2.5 turns of the cable was wound on a 262-mm diameter GFRP bobbin A triplet consisting of three pre-bent CuNb/Nb3Sn strands was also tested for comparison. The Reinforcement effect of Stainless-Steel strands in a cable was investigated to develop a high-strength large-current superconducting cable. The hoop stress test result indicated that the Stainless-Steel reinforced CuNb/Nb3Sn cable showed better performance than the CuNb/Nb3Sn triplet under the hoop stress, because the Stainless-Steel strands reduced the hoop stress on Nb3Sn strands. Furthermore, the solder impregnation of the cable, which made the seven strands a monolithic conductor, improved its performance.

  • High-strength CuNb/Nb3Sn strand cables with residual strain controlled by the repeated bending treatment
    Journal of Physics: Conference Series, 2008
    Co-Authors: K. Watanabe, Haruo Tsubouchi, Hiroki Oguro, Satoshi Awaji, Nishijima, Petre Badica, S. Meguro
    Abstract:

    We have developed practical multifilamentary Nb3Sn wires with CuNb composite Reinforcement (CuNb/Nb3Sn). In order to fabricate a CuNb/Nb3Sn superconducting magnet by a react-and-wind method, the bending strain effect was investigated in detail for CuNb/Nb3Sn wires. We found that the repeated bending treatment enhances Tc from 17.4 to 17.9 K and Bc2 from 24.0 to 25.3 T at 4.2 K for CuNb/Nb3Sn wire. As a result, the repeated bending treatment for CuNb/Nb3Sn wire outstandingly enhances the critical current in high magnetic fields. A Nb3Sn filament was prepared by chemically solving practical multifilamentary CuNb/Nb3Sn wires. After removing Cu stabilizer, CuNb Reinforcement, Nb barrier, and Bronze, Bc2 of a Nb3Sn filament was measured, and the Bc2 value of 25.9 T at 4.2 K was obtained. This means that the bending treatment for CuNb/Nb3Sn wires extremely reduces the residual strain close to the strain free state. To decrease the residual strain, it is important to control the three-dimensional strain distribution of CuNb/Nb3Sn wires. We intended to apply the bending effect to the cabling process of CuNb/Nb3Sn strands by a react-and-wind method. High strength Nb3Sn cables consisting of CuNb/Nb3Sn strands and Stainless Steel Reinforcement strands were developed for a performance test of a next phase superconductor with a large critical current and a strong mechanical property at a high magnetic field of 20 T.