22-27 September 2019
Hyatt Regency Hotel Vancouver
Canada/Pacific timezone

Tue-Mo-Po2.13-08 [115]: Investigation of the Tape Shaped RHQT-Processed Nb3Al Conductors

24 Sep 2019, 08:45
Level 3 Posters

Level 3 Posters


Akihiro Kikuchi (National Institute for Materials Science)Mr Kyohei Yamada (Sophia University)


National Institute for Fusion Science (NIFS) in Japan is considering about FFHR-d1 (Force Free Helical Reactor) for their future R&D project. Its magnet system will be needed a pair of helical typed coils with the major radius of 15.6 m. Since the maximum magnetic field on the helical coil of FFHR-d1 reaches 11.9 T, the NbTi cable is not applicable. The practical Nb3Sn cable was selected for the ITER (International Thermonuclear Experimental Reactor) project and it might be still one of candidate conductor for FFHR-d1 as well. However, the large helical coil shows 3 dimensional complex forming, it is strongly preferable to apply a React and Wind method for the coil winding. Recently, the STARS (Stacked Tapes Assembled in Rigid Structure) conductor fabricated using 2G-REBCO tapes is being investigated by a research group of NIFS and Tohoku University. The 2G-REBCO tape shows a large critical current density at 4.2 K, and also mechanically strong due to the hastelloy substrate. In addition, its thin tape shape may be good advantage to keep a small bending strain with flat-wise direction. In this paper, the RHQT(Rapid Heating/Quenching and Transformation)-processed Nb3Al tapes with 0.2 mm in thickness were fabricated, and their superconducting properties and microstructures were investigated. We propose the Nb3Al conductor as another candidate for FFHR-d1. It is well known that Nb3Al conductor shows an excellent strain tolerance and is promising very much for a React and Wind method for the coil winding. In addition, Cu stabilized long wire with over one kilometer length has already been made by NIMS (National Institute for Materials Science). We will report the transport critical current at 4.2 K of the 0.2 mm thick Nb3Al tape soldered on brass fixtures, which have different radius down to 15 mm. Maximum bending strain corresponds to 0.66% in this study.

Primary authors

Akihiro Kikuchi (National Institute for Materials Science) Mr Yasuo Iijima (National Institute for Materials Science) Mr Kyohei Yamada (Sophia University) Dr Shigeki Nimori (National Institute for Materials Science) Kiyosumi Tsuchiya (KEK) Xudong Wang (High Energy Accelerator Research Organization) Norihito Ohuchi (KEK) Akio Terashima (KEK) Yoshimitsu Hishinuma (National Institute for Fusion Science) Dr Kazuya Takahata (National Institute for Fusion Science) Toshiyuki Mito (National Institute for Fusion Science (NIFS)) Shinsaku Imagawa (National Institute for Fusion Science) Dr Shinji Hamaguchi (NIFS) Dr Hidetoshi Oguro (Tokai Uiversity) Tomoaki Takao (Sophia University)

Presentation Materials