[Table of Contents]

Plasma and Fusion Research

Volume 5, S1035 (2010)

Regular Articles

Conceptual Design and Development of an Indirect-cooled Superconducting Helical Coil in the FFHR
Hitoshi TAMURA, Kazuya TAKAHATA, Toshiyuki MITO, Shinsaku IMAGAWA and Akio SAGARA
National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292, Japan
(Received 7 January 2009 / Accepted 14 July 2009 / Published 26 March 2010)


The force-free helical reactor (FFHR) is a conceptual design of a heliotron fusion reactor being developed at the National Institute for Fusion Science. All the coils in the FFHR are made of superconductors. Several cooling schemes have been proposed for the helical coils; of these, indirect cooling is considered a good candidate. In this study, we investigated the possibility of using an indirect-cooled superconducting magnet for the FFHR. In parallel with this design study, we developed Nb3Sn superconductors, jacketed with an aluminum alloy, for use in an indirect-cooled magnet. The results of performance tests of a sub-scale superconductor showed good feasibility for application in the FFHR helical coil. Stress distribution in the helical coil was also analyzed, and the stress and strain were confirmed to be within the permissible range.


large helical device, helical reactor, indirect-cooled superconducting magnet, Nb3Sn superconductor, cable-in-conduit-conductor, stress analysis

DOI: 10.1585/pfr.5.S1035


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This paper may be cited as follows:

Hitoshi TAMURA, Kazuya TAKAHATA, Toshiyuki MITO, Shinsaku IMAGAWA and Akio SAGARA, Plasma Fusion Res. 5, S1035 (2010).