August 27, 2017 to September 1, 2017
RAI Congress Center, Amsterdam, The Netherlands
Europe/Amsterdam timezone

Nonlinear multiscale structural analysis of a superconducting coil and support structure for the helical fusion reactor

Aug 31, 2017, 1:45 PM
1h 45m
Posters Area

Posters Area

Poster Presentation of 1h45m B1 - Superconducting Magnets for Fusion Thu-Af-Po4.02


Dr Hitoshi Tamura (National Institute for Fusion Science)


The system architecture of a fusion reactor demands an enhanced magnetic field and downsizing to improve plasma-confinement and reduce the difficulties in construction. Since an electromagnetic force induced by a magnet system is proportional to the square of the magnetic field intensity ratio, the stress on the magnet system can be extremely severe. For FFHR, a helical fusion reactor, several design options are being studied. For instance, FFHR-d1A is a steady-state self-ignition demonstration reactor that operates at a magnetic field intensity of 4.7 T; moreover, the helical coil’s major and minor radii in this type of reactor are 15.6 and 3.744 m, respectively. Furthermore, FFHR-c1 is a small-size reactor that aims to realize steady electrical self-sufficiency. It has a magnetic field intensity of 7.3 T and 0.7-times reduced major and minor radii as compared with those of FFHR-d1A. According to the latest structural analysis of the magnet system of FFHR-d1A, the maximum von Mises stress in the coil support structure was 764 MPa at a typical thickness of 250 mm. The coil support structure of the reduced-size FFHR-c1, including its thickness, needs modification, otherwise the stress level will exceed 1.8 GPa. Coil components such as the superconductor, sheath, and insulation also need a detailed structural-soundness evaluation. A nonlinear multiscale finite element method analysis was performed to facilitate a detailed investigation of the superconducting coils and their support structure. Consequently, robust designs of the helical coil and its support structure were demonstrated. Moreover, considering a contact and a slide among the component materials in the coil, mechanical behaviors of the components were evaluated.

Submitters Country Japan

Primary author

Dr Hitoshi Tamura (National Institute for Fusion Science)


Dr Takuya Goto (National Institute for Fusion Science) Prof. Nagato Yanagi (National Institute for Fusion Science) Prof. Junichi Miyazawa (National Institute for Fusion Science) Dr Teruya Tanaka (National Institute for Fusion Science) Prof. Akio Sagara (National Institute for Fusion Science) Dr Satoshi Ito (Tohoku University) Prof. Hidetoshi Hashizume (Tohoku University)

Presentation materials