Applied superconductivity and cryogenics for LHD

Large Helical Device of National Institute for Fusion Science is the first fully superconducting coil system as a large-scaled fusion experimental device. Although the superconducting applications have been progressed, there have been many R and D items for the world largest reliable and high performance superconducting coils remain to be developed. These R and D items are superconductor, coil windings, bus lines, and cryogenic systems. The experience for the research will help to construct other large scale superconducting coils. For realizing the fusion reactor, we have to develop higher performance superconducting materials, especially high field conductors, and high strength mechanical materials. (author)