Feasibility Study of React-and-Wind Method for Helical Coils Wound from Cable-in-Conduit Conductors

Design study on react-and-wind method for helical coils wound from cable-in-conduit conductors has been carried out. In this concept, the conductor is wound after heat treatment with being pulled aside from a reel, that is, being twisted. Since the superconducting wires in the conduit are multi-stage twisted, the effect of twisting the conductor on the strain of the wires is considered to be small. Furthermore, if tension is added on the wires by twisting the conductor, the compressive strain due to thermal contraction of the wires is reduced, and the critical currents of CIC conductors can be increased with the react-and-wind method. In order to examine the effect of twisting the conductor on the strain of the wires, experimental study with a model CIC conductor has been carried out. The experimental results show that the tensile strain is added in the wire by twisting the conduit in the same direction as the wire twisting direction. (C) 2016 The Japan Society of Plasma Science and Nuclear Fusion Research