Application of React-and-Wind Method to D-Shaped Test Coil Using the 20 kA Nb3A1 Conductor Developed for JT-60SC.

Using a 20 kA Nb3 Al cable-in-conduit (CIC) conductor, a two-turn fl-shaped test coil with a height of 2.0 m and a width of 1.8 m was fabricated by a react-and-wind (R&W) method. After heat treatment, the conductor was formed to the fl-shaped coil. Bending strain of the conductor is ±0.4% at critical current (I_c) test section. The I_c exceeded 31.4 kA at 7.3 T, 4.2 K. In spite of the stainless steel conduit, a critical current density (J_c) of 89% of the strand value was attained. The total strain of the fl-shaped test coil was about -0.57%, the same as the triplex-CIC sample fabricated by a W&R method, indicating that bending did not influence the 4. The 4 at 7.4 T, 5.6 K including the margin of 1 K exceeds the operational current Therefore, it was concluded that the R&W method is quite appropriate for the toroidal field coil of JT-60SC. [ABSTRACT FROM AUTHOR]