Studies on Superconducting Performance of Ultra-Fine Strand Nb 3 Al Cable Fabricated by React & Wind Method in Solenoid Coil

To improve the beam collision performance of SuperKEKB, installation of superconducting sextupole magnet in being considered. The main superconducting sextupole coils and three types of superconducting correction coils will be incorporated in this magnet. We are developing the correction coils using ultra-fine strand Nb3Al superconducting cables with strand diameters less than 50 μm fabricated by the React & Wind method. In this paper, we report the measurement results of the superconducting performance of Nb3Al cables of 0.6 to 0.8 m in length in the solenoid coils with radius of curvature from 15 mm to 25 mm.