DEVELOPMENT OF SUPERCONDUCTING HIGH CURRENT DENSITY LARGE DIAMETER INTERNAL TIN (Nb_3Sn) WIRES

摘要

A class of large diameter internal tin wires have been developed which carry over 900 Amps at a wire diameter of 1.8 mm, 4.2 K, 14 T. Historically high current density (J_c (10T, 4.2K) > 2000 A/mm~2) internal tin wires have been limited to smaller wire diameters. We report critical current and magnetization results on a wire design tested from 1.8 mm to 0.5 mm diameter. At smaller wire diameters the Modified Jelly Roll ( MJR ) element size drops below 20 μm. The small MJR elements result in a small d_(eff) which has the potential to meet the ITER specification in a wire that has a J_c in excess of 1400 A/mm~2 at 12 T, 4.2K.