| 摘要 |
LENGTH STABILIZED NB-Sn WIRE AND ANNEALING METHOD A method for contraction annealing niobium-tin wire is disclosed. An improved niobium-tin wire is provided by loosely winding the wire on a mandrel, or by coiling the wire on a circumferentially retractile mandrel, and contraction annealing the wire without reaction-forming substantial amounts of Nb3Sn. Such contraction annealing allows the wire to contract in length unconstrained thereby preventing the formation of internal tensile stresses in the wire and its surrounding insulation. Prevention of internal stresses in the wire greatly reduces the susceptibility of the wire to breakage, cracking, sintering, shorting, tin leakage, or substantial shifting of the wire from desired wrap positions when it is reaction annealed to form the brittle superconducting intermetallic compound Nb3Sn. |
