Effect of stress on the critical current of Nb3Sn multifilamentary composite wire

摘要

A criticalhyphen;current study of flexible Nb3Sn multifilamentary composite wires has been conducted at 4 K in magnetic fields to 90 kOe (7.2times;106A/m) while the wire is subjected to high mechanical stresses. The results show that at stresses above 1ndash;2times;108Pa (strains of 0.1ndash;0.2percnt;) the critical current is significantly degraded, with the magnitude of the reduction dependent on reinforcement techniques used in the wirersquo;s construction. The effect increases with magnetic field and results in the introduction of significant resistance at current levels well below the zerohyphen;stress critical current. Design considerations for the use of Nb3Sn wires in the highhyphen;stress environments of largehyphen;scale superconducting magnets are discussed.