EFFECT OF MAGNETIC FIELD DIRECTION ON THE CRITICAL CURRENT OF TWISTED MULTIFILAMENTARY SUPERCONDUCTING WIRES

摘要

Critical currents of a twisted Nb_3Sn multifilamentary superconducting wire are investigated in longitudinal, transverse and intermediate-angled fields. The critical current in a longitudinal field may be as much as 2.6 times that in a transverse field. It was found that the reciprocal of the critical currents normalized by the critical current of the transverse field gives a linear equation of the sine of the angle between the field and the superconductor. The actual angle between the field and the superconductor may require a correction of the twist for a wire with a large twist angle.