Strain influence on Jc behavior of Nb 3Sn multifilamentary strands fabricated by internal tin process for ITER

Abstract

Superconducting properties of Nb 3Sn strands are much affected by the strain state of strands. More attention is concentrated on the influence of axial strain and bending test on the performance of Nb 3Sn strands and cables for practical applications. J c values of Nb 3Sn strands fabricated by internal tin process were measured in the axial strain range from −0.8% (compressive) to +0.7% (tensile) at 4.2 K, 12 T for ITER use. The different strain sensitivity of J c to the strain state was elaborated for the strands. The degradation of the superconducting critical current density and the n-value due to strain effect were analyzed.