Critical Current Longitudinal and Transverse Strain Sensitivities of High JC Nb3Sn Conductors

TL;DR

This paper investigates how the critical current of Nb3Sn superconducting strands varies with longitudinal and transverse strains, providing essential data for designing high-field superconducting magnets.

Contribution

It introduces measurement apparatuses for IC versus strain and characterizes strain sensitivities of various Nb3Sn strands, including ITER high JC strands.

Findings

Different strands exhibit varying strain sensitivities.

IC irreversibility strains are identified for ITER strands.

Measurement techniques for IC strain dependence are demonstrated.

Abstract

Characterizing critical current IC of Nb3Sn strands as function of a strain is very important for large high field superconducting magnet applications such as the superconducting outsert coil of the series-connected hybrid at the NHMFL and the ITER magnets. Apparatuses for measuring IC versus longitudinal strain and transverse stress have been developed and used at the NHMFL. We have characterized the IC strain sensitivities of a few candidate strands for the series-connected-hybrid. In addition, IC irreversibility strains are measured for the recently developed ITER high JC strands. The different strain sensitivities for different strands are discussed.