Influence of Axial Strain and Transverse Compressive Load on Critical Current of Nb3Sn Wires for the FCC

S C Hopkins,M Nakamoto,T Ogitsu,S Awaji,M Sugano,M Dhakarwal,S Kawashima,A Ballarino,G Nishijima

doi:10.1109/tasc.2023.3242919

Abstract

Nb 3 Sn superconducting wires are under consideration for producing high field accelerator magnets for the proposed Future Circular Collider (FCC) due to their high critical field. R&D studies are ongoing worldwide with a target non-Cu critical current density ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Jc ) of 1500 A/mm 2 at 4.2 K, 16 T. As an accomplishment of this R&D, one of the conductor manufacturers, JASTEC, has developed Nb 3 Sn wires with non-Cu <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Jc higher than 1100 A/mm 2 at 16 T, 4.2 K by a distributed-tin (DT) method. In high field Nb 3 Sn magnets, degradation of performance has been frequently reported due to the brittleness of Nb 3 Sn and the high electromagnetic force. To realize more robust Nb 3 Sn accelerator magnets, electro-mechanical properties of the conductors should be deeply understood. In this study, the variation of the critical current with mechanical loading is evaluated for a DT Nb 3 Sn wire in two configurations, i.e. under axial strain and under transverse compression.

Full Text