Properties and performance of high current density Sn-core process MF Nb<inf>3</inf>Sn

Abstract

Commercial production quantities of Sn-core-processed MF Nb <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> Sn have recently been manufactured and delivered. The 1.73 mm (0.068") diameter strand contains 721 02, 2 micron filaments and 49% stabilizing copper protected by a diffusion barrier. Critical current density in the filament bronze region can be optimized to exceed 2×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> amps/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at 10 Tesla 4.2 K and 3.7 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> amps/ cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at 14 Tesla 4.2 K. Critical current as a function of applied tensile strain has been measured at 14 Tesla 4.2 K on samples of this material drawn to 0.36 mm (0.014") diameter. The peak in the Jc-ε curve occurs at ε = 0.28% and Jc = 1.25 Jc <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</inf> .