First results of stress effects on I/sub c/ of Nb/sub 3/Al cable in conduit fusion superconductors

Abstract

The effect of axial strain, epsilon /sub a/, on the critical current, I/sub c/, of Nb/sub 3/Al cable-in-conduit subconductors has been measured for I/sub c/<or=10 kA and a magnetic field of 12 T. The conductor exhibits a maximum of I/sub c/ at epsilon /sub a/ approximately=0.7%, but the degradation of I/sub c/ at epsilon /sub a/=0 is only 20%, compared to 50% for Nb/sub 3/Sn cables. The I/sub c/ vs. epsilon /sub a/ characteristic is completely reversible under both loaded and unloaded conditions up to a measured strain of epsilon /sub a/=1.7%. The subconductor has been developed for fusion magnets.<<ETX>>