Transverse stress effect on the critical current of jelly-roll multifilamentary Nb3Al wires

Abstract

Experiments were conducted to determine the transverse stress sensitivity of the critical current (Ic) of jelly-roll multifilamentary Nb3Al wires at 8 and 12 T. For comparison, similar experiments were conducted on bronze-process (NbTi)3Sn wires. At 12 T and under a transverse compressive stress of 150 MPa−conditions expected in fusion magnets−the Ic degradation of the Nb3Al specimen was ∼20% vs ∼65% for the (NbTi)3Sn specimen. The intrinsic superiority of Nb3Al over (NbTi)3Sn with regard to transverse compressive stress is thus clear. There is optimism that Nb3Al will eventually become a useful superconductor for large-scale, high-field applications.