The effect of transverse stress on the critical current of Nb/sub 3/Sn cable-in-conduit superconductors

The authors have investigated the effects of transverse stress on the critical current of Nb/sub 3/Sn Cable-In-Conduit Conductors (CICC). The sensitivity of the critical current (I/sub c/) to applied stress at 12 T has been determined for CICC's with helium void fractions (f/sub He/) in the range of 0.25 - 0.4. I/sub c/ has been found to be a function transverse stress with good correlation to single wire data up to stress levels of 50 MPa. At higher stress levels the CICC's show significantly higher degradation with transverse stress. No clear correlation has been found between the stress sensitivity of I/sub c/ and f/sub He/. The results fall into a broad band suggesting that geometric factors, such as wire position within the cable bundle, exert a strong influence on the I/sub c/ vs. stress dependence