Estimation of performance of Nb3Sn CICC with thermal strain distribution

In the last few years, the critical temperature (TO of several ITER cable-in-conduit conductors (CICC) was determined by magnetization measurements at zero current. The distribution of the critical temperatures (T-c), caused by variation of strain in the Nb3Sn strands, was found to vary with the number of load cycles. A comparison with mechanical modelling requires the strain distribution, while the T-c distribution is sufficient to determine the CICC performance. The current sharing temperature (T-es) is calculated supposing that the measured distribution of T-c is representative of its variation along a single strand and that the current is uniformly distributed among the strands. The T-cs values, found for background and peak magnetic field, are compared with the results of the DC test in the SULTAN facility. The presented estimation techniques lead to an overestimation of T-es. The differences of the estimated and measured T-es values are discussed including the effect of different currentvoltage characteristics of single strands and CIC conductors.