Self-field effects in NbTi subsize cable-in-conduit conductors

In the framework of the conductor optimisation task (CONDOPT) five NbTi subsize cable-in-conduit conductors with parametric variations were fabricated. The DC performance of these conductors tested in the SULTAN test facility [IEEE Trans. Appl. Supercond. 12 (2002) 520] and the strand properties including the voltage-current characteristic, are compared. The results clearly indicate that the current carrying capacity of the conductors is considerably reduced due to the self-field. In conductors with a hindered interstrand current sharing, the critical current has been found to be even below the predicted value at the peak field, suggesting an uneven current distribution among the strands