Experimental parameter study of subsize Nb3Sn cable-in-conduit conductors

An experimental study of the influence of design parameters on the short sample critical current of Nb3Sn cable-in-conduit conductors at 4.2 K is presented. These internally cooled and cabled superconductors (ICCS) are subsized versions of the conductor used in both the Westinghouse Large Coil and 12 Tesla Programs. Parameters investigated are cable compaction, conduit material, twist pitch and activation time and temperature. The results indicate that mechanical coupling between the conduit and cable has a strong effect on the residual strain of the Nb3Sn and hence its superconducting properties.