Superconducting 180 kA NbTi cable

The cable for the GEM detector superconducting magnet consists of 450 strands, which have the ratio of Cu:nonCu equal to 3.6:1. The design of the strand is a very important factor: arrangement of filaments, content of copper in the central and peripheral parts of the strand, and the thickness of Nb barrier. The quality of NbTi alloy and route of heat treatment of the strand strongly effect on the breakage of filaments. Optimal regimes of treatment the 0.73 mm strand allow to attain Ic higher than 420 A in magnetic field 2 T at 0.1 /spl mu/V/cm. The necessary equipment for production of the cable with the length of more than 1 km have been chosen, probed and adjusted.<
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