Superconducting cable

The cables house 36 strands of superconducting wire, each strand being exactly 0.825 mm in diameter. Each strand houses 6300 superconducting filaments of Niobium-titanium (NbTi). Each filament is about 0.006 mm thick, i.e. 10 times thinner than a normal human hair.

Cable	Strand	Filaments

Around each filament there is a 0.0005 mm layer of high-purity copper. Based on physical measurements it is a Rutherford cable, 1.510 cm broad, the mid-thickness being 1.480 mm, tolerances are only a few micrometers.  Copper is an insulation material between the filaments in the superconductive state, when the temperature is below -263C. When leaving the superconductive state, copper acts as a conductor transferring the electric current and the heat. Niobium-titanium is an superconducting alloy. (c/o http://www.cus.cam.ac.uk/~bag10/LHC.html)

Or according to Furukawa Electric (we have two main suppliers of superconducting cable): This niobium-titanium superconducting cable is thirty six stranded and roll formed by special equipment and technology in a cuneal cross section with a width of 15.1 millimeters and an average thickness of 1.48 millimeter strands. Each strand contains 6,426 twisted niobium-titanium filaments with a diameter of 6-micrometers embedded in an oxygen free copper matrix.

Total superconducting cable required 1200 tonnes which translates to around 7600 km of cable (the cable is made up of strands which is made of filaments, total length of filaments is astronomical - 5 times to the sun and back with enough left over for a few trips to the moon).