3.3. The thermal efficiency of the 15 kA current leads for the many LHC superconducting magnets at CERN
round the 26 km ring was significantly improved. The final Southampton design of current lead provided a heat leak
of less than 1 W at 4.2 K, when carrying the full current of 15,000 A This design greatly reduced the total
refrigeration power required, and the associated major running cost, to an acceptable practical level.