CURRENT LEAD FOR AC SUPERCONDUCTING DEVICE

摘要

PROBLEM TO BE SOLVED: To suppress the lowering of current-carrying capacity due to the generation of the differences of a current between a plurality of oxide superconducting conductors constituting low-temperature side leads to make it feasible to safely use them and further to prevent the increase of heat entry due to an AC magnetic field. SOLUTION: In a current lead which makes an AC current from an AC power source 18 flow into a superconducting coil 1 placed in a vacuum insulation container 14 and immersed in liquid helium 11, comprises a high-temperature side lead 6 and a low-temperature side lead 7 with a plurality of built-in oxide superconducting conductors, and is cooled by supplying liquid nitrogen to the lower end of the high-temperature side lead 6 from a lead cooling medium supply tube 19, an AC magnetic field shield 20 comprising cylindrical and electrically good conductive metal is provided in the periphery of the low-temperature side lead 7 to uniformize an AC magnetic field applied to the plurality of oxide superconducting conductors and further to reduce it.