A conduction cooled superconducting magnet using high-T/sub c/ oxide current leads

We demonstrated a conduction cooled (Nb,Ti)/sub 3/Sn superconducting magnet system without liquid helium. The magnet system is mainly composed of (Nb,Ti)/sub 3/Sn superconducting coil, high-T/sub c/ oxide current leads, a GM cryocooler and a cryostat. The (Nb,Ti)/sub 3/Sn superconducting coil cooled by the second stage of the cryocooler is operated at 11 K in vacuum. The cylindrical (Bi,Pb)/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/ oxide current leads were cooled below 77 K by the cryocooler. This system generates a magnetic field of 4.6 T in a 38 mm room temperature bore at the operating current of 465 A. Two hours holding at the operating current of 400 A were performed.<
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