Electrical characterization of REBCO Roebel cables

In the quest for high-current high-temperature superconducting (HTS) cables suitable for application to high-field magnets, the Roebel cable made from (RE)-Ba 2 Cu 3 O 7−δ (RE for rare earth: Y, Sm, Gd, Dy or a mixture of them) coated conductors is identified as meeting the requirements for high-current capability, compactness, transposition and good mechanical properties. In accelerator high-field magnets, Roebel cables will be operated in liquid helium at 4.2 K or lower temperatures. Previous papers have reported on the electrical characterization of Roebel cables at 77 K, but measurements at 4.2 K have not been published yet. This paper summarizes the results of the critical current measurements performed at CERN on (RE)-Ba 2 Cu 3 O 7−δ Roebel cables at 4.2 K and in external fields of up to 9.6 T.