GdBCO and YBCO long coated conductors and coils

Abstract

We developed long coated conductors and a coil of GdBa2Cu3O7−x (GdBCO). The GdBCO coated conductor exhibited higher critical current density (Jc) in a magnetic field property than that of the YBa2Cu3O7−x (YBCO) coated conductor. The GdBCO coil was wound using a 53.5m long GdBCO coated conductor. The coil was a 4 turn-83 layered solenoid with a bore diameter of 28.0mm, inner diameter of 30.0mm, outer diameter of 70.9mm, and height of 44.3mm. The coil was successfully energized to a current of 74.2A at 77K in a liquid nitrogen experiment, and 895A at 4.2K in a liquid helium experiment. Then, the generated central magnetic fields (B0) were 0.48T, and 5.68T, respectively. Thus, high current operation and high magnetic field generation were first occurred for a coated conductor coil. The maximum hoop stress of the coated conductor in the coil was 67MPa in the liquid helium experiment. In terms of 0.2% proof strength of coated conductors, the tolerable stress for GdBCO conductors can be increased. The GdBCO coated conductor is promising for magnetic field application.