Development of a 5.1 T conduction-cooled YBCO coil composed of a stack of 12 single pancakes

We fabricated and tested a 5 T-class conduction-cooled high-temperature superconducting (HTS) coil composed of a stack of 12 single pancake coils wound with YBCO-coated conductors. The length of each single pancake coil was 25 m, and the inner diameter of the coil was 50 mm. The voltage–current characteristics were measured in liquid nitrogen and under conduction-cooled conditions at 10–60 K. At 10 K, the central magnetic field of the 12 stacked pancake coils was as high as 5.1 T at 305 A. We also tested the coil operation in a 4 T background magnetic field.

► We confirmed that performance of YBCO coil was improved by using APC wire.
► We made a conduction-cooled YBCO coil composed of a stack of 12 single pancakes.
► The coil had a central magnetic field as high as 5.1 T at 10 K.
► We also tested the coil operation in a 4 T background magnetic field.