AC Loss Evaluation of a 10T Class Small REBCO Coil With Conduction-Cooled Configuration

In order to use a coil wound with REBCO-coated conductor in a conduction cooling configuration, ac loss of the coil should be quantitatively predicted and designed under the operating conditions, for example during charging-up and -down, or shutdown operation. A tape-shaped REBCO-coated conductor is suited to be composed of a stack of single pancake coils for generating high magnetic field. Various researchers have measured and evaluated the ac loss of REBCO tape; however, there are few reports about the ac loss of the coil as measured at liquid nitrogen temperature. In this report, the ac loss of REBCO coil composed of a stack of 22 single pancakes with 50 mm in inner diameter, 132 mm in outer diameter, and 105 mm in height, generating 13.5T at 10 K, was measured by electrical method and evaluated with conduction cooling configuration. The experimental results were compared with the calculated results and discussed.