Electromagnetic Stress Properties of Gd123 Monolayer Coils

This study investigates superconducting and mechanical properties of monolayer GdBa2Cu3Oy-coated conductor coils under large electromagnetic stress. We found that reversible superconducting properties can be achieved in the large hoop stress/strain states up to 1288 MPa/0.63% for the Hastelloy-outside-winding coil (coil A). This limit is larger than the results for the tensile test of the short sample. However, damage occurred near the current terminal at 640 MPa for the Hastelloy-inside-winding coil (coil B). It is considered that the degradation was due to the stress concentration at the edge of the current terminal. In the case of the Hasetelloy-inside-winding coil with a lap joint (coil C), the coil performance is limited by the shear stress of the lap joint.