Transport properties of Bi-2212/Ag multifilamentary tape under a large electromagnetic stress state

Transport and mechanical properties of two Bi-2212 superconducting coils under a large hoop stress were measured. The coils were 11-turn R&W type double pancake coils with an outer diameter of 280 mm reinforced against electromagnetic stress by co-winding with an Ag-50%Cu or a Hastelloy X tape. They were measured in an external magnetic flux density of 10 T and liquid helium (4.2 K). Critical current of the coil with the Ag-50%Cu reinforcement tape was 240 A and its transport property was severely degraded by more than 0.4% deformation at I=388 A. The coil with the Hastelloy X tape with a critical current of 350 A, showed good performance against an electromagnetic stress of 262 MPa at I=500 A and could repress deformation of the coil to within 0.22%.