Fabrication and Characterization of BSCCO-2223 Tape Compact Coils

High Temperature Superconductor (HTS) magnets are potential candidates for the future fusion reactors and electrical industries due to its compact size and operational economy. A stainless steel (SS) laminated Bi-2223 HTS solenoid coil was fabricated and tested in liquid nitrogen. The coil is a stacked pair of double-pancakes with a soldered bridge joint. This coil was charged up to 2.1 kA with maximum current ramp rate per turn of 8.5 MA/s and generated axial magnetic field of 1.1 T at 77 K, self-field. The estimated axial magnetic field ramp rate of this coil is greater than 4 kT/s. This coil has inter-turn Kapton insulation. In order to study the effect of inter-turn electrical insulation on the current ramp rate, double pancake solenoid coils with and without inter-turn Kapton insulation of similar dimensions have also been fabricated and tested up to 10 K with a cryocooler. The differences in the current and voltage profiles during current ramp up and ramp down were observed for coils with and without electrical insulation. At an operating current of 440 A, and temperature of 10 K, the coils produced a 0.2 Tesla magnetic field. The inter-double pancake joint resistance of one of the coils with overlap length of 100 mm is measured around 58 n ohm at 10 K, self-field. The first coil was operated in pulsed mode for one millisecond without any thermal damage at 77 K. I-V characteristics for all three coils, joint resistance, and axial magnetic field measurement results and analysis will be reported in this paper.