Bi2212 Powder Production with Wide Tmax Window for High Field Magnet Applications

Recently, Bi2212 wires fabricated with high quality Bi2212 powders have achieved short-term champion engineering critical current density Je ~1.9 kA/mm2 at 4.2 K and 5 T. However, such superior performance does not pass on to the superconducting coils due to the strong sensitivity of Je on Tmax. A ~37.0 cm long racetrack coil shows less than 70% Je of the corresponding high performance Bi2212 wires1. This makes a great challenge for high field magnet applications, especially for large size accelerator magnets. The superconducting community has identified an urgent need to broad the Tmax window >10 C for 75% retention Je so as to fully utilize the high performance of Bi2212 wires. nGimat, teamed with Bruker OST, will demonstrate the feasibility to broaden Tmax window of high-quality Bi2Sr2CaCu2O8+ (Bi2212) powder using its proven NanoSpray Combustion process. In this proposal, we describe a detailed plan to widen the Tmax window of Bi2212 powder with high performance Je for corresponding wires above 1.0 kA/mm2 at 4.2 K and 20 T.