Speaker
Description
Bi:2212 is a well-known high current superconductor which can be made in round wire form. It has usually been of interest for DC or low ramp applications because of both filament bridging and also a high Ag content which encourages large coupling and eddy current losses. However, a new low loss Bi:2212 has been under development which both attempts to suppress the bridging as well as eddy and coupling currents. One potential application of these new conductors is in electric propulsion motors for electric aircraft. The loss limits for this application are, however, stringent, and the required testing regime is challenging – 20 K, high frequency and moderate magnetic field amplitude. Here we present loss measurements performed in OSU’s cryo-test facility. A coil was wound with the new conductors cabled into the form of a small, flat, Rutherford-like cable, and a racetrack coil was made, instrumented, and cooled down and measured in our device. The racetrack coil was tested in a 1.5 m ID conduction cooled cryostat where a calibrated cryocooler lift was used to measure the AC losses in the coil. Here we present various DC properties such as Ic vs T as well as self-field AC loss properties by exciting the coil up to 50 Arms and 1 kHz. The electromagnetic fields simulated in FEM are used in analyzing the AC loss behavior of the coil.
This work was performed under NASA Phase 1 SBIR
