Design and fabrication of high temperature superconducting field coils for a demonstration DC motor

The design, fabrication, and characterization of field coils for a DC motor operating at 77 K are described. The DC motor uses an iron core to impress the field from the stationary superconducting coils onto a conventional armature which is nominally at room temperature. The motor has a total mechanical power output of 25 W. The coils were fabricated from BSCCO ceramic superconductor using a react and wind process. Each coil was extensively characterized both in terms of the motor configuration and individually. The tests indicated that robust superconducting coils can be produced by using ceramic superconductors. The durability of these coils as illustrated by the testing of the motor showed that high-temperature superconductors have reached a level of performance to be considered for demonstration motors.>