Characterisation of a high-T/sub c/ coil using short sample data

Characteristics of a circular superconducting coil made with BSCCO-2223/Ag tape depend on the amplitude and direction of the magnetic field in the windings. The effect can be estimated by studying a short sample of the same tape. However, the loss voltage-current and the frequency characteristics of a coil deviate considerably from those that are measured on a short sample. In order to estimate the deviation, the authors compared measured characteristics of a few small coils employing up to /spl sim/10 m of tape with those calculated from the short samples data. The comparison includes several arrangements of coils and field shaping elements around the coil edges and is performed in the frequency and temperature range typical for power applications (1-100 Hz and 64-78 K respectively). The results are applied to the design of a 100 kVA-50 Hz resonator coil with a high quality factor.