AC LOSSES IN SILVER-CLAD HIGH T-C SUPERCONDUCTING TAPES

Superconductors in changing magnetic fields and/or carrying varying tr ansport currents exhibit energy losses. The study of these losses is o f importance in the technologically important silver clad tapes. We pr esent a brief review of the mechanisms of these losses, in both the su per-conductor and silver. We then describe the measurement technique w idely used in determining these losses as well as the potential proble ms with this technique. Illustrative loss data are presented for three types of BSCCO-2223 tape (mono-core, multi-filamentary and 'rod-in-tu be') carrying ac transport current. Data are also presented for tapes carrying ac transport current in the presence of applied ac and de mag netic fields, as would be found in a number of applications of these m aterials.