Critical currents in long-length YBCO-coated conductors

Recent progress in developing large-area HTS-coated stainless-steel (SS) tapes is reported. YBCO films have been grown on IBAD-YSZ buffered 0.1 m-m-thick SS foils using a high-rate pulsed laser deposition technique which allows an increase of the deposition rate to 40 nm m(2) h(-1). YBCO-coated SS tapes containing a shunt layer, with a length up to 5.5 m, have been manufactured and tested. A model treatment was performed to describe an interchange of current between the shunt layer and the YBCO film. The optimal parameters of the shunt layer have been employed to reduce the resistive loss in the coated tapes. The critical dc current of more than 105 A was observed in a 2 m-long and 10 mm-wide coated tape.