Development of Fe-sheathed MgB/sub 2/ wires and tapes for electric power applications

Superconducting coils with different dimensions were manufactured via a wind-reaction process by using Fe-sheathed MgB/sub 2/ wires, which were fabricated using the powder-in-tube method and ultra-fine starting precursors. Very good grain connectivity as well as high core density was obtained in Fe-sheathed wires and tapes. At 20 K and self-field, the critical current of the coil with ID 12 mm and 12 turns is 360 A, which is equivalent to the J/sub c/ of 1.8/spl times/10/sup 5/ A/cm/sup 2/. At 6 Tesla external magnetic field and 4.2 K, the coil with ID 14 cm and 10 turns possesses the J/sub c/ of 1/spl times/10/sup 4/ A/cm/sup 2/. In-field current carrying capability of MgB/sub 2/ wires and tapes were further enhanced by Ti additive. These results demonstrate the potential of MgB/sub 2/ superconducting wires and tapes for large-scale applications.