Monofilamentary wires with a mechanically reinforced composite sheath of Ta(Nb)/Cu/steel were prepared. This led to dense filaments and JC values of up to 105A/cm2 at 4.2K under self-field. The reproducibility of the measured transport currents was excellent and did not depend upon the wire diameter. By using different precursors, commercial reacted powder or an unreacted Mg/B powder mixture, a strong influence upon the pinning behavior and irreversibility field was observed. The critical transport current density exhibited an almost linear temperature dependence for all wires; being 52kA/cm2 at 20K and 23kA/cm2 at 30K.

High Transport Currents in Mechanically Reinforced MgB2 Wires. W.Goldacker, S.I.Schlachter, S.Zimmer, H.Reiner: Superconductor Science and Technology, 2001, 14, 787-93