Examination of current limiting mechanisms in monocore Bi/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub x/ tape with high critical current density

Magneto-optical imaging, electromagnetic measurements and SEM have been used for the characterization of a monocore BSCCO tape made by oxide powder-in-tube process which had a transport J/sub c/ (77 K, 0 T) of 37 kA/cm/sup 2/. Our study evaluates the connectivity between superconducting grains and reconstructs the local current distribution at <10 /spl mu/m scale. Some local regions are found to carry up to 180 kA/cm/sup 2/ at 77 K, a new record for BSCCO wires.