Strain dependence of the critical current density of Bi-2223 multifilament tape conductors

Measurements of the critical current density at 77 K as a function of bend strain (0-2%) are reported for Bi-2223 silver-sheathed tapes. The irreversible strain limit, epsilon(irr), for the onset of strain damage to the superconductor core, increases from 0.2-0.3% for monofilament tapes (similar to 75 mu m filament thickness) to values up to 1.5% for 49-filament tapes (similar to 5 mu m filament thickness).