Fabrication and transport properties of MgB/sub 2//(SUS316/Cu) multifilament wires

100-m long MgB/sub 2/ multifilament wires with stainless steel (SUS316)/Cu double sheath were successfully fabricated using a PIT method. No heat treatment was carried out during the processing. The J/sub c/ of the MgB/sub 2//(SUS316/Cu) multifilament wires reached 3700 A/mm/sup 2/ at 4.2 K and 0 T, and up to 1000 A/mm/sup 2/ at 1 T, an increase of 40% over conventional mono-core MgB/sub 2//(SUS316/Cu) tapes. The relationship between transport J/sub c/ and Vickers hardness (HV) for MgB/sub 2//(SUS316/Cu) wires with various wire diameters was investigated. The results suggest that a high-density superconductor core was possible for small filament size. The multifilament structure and densification of MgB/sub 2/ core were found to be effective in improving the transport properties of MgB/sub 2/ wires.