Development of MgB2 Wires H. Fang and K. Salama Texas Center for Superconductivity and Advanced Materials University of Houston, Houston, TX 77204-5002 Texas Center for Superconductivity and Advanced Materials University of Houston NASA Commercial Space Center CSAM T

Fabrication Process (Powder-In-Tube) Texas Center for Superconductivity and Advanced Materials University of Houston NASA Commercial Space Center CSAM T Fabrication Process (Powder-In-Tube) Mg and B raw powder High-energy ball milling Ultra-fine Mg and B mixture precursor Filling precursor into 1020 iron tube Groove-rolling the powder-filled tube Square wire 1mm by 1mm Flat-rolling the square wire Tape 2.5 mm wide and 0.2 mm thick Annealing at 800 ~950 oC

Tape Morphology CSAM T Cross-sectional Longitudinal Texas Center for Superconductivity and Advanced Materials University of Houston NASA Commercial Space Center CSAM T Tape Morphology Cross-sectional Longitudinal

Critical Current Density ~ Field Texas Center for Superconductivity and Advanced Materials University of Houston NASA Commercial Space Center CSAM T Critical Current Density ~ Field T = 20 K T = 25 K T = 30 K

10-Meter Long Square Wire Texas Center for Superconductivity and Advanced Materials University of Houston NASA Commercial Space Center CSAM T 10-Meter Long Square Wire

Superconducting Coil CSAM T Texas Center for Superconductivity and Advanced Materials University of Houston NASA Commercial Space Center CSAM T Superconducting Coil The coil has an outer diameter of 12 mm and 12 turns.

Critical Current ~ Field of Coil Texas Center for Superconductivity and Advanced Materials University of Houston NASA Commercial Space Center CSAM T Critical Current ~ Field of Coil

Texas Center for Superconductivity and Advanced Materials University of Houston NASA Commercial Space Center CSAM T Conclusions Iron-clad MgB2 superconducting tapes and wires were fabricated using the standard powder-in-tube method. Nano-sized Mg and B mixture powder was used as starting precursor. Measurements on short length tape shows a Jc of 1.2 X 105 A/cm2 at 20 K and 1.5 Tesla. 10 meter long square wire with outer cross-section area 1 mm by 1 mm was manufactured. A coil wound from this wire shows a Ic of 160 A at 20 K and 1 Tesla.