Nb3Sn composites with submicrometer filaments

New fabrication techniques have been developed to produce a homogeneous array of very long - very thin filaments of Nb3Sn in a Cu matrix. With the use of chill casting and drawing techniques one can produce a superconducting composite wire 0.025 cm in diameter which has approximately 500,000 Nb3Sn filaments uniformly distributed across the cross section. Typically the filaments have a ribbon shape about 200Å thick and 4000Å wide. Critical currents based on the total area are greater than 10⁶A/cm²in zero field and greater than 10⁴A/cm²at 14 Tesla so the performance compares favorably with commercial tape or commercial multifilamentary wire. Special features of the material are the ease of fabrication, the low reaction temperatures (500&degC), strain tolerance, and the strength of the material.