Studies of ${\rm Nb}_{3}{\rm Sn}$ Strands Based on the Restacked-Rod Process for High Field Accelerator Magnets

A major thrust in Fermilab's accelerator magnet R&D program is the development of wires which meet target requirements for high field magnets, such as high critical current density, low effective filament size, and the capability to withstand the cabling process. The performance of a number of strands with 150/169 restack design produced by Oxford Superconducting Technology using the Restacked-Rod Process was studied for round and deformed wires. To optimize the maximum plastic strain, finite element modeling was also used as an aid in the design. Results of mechanical, transport and metallographic analyses are presented for round and deformed wires.