Study of ${\rm Nb}_{3}{\rm Al}$ Wires for High-Field Accelerator Magnet Applications

Rapid heating, quenching and transformation (RHQT)-processed Nb
₃
Al wires possess better strain tolerance than Nb
₃
Sn wires. However, RHQT-processed Nb
₃
Al wires so far developed show lower non-copper critical current density (J
_c
) than recently developed high-J
_c
Nb
₃
Sn wires in the field range of 12-15 T. Therefore, the development of Nb
₃
Al wires having enhancing J
_c
in this field range is a major concern for accelerator magnet designers. Among a number of fabrication parameters that might affect J
_c
properties, we analysed the effect of thickness of Al and Nb foils in the jelly-roll-shaped filaments embedded in the precursor wires. Mechanical and superconducting properties of these wires with various Al-foil thicknesses in the filaments were investigated.