Nb/sub 3/Al strand processing, transport properties, and cabling

Abstract

Nb 3 Al strands with four different designs have been processed and tested. Strand specifications and some generic aspects of strand fabrication, processing, and testing are described. One strand type was long-length RHQT processed and transport tested at various lengths. Transport results for short samples and small solenoid coils are presented and discussed for various RHQT protocols. Critical current measurements on various strands have been performed in fields from 18 to 26 T. Various strand stabilization techniques have been investigated including electroplating, plasma spray coating, and direct Nb-Cu high temperature diffusion bonding; these results are described. Fifty meters of strand was RHQ processed and then cabled into a short length of experimental 12-strand Nb 3 Al Rutherford cable in preparation for transformation ( ) and testing. Cabling properties are described.

Development of Fine Multifilamentary ${\rm Nb}_{3}{\rm Al}$ Conductors

“…This value is 62% of the best non-Cu @15 T of the high type RRP (Restacked Rod Process) conductor [11]. If the matrix ratio of the RS conductor can be reduced down to 0.5, the non-Cu can further increase by 20% [19].…”

“…All the precursor wires were fabricated by a conventional jelly-roll (JR) technique at Hitachi Cable, Ltd. The RHQ process is described in detail elsewhere [8]- [11]. The wires were finally heat-treated at 800 for 10 h, with a rate of 160 up to 800…”

Strain Dependence of Critical Current for Nb₃Al Superconducting Wire Fabricated by Restacked RHQT Process

“…In the restacking process, metastable Nb-Al solid-solution phase multifilamentary strands, obtained by RHQ process, are restacked into a stabilizing Cu tube [13]. Details of the RHQ process were published elsewhere [5], [14]- [16]. The restacked wire, i.e., RHQ strands with Cu tube, is drawn to a final form.…”