Nb3Sn Powder-in-Tube Superconductor: Processing, Design Optimization and Properties

State of the art powder-in-tube niobium–tin superconductors

“…Development of pow der manufacturing processes [23] resulted in a successful 18 filament wire with filament diameters below 60 [im and a non Cu J c of 1258 Amm 2 , and an A15 layer J c of 4158 Amm 2 . Continued development [24] resulted in filaments below 50 jum. an optimized 19 filament binary wire with a non Cu J c of 1397 Amm 2 , and a prototype 78 filament ternary wire with a non Cu J c of 2151 Amm 2 .…”

“…Optimization of the A15 fraction can be achieved by increasing the Nb or Nb-alloy fraction at the manufacturing stage, by surrounding the filaments with a diffusion barrier [24], and by preventing the formation of large grain A15 [12]. The latter two optimizations have the -theoretical -potential to increase the non-Cu current density by about 65% [28,63].…”

Titanium Doped ${\hbox {Nb}}_{3}{\hbox {Sn}}$ Superconductor Fabricated by the Internal Tin Tube (ITT) Approach

“…The work also demonstrated ease of fabrication, long piece lengths, and the ability to obtain filament diameters as small as 20 m. Given these promising results, Supercon extended the ITT process to ternary A-15 materials. A significant improvement in was seen with the PIT process ( increase from 1400 to 2100 A/mm ) when the tube material was changed to Nb-7.5Ta alloy [2]. This alloy is effectively used to increase the upper critical field , and hence [3], [4].…”