Method for decoupling a silver sheathed filament in a multifilament Htc superconductor wire and such a multifilament wire

摘要

In a multi-filament high temperature superconductor (HTSC) wire, in which the wire and each filament has a square or rectangular cross-section and in which each filament comprises a HTSC ceramic core in an Ag sheath, an electrically insulating layer is provided on one or more of the Ag sheath faces. Also claimed is a powder-in-tube process for producing the above wire, involving (a) filling a silver sleeve (1) with HTSC precursor powders (2) and then drawing to a single wire (4) of square or rectangular cross-section; (b) cutting the wire into lengths and filling (91) a second silver sleeve (7) of square or rectangular cross-section with the cut lengths (8'); (c) drawing (92) the resulting multi-filament billet (6) to a multi-filament wire (9) of square or rectangular cross-section; (d) repeating steps (b) and (c); and (e) shaping (100) and heat treating (101) the multi-filament wire (50). The novelty is that one or more faces (15) of the single wire (4) are electrically insulated (95) prior to step (b).