Fabrication and characteristics of tapes and test magnets made from Ag-Clad Bi-2223 superconductors

Pb sub 0 sub . sub 4 Bi sub 1 sub . sub 8 Sr sub 2 Ca sub 2 sub . sub 2 Cu sub 3 O sub x (Bi-2223) precursor powder is prepared by a solid-state reaction of carbonates and oxides of Pb, Bi, Sr, Ca, and Cu. The powder is then used to fabricate Ag-clad tapes by the powder-in-tube technique. Transport J sub c values > 4 times 10 sup 4 A/cm sup / 2 / at 77 K and 2 times 10 sup 5 A/cm sup 2 at 4.2 and 27 K are achieved in short tape samples. A test magnet is fabricated by stacking ten pancake coils, each containing three 16 m lengths of rolled tape, and testing it at 4.2, 27, and 77 K.