FABRICATION AND CHARACTERISTICS OF TAPES AND TEST MAGNETS MADE FROM AG-CLAD BI-2223 SUPERCONDUCTORS

Pb0.4Bi1.8Sr2Ca2.2Cu3Ox (Bi-2223) precursor powder was prepared by a s olid-state reaction of carbonates and oxides of lead, bismuth, stronti um, calcium, and copper, and the powder was then used to fabricate sil ver-clad tapes by the powder-in-tube technique. Transport critical cur rent density (J(c)) values >4 x 10(4) A/cm(2) at 77K and 2 x 10(5) A/c m(2) at 4.2 and 27K have been achieved in short tape samples. Long len gths of tape were tested by winding them into pancake coils. Recently, we fabricated a test magnet by stacking ten pancake coils, each conta ining three 16 m lengths of rolled tape, and tested it at 4.2, 27, and 77K. A maximum generated field of 2.6 T was measured in zero applied field at 4.2K and the test magnet generated significant self-field in background fields up to 20 T. The results are discussed in this paper.