PANCAKE COILS MADE FROM BI-2223 AG TAPES

Small double pancake coils with a 15 mm bore were fabricated from Ag s heathed multifilamentary Bi-2223 tapes by the 'wind and react' techniq ue. The electric insulation between the turns consists of an alumina s creen print paste. In a double pancake coil with a total tape length o f 73 m, a magnetic field of 1.34 T was generated at liquid helium temp erature. The technique for the fabrication of the test coils was optim ized in order to achieve the critical current density of the tapes in the coils. The critical current in different sections of the coils was controlled by electric field vs. current measurements. Correlations b etween the filament structure of the tapes and critical bending diamet er of the tapes in the coil are discussed. (C) 1998 Elsevier Science L td. All rights reserved.