Square and round Bi(2223) wire configurations and their AC losses

摘要: Abstract In order to reduce the effect of field anisotropy, but also in view future cabling facilities, a series Bi(2 2 2 3) wires with various square and round configurations were prepared using combination two-axial rolling drawing. As previously reported, two-axis wire configuration, filaments being perpendicular or inclined each other, cannot lead an optimized texture for both directions, e.g. parallel tape surface: it gives average. result, even same precursor powders, values J c are inherently lower than those obtained on standard powder-in-tube tapes. SEM images show that particular care has be taken avoid distorted alignment certain local areas. The influence stresses their final studied systematically. critical current measurements as function magnetic showed filament configuration rotation symmetry exhibit most angle-insensitive behavior ( B ). Due expected relatively low values, 11 kA/cm 2 at 77 K zero field, measured wires. AC loss performed twist pitches down mm. results geometry twisting have positive losses.