Properties of internally stranded RBB (ring bundle barrier) low AC loss BSCCO tapes made by PITAR route

The novel RBB-BSCCO tape design resembling a Rutherford cable structure for low AC losses was improved with respect to the conductor geometry and the superconducting properties in combination with a low level of AC losses. The PITAR route (powder in tube assemble and react) allows economical preparation of a stranded conductor composite with techniques similar to standard BSCCO tapes. The advantage is a very effective twist application to the strands and low geometrical distortions to the filament cross sections. Data of the transport current anisotropy and current homogeneity (by MOI) for differently twisted conductors are presented. Transport currents up to 9 kAcm^-2 were achieved. Filament twist pitches down to 3.4 mm were realized and the achieved effective decoupling of the strands shifts the maximum of the AC losses in perpendicular external AC fields to frequency values above 500 Hz. This was the first time realization for a BSCCO conductor