Coupling current losses and time constants in multifilamentary BSCCO(2223) tapes with resistive barriers in external magnetic fields

Multifilamentary DCMB (dip coated mixed barriers) BSCCO tapes were improved with respect to thin and continuous barrier layers. We used different barrier materials like SrCO₃, SrZrO₃ and a mixture of both materials. Rutherford cable-like design of RBB (ring bundle barrier) tapes were improved by modifying the application of the central resistive core. The coupling current losses of the different tapes were measured in perpendicular and parallel external magnetic fields and the coupling current decay time constants were calculated. For tapes with a barrier of SrZrO₃ or a mixed barrier a time constant of 0.6 ms was obtained for a single tape in perpendicular fields and 12 μs for a stack of 4 tapes in parallel external fields, for tapes with a twist length of 10 mm. For the RBB tapes we calculated a coupling current decay time constant of 0.2 ms in perpendicular fields for a single tape with a twist length of 3.4 mm