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. Wt used different barr ier materials like SrCO3, SrZrO3 and a mixture of both materials. Rutherfor d cable-like design of RBB (ring bundle barrier) tapes were improved by mod ifying the application of the central resistive core. The coupling current losses of the different tapes were measured in perpendicular and parallel e xternal magnetic fields and the coupling current decay time constants were calculated. For tapes with a barrier of SrZrO3 or a mixed barrier a time co nstant of 0.6 ms was obtained for a single tape in perpendicular fields and 12 mus for a stack of 4 tapes in parallel external fields, for taper 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 wi th a twist length of 3.4 mm.