Connectivity between filaments in BSCCO-2223 multi-filamentary tape

Technologically, the most advanced conductor utilising high temperature superconductors is the multifilamentary tape produced by the powder in tube method. Previous investigations have indicated that the filaments in these materials are strongly connected by superconducting paths. This connectivity is of particular importance in, amongst other things, governing the dissipation of the conductors when carrying AC currents or exposed to varying magnetic fields. In this paper we report direct measurements of the transverse (in contrast to the more usual longitudinal) current carrying capability. Measurements of electric field versus current ('E-I characteristics') for transverse and longitudinal transport currents as a function of applied magnetic field and temperature are reported. Our data indicates that the filaments are indeed strongly connected by superconducting paths but also that the E-I characteristics for the transverse and longitudinal connections are different.