Critical Current Distributions of BSCCO Tapes in the Multi-Layer HTS Conductors

AbstractWe have successfully constructed a 200 m high temperature superconducting (HTS) cable test facility for DC transmission in 2010. This coaxial power cable is composed of two superconducting (SC) conductors of DI-BSCCO tapes spirally surrounding a copper former. The tapes are arranged closely to make the magnetic field lines surrounding the cable uniformly. The number of tapes in each conductor is different because of their different radii. Previously, wehaveinvestigated the dependenceof critical current(Ic)onthegap betweenthe tapesin orderto optimizethe cable configuration for DC transmission.This paper report the investigation of Ic distributionsin the multi-layer conductors which consistof2,3and4tapes with a tape-on-tape structure by setting currents in each tape separately. The Ic measurement is performed with four probe method at 77K. The Ics of the tapes in the different structures are measured and compared with that of the single one. The enhancement and degradation of Ic are observed due to magnetic field interaction and magnetic shielding between the tapes in the multi-layer conductors. We will present the experimental results and show the dependence of the Ic distribution in the multi-layer conductors on the structures and transport currents in the neighboring tapes