Ramp rate dependence of E–I characteristics in Bi2223/Ag HTS tapes Original Research Article

We have been studying the ramp rate dependence of the E–I characteristics under self-magnetic field in Bi2223/Ag HTS tapes at 77 K. In this paper, we have examined an experimental result and a numerical analysis. Experimentally, we applied about 70 A, which is about twice that of the Ic into Bi2223/Ag HTS tapes at ramp rates of 14 kA/s to 1.4 MA/s. When the ramp rate increases, the electric field of the E–I characteristics increases. The experimental results were compared to that of numerical analysis using finite element method. As a result, when the ramp rate increases, the transport current concentrates to the outer filaments. Therefore, the skin effect occurs for the higher ramp rate, and eddy current loss in Ag sheath increases.