The distribution of magnetization and transport currents in DyBCO tape

Abstract

The results of Hall probe magnetic measurements in the vicinity of a DyBCO tape carrying transport or magnetization currents at 77 K were used in the inverse calculation to obtain the current distribution across the tape width. Two different methods of the inverse problem calculation were used and the results compared. The transport current applied in the absence of the external magnetic field was stepwise increased and the determined current distribution was compared with that predicted by Brandt and Indenbom. The predicted convex shape of the current distribution in the central tape section was proved. Contrary to the prediction, we have observed a drop of the current at the tape edges. This result supports the conclusions of the loss measurements in YBCO tapes [O. Tsukamoto, Supercond. Sci. Technol. 18 (5) (2005) 596]. We also mapped the magnetic field in the vicinity of the tape carrying induced magnetization currents in the absence of the transport current and determined the corresponding current distribution. Superposition of the self magnetic field and a homogeneous external magnetic field (36 mT) flattens the magnetization current distribution evidently.