Study of 2D Residual Current Density Profiles of BSCCO and YBCO HTS Tapes by Means of 3D Hall Probe System

The residual current distribution in the high-temperature superconducting (HTS) tapes effects the operation of power cables, superconducting magnets, and other devices built using these tapes. This effect is crucial for the restarting procedure of the devices after either emergency or scheduled shutdown or after the short circuit. Furthermore, the current distribution along and across the HTS tape provides us with information on the quality of the tape performance. In this paper, we examine a two-dimensional (2D) residual current density distribution in different BSCCO and YBCO tapes by means of a three-dimensional Hall probe system after the emergency shutdown of the 100-A direct current. After the experimental measurement of the self-magnetic field near the tape inducted by residual current, the inverse problem solver, which aims at calculating the current density distribution throughout the tape, is applied. The results of the calculation show the strong asymmetry and vortex-like structure of the 2D residual current flow in the BSCCO tape, whereas the current flow in YBCO tapes has a tendency toward symmetry about the center of the HTS tape. The significant difference in shape and amplitude of the residual current density profiles is observed as well.