The Current Distribution in Bi-2223/Ag HTS Conductors: Comparing Hall Probe and Magnetic Knife

We analyzed the current distribution in three Bi-2223/Ag tapes with different filament lay-out, comparing the results of magnetic knife and Hall probe experiments. Detailed knowledge of the current distribution can be useful for the diagnostics of HTS conductors. The lateral current distribution was measured with the non-destructive magnetic knife technique and used to calculate the corresponding magnetic field profile above the tape. These calculated profiles were then compared to those actually measured by a Hall probe. Additionally, the Hall probe data were also compared with “ideal” field profiles, assuming uniform current flow across the tapes. This assumption is often used in measurement interpretation. The Hall probe and magnetic knife data correspond very well, but deviate significantly from the ideal profiles. Further analysis of the current distribution shows that this deviation is mainly due to suppression of the critical current density at the tape edges.