The gradient of potential from the current contact of a mono-core MgB2/Fe wire along the wire was monitored for various transport currents and external magnetic fields. It was found that the current transfer length was below 1cm for an applied external field of 5.2T and a critical current of 31.68A. The measured results were compared with those obtained by finite element analysis. The interval of resistivities for the MgB2/Fe interface reactive layer was estimated by finite element method analysis. The resistivity of this layer was more than 2 orders of magnitude higher than the Fe resistivity.

Current Transfer Length in MgB2/Fe Mono-Core Wire and Approximation of the Interface Layer Resistivity. T.Holúbek, P.Kovác, T.Melisek: Superconductor Science and Technology, 2005, 18, 1218-21