Errors in measurement of current distribution in a superconducting tape

The paper reports on the role of the typical mapping errors in measurement of the lateral sheet current distribution Iy(x) in a superconducting tape. The sheet current is calculated indirectly, from the mapped data of the self magnetic field of the superconducting layer. The field is generated by transport or induced current in a tape. In model calculations examples of the influence of the different types of errors on false shaping of the lateral sheet current profile are given. The field mapping is made outside and over the tape. The lateral profile Bz(x, z) of the magnetic field component, perpendicular to the superconducting layer, is input to the Biot-Savart inverse procedure. In the experiment we have used superconducting tape as a sample and an InSb Hall probe with active surface 20 x 20 μm2 as a magnetic field sensor. We demonstrate the details, together with obstacles and errors encountered in measurement and subsequent evaluation. The demonstrations serve for the reader to be aware of limits in interpretation of the measured data and to overcome the natural barrier in understanding, insight and use of this fruitful method.