Magnetic characterization of welded YBaCuO-bulk samples

The welding of individually grown pieces of high temperature superconductor bulk material is the most promising way to obtain larger single domain tiles which are required for cryomagnetic applications. In this paper we present a method for the characterization of this kind of material. The method is based on the inductive measurement of the total current in ring samples using a Rogowski coil and an integrator circuit. The advantage of this technique is that it allows a direct measurement of the current crossing the artificial grain boundary without being influenced by the intergrain current and is independent of the sample size and geometry. We present the principle of the measurement and the calibrations of the system. The independence of the output signal on intragrain currents is demonstrated. The application of the method for the characterization of a welded sample is shown.