Magnetic Mapping - A Way to Test and Understand Current Flows in Thin and Bulk Superconductors
Nondestructive testing of superconducting blocks and thin films is a worth point in their development and their industrial production. The most intrinsic characteristic to be tested is the critical current, so is the maximum current can be carried in the superconducting state. The measurement of the current flowing through the samples could be done by direct transport experiments but this means using specific samples, and only the mean current may be found. Distribution of current density in the sample is more relevant because it yields the map of inhomogeneity of the samples, and its effect in the current density distribution. Magnetic measurements have been developed by Hall scanning and magneto-optical effect, allowing the mapping of the component of the magnetic field perpendicular to a surface of the sample created by the current distribution. By solving the inverse Biot-Savart problem a map of current densities can be obtained. We will present the status of the magnetic measurements obtained by exploring superconducting bulks and tapes magnetized by an external field and the magnetic map generated by the current carried through superconducting wires.
P. VINCENZINI and A. RIGAMONTI
X. Granados et al., "Magnetic Mapping - A Way to Test and Understand Current Flows in Thin and Bulk Superconductors", Advances in Science and Technology, Vol. 47, pp. 1-6, 2006