Measurement of local currents in superconductors using an in-situ high field magneto-optical microscope

A contactless method is used to measure the local current density in superconductors at fields up to 7 T with a spatial resolution better than 1 {mu}m. The local currents are derived from magneto-optical images using a powerful inversion scheme. The interpretation of global experimental data on flux flow, flux creep and relaxation phenomena is hindered if the magnetic moment of the sample as a whole is measured, while the current flow in the sample is not uniform. This problem can be overcome by the local measurement of the currents flowing in the sample that is discussed below