Method for selective detection of magnetic flux sources, using a system of superconductors, a ferromagnetic substance, and a magnetic sensor

The authors have studied a system, consisting of superconducting and ferromagnetic cylinders and a magnetic sensor, for selectively detecting a magnetic dipole parallel to the extension of the axis of the cylinders. The superconducting cylinder has an open slit in its side so that the magnetic fields from the dipole can be measured selectively according to its diamagnetic characteristics. The magnetic fields detected by the sensor are estimated with the aid of magnetostatic field analysis. It may be also possible to use the system for positioning of one dipole or two parallel dipoles. The system will be useful for non-destructive testing of metallic materials. (author)