Experiments for selective detection of magnetic dipoles using superconducting and ferromagnetic cylinders

The authors have studied the system, consisting of superconducting, 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 experiments using Bi-Sr-Ca-Cu-O based superconducting cylinder were carried out to confirm the effectiveness of the system. It may be possible to use the system for positioning of the dipoles. The system will be useful for non-destructive testing of metallic materials.