| 摘要 |
PURPOSE:To form a magnetic field having a magnetic flux perpendicular to the surface of material to be inspected efficiently inside an object being inspected, by providing a superconductor sandwiched by ferromagnetic bodies between all of magnet segments. CONSTITUTION:Ferromagnetic bodies 5a, 5b'-5x and 5x' sandwiching super conductors 6a-6x are arranged between magnet segments 2a-2y so arrayed with adjacent poles opposite to each other. Then, a coil is wound. Magnetic fields lj and lk generated with the magnet segments 2j and 2k are led to ferro magnetic bodies 5j and 5j' to facilitate the formation thereof. Moreover, the magnetic fields are shielded from each other by the action of diamagnetism of a superconductor 6j. This enables effective generation of a magnetic flux perpendicular to the surface of the object 4 being inspected. |
