| 摘要 |
PURPOSE:To obtain a magnetic field stabilizer effective for keeping a constant magnetic field by arranging a sheet type or cylinder type molded body in a magnetic field generating apparatus capable of changing the magnetic field intensity, which body contains the following as a constitutional member; superconductor shifting to a mixed state when exposed to magnetic field whose intensity is larger than or equal to the maximum value of magnetic shield. CONSTITUTION:Current applying leads 21, 21 are led out from a superconducting magnet 2 in a low temperature vessel 1, and a molded body 3 is arranged in the inner space of the vessel. The low temperature vessel 1 is constituted of an inner vacuum layer 11 and an outer vacuum layer 11; the part between the vacuum layers 11, 11 is filled with liquid nitrogen 4; the low temperature vessel 1 is filled with liquid helium 5; the superconducting magnet 2 and the molded body 3 are kept in a superconducting state. By applying a current to the superconducting magnet 2, the magnetic field intensity is increased until the molded body 3 turns to a mixed state. In this state, the intensity of environmental magnetic field is slightly decreased, and the inner space of the molded body 3 is put in a region where constant magnetic field is kept. Thereby the inner space can be kept in an extremely stabilized constant magnetic field. |
