| 摘要 |
PROBLEM TO BE SOLVED: To provide a superconducting magnet capable of appropriately cooling a radiation shield disposed inside a vacuum container of the superconducting magnet, and a magnetic resonance imaging apparatus using the same. SOLUTION: The superconducting magnet comprises a superconducting coil 33, a cooling means 34 for cooling the superconducting coil 33 at or below a prescribed temperature or lower, the vacuum container 36 whose inside is vacuum to store the superconducting coil 33, the radiation shield 35 disposed to surround the superconducting coil 33 between the superconducting coil 33 and the vacuum container 36 for preventing penetration of heat by the radiation from outside, and a refrigerator 39. Part or the whole of the radiation shield 35 is a container-structure. The radiation shield 35 is cooled by storing liquid nitrogen in the container, and as the radiation shield 35 is connected to a cooling part of the refrigerator 39, the vaporized nitrogen gas is cooled by the cooling part of the refrigerator 39 to be recondensed. COPYRIGHT: (C)2006,JPO&NCIPI |
