| 摘要 |
PURPOSE: To improve the reliability of a cryogenic refrigerator by moving a cryogenic refrigerating means on an attachment means, attaching at least one of the two cryogenic refrigerating means, so as not to be practically in contact with a magnet and providing an adjustment means for moving at least one cryogenic refrigerating means. CONSTITUTION: This cryogenic refrigerator is constituted of the two cryogenic refrigerating devices 4 and 6, housed in this cryogenic refrigerating apparatus 2 for bringing one cryogenic refrigerating device 4 into contact with a superconducting magnet 3 to be cooled and holding the other cryogenic refrigerating device 6 at a standby position. When the first cryogenic refrigerating device 4 becomes functionally insufficient, a set of screw jacks 28 for the second cryogenic refrigerating device 6 is operated by an operator, the second cryogenic refrigerating device 6 is lowered and brought into contact with the magnet 3 and the cooling of the magnet is continued. Then, the operator operates the screw jacks 28 for the first cryogenic refrigerating device 4, elevates the cryogenic refrigerating device, disposes it at the standby position and repairs, maintains, or exchanges it. Thus, reliability and economical efficiency are improved and repair and exchange are facilitated. |
