| 摘要 |
PROBLEM TO BE SOLVED: To provide a cryogenic device that can cool an object to be cooled to a lower temperature by making the temperature of a refrigerant lower than the condensation temperature in a refrigerant container in a device to be cooled, such as a superconducting magnet. SOLUTION: In this cryogenic device, very-low-temperature liquid nitrogen 5 is generated in a liquid nitrogen container 4 by condensing and liquefying a nitrogen gas by means of a condensing heat exchanger 9. The liquid nitrogen 5 is supplied to a condenser tube 8 through a liquid nitrogen supply pipeline 11 after the nitrogen 5 is cooled to a temperature which is lower than the condensation temperature of the nitrogen gas by 5-10 K by means of a supercooling heat exchanger 10. By using this liquid nitrogen 5, the radiation shield plate 7 of the superconducting magnet is cooled to a temperature which is lower than the conventional example by 5-10 K. Thereafter, the nitrogen gas produced in the condenser tube 8 is returned to the upper-layer space section of the liquid nitrogen container 4 through an evaporative emission exhaust pipe 12. |
