| 摘要 |
PURPOSE:To improve insulating properties, and to enhance reliability by directly coupling a vessel housing an absorbent such as porous activated carbon with a vacuum vessel and cooling the vessel by liquid nitrogen. CONSTITUTION:A superconductive element 4 is housed into a vessel 6 for liquid nitrogen 5 and cooled, and the vessel 6 is further stored into a vacuum vessel 7 through a vacuum layer. The vacuum vessel 7 is connected to a vessel 10 being installed through a valve 9 and housing an absorbent 10a such as porous activated carbon, and the adsorbent 10a is stored into a liquid nitrogen vessel 11 mounted outside the vessel 10, and cooled at a temperature of approximately the boiling point of liquid nitrogen. Accordingly, even when a gas absorbed to the metallic surface of the vacuum vessel 7, etc., and the surface of an insulator is discharged into the vacuum vessel 7, the gas is absorbed physically to the absorbent 10a, thus maintaining the inside of the vacuum vessel 7 under the state of a high vacuum. |
