| 摘要 |
PURPOSE:To reduce the amount of radiation heat intruding into a helium container as well as to effectively reduce the temperature of the titled heat insulating container by a method wherein a radiation shielding cover is directly attached to the external circumference of the penetrated part of a supply pipe or an exhaust pipe. CONSTITUTION:A radiation shielding cover 4b is directly welded or silver- soldered on the outer circumference of the penetrated part of a supply tube 7. Liquid nitrogen is supplied through the supply pipe 7, and the entire helium container is cooled. As the radiation shielding cover 4b is directly attached, the entire container is cooled with excellent efficiency and the temperature falls down to that of the liquid nitrogen, thereby enabling to reduce the amount of radiation heat intruding into the helium container. Also, as the radiation shielding cover can be installed when a single unit fixing flange is assembled, the assembling to the entire heat-insulating container can be performed easily. |
