| 摘要 |
PURPOSE:To improve heat insulation by covering surfaces which face any of vacuums of an inner tank, a radiation shield and a vacuum tank with high temperature superconductor film. CONSTITUTION:The outer surface of an inner tank 2 for storing liquid helium 1 is surrounded by a vacuum tank 3 for holding high vacuum for heat insulation, and the outer and inner shells 4 and 5 of radiation shield for intercepting radia tion heat from the tank 3 to the tank 2 are interposed. Liquid nitrogen LN26 cools the radiation shields 4, 5. A multilayer heat-insulating material 8 is filled in a vacuum space 7. A foil 9 of yttrium oxide superconductor is bonded to the outer surfaces of the tank 2 and the shield 5. The superconductor 9 is a high temperature superconductor whose critical temperature is the temperature of liquid nitrogen temperature or higher, and has approx. 1 of infrared ray reflectivity. |
