| 摘要 |
PURPOSE:To obtain an apparatus characterized by few amount of useless evaporation of refrigerant, by providing a shielding body, which shields radiant heat intruded through a pipe, at an opening part in a refrigerant tank, thereby preventing the intruded heat from the pipe from directly reaching to the refrigerant. CONSTITUTION:A shielding body 9 covers the opening part of a pressure release pipe 8a and is fixed to the inner wall of a helium tank 3. Said shielding body comprises a flat plate part 9a, which receives radiant heat directly, and a cylinder part 9b, which supports the plate part. An opening 9c, through which helium gas freely passes, is provided in the side surface of said cylinder part. The surface of the flat plate part 9a, which receives the radiant heat, is finished in a mirror surface state. The radiant heat intruded through the pressure release pipe 8a is shielded by the flat plate part 9a. In this superconductive device, the shielding body 9 is located in the atmosphere of helium vapor. Said helium vapor absorbs the intruded heat, which is shielded by the shielding body 9, and is exhausted through a recovery pipe 8c. Since the surface of the flat plate part 9a of the shielding body is finished in the mirror surface state, the radiant heat is reflected by the flat plate part, and the heat capacity of the heat intruded in a cryogenic part can be decreased to a large extent. |
