| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a terminal structure which eliminates the generation of an evaporation gas due to the gasification of a refrigerant liquid and which prevents a drop in an insulating performance due to the gas by a method wherein the refrigerant liquid which cools a conductor derivation rod is pressurized by a gas whose boiling point is lower than that of the refrigerant liquid. SOLUTION: A gas pressurization device 13 is connected to a refrigerant gas layer 9, and a gas is supplied through the pressurization device 13 so as to pressurize a refrigerant liquid layer 8 which is used to cool a conductor derivation rod 2. As the gas which is used to pressurize the layer, a gas such as, e.g. helium, hydrogen, neon or the like, whose boiling point is lower than that of liquid nitrogen as a refrigerant liquid is used. In this manner, when the liquid nitrogen is pressurized by the gas, its boiling point is raised to about 84K from about 77K at atmospheric pressure when the pressure of the liquid nitrogen becomes two atmospheric pressure. Consequently, until the temperature of the liquid nitrogen reaches 85K, a vapor is not generated, and a gas is not generated. Thereby, it is possible to obtain a terminal part whose insulating performance is not lowered and whose reliability is high.</p> |
