| 摘要 |
PURPOSE:To effectively utilize the low temperature of the evaporated helium gas flowing in a neck pipe to suppress the heat intrusion to a liquid helium tank, and effectively reduce the helium evaporating quantity. CONSTITUTION:In a low temperature vessel such as a cryostats in which a neck pipe 14a extended from a liquid helium tank 14 for receiving a liquid helium is fixed to a vacuum vessel 20 for receiving the liquid helium tank 14, a heat insulating member 42 is provided in the neck pipe 14a, so that a vapor gas such as helium gas flows in a passage 45 formed between the outer circumferential surface of the heat insulating member 42 and the inner circumferential surface of the neck pipe 14a. |
