| 摘要 |
PURPOSE:To remove clogging in a helium introducing pipe due to air freezing with helium being stored, by providing a heater in the helium introducing pipe to a sample chamber, in a cryostat having a structure, wherein the sample can be replaced with the liquid helium being stored, and the liquid helium can be introduced from a storing chamber to the sample chamber. CONSTITUTION:In a cryostat 50, a sample chamber 1 is independently provided from a liquid helium storing chamber 2 and a vacuum heat insulating chamber 5. The sample can be replaced with liquid helium 3 being stored. The liquid helium, which cools the sample chamber 1, is introduced to the sample chamber 1 through a flow-rate regulating valve 7 and a liquid helium introducing pipe 8. In the introducing pipe 8, a helium introducing pipe heater 12 is provided. Even when air and moisture are mixed in the sample chamber 1 and frozen in the introducing pipe 8 when the sample is replaced and the introducing pipe is clogged, the frozen air and moisture are melted and removed by heating the heater 12 with the liquid helium 3 being stored. |
