| 摘要 |
PROBLEM TO BE SOLVED: To prevent the blockade of a helium gas exhaust pipe, and to quickly remove the blockade thereof. SOLUTION: A cryostat is provided with a supply pipe 11, which is installed along the pipe route of a helium gas exhaust gas pipe 10 communicated with air side of the outside of a vacuum vessel and can supply helium gas to at least the upstream side, in a direction of exhausting the helium gas out of the helium gas exhaust pipe 10. The supply pipe 11 is provided with a plurality of supply ports 11a-11d for feeding helium gas to the helium gas exhaust pipe 10 at a predetermined spacing in the direction of the pipe route, wherein differential pressure regulating valves 21a-21d are provided at the supply ports 11a-11d, and they are opened, when the differential pressure between the helium gas exhaust pipe 10 and the supply pipe 11 exceeds a predetermined value, and they feed the helium gas to the helium gas exhaust pipe 10 from the supply pipe 11. COPYRIGHT: (C)2009,JPO&INPIT |
