| 摘要 |
Apparatus and method of thermally disconnecting a cryogenic vessel 2 of a cryostat 1 from a refrigerator 7, e.g. during transportation of the cryostat 1. The cryogenic vessel 2 is connected to the refrigerator 7 by means of an input channel 17 and an output channel 18, wherein the input channel 17 and the output channel 18 are adapted to provide a loop system for a convection circulation of cryogen through the refrigerator 7. Thermal isolation of the refrigerator and cryogenic vessel is achieved by preventing the circulation of cryogen. Prevention of circulation may be achieved by way of a valve 25 or the creation of a stratified column of gas within the inlet and outlet. Where a valve 25 is used the valve is preferably closed automatically when the refrigerator is not operating. The refrigerator may be a two-stage refrigerator. The inlet and outlet channels are preferably arranged to have equalised gas pressures at either end. |
