Cooling system which includes a cryogenic refrigerator and a condensed gas thermal interface

摘要

A cooling system includes a thermal interface between a refrigerator 4 and a cooled article 10. The article consists of a primary recondensing chamber 5 filled with a condensed gas, which can be located around the refrigerator and sealed. The refrigerator can be a cryogenic refrigerator removably attached to a cryostat 1, and the gas may be a cryogenic fluid which may form a pool of liquid 12 at the upper surface 10a of the cooled article. A secondary recondensing chamber 11 which includes a recondenser 11a may also be provided. The chamber may be fluidly isolated from the primary recondensing chamber but thermally coupled to it. The refrigerator has a cooling surface 9 which may be provided with fins to increase the effective cooling area. The arrangement may provide condensation of gases in adjoining recondensing chambers such that the refrigerator can be fluidly isolated from the gas and liquid within the cryostat. This provides ease of removal and replacement of the refrigerator without degrading the performance of the thermal interface between the refrigerator and the cryostat. The cryostat may be used for MRI magnet systems which incorporate thermal shields 2 and a vacuum jacket (3 fig 1).