Patent ID: 7503181

Claim:
A cryostat configuration containing a cryogenic fluid, the configuration comprising: an outer shell; a cryogenic container disposed within said outer shell and holding the cryogenic fluid; at least two suspension tubes connected between said cryogenic container and said outer shell; a neck tube, said neck tube having an warm upper end connected to said outer shell and a cold lower end connected to said cryogenic container; a multi-stage cryogenic cooler, said cryogenic cooler having a cold head installed within said neck tube, wherein said outer shell, said cryogenic container, said suspension tubes, and said neck tube delimit an evacuated space; at least one radiation shield surrounding said cryogenic container and connected to said suspension tubes and optionally to said neck tube in a thermally conducting fashion; and a seal, which can be manually and/or automatically activated to separate said cold end of said neck tube from said cryogenic container, thereby minimizing or completely interrupting fluid flow between said cryogenic container and said neck tube, wherein said seal has a working position that permits fluid flow and a working position that stops fluid flow.