Method and apparatus for controlling temperature in a cryocooled cryostat using static and moving gas

A cryostat apparatus for regulating temperatures, the apparatus comprising:

• an outer shell having an interior and having a top with an outer surface, the outer surface of said outer shell top being at ambient temperature,
• at least one refrigerated component within the cryostat, said at least one refrigerated component requiring cooling selectively with variable heat loads and operating temperatures;
• a cryogenic cooler with at least one reduced-temperature stage;
• a cryogenic cooler chamber containing said at least one reduced-temperature stage of the cryogenic cooler;
• at least one ambient-temperature coolant gas inlet port penetrating said cryogenic cooler chamber;
• means for connecting the cryostat apparatus to a source of ambient temperature coolant gas;
• a main gas inlet conduit for connecting said source of ambient temperature coolant gas to said ambient temperature coolant gas inlet port, said at least one ambient-temperature coolant gas inlet port being at ambient temperature;
• at least two siphoning ports comprising a first siphoning port and a second siphoning port, in fluid communication with the cryogenic cooler chamber, said first siphoning port being arranged to remove refrigerated coolant from said cryogenic cooler chamber in gas form and said second siphoning port being arranged to remove refrigerated coolant from said cryogenic cooler chamber in liquefied form, the refrigerated coolant having been cooled from ambient temperature by thermal exchange with said at least one reduced-temperature stage of said cryogenic cooler;
• a first coolant conduit and a separate second coolant conduit connecting said first and second siphoning ports, respectively, to said at least one refrigerated component, the first and second coolant conduits being separate and distinct from each other;
• and
• at least one cryostat exit extending from said at least one refrigerated component to outside the cryostat and configured to flow coolant out of the cryostat after providing cooling to said at least one refrigerated component,
• a first ambient temperature flow control valve located external to said outer shell;
• a counter-flow heat exchanger in fluid communication with said first coolant conduit and arranged to warm said refrigerated coolant to ambient temperature wherein said refrigerated coolant passes through said first ambient temperature flow control valve and is then cooled back down by the thermal action of the counter-flow heat exchanger and is subsequently delivered to said at least one refrigerated component, wherein said at least one refrigerated component comprises a sample chamber for measurement of or preparation of a laboratory specimen;
• said counter-flow heat exchanger and said first ambient temperature flow control valve being configured to control the flow of said refrigerated coolant to said thermal environmental chamber.