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A cryostat for providing temperature regulation, one purpose being measuring physical properties of materials, the cryostat employing a superconducting magnet assembly for generating variable magnetic field in the sample space and a cryogenic cooler for cooling the sample space. The cryogenic cooler

A cryostat for providing temperature regulation, one purpose being measuring physical properties of materials, the cryostat employing a superconducting magnet assembly for generating variable magnetic field in the sample space and a cryogenic cooler for cooling the sample space. The cryogenic cooler chamber configuration provides for efficient heat exchange between different stages of the cryogenic cooler without the need for physical heat links. This construction enables selective delivery of cooling power from the cryogenic cooler to the desired areas within the cryostat without using flexible physical thermal links. A counter flow exchanger and ambient temperature valves facilitate efficient use of the cryogenic cooler stages. The removal of large heat load generated by the superconducting magnet while operating in the sweeping mode is achieved, in part, by employing a solid plate thermal coupling element between the cryogenic cooler chamber and the magnet assembly.

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1. 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 r

1. 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; andat 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. 2. The cryostat apparatus recited in claim 1, wherein said cryogenic cooler chamber has at least one thermally conducting region at a reduced temperature portion of the wall, said region being arranged to provide a thermal conduction path between said at least one refrigerated component located outside said cryogenic cooler chamber and an exchanger surface located inside said cryogenic cooler chamber, said exchanger surface being in thermal contact with the refrigerated coolant within said cryogenic cooler chamber. 3. The cryostat apparatus recited in claim 1, where said at least one refrigerated component further comprises a thermal radiation shield. 4. The cryostat apparatus recited in claim 1, wherein said at least one refrigerated component further comprises a superconducting magnet assembly. 5. The cryostat apparatus recited in claim 1, wherein said at least one refrigerated component further comprises a cryopump assembly. 6. The cryostat apparatus recited in claim 1, wherein said at least one refrigerated component further comprises a cryopump assembly comprising: a first conduit extending from an ambient temperature isolation valve through said outer shell top into the interior of said outer shell;a first stage cold trap within said outer shell to which said conduit is connected; a second stage cold trap within said outer shell;a second conduit extending from said first stage cold trap to said second stage cold trap; anda sorption pump coupled within said second stage cold trap. 7. The cryostat apparatus recited in claim 1, wherein the coolant gas is helium or an isotope of helium. 8. The cryostat apparatus recited in claim 1, wherein said cryogenic cooler is formed with upper and lower surfaces and said cryogenic cooler chamber is formed with upper and lower surfaces, said cryogenic cooler and said cryogenic cooler chamber are oriented vertically and arranged so that the upper surfaces of both said cryogenic cooler and said cryogenic cooler chamber are warmer than the lower surfaces of both said cryogenic cooler and said cryogenic cooler chamber and coolant within said cryogenic cooler chamber thermally stratifies, with colder, more dense coolant below the warmer, less dense coolant. 9. The cryostat apparatus recited in claim 1, and further comprising a gas recirculation pump external to said outer shell and having an inlet port and an outlet port, said outlet port being coupled to said main gas inlet conduit and said inlet port being coupled to said at least one cryostat exit conduit, said recirculation pump providing a pressure drop for driving the coolant. 10. The cryostat apparatus recited in claim 8, where coolant gas entering said cryogenic cooler chamber is cooled by said cryogenic cooler to collect as liquid coolant at the bottom of said cryogenic cooler chamber. 11. The cryostat apparatus recited in claim 10, and further comprising a thermally conducting element thermally coupled between the bottom of said cryogenic cooler chamber and said at least one refrigerated component external to said cryogenic cooler chamber and within said cryostat. 12. The cryostat apparatus recited in claim 10, wherein the bottom of said cryogenic cooler chamber is configured with a heat exchanger surface on the inside of said cryogenic cooler chamber which is in direct contact with the liquid coolant located in the bottom of said cryogenic cooler chamber, the bottom of said cryogenic cooler chamber being a thermally conducting region configured to provide a thermal conduction path between said heat exchanger surface and said at least one refrigerated component. 13. The cryostat apparatus recited in claim 8, wherein said cryogenic cooler chamber has an inside and a bottom, the bottom being configured with a heat exchanger surface on said inside which is in direct contact with the refrigerated coolant at the bottom of said cryogenic cooler chamber, the bottom of said cryogenic cooler chamber being a thermally conducting region configured to provide a thermal conduction path between said heat exchanger surface and said at least one refrigerated component. 14. The cryostat apparatus recited in claim 13, wherein said cryogenic cooler chamber adjacent to said heat exchanger surface is configured to permit thermal exchange between said at least one reduced temperature stage and said heat exchanger surface via buoyant convection under a condition that the at least one reduced temperature stage is colder than said heat exchanger surface. 15. The cryostat apparatus recited in claim 12, wherein said at least one refrigerated component further comprises a superconducting magnet assembly. 16. The cryostat apparatus recited in claim 13, wherein said at least one refrigerated component further comprises a superconducting magnet assembly. 17. The cryostat apparatus recited in claim 10, and further comprising: a flow restricting device; andan evaporation chamber;said flow restricting device being connected in one said second coolant conduit between the bottom of said cryogenic cooler chamber and said evaporation chamber to deliver liquid coolant to said evaporation chamber at a pressure less than the pressure at the bottom of said cryogenic cooler chamber to enable the temperature in said evaporation chamber to be below the temperature of the liquid coolant in the bottom of said cryogenic cooling chamber. 18. The cryostat apparatus recited in claim 1, and further comprising a second ambient temperature flow control valve in one said at least one cryostat exit conduit downstream of said at least one refrigerated component, said second ambient temperature flow control valve being coupled and configured to control flow of refrigerated coolant upstream to said at least one refrigerated component. 19. The cryostat apparatus recited in claim 17, wherein the evaporated coolant from said evaporation chamber is provided to cool said at least one refrigerated component. 20. The cryostat apparatus recited in claim 17, wherein said evaporation chamber is in thermal communication with said at least one refrigerated component. 21. The cryostat apparatus recited in claim 10, wherein said sample chamber is a thermal environmental chamber. 22. A cryostat apparatus for regulating temperatures, the apparatus comprising: a sample chamber;a cryogenic cooler having at least one reduced-temperature stage;a cryogenic cooler chamber containing the at least one reduced-temperature stage of the cryogenic cooler;a main gas inlet conduit in fluid communication with said cryogenic cooler chamber;a source of ambient temperature coolant gas fluidly connected to said main gas inlet conduit;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;a first coolant conduit and a separate second coolant conduit connecting said first and second siphoning ports, respectively, to said sample chamber, the first and second coolant conduits being separate and distinct from each other;an ambient temperature flow control valve located external to said cooler chamber;a counter-flow heat exchanger in fluid communication with said first coolant conduit and said ambient temperature flow control valve, and configured to warm said refrigerated coolant to ambient temperature where said refrigerated coolant passes through said ambient temperature flow control valve and thereafter cool said refrigerated coolant back down by the thermal action of the counter-flow heat exchanger and subsequently deliver said refrigerated coolant to said sample chamber;said counter-flow heat exchanger and ambient temperature flow control valve being configured to control the flow of refrigerated coolant to said sample chamber.