Abstract: A cryogenic cooling system is provided comprising a primary insert (118) and a demountable secondary insert (128). The primary insert (118) comprises a plurality of primary plates (111, 112), each primary plate having a primary contact surface, and one or more primary connecting members (117) arranged so as to connect the plurality of primary plates (111, 112). The demountable secondary insert (128) comprises a plurality of secondary plates (121, 122), each secondary plate having a secondary contact surface, and one or more secondary connecting members (127) arranged so as to connect the plurality of secondary plates (121, 122) such that the secondary insert (128) is self-supporting. One or more adjustment members are configured such that, when the secondary insert (128) is mounted to the primary insert (118), the adjustment members cause the primary and secondary contact surfaces of the respective primary (111, 112) and secondary plates (121, 122) to be brought into conductive thermal contact.

Abstract: A heat exchanger for a cryogenic cooling apparatus is provided. The heat exchanger has a first conduit, a second conduit and a chamber, wherein the chamber is arranged to receive a fluid from the first conduit, and wherein second conduit is thermally coupled to the outside of the chamber. The chamber has a first region and a second region, the first region separated from the second region by a plate extending through the chamber, the plate comprising one or more apertures for allowing a flow of the fluid from the first region to the second region.

Abstract: A cryogenic cooling system is provided comprising a cryogenic refrigerator assembly and two or more connected modules. The cryogenic refrigerator assembly comprises one or more cryogenic refrigerators. Each said connected module comprises: a housing defining an internal volume for the module, the housing having a plurality of side faces, and a plurality of stages arranged within the internal volume for the module, wherein one or more of the plurality of stages is thermally coupled to the cryogenic refrigerator assembly. The two or more said modules are mutually connected at respective side faces, and a first said stage of a first said module is thermally coupled to a first said stage of a second said module.

Abstract: A cryogenic cooling system has one or more heat exchangers that are thermally coupled to a target assembly and fluidly coupled to a helium refrigeration plant. Each heat exchanger includes a stack of plates. The plates are profiled to form channels between each adjacent plate, which channels convey supercritical helium between an inlet and an outlet of the heat exchanger.

Abstract: A cryogenic cooling system is provided comprising a cryogenic refrigerator assembly and two or more connected modules. The cryogenic refrigerator assembly comprises one or more cryogenic refrigerators. Each said connected module comprises: a housing defining an internal volume for the module, the housing having a plurality of side faces, and a plurality of stages arranged within the internal volume for the module, wherein one or more of the plurality of stages is thermally coupled to the cryogenic refrigerator assembly. The two or more said modules are mutually connected at respective side faces, and a first said stage of a first said module is thermally coupled to a first said stage of a second said module.

Abstract: A cryogenic cooling system is provided comprising a cryogenic refrigerator assembly and two or more connected modules. The cryogenic refrigerator assembly comprises one or more cryogenic refrigerators. Each said connected module comprises: a housing defining an internal volume for the module, the housing having a plurality of side faces, and a plurality of stages arranged within the internal volume for the module, wherein one or more of the plurality of stages is thermally coupled to the cryogenic refrigerator assembly. The two or more said modules are mutually connected at respective side faces, and a first said stage of a first said module is thermally coupled to a first said stage of a second said module.

Abstract: A cryogenic cooling system that includes a cooled plate thermally coupled to a cryogenic refrigerator, a target assembly that includes a target refrigerator configured to achieve a lower base temperature than the cryogenic refrigerator, and a heat switch assembly with one or more gas gap heat switches. The heat switch assembly has a first end thermally coupled to the cooled plate and a second end thermally coupled to the target assembly. A sorption pump is configured to control thermal conductivity across the heat switch assembly based on the temperature of the sorption pump. The sorption pump is thermally coupled to the cryogenic refrigerator by a thermal link extending from the cooled plate to the heat switch assembly, with the sorption pump positioned along the thermal link between the cooled plate and the heat switch assembly.

Abstract: A cryogenic cooling system is provided comprising a cryogenic refrigerator assembly and two or more connected modules. The cryogenic refrigerator assembly comprises one or more cryogenic refrigerators. Each said connected module comprises: a housing defining an internal volume for the module, the housing having a plurality of side faces, and a plurality of stages arranged within the internal volume for the module, wherein one or more of the plurality of stages is thermally coupled to the cryogenic refrigerator assembly. The two or more said modules are mutually connected at respective side faces, and a first said stage of a first said module is thermally coupled to a first said stage of a second said module.

Abstract: A heat exchanger for a cryogenic cooling apparatus is provided. The heat exchanger has a first conduit, a second conduit and a chamber, wherein the chamber is arranged to receive a fluid from the first conduit, and wherein second conduit is thermally coupled to the outside of the chamber. The chamber has a first region and a second region, the first region separated from the second region by a plate extending through the chamber, the plate comprising one or more apertures for allowing a flow of the fluid from the first region to the second region.

Abstract: A cryogenic cooling system is provided comprising: a cooled plate (2) thermally coupled to a cryogenic refrigerator (9), a heat switch assembly and a target assembly (5). The target assembly (5) comprises a target refrigerator (12) configured to obtain a lower base temperature than the cryogenic refrigerator (9). The heat switch assembly (18) comprises one or more gas gap heat switches, the heat switch assembly (18) having a first end thermally coupled to the cooled plate (2) and a second end thermally coupled to the target assembly (5). A sorption pump (22) is provided for controlling the thermal conductivity across the heat switch assembly (18) in accordance with the temperature of the sorption pump (22) The sorption pump (22) is thermally coupled to the cryogenic refrigerator (9), by a thermal link (46) extending from the cooled plate (2) to the heat switch assembly (18).

Abstract: A cryogenic cooling system is provided comprising a primary insert (118) and a demountable secondary insert (128). The primary insert (118) comprises a plurality of primary plates (111, 112), each primary plate having a primary contact surface, and one or more primary connecting members (117) arranged so as to connect the plurality of primary plates (111, 112). The demountable secondary insert (128) comprises a plurality of secondary plates (121, 122), each secondary plate having a secondary contact surface, and one or more secondary connecting members (127) arranged so as to connect the plurality of secondary plates (121, 122) such that the secondary insert (128) is self-supporting. One or more adjustment members are configured such that, when the secondary insert (128) is mounted to the primary insert (118), the adjustment members cause the primary and secondary contact surfaces of the respective primary (111, 112) and secondary plates (121, 122) to be brought into conductive thermal contact.

Abstract: A cryogenic cooling system is provided comprising: a mechanical refrigerator, a heat pipe and a heat switch assembly. The mechanical refrigerator has a first cooled stage and a second cooled stage. The heat pipe has a first part coupled thermally to the second cooled stage and a second part coupled thermally to a target assembly. The heat pipe is adapted to contain a condensable gaseous coolant when in use. The heat switch assembly comprises one or more gas gap heat switches, a first end coupled thermally to the second cooled stage and a second end coupled thermally to the target assembly. The cryogenic cooling system is adapted to be operated in a heat pipe cooling mode in which the temperature of the second cooled stage is lower than the first cooled stage and wherein the temperature of the target assembly causes the coolant within the second part of the heat pipe to be gaseous and the temperature of the second cooled stage causes the coolant in the first part of the heat pipe to condense.

Abstract: A cryogenic cooling system is provided comprising a first stage 6, a second stage 7, and a third stage 8, wherein the second stage 7 is arranged between the first stage 6 and the third stage 8. A first dilution unit 12 is provided comprising a first still 11 and a first mixing chamber 13, wherein the first still 11 is thermally coupled to the first stage 6 and the first mixing chamber 13 is thermally coupled to the third stage 8. A second dilution unit 32 is further provided comprising a second still 31 and a second mixing chamber 33, wherein the second still 31 is thermally coupled to the first stage 6 and the second mixing chamber 33 is thermally coupled to the second stage 7.

Abstract: A method for forming a gas gap heat switch is provided comprising the following steps: (a) providing first and second conductors, and first and second connecting members, wherein the connecting members each have a thermal conductivity at least five times smaller than that of the conductors when at a temperature of 100K; (b) fusing the first conductor to the first connecting member and the second conductor to the second connecting member; (c) aligning the conductors such that the first and second conductors extend along a common major axis; (d) bringing proximal ends of the aligned conductors into contact with each other when said conductors are at a first temperature; and (e) joining the first connecting member to the second connecting member so as to form a chamber around at least the proximal ends of the conductors.

Abstract: A cryogenic cooling system is provided comprising a first stage 6, a second stage 7, and a third stage 8, wherein the second stage 7 is arranged between the first stage 6 and the third stage 8. A first dilution unit 12 is provided comprising a first still 11 and a first mixing chamber 13, wherein the first still 11 is thermally coupled to the first stage 6 and the first mixing chamber 13 is thermally coupled to the third stage 8. A second dilution unit 32 is further provided comprising a second still 31 and a second mixing chamber 33, wherein the second still 31 is thermally coupled to the first stage 6 and the second mixing chamber 33 is thermally coupled to the second stage 7.

Abstract: A cryogenic cooling system is provided comprising: a mechanical refrigerator, a heat pipe and a heat switch assembly. The mechanical refrigerator has a first cooled stage and a second cooled stage. The heat pipe has a first part coupled thermally to the second cooled stage and a second part coupled thermally to a target assembly. The heat pipe is adapted to contain a condensable gaseous coolant when in use. The heat switch assembly comprises one or more gas gap heat switches, a first end coupled thermally to the second cooled stage and a second end coupled thermally to the target assembly. The cryogenic cooling system is adapted to be operated in a heat pipe cooling mode in which the temperature of the second cooled stage is lower than the first cooled stage and wherein the temperature of the target assembly causes the coolant within the second part of the heat pipe to be gaseous and the temperature of the second cooled stage causes the coolant in the first part of the heat pipe to condense.

Abstract: A method for forming a gas gap heat switch is provided comprising the following steps: (a) providing first and second conductors, and first and second connecting members, wherein the connecting members each have a thermal conductivity at least five times smaller than that of the conductors when at a temperature of 100K; (b) fusing the first conductor to the first connecting member and the second conductor to the second connecting member; (c) aligning the conductors such that the first and second conductors extend along a common major axis; (d) bringing proximal ends of the aligned conductors into contact with each other when said conductors are at a first temperature; and (e) joining the first connecting member to the second connecting member so as to form a chamber around at least the proximal ends of the conductors.

Abstract: A method is provided of operating a cryogenic cooling system, in which a target region for receiving a sample is cooled by a dilution refrigerator containing an operational fluid. Firstly any operational fluid is removed from the dilution refrigerator. Target apparatus comprising the sample is loaded from a high temperature location to the target region. The target apparatus is then pre-cooled in the target region to a first temperature using a mechanical refrigerator. The operational fluid is then supplied to the dilution refrigerator and the dilution refrigerator operated so as to cool the target apparatus in the target location to a second temperature that is lower than the first temperature. A suitable system for performing the method is also disclosed.

Abstract: Cooling apparatus is provided which comprises a mechanical refrigerator and a heat pipe. The mechanical refrigerator has a first cooled stage and a second cooled stage, the second cooled stage being adapted to be coupled thermally with target apparatus to be cooled. The heat pipe has a first part coupled thermally to the first stage of the mechanical refrigerator and a second part coupled thermally to a cooled member which may comprise the second stage of the mechanical refrigerator. The heat pipe is adapted to contain a condensable gaseous coolant when in use. An example coolant is Krypton. The apparatus is operated in a first cooling mode in which the temperature of the cooled member causes the coolant within the second part of the heat pipe to be gaseous and the temperature of the first stage causes the coolant in the first part to condense, whereby the cooled member is cooled by the movement of the condensed liquid from the first part to the second part of the heat pipe.

Abstract: A method is provided of operating a cryogenic cooling system, in which a target region for receiving a sample is cooled by a dilution refrigerator containing an operational fluid. Firstly any operational fluid is removed from the dilution refrigerator. Target apparatus comprising the sample is loaded from a high temperature location to the target region. The target apparatus is then pre-cooled in the target region to a first temperature using a mechanical refrigerator. The operational fluid is then supplied to the dilution refrigerator and the dilution refrigerator operated so as to cool the target apparatus in the target location to a second temperature that is lower than the first temperature. A suitable system for performing the method is also disclosed.