A cryogenic apparatus (10) includes an enclosure (12), a first thermo-mechanical cooler (20) and a second thermo-mechanical cooler (22) which project into the enclosure (12), at least the second thermo-mechanical cooler (22) being a two-stage cooler, and each cooler (20, 22) having a fluid inlet and a fluid outlet for each stage, and a helium gas extraction flow duct (40) which extends into the enclosure (12) and which communicates with a vessel (42) to contain liquid helium within the enclosure (12). There is a first heat exchanger (62) within the gas flow duct (40). A first duct (74) carries cold helium gas from a fluid outlet (73) of the first thermo-mechanical cooler (20) and through the first heat exchanger (62) to the fluid inlet (75) of the second stage of the second thermo-mechanical cooler (22).

Provided is a helium recondensation apparatus for a cryostat, which can stably recondense vapor of helium in the cryostat while preventing a pipeline for the recondensation from being clogged. A recondensation apparatus includes a freezer, a first heat exchanger, a first recondensing chamber, and a first connection part. The first heat exchanger stores heat-exchanging helium in a helium tank included in an NMR apparatus, and permits the heat-exchanging helium to evaporate owing to heat of vaporization taken from vapor of coolant helium in the helium tank, thereby permitting the coolant helium to recondense through heat exchange with the heat-exchanging helium. The first connection part is separated from the coolant helium in the helium tank and permits the heat-exchanging helium to flow between the first heat exchanger and the first recondensing chamber therethrough.

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). The sorption pump (22) is arranged at a position along the thermal link (46) between the heat switch assembly 18 and the cooled plate (2).

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.

The invention relates to a method and a magnetoencephalography (MEG) measurement device. In the method there is determined the ending of a scheduled inactivity period of the MEG device. At the ending of the inactivity period a cryocooler of the MEG device is switched off. Helium is allowed to boil in the Dewar vessel of the MEG device when the MEG device is active and used to perform patient measurements. The boiled helium is collected via a compressor to an external storage tank. When a new inactivity period for the MEG device commences, the cryocooler is started anew and helium is let from the external storage tank in-to the Dewar vessel, where it is re-liquefied by the cryocooler. The compressor may be switched off when the cryocooler is switched on.

Containers (100) for cryopreserved biological samples (102) may include an insulated housing including a cavity (108) for containing at least one cryopreserved biological sample; and a sealed reservoir (106) at least partly surrounding the cavity, the sealed reservoir including liquified gas (120) such as liquified air, the gas being kept largely liquified by a heat transfer engine (112) such as a Stirling cryocooler. A valve (114) may be provided to function as both a pressure relief valve and an inlet valve. The inlet valve may be coupled to a sensor (122) for sensing a volume of liquified gas within the sealed reservoir. The container may further include a heat exchanger (116) coupled to the heat engine and extending into the sealed reservoir.

An arrangement for cryogenic cooling comprising a cryogen tank (14), a cryogenic recondensing refrigerator (12) arranged to cool a heat exchanger which is exposed to the interior of the cryogen tank (14) and an arrangement (16; 26) for conducting heat from a cooled article (10) to the cryogen tank. A further cryogen tank (20) is provided below the heat exchanger and arranged to receive cryogen liquid recondensed on the heat exchanger.

A thermal interface between a removable cryogenic refrigerator (4) and an article (10) to be cooled by the cryogenic refrigerator. The thermal interface consists of a recondensing chamber filled with a gas (12), the recondensing chamber being in thermal contact with a cooling surface (9) of the refrigerator and the article (10) to be cooled.

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. The target assembly is cooled by the movement of the condensed liquid coolant from the first part of the heat pipe to the second part of the heat pipe during the heat pipe cooling mode. The cryogenic cooling system is further adapted to be operated in a gas gap cooling mode in which the temperature of the second cooled stage causes freezing of the coolant. The heat switch assembly is adapted to provide cooling from the second cooled stage to the target assembly during the gas gap cooling mode via the one or more gas gap heat switches.

A cryogenic apparatus comprising a first enclosure, a thermo-mechanical cooler thermally coupled to said first enclosure, a second enclosure spatially distanced from the first enclosure. An elongate tubular link member configured to thermally couple the first and second enclosures across the space between them. A liquid helium containing vessel located in or proximal to said second enclosure for holding liquid helium, in use, a liquid helium delivery assembly for delivering helium from said thermo-mechanical cooler to said liquid helium containing vessel. A helium gas extraction duct for carrying helium gas returned from said from said second enclosure, via said link member, to said thermo-mechanical cooler. A connecting device located in said first enclosure and comprising a plurality of fluidly coupled ports, wherein a first port of said connecting device is coupled, via first vibration-suppressing means, to an end of said tubular link member. A second port of said connecting device is coupled, via second vibration-suppressing means, to an end of said helium gas extraction duct, and a third port of said connecting device is coupled, via third vibration suppressing means, to a wall of said first enclosure.