CRYOGENIC COOLING DEVICE

Description

[0001] The invention relates to a cryogenic refrigeration device.

[0002] The invention relates more particularly to a cryogenic refrigeration device, as defined in claim 1, comprising an enclosure delimiting a vacuum-sealed volume closed by a cover, the device comprising at least one cryogenic cooler mounted through the cover and having a first end located outside the enclosure and a second end located in the enclosure, the cryogenic cooler being configured to provide cold at its second end, the device comprising at least two thermally conductive plates distributed in a distribution direction in the enclosure and forming thermal stages, at least a portion of the plates being cooled by the cryogenic cooler to respective determined temperatures decreasing in the distribution direction, at least one of the plates being connected to a thermal shield forming a volume encompassing at least one following plate,the cryogenic cooler being of the type using a cold source of liquefied cycle fluid such as helium or nitrogen.,

[0003] The invention relates to a refrigeration device for cooling elements to a cryogenic temperature below 100k and in particular below 50k and / or below 4k.

[0004] In particular, the invention relates to refrigeration devices which allow cooling to very low temperatures, of the order of millikelvin ("subKelvin refrigeration"). These very low temperatures are conventionally obtained via a dilution refrigerator or a Joule Thomson type cryogenic cooler using He4 or He3.

[0005] In these devices it is necessary to provide cooling power up to a temperature of, for example, 4K to one or more refrigeration stages.

[0006] This cooling power must also be able to quickly cool the device (cooling from a hot state). The device must also be able to be reheated for maintenance purposes, for example.

[0007] Known dilution refrigerators require cooling powers of at least 4.2K to operate. This cooling power is conventionally obtained from pulsed gas tube cryogenic refrigerators or equivalents known as "dry". According to another so-called "wet" solution, a liquid helium bath is used in the enclosure to cool the trays or other. This solution poses problems in managing the sealing between the different parts, which complicates access for samples and cables in the enclosure. These known "wet" solutions also require relatively long cooling and heating times.

[0008] Applications (cooling of Qbits for example) require an increase in the necessary cooling power up to approximately 4.2K. The cooling powers of pulsed gas tubes are limited and poorly adapted. EP 3 477 225 A1 discloses a cryogenic refrigeration device according to the preamble of claim 1.

[0009] An aim of the present invention is to overcome all or part of the drawbacks of the prior art noted above.

[0010] To this end, the device according to the invention, moreover in accordance with the generic definition given in the preamble above, is essentially characterized in that at least part of the plates is cooled by the cycle fluid via a set of heat exchangers in heat exchange with said plates and with a flow of cycle fluid.

[0011] Furthermore, embodiments of the invention may include one or more of the following features: the set of heat exchangers in heat exchange with said plates comprises several separate heat exchangers respectively associated with the plates, the exchangers of at least two plates being mechanically connected to each other, said heat exchangers are arranged and spaced according to the distribution direction, the distribution direction being vertical in the operating position in the enclosure, said heat exchangers are mounted in the enclosure via the same passage in the cover, for example via the same support flange of the cover, the heat exchangers comprise a block of thermally conductive material, for example copper, in contact with a tube of thermally conductive material, for example copper, transporting the flow of cycle fluid, said tube being brazed to the block and / or machined in the block and / or molded and / or cast in the block,at least a portion of the heat exchangers are mounted on the trays and in heat exchange with said trays by conduction and contact, via at least one of: bolting, at least one thermal connecting braid, a clamp, at least a portion of the set of heat exchangers is arranged in a sealed sheath delimiting a volume independent of the rest of the volume of the enclosure, at least a portion of the heat exchangers are in heat exchange with said trays without contact with the trays but via an intermediate gas, for example a gas containing at least one of: helium, nitrogen, argon or hydrogen, at least a portion of the heat exchangers comprises a gilding layer configured to increase the heat exchange, the cryogenic cooler comprises a refrigerator with a cycle for refrigerating a cycle fluid, said refrigerator comprising,a cycle circuit composed of the following elements arranged in series: a cycle fluid compression mechanism, at least one cycle fluid cooling member, a cycle fluid expansion mechanism and at least one expanded cycle fluid heating member, in which the cycle fluid comprises at least one of: helium, hydrogen, nitrogen, argon, the cycle circuit being configured to subject the cycle fluid to a thermodynamic cycle bringing the cycle fluid to at least one end of the cycle circuit at a determined cold temperature, the flow of cycle fluid in heat exchange with said plates in the set of heat exchangers comprising the cycle fluid at the cold temperature,the device comprising a set of pipe(s) for supplying at least a portion of the fluid from the cycle circuit to the exchanger assembly and for returning said fluid from the exchanger assembly to the cycle circuit of the refrigerator, the cycle circuit is configured to subject the cycle fluid to a thermodynamic cycle bringing the cycle fluid to several distinct cold temperatures at respectively several ends of the cycle circuit, several distinct flows of the cycle fluid at said distinct cold temperatures being put into heat exchange with respectively the at least two distinct plates via two sets of respective heat exchangers, the cycle fluid is or contains predominantly helium, the cycle circuit being configured to bring the cycle fluid to at least one cold temperature from: approximately 80K, between 20 and 70K, between 2K and 5K and / or in a supercritical state,the cryogenic cooler comprises a reserve of liquefied cryogenic gas, for example liquid nitrogen, and a set of pipe(s) for supplying liquefied cryogenic gas from the reserve to the exchanger assembly, the device comprises a heat exchange dilution refrigerator with at least one tray, the trays are made of a thermally conductive material, for example copper or any other alloy or any suitable material, the trays may be spaced apart from each other by rods with low thermal conductivity, the trays are configured to be the support for various devices or samples to be cooled at low temperature, the device comprises one or more electrical insulation elements ensuring electrical insulation between the enclosure and the cooler.

[0012] The invention also relates to a method for cryogenic refrigeration of sample(s), as defined in claim 15, using a cryogenic refrigeration device according to any one of the characteristics above or below, comprising a step of storing and / or producing a cold source of liquefied cycle fluid such as helium or nitrogen at the first end of the cryogenic cooler, a step of transferring a flow of this cycle fluid from the first end to the second end of the cryogenic cooler, said flow of cycle fluid being put into heat exchange with the set of heat exchangers at the second end in a sealed manner without communicating with the internal gaseous volume of the enclosure.

[0013] The invention may also relate to any alternative device or method comprising any combination of the above or below features within the scope of the claims.

[0014] Other features and advantages will appear on reading the description below, made with reference to the figures in which: [ Fig. 1 ] represents a schematic and partial vertical sectional view, illustrating an exemplary embodiment of a cooling device according to the invention, [ Fig. 2 ] represents a schematic and partial view illustrating an exemplary embodiment of a cryogenic cooler which can be used in such a cooling device, [ Fig. 3 ] represents a schematic and partial vertical sectional view, illustrating another exemplary embodiment of a cooling device according to the invention.

[0015] The cryogenic refrigeration device 1 illustrated comprises an enclosure 2 delimiting a sealed volume under vacuum closed by a cover 3.

[0016] The device 1 comprises at least one cryogenic cooler 4 mounted through the cover 3 and having a first end located outside the enclosure 2 and a second end located inside the enclosure 2.

[0017] The cryogenic cooler 4 is configured to provide cold at its second end. For example, one or more cold power sources are stored and / or generated at the first end of the cryogenic cooler.

[0018] The first and second ends of the cryogenic cooler may form a single physical entity. Alternatively or in combination, the cold power could be produced in another installation / device (other physical entity) and transferred to this first end, for example by a heat transfer fluid or any other heat transfer member. Thus, the cold power (or cold source) is produced or stored outside the enclosure 2.

[0019] At least some of this cold power can be transferred from the first end to the second end.

[0020] The cryogenic cooler 4 is for example a refrigerator of the type using a cycle fluid subjected to a thermodynamic cycle in a closed cycle circuit (other than a dilution refrigerator). This cycle fluid is brought to a relatively colder temperature at a cold end of the cycle to provide cooling power. At least part of the cycle circuit may be located outside the enclosure 2, in particular the cold end. Thus, the cycle fluid is cooled outside the enclosure 2 and may be circulated in the enclosure to provide cooling power there (at at least one plate 5, 6, 10). The cooling power is thus produced outside the enclosure 2. The reheated cycle fluid which has exchanged heat with the plates in the enclosure 2 may return outside the enclosure to be cooled again (cycle which begins again).In particular, the compression and expansion organs of the cycle can be located outside the enclosure 2.

[0021] This configuration limits the number of components of the cryogenic refrigerator 4 in the vacuum enclosure 2, which preferably includes a dilution refrigerator. This allows for a very high vacuum in enclosure 2, which is favorable to the dilution refrigerator. This limits the risk of leakage and increases the operating time of the dilution refrigeration.

[0022] In this example, the device 1 comprises three thermally conductive trays 5, 6, 10 distributed vertically in the enclosure 2 and forming thermal stages at determined temperatures. The trays are configured to receive and cool elements or samples.

[0023] The device 1 preferably comprises a set of passages 17 formed through the cover 3 and the plates 5, 6 for the sealed passage of cable(s) and / or equipment(s) in the enclosure 2.

[0024] At least some of the trays 5, 6 (two in this example) are cooled by the cryogenic cooler 4 to respective determined temperatures decreasing from top to bottom (for example a first tray 5 can be cooled to a temperature between 20K and 80K, in particular around 50K, and the other tray 6 can be cooled to a temperature between 2K and 5K, in particular around 4K).

[0025] The invention is not limited to this embodiment and other configurations for the trays are possible. For example, the trays could be thermalized at a decreasing temperature from bottom to top, or they could be arranged in a horizontal direction and be thermalized at decreasing temperatures from left to right or vice versa or according to another distribution.

[0026] As illustrated, the tray(s) 5, 6 may be connected to a thermal screen 19, 20 forming a volume encompassing at least one following lower tray.

[0027] That is to say that the screens 19, 20 can form volumes which are contained within each other (“nested” volumes). All or part of the screens 19, 20 can be cooled by a cryogenic cooler 4 by the aforementioned thermal coupling.

[0028] According to an advantageous feature, the cryogenic cooler 4 is of the type using a cold source of liquefied cycle fluid such as helium, hydrogen or nitrogen, at least a portion of the plates 5, 6, 10 being cooled by the cycle gas via a set of heat exchangers in exchange with said plates 5, 6 and with a flow of the cycle fluid. That is to say that the cryogenic cooler 4 is connected to a cold source located outside the enclosure 2, this cold source providing a flow of liquefied fluid, cooled outside the enclosure 2, this flow circulates in the cryogenic cooler 4 and is put into heat exchange with at least a portion of the plates 5, 6, 10 in the enclosure 2.

[0029] The cycle fluid flow is brought into the enclosure via a sealed circuit so that the cycle fluid does not communicate with the interior of the enclosure 2 (unlike known wet solutions).

[0030] The set of heat exchangers in exchange with said plates 5, 6 comprises for example several, for example separate heat exchangers mounted respectively on the plates 5, 6. In addition, the exchangers of at least two adjacent plates 5, 6 are preferably mechanically connected (so as to form a single mechanical entity which is introduced or removed from the enclosure 2).

[0031] Preferably, these elements are held together by the rigid pipes for the cycle fluid and / or via additional supports made of thermally insulating material such as fiberglass, and / or via a frame. This allows the assembly to be inserted and removed in a single easy operation. The heat exchangers are, for example, arranged in a line and spaced apart in a distribution direction, for example a stacking direction which is vertical in the operating position in the enclosure 2.

[0032] These cooling stages are arranged one above the other in a spaced manner but the heat exchangers are not necessarily aligned on the same vertical axis as shown in the non-limiting example.

[0033] The heat exchangers can be mounted in the enclosure 2 via the same passage in the cover 3, for example via the same flange 15 supporting the cover 3.

[0034] At least part of the set of heat exchangers can be arranged in a sealed sheath 21 delimiting for example a volume independent of the rest of the volume of the enclosure 2, and which can contain gas at a pressure of between a few millibars and a few bars, or else be placed under vacuum, that is to say at a pressure of less than 0.01 mbar.

[0035] The heat exchangers can be in exchange with said plates 5, 6 by conduction and direct or indirect contact, for example via at least one of: bolting, at least one thermal connecting braid, a clamp, etc.

[0036] In the non-limiting example illustrated, the heat exchangers comprise a block 7 of conductive material, for example copper, in contact with the plate 5, 6 and a tube 8, 18 or circuit of conductive material transporting the cycle fluid flow (for example copper, aluminum or other).

[0037] This tube or circuit can be brazed onto block 7 and / or machined into block 7 and / or molded into block 7 and / or cast into block 7.

[0038] Similarly, at least part of the heat exchangers may comprise (in particular at the junction between two elements) a layer of gilding configured to increase the heat exchange with the plate concerned.

[0039] As schematically illustrated in [ Fig. 2 ], the cryogenic cooler 4 producing the cold power (cold cycle fluid flow) may comprise a cryogenic refrigerator with a continuous refrigeration cycle of a cycle fluid.

[0040] Such a refrigerator comprises a cycle circuit 11 composed of the following elements arranged in series: a mechanism 12 for compressing the cycle fluid (one or more compressors in series and / or parallel), at least one member 13 for cooling the cycle fluid (heat exchanger(s)), a mechanism 14 for expanding the cycle fluid (one or more turbine(s) or valve(s) in series and / or in parallel) and at least one member 13 for heating the expanded cycle fluid (exchanger(s) in particular counter-current for simultaneously cooling and heating two parts of the circuit 11).

[0041] The cycle fluid preferably comprises at least one of: helium, hydrogen, nitrogen, argon.

[0042] The cycle circuit 11 is configured to subject the cycle fluid to a thermodynamic cycle bringing the cycle fluid to at least one cold end of the cycle circuit 11 at a determined cold temperature.

[0043] The cycle fluid flow which is put into heat exchange with said plates 5, 6 in the heat exchanger assembly comprises at least a fraction of this cycle fluid at the cold temperature. For example, the cooled liquefied fluid which circulates in the pipes 8, 18 is a portion taken from the flow circulating in the cycle circuit 11.

[0044] The device 1 comprises a set of pipe(s) 8, 18 for supplying fluid from the cycle circuit 11 to the exchanger assembly and for returning said fluid from the exchanger assembly to the cycle circuit 11 of the refrigerator 4 (through the cover 3).

[0045] The cycle circuit 11 may be configured to subject the cycle fluid to a thermodynamic cycle bringing the cycle fluid to several distinct cold temperatures at respectively several cold ends of the cycle circuit 11.

[0046] Thus, several distinct flows of the cycle fluid at said distinct cold temperatures can be put into heat exchange with respectively several distinct plates 5, 6 via respective sets of heat exchangers (two or more).

[0047] In the example illustrated, two sets of pipes 8, 18 provide cold power at distinct temperatures at two plates 5, 6 respectively. The two sets form distinct circulation loops of the cycle fluid which come into the enclosure 2.

[0048] The device 1 preferably comprises one or more electrical insulation elements 22 providing electrical insulation between the enclosure 2 and the cold source of the cooler 4 (in particular with respect to the electrical voltages of the cold source of the cooler 4). For example, insulation elements 22 are interposed at the junction between the tubes or pipes 8, 18 and the flange 15, and / or in an intermediate position along the portion of pipe between the cold source of the cooler 4 and the flange 15. These elements 22 may be, for example, sleeves or portions of tube 8 made of ceramic or any other suitable material. For example, a portion of the tubes or pipes 8, 18 incorporate an electrically insulating portion of this type.

[0049] As schematized in [ Fig. 1 ], the device may further comprise in the enclosure 2, connected to the plate 6, a sub-kelvin refrigerator 9, for example a dilution refrigerator or a JT (Joule-Thomson) refrigerator, in heat exchange with this at least one plate 10 to reach temperatures lower than 4K, in particular lower than 1K, and in particular around milliKelvin.

[0050] Such a dilution refrigerator 9 conventionally uses a mixture of helium 3 and helium 4 in a working circuit comprising a boiler, a mixing chamber and a helium flow circulation device. Cooling is obtained at the mixing chamber from the mixing enthalpy when helium-3 is diluted in helium 4.

[0051] For example, the refrigeration device has a looped working circuit containing a cycle fluid comprising a mixture of helium of isotope 3 (3He) and helium of isotope 4 (4He). The working circuit comprises, arranged in series and fluidically connected via a first set of pipes, a mixing chamber, a boiler and a fluid transfer member. The first set of pipes is configured to transfer cycle fluid from an outlet of the mixing chamber to an inlet of the boiler and from an outlet of the boiler to an inlet of the transfer member. The working circuit comprises a second set of pipes connecting an outlet of the transfer member to an inlet of the mixing chamber.The working circuit comprises at least a first heat exchange portion between at least a part of the first set of pipes and the second set of pipes, this first heat exchange portion being located between the boiler and the mixing chamber. A cooling member is generally provided in heat exchange with the working circuit and configured to transfer frigories to the cycle fluid.

[0052] Device 1 thus integrates a set of heat exchangers in enclosure 2 which are cooled by an external cold source providing cold power up to 4K, or even up to 2K, in particular via a flow of cryogenic fluid. This configuration makes it possible to provide more power than a pulsed gas tube.

[0053] Cooling can be accelerated by increasing the cycle fluid flow rates above the nominal flow rate. When the system is stopped, simply shutting off the cycle fluid supply disconnects the cooling power. This is easier than known wet solutions.

[0054] Thus, the structure according to the invention makes it possible to replace a pulsed gas tube with a set of exchangers having the same thermal and mechanical interfaces as in the case of a pulsed gas tube.

[0055] As mentioned above, heat exchangers can be powered, for example, by a helium refrigerator or liquefier (open or closed loop), or by liquid nitrogen (open or closed loop connected to a liquid nitrogen tank) or another liquefied fluid.

[0056] The exchanger assembly(s) can be installed in any installation using a pulsed gas tube. This makes it easy to modify existing installations using pulsed gas tubes.

[0057] The invention can make it possible to overcome the rigidity of a pulsed gas tube. The exchangers can be arranged in a horizontal direction, and / or mounted in a manner not integral with each other.

[0058] As mentioned above, the heat exchanger assembly can have one or more stages (for example one at a temperature of around 4K, around 20K, 50 to 70K, 80K...).

[0059] This allows the cooling power requirement to be staggered according to the temperatures and thus limits the power required for the installation to operate. The more samples the device has to cool, for example Qbits, the more interesting it is to add cooling stages of this type. All the heat exchangers can be supplied (cooled) by one or more cycle fluid flows at different temperatures. Similarly, the same cycle fluid flow can supply several cooling stages in series.

[0060] Particularly at temperatures around 4K, the cycle fluid (typically helium) may be in a supercritical and subcooled state to limit vibrations resulting from its vaporization as it warms up.

[0061] All heat exchangers can be inserted into the enclosure via a single tapping on the flange or top cover. This facilitates installation and optimizes the experimental space in the enclosure.

[0062] The exchanger assembly(s) may be integrated into a volume or void separate from the rest of enclosure 2 to limit the risk of cycle fluid leaking into enclosure 2.

[0063] The thermal interface between enclosure 2 and the heat exchangers can be achieved by bolting the exchanger against a plate of the associated stage or tray, and / or using conductive thermal braids.

[0064] As illustrated in [ Fig. 3], all or part of the heat exchangers may be in exchange with the plates 5, 6 solely by gas exchange of the helium, nitrogen, argon or hydrogen type. The device 1 then preferably comprises one or more heat exchangers arranged in a sealed sheath 21 delimiting a volume of gas independent of the rest of the volume of the enclosure 2 and in exchange with said plates 5, 6 via the thermal conduction of the gas present in the sheath.

[0065] In this example, a two-stage heat exchanger is integrated into enclosure 2. It can, for example, supply one stage or tray with cold power at a temperature around 50-70K with gaseous helium and another stage / tray around 4K with subcooled supercritical helium. The helium can be supplied by one or more multiple lines whose screens are supplied by the return of the heated gaseous helium. The heat exchanger(s) can have any other suitable structure. See for example FR3065064A1.

Claims

1. Cryogenic refrigeration device comprising an enclosure (2) delimiting a vacuum-sealed volume closed by a cover (3), the device (1) comprising at least one cryogenic cooler (4) mounted through the cover (3) and having a first end located outside the enclosure (2) and a second end located inside the enclosure (2), the cryogenic cooler (4) being configured to supply cold at its second end, the device (1) comprising at least two thermally conductive plates (5, 6, 10) distributed in a distribution direction in the enclosure (2) and forming thermal stages, at least some of the plates (5, 6, 10) being cooled by the cryogenic cooler (4) to respective determined temperatures which decrease in the distribution direction, the device (1) comprising a shield (19, 20) and a set of heat exchangers, at least one of the plates (5, 6, 10) being connected to said thermal shield (19, 20) forming a volume which encloses at least one following plate, the cryogenic cooler (4) being of the type which uses a cold source of liquefied cycle fluid such as helium or nitrogen, characterized in that in the device (1) the cooling power of the cryogenic cooler (4) is stored and / or produced at its first end, in that at least some of the plates (5, 6, 10) are cooled by the cycle fluid via a set of heat exchangers in heat exchange with said plates (5, 6) and with a flow of the cycle fluid which transfers cooling power from the first end to the second end of the cryogenic cooler (4).

2. Device according to Claim 1, characterized in that the set of heat exchangers in heat exchange with said plates (5, 6) comprises a plurality of separate heat exchangers respectively associated with the plates (5, 6), the exchangers (5, 6) of at least two plates (5, 6) being mechanically connected to one another.

3. Device according to Claim 2, characterized in that said heat exchangers are arranged and spaced apart in the distribution direction, the distribution direction being vertical in the operating position in the enclosure (2).

4. Device according to Claim 2 or 3, characterized in that said heat exchangers are mounted in the enclosure (2) via one and the same passage in the cover (3), for example via one and the same support flange (15) of the cover (3).

5. Device according to any one of Claims 1 to 4, characterized in that the heat exchangers comprise a block (7) of thermally conductive material, for example made of copper, in contact with a tube (8, 18) of thermally conductive material, for example made of copper, transporting the cycle fluid flow, said tube (8, 18) being soldered to the block (7) and / or machined in the block (7) and / or moulded and / or cast in the block (7).

6. Device according to any one of Claims 1 to 5, characterized in that at least some of the heat exchangers are mounted on the plates (5, 6) and in heat exchange with said plates (5, 6) by conduction and contact, via at least one of the following: bolting, at least one thermal connecting braid, a clamp.

7. Device according to any one of Claims 1 to 6, characterized in that at least some of the set of heat exchangers are arranged in a sealed casing (21) delimiting a volume that is independent of the rest of the volume of the enclosure (2).

8. Device according to Claim 7, characterized in that at least some of the heat exchangers are in heat exchange with said plates (5, 6) without contact with the plates but via an intermediate gas, for example a gas containing at least one of the following: helium, nitrogen, argon or hydrogen.

9. Device according to any one of Claims 1 to 8, characterized in that at least some of the heat exchangers comprise a layer of gilt configured to increase the heat exchange.

10. Device according to any one of Claims 1 to 9, characterized in that the cryogenic cooler (4) comprises a refrigerator having a refrigeration cycle for a cycle fluid, said refrigerator comprising a cycle circuit (11) composed of the following elements arranged in series: a mechanism (12) for compressing the cycle fluid, at least one member (13) for cooling the cycle fluid, a mechanism (14) for expanding the cycle fluid, and at least one member (13) for reheating the expanded cycle fluid, wherein the cycle fluid comprises at least one of the following: helium, hydrogen, nitrogen, argon, and in that the cycle circuit (11) is configured to subject the cycle fluid to a thermodynamic cycle which brings the cycle fluid at at least one end of the cycle circuit (11) to a determined cold temperature, and in that the cycle fluid flow in heat exchange with said plates (5, 6) in the set of heat exchangers comprises the cycle fluid at the cold temperature, the device comprising a set of pipe(s) (8, 18) for supplying at least some of the fluid from the cycle circuit (11) to the set of exchangers and for returning said fluid from the set of exchangers to the cycle circuit (11) of the refrigerator (4).

11. Device according to Claim 10, characterized in that the cycle circuit (11) is configured to subject the cycle fluid to a thermodynamic cycle which brings the cycle fluid to a plurality of different cold temperatures at, respectively, a plurality of ends of the cycle circuit (11), and in that a plurality of separate flows of the cycle fluid at said different cold temperatures are placed in heat exchange with, respectively, the at least two separate plates (5, 6) via two respective sets of heat exchangers.

12. Device according to Claim 10 or 11, characterized in that the cycle fluid is or contains predominantly helium, the cycle circuit (11) being configured to bring the cycle fluid to at least one of the following cold temperatures: approximately 80 K, between 20 and 70 K, between 2 K and 5 K, and / or into a supercritical state.

13. Device according to any one of Claims 1 to 12, characterized in that the cryogenic cooler (4) comprises a reserve of liquefied cryogenic gas, for example of liquid nitrogen, and a set of pipe(s) (8, 18) for supplying liquefied cryogenic gas from the reserve to the set of exchangers.

14. Device according to any one of Claims 1 to 13, characterized in that it comprises a dilution refrigerator (9) in heat exchange with at least one plate (5, 6, 10).

15. Method for cryogenic refrigeration of sample(s) using a cryogenic refrigeration device according to any one of Claims 1 to 14, comprising a step of storing and / or producing a cold source of liquefied cycle fluid such as helium or nitrogen at the first end of the cryogenic cooler (4), a step of transferring a flow of this cycle fluid from the first end to the second end of the cryogenic cooler (4), said flow of cycle fluid being placed in heat exchange with the set of heat exchangers at the second end in a sealed manner without communicating with the internal gas volume of the enclosure (2).