Cryogenic cooling module and cryogenic cooling system

Abstract

A cryogenic cooling module comprises a vacuum chamber module (501) and a plurality of thermal stages (301, 302, 303) supported inside thereof spatially staggered from each other along a first direction (310) and one or more thermal radiation shields (304, 305, 306) corresponding to at least a subset of the thermal stages (301, 302, 303). The shape of the vacuum chamber module (501) is at least partially defined by one or more planar sides extending along the first direction (310). The vacuum chamber module (501) has an opening on one planar side, the edge (502) of the opening having a vacuum sealing structure for achieving a hermetically closed. The thermal stages (301, 302, 303) extend along a second direction (311) perpendicular to the first direction (310) to a first common interface plane (503) located at or close to the plane defined by the edge (502) of the opening. Each of the one or more thermal radiation shields has a corresponding second opening, the edge of the second opening extending to the first common interface plane (503).

Description

Technical Field

[0001] This invention relates to the field of cryogenic cooling system technology. Specifically, this invention relates to structural and functional solutions that enable easier construction, operation, maintenance, and subsequent modification of large-scale cryogenic cooling systems or cryogenic platforms. Background Technology

[0002] A cryogenic cooling system is a precision mechanical device designed to cool a target area or payload volume to extremely low temperatures and maintain such conditions for a desired period of time. The payload to be cooled may include, for example, scientific experiments, quantum computers, measuring devices, and / or other objects that require temperatures of only a few Kelvin or even well below 1 Kelvin to operate correctly. A cryogenic cooling system may also be called a cryostat. In some literature, the term cryogenic cooling system is used only for the subsystem within a cryostat that generates the low temperature, while the cryostat is also referred to as including other subsystems such as mechanical supports, vacuum pumping, radiation shielding, and wiring. In this document, the terms cryostat and cryogenic cooling system are used synonymously, possibly including the following interpretation: a cryostat can be relatively simple, such as a vacuum tank with a single cold source (mechanical cooler or liquid cryogenic bath), while a cryogenic cooling system can be more complex, with one or more external cold sources for pre-cooling and one or more internal cold sources (e.g., dilution refrigerators) for reaching the minimum temperature.

[0003] Figure 1 This is a simplified schematic diagram of a cryogenic cooling system equipped with a dilution refrigeration unit and a mechanical precooling unit. The outermost structure is a vacuum tank 101, which... Figure 1 The image is shown in dashed lines. The topmost flange 102 is the cover of the vacuum tank. The room temperature stage 103 of the mechanical precooler is attached here. The first stage 104 of the mechanical precooler is attached to the first flange 105, and the second stage 106 of the mechanical precooler is attached to the second flange 107. The first and second flanges may be referred to, for example, as 50K flanges and 4K flanges, reflecting their temperature during operation.

[0004] Further down are more flanges, such as still flange 108, to which still 109 of the dilution refrigeration unit is attached. Figure 1 In this configuration, the mixing chamber 110 of the dilution refrigeration unit is attached to a reference temperature flange 111. Reference numeral 112 indicates the payload to be refrigerated, commonly referred to as the sample. It is securely attached to the reference temperature flange 111 to ensure the best possible thermal conductivity. Because the reference temperature flange 111 is made of a material with the best possible thermal conductivity at low temperatures, the sample (or other form of payload) can be attached to any part of it. An extension structure, known as a cold finger, thermally coupled to the mixing chamber 110, can also be provided to offer a more suitable attachment position for the payload.

[0005] Cylindrical flat-bottomed radiation shield (not shown for clarity of the image) Figure 1 (As shown in the diagram) They are typically attached to flanges in a nested configuration to block radiative heat transfer from surrounding higher-temperature components to internally lower-temperature components. This configuration may include other intermediate flanges, such as the so-called 100mK flange between the still flange 108 and the reference temperature flange 111. Aligned holes 113, 114, and 115 may be present in the flanges to provide so-called line-of-sight ports to the sample 112, together with the cap 116 at the top.

[0006] Figure 2 Another cryogenic cooling system is shown, which in other respects is similar to... Figure 1 Similar, but includes the possibility of loading samples using a quick sample change mechanism (often simply referred to as a sample changer). This includes a loading lock 201 that can be attached to the gate valve 202. Figure 2 The system shown is a top-loading type, therefore the gate valve 202 is located in the cover 102 of the vacuum chamber 101. The sample holder 203 is located at the lower end of the elongated probe 204, which is detachable in its longitudinal direction ( Figure 1 The sample holder 203 moves vertically to ultimately attach to the target area 205 located on the reference temperature flange. In bottom-loading systems, the gate valve is located at the bottom of the vacuum chamber, allowing the sample to be loaded from below. Side-loading systems are also known, in which the sample loader is connected to a gate valve on the side of the vacuum chamber.

[0007] Figure 1 and Figure 2 The schematic illustration of this type of conventional cryogenic cooling system is roughly the size of a freestanding cabinet, with the reference temperature flange having a diameter on the order of tens of centimeters. In certain applications, particularly quantum computing, increasingly larger payload volumes and payload footprints are required. A straightforward way to provide larger payload volumes and / or footprints is to simply scale up the size of conventional structures. An example of a large cryogenic cooling system is proposed by M. Hollister, R. Dhuley, and G. Tatkowski in “A largemillikelvin platform at Fermilab for quantum computing applications,” available at https: / / arxiv.org / abs / 2108.10816v1. In this system, the cryostat has a payload volume of 2 meters in diameter and 1.5 meters in height.

[0008] Another method for increasing the effective payload volume and floor space of a cryostat is known from an online publication available at https: / / www.cryoworld.com / projects / project-1 / . In this method, a cylindrical main vacuum chamber is placed horizontally and fitted with a liquid helium-cooled 4 Kelvin base plate, measuring 4 meters in length and 60 centimeters in width. Rectangular doors on the sides of the vacuum chamber facilitate internal maintenance.

[0009] Other known methods for increasing the effective payload volume and occupied area of ​​cryogenic thermostats are known from patent publications EP 4184 081 and WO 2023 / 156801. In both, the cryogenic cooling system consists of modules that can be attached side-by-side to each other. Lateral extension structures are used to mechanically couple the thermal stages of adjacent modules, and also thermally couple them together if necessary.

[0010] Despite the known attempts mentioned above, providing cryogenic cooling systems with large payload volumes is no easy task. In particular, there is a desire to develop solutions that can flexibly provide large cryogenic cooling systems, adaptable to various and changing requirements regarding cooling capacity, cooling technology, reference temperature, and payload size and shape. More advanced solutions will also be welcome in the sense of facilitating the manufacture of large cryogenic systems and their transport between manufacturing and installation sites. Summary of the Invention

[0011] One objective is to provide a cryogenic cooling system with a large and flexibly adaptable payload volume; allowing for a large payload area at desired temperature levels; easy access to the payload area and components requiring maintenance; ease of operation and maintenance; and the ability to reach temperatures in the milliKelvin range or lower when needed. Another objective is that the cryogenic cooling system can flexibly adapt to different types of needs. Yet another objective is to ensure that the cryogenic cooling system is reliable in operation while being manufactured, assembled, and operated at a reasonable cost.

[0012] These and other advantageous objectives are achieved by constructing the cryogenic cooling system as a modular system having a constant structure of interfaces between the modules, wherein at least some structural elements that should continue to the next module extend to an interface plane defined by the edges of the modules.

[0013] According to a first aspect, a cryogenic cooling module is provided, comprising a vacuum chamber module. Supported within the vacuum chamber module are a plurality of thermal stages and one or more thermal radiation shielding elements, the plurality of thermal stages being spatially offset from each other at least along a first direction. The shape of the vacuum chamber module is at least partially defined by one or more planar sides extending along the first direction. The vacuum chamber module has at least one first opening on a first of the one or more planar sides, the edge of the first opening having a vacuum-sealing structure for achieving an airtight seal of the first opening. The thermal stages extend along a second direction perpendicular to the first direction to a first common interface plane located at or near the plane defined by the edge of the first opening. Each of the one or more thermal radiation shielding elements has a corresponding second opening, the edge of the second opening extending to the first common interface plane.

[0014] According to one embodiment, each of the one or more heat radiation shields is mechanically supported by one of the plurality of thermal levels. This involves at least the advantage of relatively simple mechanical structure, since it is not necessary to provide a dedicated support structure for each of the one or more heat radiation shields.

[0015] According to one embodiment, the cryogenic cooling module includes a dedicated support structure attached to the inside of the vacuum chamber module, and the dedicated support structure is configured to mechanically support one or more of the thermal radiation shielding elements independently of the plurality of thermal stages. This involves at least the following advantages: at least some of the thermal radiation shielding elements can be cooled independently of the thermal stages using a separate cooling system, which can have favorable results in determining the size of the cooling system.

[0016] According to one embodiment, the vacuum chamber module has at least two planar sides extending along the first direction and a third opening on the second planar side. The cryogenic cooling module may then include an openable seal attached hermetically to cover the third opening. This provides at least the advantage that access to the interior of the module can be arranged relatively easily even in a complete, assembled cryogenic cooling system.

[0017] According to one embodiment, at least a subset of one or more of the said thermal radiation shielding elements comprises modular thermal radiation shielding elements, each of which has a corresponding removable shielding component on the side facing the second of the planar sides. This involves at least the advantage of being able to arrange access to the internal space of each such modular thermal shielding element relatively simply.

[0018] According to one embodiment, the vacuum chamber module has at least three planar sides extending along the first direction and a fourth opening on the third planar side, the edge of the third opening having a vacuum-sealed structure for achieving an airtight seal of the fourth opening. The thermal stage then extends to a second common interface plane located at or near the plane defined by the edge of the fourth opening. Each of one or more of the thermal radiation shielding elements may have a corresponding fifth opening, the edge of which extends to the second common interface plane. This provides at least the advantage that the module can be used as part of a variety of differently assembled modular cryogenic cooling systems.

[0019] According to one embodiment, the cryogenic cooling module includes a shielding ring configured to block radiant heat from passing through any slit located at the edge of the second opening. This provides at least the following advantages: the thermal radiation shielding can be freely contracted during cooling, and radiant heat from external components can still be prevented from penetrating the interior of the thermal radiation shielding composed of portions located in adjacent modules.

[0020] According to one embodiment, the shielding ring is movable between a retracted position and an extended position, wherein in the retracted position, the shielding ring does not extend beyond the corresponding edge of the corresponding thermal radiation shield, and in the extended position, the shielding ring extends beyond the corresponding edge of the corresponding thermal radiation shield. This provides at least the advantage of preventing the shielding ring from making the removal and insertion of modules in a modular cryogenic cooling system excessively difficult.

[0021] According to a second aspect, a cryogenic cooling system is provided, comprising at least one cryogenic cooling module of the type described above and a first vacuum chamber end, the first vacuum chamber end being hermetically attached to cover the first opening in the vacuum chamber module of at least one of the cryogenic cooling modules. The cryogenic cooling system includes a cryogenic refrigerator configured to establish and maintain a cryogenic cooling state within at least one of the cryogenic cooling modules, and within the first vacuum chamber end, includes heat radiation shielding end pieces equal in number to heat radiation shielding pieces, the edges of the heat radiation shielding pieces corresponding to the second openings extending to the first common interface plane. Each heat radiation shielding end piece is connected to a corresponding at least one heat radiation shielding piece to cover the corresponding second opening on the corresponding at least one heat radiation shielding piece.

[0022] According to one embodiment, the cryogenic cooling system includes two or more cryogenic cooling modules, each of the type described above, which are attached to each other at the edges of openings on the sides of corresponding thermal stages and thermal radiation shields extending to corresponding common interface planes. The cryogenic cooling system may then include end modules equal in number to other openings on the sides of the two or more cryogenic cooling modules, each end module including a corresponding vacuum cavity end and a corresponding thermal radiation shield end of the type described above, on which the corresponding thermal stages and thermal radiation shields extend to corresponding common interface planes. The end modules may be attached hermetically to cover corresponding other openings in the assemblies of the two or more cryogenic cooling modules. This involves at least the advantage that hermetically sealed systems can be assembled in a variety of different configurations.

[0023] According to one embodiment, the two or more cryogenic cooling modules are different from each other in terms of the capacity of their built-in cryogenic refrigerators. This involves at least the following advantages: in a modularly assembled cryogenic cooling system, certain modules can be dedicated to essentially only cooling, while other modules can be dedicated, for example, to payload modules.

[0024] According to one embodiment, the two or more cryogenic cooling modules are different from each other in terms of the configuration of their built-in refrigeration payloads. This involves at least the following advantages: in a modularly assembled cryogenic cooling system, certain modules can be dedicated to essentially only cooling, while other modules can be dedicated, for example, to payload modules.

[0025] According to one embodiment, the thermal levels within the two or more cryogenic cooling modules form at least two subsets. One subset of thermal levels can be thermally coupled to form a common thermal level spanning at least two adjacent cryogenic cooling modules. The other subset of thermal levels can be thermally isolated from each other. This provides at least the advantage of enabling the construction of dedicated cooled payload areas within the cryogenic cooling system, where the cooling capacity of the cooling device is rationally distributed among various spaces and structures within the system.

[0026] According to one embodiment, the cryogenic cooling system includes thermal and mechanical coupling between two coplanar thermal stages within two adjacent cryogenic cooling modules of at least two or more cryogenic cooling modules. This thermal and mechanical coupling may include a slot or gap between two layers of a first material of the two coplanar thermal stages, the first material having a first coefficient of thermal expansion at cryogenic temperatures. At least one layer of a second material may be disposed within the slot or gap, the second material having a second coefficient of thermal expansion at cryogenic temperatures that is less than the first coefficient of thermal expansion. Thus, the two layers are part of one of the two coplanar thermal stages, with a part of the other coplanar thermal stage located therebetween, or the two layers are different parts of the two coplanar thermal stages. This involves at least the following advantage: the contraction caused by the temperature reduction can serve as a factor in maintaining good connections between the internal structural components of the cryogenic cooling system.

[0027] According to one embodiment, the cryogenic cooling modules of the cryogenic cooling system are located on more than one level relative to each other, wherein the more than one level is a level perpendicular to the first direction. The cryogenic cooling system may then include at least one interface between cryogenic cooling modules adjacent to each other in the first direction, wherein at this at least one interface, the shielding space inside the cryogenic cooling system extends through the plane where the two cryogenic cooling modules are attached to each other. This involves at least the following advantage: payload space of various sizes and shapes can be provided in a very flexible manner.

[0028] According to one embodiment, the cryogenic cooling system includes a support structure for supporting the cryogenic cooling module in an assembled configuration. This provides at least the advantage that the cryogenic cooling module itself does not need to bear all structural loads.

[0029] According to one embodiment, the support structure includes a track that supports one or more of the cryogenic cooling modules, enabling the one or more cryogenic cooling modules to move relative to other cryogenic cooling modules between a disassembled configuration and an assembled configuration along the track. This provides at least the advantage of facilitating the assembly and disassembly of the cryogenic cooling system. Attached Figure Description

[0030] The accompanying drawings, which are provided to further illustrate the invention and form part of this specification, depict embodiments of the invention and, together with the description, help explain the principles of the invention. In the drawings: Figure 1 This is a schematic diagram of a low-temperature thermostat equipped with a dilution refrigeration unit. Figure 2 This is a schematic diagram of a cryostat equipped with a dilution refrigerator and a sample changer. Figure 3The arrangement of nested cold stages and radiation shielding is schematically shown. Figure 4 The arrangement of nested cold stages and radiation shielding is schematically shown. Figure 5 The schematic diagram illustrates a component with one central module and two end modules. Figure 6 The assembly configuration is shown. Figure 5 Components, Figure 7 The schematic diagram illustrates a component with two central modules and two end modules. Figure 8 The isometric drawing schematically shows Figure 7 Type of component, Figure 9 The schematic diagram illustrates a component with multiple central modules and multiple end modules. Figures 10a to 10e An example of a modular configuration is shown. Figure 11 This illustrates one possible way to support a heat radiation shield inside the module. Figure 12 This illustrates one possible way to divide a cryogenic cooling domain into subdomains. Figure 13 This illustrates one possible manner in which the edge of a section of the coupling cold plate and / or radiation shielding is positioned. Figure 14 This illustrates one possible manner in which the edge of a section of the coupling cold plate and / or radiation shielding is positioned. Figure 15 This illustrates one possible manner in which the edge of a section of the coupling cold plate and / or radiation shielding is positioned. Figure 16 This illustrates one possible manner in which the edge of a section of the coupling cold plate and / or radiation shielding is positioned. Figure 17 The diagram schematically illustrates a component having modules located in more than one horizontal layer. Figure 18 It shows Figure 17 The cross-section of the component of the type shown. Figure 19 The diagram schematically illustrates a component having modules located in more than one horizontal layer. Figure 20 The diagram schematically illustrates a component having modules located in more than one horizontal layer. Figure 21 The diagram schematically illustrates a component consisting of two central modules and one example end module. Figure 22 Two heat radiation shields are shown before and after cooling. Figure 23 Two heat radiation shields and a shielding ring are shown before and after cooling. Figure 24 A thermal radiation shield and a movable shielding ring are shown. Figure 25 Details of the shielding ring are shown. Figure 26 A thermal radiation shield and a movable shielding ring are shown. Figure 27 Two thermal radiation shielding elements and a movable shielding ring are shown, as well as Figure 28 The image shows two thermal radiation shields, a shielding ring, and a coupling plate before and after cooling. Detailed Implementation

[0031] In the following description, reference is made to the accompanying drawings, which form part of the disclosure, in which specific aspects of the disclosure may be incorporated by way of example. It should be understood that other aspects may be utilized, and structural or logical changes may be made without departing from the scope of the disclosure. Therefore, the following detailed description should not be considered limiting, as the scope of the disclosure is defined by the appended claims.

[0032] For example, it should be understood that the disclosure of the described method is also applicable to corresponding devices or systems configured to perform the method, and vice versa. For example, if specific method steps are described, the corresponding device may include units for performing the described method steps, even if such units are not explicitly described or shown in the drawings. On the other hand, for example, if a specific device is described based on functional units, the corresponding method may include steps for performing the described functions, even if such steps are not explicitly described or shown in the drawings. Furthermore, it should be understood that, unless otherwise specifically stated, features of the various exemplary aspects described herein can be combined with each other.

[0033] Figure 3 An example is shown of how multiple thermal levels and nested thermal radiation shielding can be arranged. Figure 3 Multiple heat exchange plates 301, 302, and 303 are shown, spatially offset from each other in a first direction 310. For ease of description, the first direction 310 may be referred to as the vertical direction. However, this is not intended to limit the scope. Figure 3 The system of the type shown can be constructed and / or used in a manner or orientation. Following the same non-limiting convention, each of the heat-generating plates 301, 302, and 303 can be said to be in... Figure 3The orientation is horizontal. The heat stage plates 301, 302, and 303 are each shown as being composed of corresponding uniform elements, but this is not limiting, as one or more of them may consist of an arrangement of coplanar or substantially coplanar heat stage plate portions. As their names suggest, each of the heat stage plates 301, 302, and 303 (and each coplanar heat stage plate portion, if included in such an arrangement) is preferably made of a material that is a good thermal conductor at low temperatures. In cryogenic technology, good thermal conductivity can be, for example, at least 100 W / (m·K) at 10 K or higher, at least 10 W / (m·K) at 1 K, at least 1 W / (m·K) at 0.1 K, or at least 0.1 W / (m·K) at 0.01 K.

[0034] A support system is used to maintain this configuration of multiple thermal stage plates 301, 302, and 303. The support system may include, for example, a group of rods made of a material having low thermal conductivity at cryogenic temperatures. Such rods, if used, may be vertically oriented, i.e., oriented along a first direction 310, and / or inclined between adjacent thermal stage plates. In cryogenic technology, low thermal conductivity may be, for example, less than 50 W / (m·K) at 100 K, less than 5 W / (m·K) at 10 K, less than 0.75 W / (m·K) at 1 K, less than 0.075 W / (m·K) at 0.1 K, and less than 0.0075 W / (m·K) at 0.01 K. Furthermore, structural forms such as long, thin-walled tubes may be selected for parts of the support system to minimize the thermally conductive cross-section at each part intended to achieve low thermal conductivity. Some or all of the support structures may include thermal switches for selectively coupling selected thermal stage plates to each other for heat conduction and equally selectively thermally insulating them from each other.

[0035] Figure 3 The diagram also shows one or more thermal radiation shielding elements 304, 305, and 306 corresponding to at least a subset of thermal plates 301, 302, and 303. Figure 3 In the diagram, each of the three thermal plates 301, 302, and 303 has a corresponding heat radiation shielding element. For clarity, Figure 3 The support structures for mechanically supporting the thermal radiation shields 304, 305, and 306 are omitted. One possibility is that each thermal radiation shield is mechanically supported by a corresponding one of the multiple thermal stage plates. Another possibility is to provide a dedicated support structure configured to mechanically support one or more thermal radiation shields 304, 305, and 306 independently of the thermal stage plates 301, 302, and 303. Hybrid embodiments are also possible, in which one or more thermal radiation shields are mechanically supported by corresponding thermal stage plates, while one or more other thermal radiation shields are mechanically supported by a dedicated support structure.

[0036] exist Figure 3In the illustrated embodiment, at least a subset of thermal radiation shielding elements 304, 305, and 306 comprises modular thermal radiation shielding elements. Each such modular thermal radiation shielding element has a corresponding removable shielding component 307, 308, or 309 on one side of this arrangement. Any modular thermal radiation shielding element, or even all modular thermal radiation shielding elements, may have more than one corresponding removable shielding component. In such cases, more than one corresponding removable shielding component may all be located on the same side and / or different sides of this arrangement.

[0037] If the first direction 310 is referred to as the vertical direction, then two other directions 311 and 312 may be considered. These two directions may be perpendicular to each other and perpendicular to the first direction 310, such that directions 310, 311, and 312 define the three axes of a three-dimensional Cartesian coordinate system. Perpendicular to the first or “vertical” direction 310 makes the other two directions 311 and 312 “horizontal” directions. For clarity of reference, they may be referred to as the second direction 311 and the third direction 312.

[0038] In the second direction 311, thermal plates 301, 302, and 303 extend to the common interface plane. In other words, all visible edges of thermal plates 301, 302, and 303 that are not attached to removable shielding components are located at the same height of an imaginary vertical plane.

[0039] Compared to most existing cryostats, Figure 3 A key feature is that even when the removable shielding components 307, 308, and 309 are attached to their corresponding positions as shown by the dashed lines, no combination of the thermal stage plates and their corresponding heat radiation shields constitutes a completely enclosed structure. Instead, each of the heat radiation shields 304, 305, and 306 has a corresponding opening whose edges extend to the same common interface plane to which the thermal stage plates 301, 302, and 303 also extend. The same applies to opposite sides of the structure, such that each thermal stage plate and its corresponding heat radiation shield constitutes a three-dimensional (here, also rectangular) ring-shaped structural element. Viewed along the second direction 311, in Figure 3 The structure shown has similar openings and a common interface plane at both ends.

[0040] Figure 4 In the future is Figure 3 The arrangement of the heat-generating plates and heat radiation shielding components, wherein the removable shielding components are in appropriate positions. Figure 4In the background is a set of heat radiation shielding end pieces 401, 402, and 403. The number of heat radiation shielding end pieces 401, 402, and 403 is equal to the number of heat radiation shielding pieces 304, 305, and 306. Therefore, this set of heat radiation shielding end pieces 401, 402, and 403 is very similar to the components of heat stage plates 301, 302, and 303 and heat radiation shielding pieces 304, 305, and 306; however, there is one important difference. Each heat radiation shielding end piece 401, 402, and 403 is concave, not annular. This means that although each heat radiation shielding end piece 401, 402, and 403 is concave, it is not annular. Figure 4 It has an opening on one visible side, but is closed on the other side. Figure 4 The edge of each visible opening extends to the common interface plane, but the thermal radiation shielding ends 401, 402 and 403 have different dimensions in the second direction 311: the innermost thermal radiation shielding end 403 is the shallowest and the outermost thermal radiation shielding end 401 is the deepest, making the set of thermal radiation shielding ends 401, 402 and 403 like a set of nested open boxes or containers that do not contact each other.

[0041] Figure 5 and Figure 6 This is a cross-sectional view of a cryogenic cooling system that includes three cryogenic cooling modules. Figure 5 In the middle, the three modules are shown offset from each other in the horizontal direction, while... Figure 6 In this context, identical modules are attached together.

[0042] The largest central module is in Figure 5 and Figure 6 The system includes a vacuum cavity module 501 as its outermost structural element. Supported within the vacuum cavity module 501 are a plurality of thermal stage plates 301, 302, and 303 spatially offset from each other in a first direction 310. Also supported within the vacuum cavity module 501 are one or more heat radiation shields 304, 305, and 306 corresponding to at least a subset of the thermal stage plates 301, 302, and 303. As indicated by the same reference numerals, the thermal stage plates 301, 302, and 303 and the heat radiation shields 304, 305, and 306 may conform to the above description. Figure 3 and Figure 4 The same structural principle applies. For clarity of the diagram, Figure 5 and Figure 6 The supporting structure is not shown, but it can be supported inside the vacuum chamber module 501 by following a similar principle as explained above.

[0043] The polyhedral shape of the vacuum cavity module 501 is at least partially defined by a planar side extending along a first direction 310, in which... Figure 5 and Figure 6The direction is also vertical. Therefore, the vacuum chamber module does not need to have a polyhedral shape, because for the purposes of the following explanation, it is sufficient to have at least one planar side extending along the first direction 310. The vacuum chamber module 501 has a first opening on the first of said planar sides. Figure 5 This is the opening on the left side of the central module. A vacuum-sealing structure is provided on the edge 502 of the first opening to achieve an airtight seal. The vacuum-sealing structure can be as simple as a solid, appropriately designed edge surface to which a sealing member can be airtightly attached, possibly with a sealing member such as an O-ring or indium layer. More complex forms of vacuum-sealing structures may include, for example, multiple sealing surfaces and / or integrally attached sealing members.

[0044] Second direction 311 Figure 5 and Figure 6 The middle direction is also horizontal, and therefore perpendicular to the first (vertical) direction 310. In the second direction 311, the thermal plates 301, 302, and 303 inside the vacuum chamber module 501 extend to a first common interface plane 503 located at or near the plane defined by the edge 502 of the first opening in the vacuum chamber module 501. Each of one or more thermal radiation shielding elements 304, 305, and 306 has a corresponding second opening, the edge of which also extends to the first common interface plane 503.

[0045] exist Figure 5 and Figure 6 To the left of the central module is another cryogenic cooling module, whose basic structure corresponds to the structure explained above for the central module. For clarity of reference, the outermost structural element of this other cryogenic cooling module is hereinafter referred to as vacuum chamber end 504. However, it may also be referred to as a vacuum chamber module, as it is part of a modular vacuum chamber, as will become clear from the following description.

[0046] Figure 5 and Figure 6 The leftmost module includes, within the first vacuum cavity end 504, thermal radiation shielding ends 401, 402, and 403 in number equal to those in the central module, representing thermal radiation shielding ends 304, 305, and 306. When the central module and the leftmost module are attached together at the first common interface plane 503, each of the thermal radiation shielding ends 401, 402, and 403 connects to at least one corresponding thermal radiation shielding end 304, 305, or 306 to cover a corresponding (“second”) opening in that at least one thermal radiation shielding end 304, 305, or 306.

[0047] Figure 5 and Figure 6The cryogenic cooling system shown is symmetrical with respect to its vertical centerline. Therefore, to the right of the central module is another cryogenic cooling module, whose components and structure are essentially a mirror image of the left-hand module. In the second direction 311, thermal plates 301, 302, and 303 extend to a second common interface plane 506 located at or near the plane defined by the edge 505 of the openings of the vacuum chamber module 501 on that side. Similar to the left edge 502, the right edge 505 of the vacuum chamber module 501 also includes a vacuum-sealing structure for achieving an airtight seal of the corresponding opening.

[0048] The vacuum cavity end in the rightmost module is marked with reference numeral 507. The number of heat radiation shielding ends 508, 509, and 510 is equal to the number of heat radiation shielding ends 304, 305, and 306, with the edges of their corresponding openings extending to the second common interface plane 506. Each of the heat radiation shielding ends 508, 509, and 510 is connected to at least one corresponding heat radiation shielding end 304, 305, or 306 to cover the corresponding opening in that heat radiation shielding end 304, 305, or 306.

[0049] exist Figure 5 and Figure 6 It is important to note that, individually, each of the three modules conforms to the definition of a cryogenic cooling module. Each of them has a corresponding vacuum chamber module, within which multiple thermal stage plates and one or more thermal radiation shielding elements are supported. The shape of each vacuum chamber module is at least partially defined by one or more planar sides extending along a first (vertical) direction, and each vacuum chamber module has at least one first opening on the first of the one or more planar sides, the edge of which has a vacuum-sealed structure for achieving an airtight seal. The corresponding thermal stage plate extends along a second direction perpendicular to the first direction to a first common interface plane located at or near the plane defined by the edge of the first opening. And each of the one or more thermal radiation shielding elements has a corresponding second opening, the edge of which extends to the first common interface plane.

[0050] However, the end modules can be constructed in a slightly different manner. Since the ends 401, 402, 403, 508, 509, and 510 of the heat radiation shielding essentially function to close the corresponding sides of the corresponding heat radiation shielding, it is not necessary to have a section of thermal plate on top of each of them. In other words, each end of the heat radiation shielding can simply be an open box or enclosure appropriately formed from a sheet of material used only for heat radiation shielding (such as aluminum, copper, brass, or other materials that are good thermal conductors at low cooling temperatures).

[0051] Another point to note is that Figure 5 and Figure 6 The cryogenic cooling system does not need to be symmetrical about its central vertical axis, or in fact, it does not need to be symmetrical about any axis. For example, Figure 5 and Figure 6 The end of a vacuum cavity and the end of its internal heat radiation shielding may not be, for example, such as Figure 5 and Figure 6 Instead of detachable modules like those in the middle, the remaining modules are integrated with the central module, resulting in only one common interface plane where the two remaining modules are attached to each other.

[0052] Figure 7 This illustrates an example of how the modular approach explained above can be applied to construct a cryogenic cooling system. The cryogenic cooling system includes at least one inner-type cryogenic cooling module, meaning such as... Figure 5 and Figure 6 A module like the central module. In Figure 7 In this embodiment, there are two internally shaped cryogenic cooling modules 701 and 702, which are attached together at their corresponding common interface planes. Furthermore, since the presence of at least one internally shaped cryogenic cooling module implies the presence of at least one first-type opening with a vacuum-sealed edge, the cryogenic cooling system includes a first vacuum chamber end (see [link]). Figure 5 Vacuum cavity ends 504 and 507 are hermetically attached to cover the first type of opening in the vacuum cavity module of the at least one inner-type cryogenic cooling module. Figure 7 In one embodiment, there are two outer-type modules 703 and 704, each attached to cover the corresponding remaining opening in one of the inner-type cryogenic cooling modules 701 and 702.

[0053] The cryogenic cooling system includes at least one cryogenic refrigerator configured to establish and maintain a cryogenic cooling state within the at least one cryogenic cooling module. Figure 7 In one embodiment, the cryogenic refrigerator is included in block 705, which is schematically shown and forms part of the leftmost inner cryogenic cooling module 701.

[0054] One advantage of the modular approach is that the modules of a cryogenic cooling system do not need to be similar to each other in terms of cryogenic refrigerator capacity and / or the space available for the payload on the cryogenic cooling heat stage plate. According to Figure 7 The principle illustrated allows for the inclusion of one or more modules dedicated to refrigeration, gas handling, and general housekeeping. This is Figure 7The function of the leftmost inner cryogenic cooling module 701 is as follows. Modules 701 and 702 differ in their built-in cryogenic capacity because the other inner cryogenic cooling module 702 does not include any cryogenic refrigerator of its own. The thermal coupling between the corresponding hot plate stage and the corresponding heat radiation shield is responsible for keeping the hot plate stage and heat radiation shield in the other inner cryogenic cooling module 702 sufficiently cold. Similarly, the thermal coupling ensures that the ends of the heat radiation shields in the outermost modules 703 and 704 are also maintained at their desired low temperatures during operation.

[0055] Various types of cooling mechanisms and devices can be used within block 705, which is schematically shown, to cool portions of the cryogenic cooling system. This also applies to all cryogenic cooling systems indicated and described herein. As an example, in Figure 7 Of the three nested thermal radiation shields shown, the two outer thermal radiation shields can be cooled using one or more mechanical chillers (such as pulse tubes, Gifford-McMahon cryogenic chillers, etc.). Alternatively, or particularly if there is an outermost thermal radiation shield that only needs cooling to slightly below zero degrees Celsius, a compressor-type mechanical chiller can be used. One or more inner thermal radiation shields (if present) can be cooled, for example, using one or more dilution chillers. Another possible way to cool certain dedicated sections within the cryogenic cooling system is to circulate a cooled working fluid (such as liquid helium) through appropriately positioned conduits that are thermally coupled to one or more sections to be cooled.

[0056] The configuration of the cooling payload of the cryogenic cooling modules does not need to be equal. Figure 7 The innermost low-temperature cooling module 702 on the far right is the payload module. Its significance lies in providing as much space as possible for experiments and signal lines. Figure 7 Block 706 in the diagram represents this. The concept of a refrigerated payload refers to all parts and components that are intentionally exposed to arranged refrigeration to maintain them at temperatures below room temperature during operation. Examples of refrigerated payloads include, but are not limited to, refrigerated circuits (such as those in a quantum computer) and signal lines traveling to and from those circuits. Other examples are scientific experiments that require at least some of the materials and components involved to be cooled to cryogenic temperatures. Still others are stored samples that must be kept at extremely low temperatures to prevent undesirable changes in their composition and / or properties. Yet still others are electromagnets whose current-carrying parts are made of superconducting materials.

[0057] Figure 8 This is an exploded isometric view of an example of a cryogenic cooling system consisting of two internal cryogenic cooling modules 701 and 702 and two external modules 703 and 704, as shown in the image. Figure 7The outermost structural element of each module is the corresponding vacuum chamber module, so that in the assembled configuration, the cryogenic cooling system will generally appear as a large vacuum chamber. Each vacuum chamber module has a shape defined by one or more generally vertical planar sides, as well as a top and a bottom.

[0058] The second inner cryogenic cooling module 702 can be observed more closely. The vacuum chamber module 501, as its outermost structural element, has an opening on one of the planar sides defining its polyhedral shape, referred to herein as the third opening for clarity. The cryogenic cooling module includes an openable seal 801, which is hermetically attached in the assembled configuration to cover the third opening. The third opening in the vacuum chamber module 501 coincides with the position of corresponding removable shielding components 307, 308, and 309 on the corresponding sides of the thermal radiation shielding components 304, 305, and 306 facing that side of the vacuum chamber module 501.

[0059] The openable seal 801 and the correspondingly positioned removable shielding components 307, 308, and 309 facilitate access to the interior of at least the second inner cryogenic cooling module 702. This access is readily available during the assembly phase (where cryogenic cooling system modules 701, 702, 703, and 704 are assembled together) and during use, allowing the user to access the internal components without disassembling modules 701, 702, 703, and 704 from each other.

[0060] exist Figure 8 In the embodiments, the first internal cryogenic cooling module 701 also includes a similar solution with similar advantages, although the openable seal 802 and its internal removable shielding components... Figure 8 The corresponding attachment position is shown in the figure.

[0061] Figure 8 Another advantageous possibility shown is that the internal cryogenic cooling modules 701 and 702 have been derived from... Figure 5 The known "see-through" configuration: both have two distinct sides on which another internal cryogenic cooling module or an external module can be attached. For example, in an assembly configuration, a first internal cryogenic cooling module 701 will have a second internal cryogenic cooling module 702 attached to one side, and an external module 703 attached to the opposite side. These two sides can be more accurately characterized as follows: the vacuum chamber has an opening on the corresponding planar side, and the edge of the third opening has a vacuum-sealed structure for achieving an airtight seal of the fourth opening. Inside the corresponding vacuum chamber module, a thermal stage plate extends to a common interface plane located at or near the plane defined by the edge of the opening. Each of one or more thermal radiation shielding elements has a corresponding opening whose edge extends to the common interface plane.

[0062] If all modules of the cryogenic cooling system are such as Figure 4 Low-temperature cooling modules such as the 701 and 702, or similar internal types. Figure 4 For modules with external shapes like 703 and 704, the assembled cryogenic cooling system can be described as follows: There are two or more internal cryogenic cooling modules 701 and 702, attached to each other at the edge of the opening on the side where their corresponding heat stage plates and heat radiation shields extend to the corresponding common interface plane. Furthermore, there are a plurality of external modules 703 and 704, equal in number to the number of other openings on the side surfaces of the two or more internal cryogenic cooling modules 701 and 702, each including a corresponding vacuum chamber end and a corresponding heat radiation shield end, on the side surfaces of the two or more internal cryogenic cooling modules 701 and 702, where the corresponding heat stage plates and heat radiation shields extend to the corresponding common interface plane. The external modules 703 and 704 are attached hermetically to cover the corresponding other openings in the assembly of the two or more internal cryogenic cooling modules 701 and 702.

[0063] The fact that the number of external modules is equal to the number of other openings on the sides of the internal modules means that embodiments without any external modules are also possible. That is, two internal modules can exist, each having only one opening on a single planar side, the edges of which have a vacuum-sealed structure for hermetic sealing. The thermal stage inside the module can then extend to a common interface plane located at or near the plane defined by the edges of such openings. Similarly, each of the internal thermal radiation shielding elements can have a corresponding second opening, the edges of which extend to the common interface plane. A modularly assembled cryogenic cooling system would then consist of such two internal modules attached to each other via the edges of their corresponding openings.

[0064] In all embodiments with two or more internal cryogenic cooling modules, the modules may differ in terms of the capacity of their built-in cryogenic chillers. Similarly, the modules may differ in terms of the configuration of their built-in refrigeration payload space. As explained above, for example, there may be one or more dedicated cooling modules that primarily contain cryogenic chillers and one or more dedicated payload modules that primarily contain space for the payload to be refrigerated.

[0065] Figure 9 and Figures 10a to 10e Examples of various possible module configurations for a cryogenic cooling system that follow the basic principles explained above are shown. Figure 9 The low-temperature cooling system in the middle has such as Figure 7 and Figure 8The module includes two similar internal cryogenic cooling modules 701 and 702, and an external module 703 attached to another opening of one of them. Furthermore, Figure 9 The low-temperature cooling system in the middle has an attachment to Figure 7 and Figure 8 Another hexagonal-shaped cryogenic cooling module 901 is attached to the location of another external module 704. The hexagonal module 901 has two additional openings on its vertical side to which the two other external modules 704 and 902 are attached. Such as Figure 9 More spacious modules, such as the 901 hexagonal module, can be particularly advantageous because they provide more area that can be used to accommodate the cooling payload.

[0066] Figures 10a to 10e This is a schematic footprint of various modular cryogenic cooling systems assembled from modules. In each of these schematic footprints, a common interface plane is marked by a dashed line, at which the thermal stage plate and thermal radiation shield can extend from one module to the adjacent module without any extension plates, because the thermal stage plate and thermal radiation shield advantageously extend from both sides to the corresponding common interface plane. Flat side plates on slightly protruding edges, such as... Figure 10a Side panels 1001 and 1002 show openable seals that can be hermetically attached to cover openings on the module side. Most advantageously, at corresponding locations within the corresponding modules, at least some of the thermal radiation shielding components contain removable shielding elements, thereby allowing for [further details referenced above]. Figure 8 The interior of the corresponding module is near.

[0067] Figure 10a Is it like this? Figure 5 and Figure 6 The low-temperature cooling system occupies an area with an internal low-temperature cooling module 701 and two external modules 703 and 704. Figure 10b Is it like this? Figure 7 and Figure 8 The low-temperature cooling system occupies an area with two internal low-temperature cooling modules 701 and 702 and two external modules 703 and 704, all arranged linearly in a row. Figure 10c Other aspects, such as Figure 7 , Figure 8 and Figure 10b The cryogenic cooling system occupies a certain area, but there is another internal cryogenic cooling module 1003 in the middle of the linear arrangement of modules, although it is slightly narrower in one dimension. This reminds us that not all cryogenic cooling modules in a cryogenic cooling system need to have the same size.

[0068] Figure 10d Is it like this? Figure 9The cryogenic cooling system occupies an area with three internal cryogenic cooling modules 701, 702, and 901, one of which is larger than the other two and has a different shape (hexagon versus rectangle). There are three external modules 703, 704, and 902 attached to such openings, or the modular cryogenic cooling system can continue to accommodate other modules at these openings. This reminds us that not all cryogenic cooling modules in a cryogenic cooling system need to have the same size or shape.

[0069] Figure 10e This refers to the footprint of the cryogenic cooling system. One of the internal cryogenic cooling modules 1004 has three sides with openings to which other modules of the cryogenic cooling system can be attached. The three internal cryogenic cooling modules 701, 702, and 1004 are located together in… Figure 10e The L-shaped footprint of the module reminds us of two things. First, a cryogenic cooling module can have one, two, or more of these sides to which other modules of the cryogenic cooling system can be attached. Second, in an assembly configuration, the modules of the cryogenic cooling system do not necessarily have to be arranged linearly one after another.

[0070] Figure 11 An example of a dedicated support structure 1101 that can be attached to the interior of a vacuum chamber module is shown. The dedicated support structure 1101 can thus mechanically support at least some of the thermal radiation shielding elements within the vacuum chamber module independently of the thermal stage plate. In this example, the dedicated support structure 1101 includes an array of support rods to which shielding components 304, 305, and 306 of corresponding modular thermal radiation shielding elements can be attached. In this example, each thermal radiation shielding element can be assembled within the module from two similar halves, each half including an extension extending from... Figure 11 The bottom half of the imaginary center line of the structure extending from left to right. Figure 11 Only the halves facing the observer are shown.

[0071] Figure 12 This is a schematic cross-section of a cryogenic cooling system, where not all heat exchange plates extend across the entire length of the system through all modules. Figure 12 The main structural system can be assembled, for example, by arranging five inner-shaped cryogenic cooling modules in a row, with corresponding outer-shaped modules at each end of the row. Of the five inner-shaped cryogenic cooling modules, the first, third, and fifth modules are full-size, while the second and fourth modules are smaller in size along the linear direction through which the assembled modules are located. Inside the second and fourth modules, at least some heat radiation shielding does not extend through the entire module. Instead, inside the second and fourth modules, some heat radiation shielding modules are similar to those also present inside the outer-shaped modules, but placed back-to-back, such that they enclose the corresponding heat radiation shielding in adjacent modules rather than extending across them.

[0072] Thus, the thermal levels within the cryogenic cooling module can be formed into at least two subsets in terms of their thermal coupling or thermal isolation from each other. Figure 12 In the example shown, thermal stage plates 1201, 1204, and 1207 are thermally coupled and form a common thermal stage spanning at least two (in this case, five) adjacent modules. Thermal stages 1203, 1206, and 1209 form another subset by thermally isolating each other.

[0073] Regarding coplanar thermal plates that should be thermally coupled to each other within adjacent cryogenic cooling modules, it is advantageous to use some suitable type of combined thermal and mechanical coupling between them. This coupling should take into account the changes in the physical dimensions of the objects caused by relatively large temperature variations when the assembled cryogenic cooling system is put into operation. Figures 13 to 16 Some advantageous forms of thermal and mechanical coupling are shown in cross-section.

[0074] exist Figure 13 In this configuration, the edge of the first coplanar heating plate 1301 is thinned and formed into an arch, with its distal end bolted to the edge of the second coplanar heating plate 1302. Figure 14 In this configuration, the flexible material of strip 1401 connects two coplanar thermal plates 1301 and 1302. The flexible material may be, for example, copper braid or a section of good thermal conductor material bent into an arc or meandering cross-sectional shape.

[0075] Figure 15 and Figure 16 An example is shown where the mechanical-thermal coupling includes a slot or gap between two layers 1501, 1502, 1601, and 1602 of a first material of two coplanar thermal plates 1301 and 1302. This first material has a first coefficient of thermal expansion at low temperatures. Within the slot or gap, there is at least one layer of a second material 1503, 1603, or 1604. The second material is selected to have a second coefficient of thermal expansion at low temperatures that is less than the first coefficient of thermal expansion. In other words, the relative effect of temperature changes on the dimensions of the second material is less than the corresponding change in the dimensions of the first material. When cooled, the second material contracts less than the first material.

[0076] exist Figure 15In the example shown, layers 1501 and 1502 are part of one of the two coplanar thermal plates (here: thermal plate 1301 on the right). A portion 1504 of the other coplanar thermal plate (thermal plate 1302 on the left) extends between them. A layer 1503 of the second material is stacked in the same gap along with a portion 1504 of the other thermal plate 1302 extending into the gap. Now, as layers labeled 1501, 1502, and 1504 shrink in thickness due to the drop in temperature, layer 1503 shrinks relatively less, causing the gap to be tightly compressed around portion 1504 and layer 1503. Thus, the colder it gets, the stronger the mechanical support provided by the joint.

[0077] exist Figure 16 In the example shown, layers 1601 and 1602 are portions of different heat stages in the two coplanar heat stage plates 1301 and 1302. As shown in the enlarged view, layers 1603 and 1604 of the second material are located between them. Thermal shrinkage reduces all dimensions of the structure to a relatively equal degree, except for the dimensions of layers 1603 and 1604, which again leads to extrusion. Furthermore, the matching patterns of the serrated ridges and grooves in the mating surfaces of layers 1603 and 1604 are formed such that any tendency for the coplanar heat stage plates 1301 and 1302 to pull apart from each other in the horizontal direction will increase the total thickness of the two stacked layers, thereby enhancing the extrusion effect.

[0078] Figures 13 to 16 The example also illustrates the meaning of the definition of "a common interface plane located at or near the plane defined by the edge of the first opening." The thermal stage extending to this common interface plane must extend sufficiently close to the plane where the two adjacent vacuum chamber modules are attached to each other, so that the thermal stages within the adjacent vacuum chamber modules can couple together without the aid of an additional intermediate extension. Figures 13 to 16 In each of these examples, the vertical dashed line in the middle indicates one possible location on the plane where two adjacent vacuum chamber modules are attached to each other. In many examples, at least one edge of the thermal stage does not extend completely into the dashed line. There are also examples where at least one edge of the thermal stage extends beyond the dashed line. For those thermal stages (and other structures to be joined) that should extend from module to module, the chosen joining method thus defines how close is close enough.

[0079] In a cryogenic cooling system, modules may be located on one or more horizontal levels relative to each other, and the interfaces between adjacent modules may also open in other directions that would be considered horizontal in the examples discussed above. Figure 17This is a schematic isometric view of a cryogenic cooling system comprising five inner cryogenic cooling modules. Modules 1701, 1702, 1703, and 1704 are located on the same horizontal level, forming a T-shaped footprint in this example. The fifth inner cryogenic cooling module, 1705, is directly above module 1701.

[0080] Figure 17 The cryogenic cooling system comprises a total of eight external modules. Figure 17 The figures are shown with reference numerals 1711 to 1718. In the lower horizontal plane, external modules 1711, 1712, 1713, and 1714 are attached to selected free sides of modules 1701, 1702, 1703, and 1704, respectively. In the upper horizontal plane, corresponding external modules 1715, 1716, 1717, or 1718 are attached to each side of the fifth internal cryogenic cooling module 1705.

[0081] Figure 18 yes Figure 17 A schematic cross-section of a cryogenic cooling system in an imaginary plane, which will extend along... Figure 17 The system is cut by the dashed line shown. Figure 18 The external shape of each of the modules is shown (where...) Figure 18 The visible modules 1711, 1712, 1715, and 1716 have an arrangement of nested concave thermal radiation shielding portions that enclose the shielding space inside the cryogenic cooling system at their respective ends. The first inner cryogenic cooling module 1701 on the left and the fifth inner cryogenic cooling module 1705 above it have their internal structures and special arrangements of their respective upper and lower surfaces, such that the shielding space inside the cryogenic cooling system extends through the horizontal plane where the two inner cryogenic cooling modules are attached to each other.

[0082] The arrangement of cryogenic cooling modules across multiple horizontal levels can be used, for example, in situations where a certain payload requires an exceptionally high space within the cryogenic cooling system.

[0083] Whether the modules are located in one or more horizontal planes, it is advantageous (though not mandatory) that the assembly system allows each internal module to be reasonably easily accessed in the finished system from at least one side, either by removing the corresponding external module on that side, or—more advantageously—by opening, such as Figure 8 The openable seal is shown in the attached drawing 801. Even more advantageous is to design the system so that as many sides of each internal module remain accessible.

[0084] Examples of such components are shown in Figure 19 and Figure 20 In. Figure 19 In some embodiments, the inner modules form a wall, and the columns may have the same number of stacked modules or different numbers of stacked modules. Figure 19 In the first column of the example system shown, there are three stacked modules 1901, 1902, and 1903. In the next column, there is only one module 1904, and so on.

[0085] Figure 19 It also demonstrates the principle that supporting functions such as gas handling subsystems, power, communication, and telemetry can be added as add-ons to modular components. Figure 19 In this embodiment, support functional subassemblies 1905 and 1906 are positioned at appropriate locations adjacent to the wall comprised of inner-type modules. The connection between each support functional subassembly and a corresponding one (or more) of the inner-type modules is schematically shown using reference numerals 1907 and 1908. This connection may, for example, include cables, gas conduits, mechanical support entities, and / or the like. As an advantageous detail, support functional subassemblies 1905 and 1906 are constructed in the form of brackets with lockable wheels, making it easier to find a suitable position adjacent to the inner-type modules and then secure them in place.

[0086] exist Figure 20 In one embodiment, the inner-shaped module forms several parallel walls; Figure 20 Three of these walls are shown. A bridging module can be used to connect selected modules within this wall; see [link to relevant documentation]. Figure 20 The bridging modules 2001, 2002, and 2003 are included. Figure 20 It is worth noting that although, for example, bridging modules 2001 and 2002 are located between the same two module walls, they are on different horizontal levels: the preceding bridging module 2001 is on the lower level, and the following bridging module 2002 is on the upper level. In the next gap between adjacent module walls, bridging module 2003 is on the upper level; another bridging module may exist in the same gap but on the lower level, such that bridging modules alternate between levels in two orthogonal directions across the module grid. This alternating strategy of placing bridging modules helps to maintain the maximum possible lateral accessibility of the internal modules.

[0087] Which sides of the internal module have built-in openable seals and which sides are covered by the corresponding external module, as mentioned above... Figure 19 and Figure 20 The considerations are not important. Figure 19 and Figure 20 The module space arrangements shown are for illustrative purposes only, as they can vary in terms of where and how many modules are placed within the finished component.

[0088] Figure 21A portion of a cryogenic cooling system with two internal modules 2101 and 2102 is shown. An example of the external module 2103 is shown in... Figure 21 As shown on the right side. Figure 21 In the system, each inner module has a general cylindrical shape, but with two planar sides extending vertically. On each planar side, there are two openings with vacuum-sealed edges, allowing connection to another inner module or an outer module. In this embodiment, the outer module consists of two sub-modules.

[0089] exist Figure 21 In this embodiment, not all thermal stages within each internal module are necessarily planar. Instead, at least some thermal stages may have a three-dimensional form, allowing their edges to extend through openings to the common interface plane between modules. In this way, the effects of thermal stages and associated radiation shielding can become intertwined, such that a three-dimensional solid made of one or more thermally conductive materials can simultaneously constitute both thermal stages and associated radiation shielding.

[0090] Figure 21 The lower part shows how an openable seal can be present on the circular side portion of the vacuum chamber module. Figure 21 In this configuration, one of the openable seals is an arc-shaped door 2104 that has been opened and is supported by a hinge 2105 on one of its edges. The radiation shielding inside the vacuum chamber module can then have a correspondingly formed openable portion through which access to the innermost part of the system is made.

[0091] As a noteworthy detail, it is not always necessary to attach two adjacent inner modules to each other to have a thermally conductive connection between them. According to one embodiment, any subset of the mutually matching mechanical features (or even all the mutually matching mechanical features in the two adjacent inner modules) can have a mechanically supported but thermally insulated connection between them.

[0092] The cryogenic cooling system may include various support structures for supporting the module in its assembled configuration, but possibly also prior to its final assembly. An example of such a support structure includes a track that supports one or more modules, enabling the modules to move relative to other modules between disassembled and assembled configurations. The track, if configured, may be located below, to the side of, and / or above the module in question.

[0093] In all the above embodiments, thermal shrinkage of structural components should be appropriately addressed. The following considers some aspects related to the thermal shrinkage of thermal radiation shielding components.

[0094] Figure 22The left portion shows two thermal radiation shielding elements 304 and 2201. Based on the principles described above, it is assumed that each of them is a thermal radiation shielding element inside the corresponding vacuum cavity module. Figure 8 In contrast, thermal radiation shielding component 304 can be the corresponding thermal radiation shielding component marked inside module 702, and thermal radiation shielding component 2201 can be the thermal radiation shielding component inside module 701 that needs to be cooled to the same temperature. The openings of thermal radiation shielding components 304 and 2201 that face each other abut against each other during assembly.

[0095] Whether the components of the thermal radiation shield described herein include the corresponding heat-generating stage or flange in the cryostat is irrelevant to this description. Typically, the flange of the cryostat and the thermal radiation shield attached to its edge form an enclosure. This description also applies to solutions where the thermal radiation shield is structurally independent of the heat-generating stage or flange.

[0096] The outer walls of each vacuum chamber module face room temperature, thus they remain at room temperature during operation. Therefore, the outer walls do not exhibit any significant thermal shrinkage during cooling. Conversely, the cooled portions inside each vacuum chamber module will shrink proportionally with the temperature drop. Aluminum (a material commonly used in heat radiation shielding) can shrink several millimeters per meter. Thermal shrinkage can cause slits 2202 to form between adjacent heat radiation shielding elements, such as... Figure 22 The right part and a close-up view are shown.

[0097] Any slit in a thermal radiation shield exposes the colder parts inside the shield to radiant heat from the warmer parts outside. If aligned slits exist in nested thermal radiation shields, such as those extending at their edges to the common interface plane between modules, some radiant heat can penetrate two or more shields, resulting in a significant heat load on the cryogenic refrigerator that keeps the innermost part of the cryostat as cold as possible.

[0098] Figure 23 A solution to the potential problem of contraction-based slits is shown. For example... Figure 23 As shown, a shielding ring 2301 can be installed to block any direct line-of-sight path through any possible slit. Figure 23In other parts of this description, an embodiment is considered in which a shielding ring externally surrounds an assembly of two adjacent thermal radiation shields. However, it should be noted that this description is equally applicable to any shielding ring placed inside two thermal radiation shields, provided it effectively blocks a direct line-of-sight path through any slits that may form between the thermal radiation shields due to thermal contraction. In some embodiments, the shielding ring may be located both externally and internally. In some embodiments, one or more portions of the shielding ring may be external, and one or more other portions of the shielding ring may be internal, such that these portions together form a conceptual shielding ring, even if neither the external nor the internal portion is itself a complete shielding ring.

[0099] exist Figure 22 and Figure 23 For clarity, only a single thermal radiation shield is shown in the diagram. However, it should be noted that this description is equally applicable to solutions with two or more nested thermal radiation shields, such as... Figure 8 Such a system. Shielding rings can be used on one or more of the heat radiation shielding components at different temperatures.

[0100] If a shielding ring is provided, it can be a structural component independent of the two thermal radiation shields. However, making it an additional part of the respective thermal radiation shields can offer certain advantages. On the other hand, the placement of the shielding ring should not make removing the module from the modular cryogenic cooling system overly difficult. Advantageously, the module can even be removed from the middle of an array of adjacent modules, possibly without even needing to move other modules attached to the module to be removed in the assembly configuration.

[0101] A schematic diagram of a solution to meet this requirement is shown below. Figure 24 In the middle. Two shielding rings 2301 and 2401 are slidably mounted on the thermal radiation shield 304, such that they can move between at least two positions in a direction substantially perpendicular to the aforementioned respective common interface plane. Figure 24 In the retracted position shown on the left, shielding rings 2301 and 2401 do not extend beyond the respective edges of the thermal radiation shield 304 in the stated direction. If the thermal radiation shield 304 is part of a vacuum module mounted in a horizontal module row, and if the vacuum module is to be movable in and out of its position in the row in a direction perpendicular to the row, then the shielding rings in the retracted position will not prevent such movement.

[0102] Figure 24 The short black arrow on the left shows how shielding rings 2301 and 2401 can be moved to... Figure 24The extended position is shown on the right. In this extended position, the shielding ring extends beyond the corresponding edge of the thermal radiation shield in a direction perpendicular to the plane of the common interface. This fact, in any case, allows the shielding ring to block radiant heat from passing through any gaps that might form at the interface between two adjacent thermal shields due to thermal contraction.

[0103] Figure 24 The diagram shows two shielding rings 2301 and 2401 relative to a single thermal radiation shield 304. Such a solution can be used, for example, in a modular cryogenic cooling system with multiple vacuum modules in a direct horizontal row, where the thermal shield of every other module is equipped with a shielding ring. However, the system can also be designed so that each thermal radiation shield has a corresponding slidably mounted shielding ring at only one edge, such that in adjacent rows of vacuum modules, each shielding ring moves in the same direction from its retracted position to its extended position. Different principles of this kind can also be applied at different nesting levels of thermal radiation shields and / or in different modules of the modular cryogenic cooling system.

[0104] To achieve optimal results in blocking radiant heat through the slits it covers, the shielding ring should at least reach approximately the same temperature as the corresponding thermal radiation shield. The most direct way to ensure this is by establishing a thermally conductive coupling between the shielding ring and the thermal radiation shield. It is worth noting that even if the shielding ring does not reach the exact same low temperature as the main components of the thermal radiation shield, this may not be a significant drawback, especially if the shielding ring externally covers the slits between adjacent thermal radiation shields. That is, any additional heat radiated by the slightly warmer shielding ring has only a very narrow slit available to penetrate into the interior of the thermal radiation shield. Furthermore, because the shielding ring itself is relatively narrow at its outer surface, the radiant heat absorbed by the shielding ring from warmer parts of the system outside is relatively small compared to the radiant heat absorbed by the thermal radiation shield.

[0105] Figure 25 , Figure 26 and Figure 27 An example is shown of providing at least one of sliding support and thermal coupling to a shielding ring. Figure 25 The image shows a portion of the corner of the shielding ring 2301. The interior of the shielding ring 2301 includes two rows of thermally conductive springs 2501 that extend along the longitudinal direction of the section of the shielding ring 2301. Figure 26 A portion of the shielding ring 2301 in its retracted position is shown, mounted on the heat radiation shield 304. The common interface plane defined by the edge of the opening at one end of the heat radiation shield 304 is shown. Figure 26 On the right side. It's easy to see that in its retracted position, no part of the shielding ring 2301 is present. Figure 26The center extends to the right beyond the edge of the heat radiation shield 304. Conversely, if the retracted position of the shielding ring 2301 is like... Figure 26 If it's positioned so far back, the shielding ring 2301 might not even extend to the common interface plane. Figure 26 In the middle, both rows of thermally conductive springs abut against the same thermal radiation shielding component 304.

[0106] Figure 27 A portion of the shielding ring 2301 in its extended position is shown, covering any possible slits between the heat radiation shield 304 to which it was originally mounted and the adjacent heat radiation shield 2201. If the extended position of the shielding ring 2301 is symmetrical with respect to the interface between adjacent heat radiation shields, such as... Figure 27 In that case, the middle part of the shielding ring 2301 coincides with the interface in the extended position, as shown. Figure 27 As shown in the image. One row of thermally conductive springs rests against the heat radiation shield 304 initially mounted on the shielding ring 2301, while another row of thermally conductive springs rests against the adjacent heat radiation shield 2201. Therefore, regardless of whether the cooling of the heat radiation shield occurs... Figure 27 Whether on the left or right side of the orientation shown, the shielding ring 2301 will achieve a temperature that is the same as or at least sufficiently close to the temperature of the thermal radiation shields 304 and 2201.

[0107] Use sliding installation (e.g.) Figures 25 to 27 A sliding thermally conductive spring is also advantageous because it allows for various relative changes in size. (See previous reference.) Figure 22 As described above, when the modular cryogenic cooling system is in its assembly phase and all parts are therefore essentially at room temperature, adjacent thermal radiation shields can be very close to each other, or even directly abutting each other. Thermal contraction during cooling causes them both to retract towards the center of their respective vacuum modules. Any such movement of adjacent thermal radiation shields in opposite directions within the area covered by the shielding ring is readily permitted because the thermally conductive springs simply slide on the surface of each corresponding thermal radiation shield. If, for some reason (e.g., the use of different materials), the shortest vertical distance between the shielding ring and the surface of the thermal radiation shield increases or decreases during cooling, the thermally conductive springs will simply adapt to the change in gap width by bending or straightening more as needed.

[0108] A single-piece shielding ring does not necessarily encircle the entire seam between two adjacent thermal radiation shields. The shielding ring can be composed of separate segments. If a sliding or otherwise movable shielding ring is considered, these segments can move independently of each other.

[0109] Figure 28An embodiment is shown in which two adjacent thermal radiation shields 304 and 2201 both have a U-shape, such that in each case, the corresponding thermal stage connects to the top of the U-shaped branch. A U-shaped, slidable shielding ring 2801 is used to cover any gaps that may form between the two adjacent thermal radiation shields due to thermal contraction. A coupling plate 2802 is used to connect the two adjacent thermal stages together. The coupling plate 2802 may include means for absorbing any effects caused by the thermal contraction of the thermal stages. Additionally, or alternatively, it may utilize, for example, [the following is an example of a different embodiment]. Figures 13 to 16 Any principle.

[0110] Using connecting plates for the thermal stages and (partially) shielding rings for the thermal radiation shielding offers the advantage of creating stronger thermal coupling between the thermal stages. As mentioned above, the thermal coupling into and out of the shielding ring does not need to be that strong, as it is sufficient to ensure that the shielding ring reaches at least approximately the same temperature as the corresponding thermal radiation shielding. On the other hand, ensuring that adjacent thermal stages reach and remain at the same temperature may be very important, thus advocating for the use of the strongest possible thermal coupling.

[0111] exist Figure 28 In this configuration, the connecting plate 2802 is a separate component that can be bolted to two adjacent thermal stages during the assembly of the modular cryogenic cooling system. Alternatively, some extendable portion of any thermal stage can be used as a coupling plate for the same purpose.

[0112] It will be apparent to those skilled in the art that the basic idea of ​​this invention can be implemented in various ways as technology develops. Therefore, this invention and its embodiments are not limited to the examples described above, but can be varied within the scope of the claims.

Claims

1. A cryogenic cooling module, comprising: Vacuum chamber module (501). Multiple thermal stages (301, 302, 303) are supported inside the vacuum cavity module (501), and the multiple thermal stages (301, 302, 303) are spatially offset from each other at least along a first direction (310). One or more thermal radiation shielding elements (304, 305, 306) are supported inside the vacuum cavity module (501), the thermal radiation shielding elements (304, 305, 306) corresponding to at least one subset of the thermal levels (301, 302, 303); The shape of the vacuum cavity module (501) is at least partially defined by one or more planar sides extending along the first direction (310). Furthermore, the vacuum chamber module (501) has at least one first opening on the first of the one or more planar sides, and the edge (502) of the first opening has a vacuum sealing structure for achieving airtight sealing of the first opening; Its features are: The thermal stages (301, 302, 303) extend along a second direction (311) perpendicular to the first direction (310) to a first common interface plane (503) located at or near the plane defined by the edge (502) of the first opening, and At least one of the one or more of the thermal radiation shielding elements (304, 305, 306) has a corresponding second opening, the edge of which extends to the first common interface plane (503).

2. The low-temperature cooling module according to claim 1, wherein, Each of the one or more of the said thermal radiation shielding elements (304, 305, 306) is mechanically supported by a corresponding one of the plurality of said thermal levels (301, 302, 303).

3. The cryogenic cooling module according to claim 1, comprising a dedicated support structure (1101) attached to the inside of the vacuum chamber module (501), and the dedicated support structure (1101) being configured to mechanically support one or more of the thermal radiation shields (304, 305, 306) independently of the plurality of thermal stages (301, 302, 303).

4. The cryogenic cooling module according to any one of the preceding claims, wherein: The one or more planar sides include at least two planar sides extending along the first direction (310). The vacuum chamber module (501) has a third opening on the second planar side, and The cryogenic cooling module includes an openable seal (801) that is attached in an airtight manner to cover the third opening.

5. The low-temperature cooling module according to claim 4, wherein, At least a subset of one or more of the said thermal radiation shielding elements (304, 305, 306) consists of modular thermal radiation shielding elements, each of which has a corresponding removable shielding component (307, 308, 309) on the side facing the second of the said planar sides.

6. The cryogenic cooling module according to any one of the preceding claims, wherein: The one or more planar sides include at least three planar sides extending along the first direction (310). The vacuum chamber module has a fourth opening on the third planar side, and the edge (505) of the third opening has a vacuum sealing structure for achieving an airtight seal of the fourth opening. The thermal stages (301, 302, 303) extend to a second common interface plane (506) located at or near the plane defined by the edge (505) of the fourth opening, and Each of one or more of the said thermal radiation shielding elements (304, 305, 306) has a corresponding fifth opening, the edge of which extends to the second common interface plane (506).

7. The cryogenic cooling module according to any of the preceding claims, comprising a shielding ring (2301, 2401, 2801) configured to block radiant heat from passing through any slit (2202) located at the edge of the second opening.

8. The low-temperature cooling module according to claim 7, wherein, The shielding rings (2301, 2401, 2801) are movable between a retracted position and an extended position, wherein in the retracted position, the shielding rings (2301, 2401, 2801) do not extend beyond the corresponding edge of the corresponding thermal radiation shield (304), and in the extended position, the shielding rings (2301, 2401, 2801) extend beyond the corresponding edge of the corresponding thermal radiation shield (304).

9. A cryogenic cooling system, characterized in that: The cryogenic cooling system includes at least one cryogenic cooling module (701, 702) according to any of the preceding claims and a first vacuum chamber end (504), the first vacuum chamber end (504) being hermetically attached to cover the first opening in the vacuum chamber module (501) of at least one of the cryogenic cooling modules (701, 702). The cryogenic cooling system includes a cryogenic refrigerator configured to establish and maintain a cryogenic cooling state within at least one of the cryogenic cooling modules (701, 702), and The cryogenic cooling system includes, inside the first vacuum chamber end (504), heat radiation shielding end (401, 402, 403) in number equal to the number of heat radiation shielding elements (304, 305, 306), with the edges of the heat radiation shielding elements (304, 305, 306) corresponding to the second opening extending to the first common interface plane (503). Each of the heat radiation shielding end pieces (401, 402, 403) is connected to at least one corresponding heat radiation shielding piece (304, 305, 306) to cover the corresponding second opening on the at least one corresponding heat radiation shielding piece (304, 305, 306).

10. The cryogenic cooling system according to claim 9, comprising: Two or more cryogenic cooling modules (701, 702), each cryogenic cooling module being a cryogenic cooling module according to any one of claims 1-6, the two or more cryogenic cooling modules being attached to each other at the edge of the opening on the side of the corresponding common interface plane where their corresponding thermal levels and thermal radiation shielding extend, and End modules (703, 704) having an equal number of other openings on the sides of the two or more cryogenic cooling modules (701, 702), each of the end modules (703, 704) including a corresponding vacuum cavity end (504, 507) and a corresponding thermal radiation shielding end (401, 402, 403, 508, 509, 510) of the type defined in claim 7, wherein on the sides of the two or more cryogenic cooling modules (701, 702), the corresponding thermal level and thermal radiation shielding extend to the corresponding common interface plane; The end modules (703, 704) are attached in an airtight manner to cover corresponding other openings in the components of the two or more cryogenic cooling modules (501).

11. The cryogenic cooling system according to claim 10, wherein, The two or more cryogenic cooling modules (701, 702) are different from each other in terms of the cryogenic refrigerator capacity (705) built into them.

12. The cryogenic cooling system according to claim 10 or 11, wherein, The two or more cryogenic cooling modules (701, 702) are different from each other in terms of the configuration of their built-in cooling payload (706).

13. The cryogenic cooling system according to any one of claims 10 to 12, wherein, The thermal stages inside the two or more cryogenic cooling modules (701, 702) form at least two subsets, wherein: A subset (1201, 1204, 1207) of thermal stages are thermally coupled to form a common thermal stage spanning at least two adjacent cryogenic cooling modules (701, 702), and The thermal levels of another subset (1203, 1206, 1209) are thermally isolated from each other.

14. The cryogenic cooling system according to any one of claims 10 to 13, comprising thermal and mechanical coupling between two coplanar thermal stages within two adjacent cryogenic cooling modules in at least two or more cryogenic cooling modules, wherein, The thermal and mechanical coupling includes: The slots or gaps between the two layers (1501, 1502, 1601, 1602) of the first material in the two coplanar thermal stages, wherein the first material has a first coefficient of thermal expansion at low temperatures, and At least one layer of a second material (1503, 1603, 1604) is disposed within the slot or gap, the second material having a second coefficient of thermal expansion that is less than the first coefficient of thermal expansion at low temperatures; The two layers (1501, 1502) are part of one of the two coplanar thermal stages, with part of the other coplanar thermal stage located between them; or the two layers (1601, 1602) are different parts of the two coplanar thermal stages.

15. The cryogenic cooling system according to any one of claims 10 to 14, wherein: The cryogenic cooling modules (1701, 1702, 1703, 1704, 1705) of the cryogenic cooling system are located on more than one level relative to each other, wherein the more than one level is a level perpendicular to the first direction, and The cryogenic cooling system includes at least one interface between cryogenic cooling modules (1701, 1705) that are adjacent to each other in the first direction, wherein at the at least one interface, a shielding space inside the cryogenic cooling system extends through the plane to which the two cryogenic cooling modules (1701, 1705) are attached to each other.

16. The cryogenic cooling system according to any one of claims 10 to 15, comprising a support structure for supporting the cryogenic cooling module in an assembled configuration.

17. The cryogenic cooling system according to claim 16, wherein, The support structure includes a track that supports one or more of the cryogenic cooling modules, enabling the one or more cryogenic cooling modules to move along the track relative to other cryogenic cooling modules between a disassembled configuration and an assembled configuration.

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