Cryogenic apparatus

Abstract

The present invention relates to quantum computing, in particular, a cryogenic apparatus for a quantum computer. A cryogenic apparatus for a quantum computer, the cryogenic apparatus comprising: an enclosure defining an enclosed volume; a sample volume disposed within the enclosed volume; wiring for connecting to the sample volume, wherein the wiring is disposed within the enclosed volume; and, a cooling device, wherein the cooling device is disposed at least partially within the enclosed volume; a cooling frame extending in an enclosed volume, wherein the cooling frame is configured to couple the cooling device and the wiring thereby to permit conductive cooling of the wiring by the cooling device in use, wherein the cooling frame comprises: a first cooling frame portion extending, along a first axis, between the cooling device toward the sample volume; and, a second cooling frame portion extending, along a second axis, between the sample volume to the wiring; wherein the first axis is transverse to the second axis.

Description

[0001] CRYOGENIC APPARATUS

[0002] FIELD OF INVENTION

[0003] The present invention relates to quantum computing, in particular, a cryogenic apparatus for a quantum computer.

[0004] BACKGROUND

[0005] A quantum computer is a physical device that operates according to the laws of quantum mechanics. It can perform high-speed mathematical and logical operations, and store and process qubit information. Because quantum mechanics has superposition, coherence, entanglement and other characteristics different from classical mechanics, quantum computers can solve some problems that are difficult to solve on classical computers in a very short time.

[0006] For the quantum mechanical effects to manifest, and therefore, for the quantum computer to operate correctly, low temperatures are required e.g. temperatures within a few Kelvin of absolute zero, or in examples, temperatures below 1 K. Therefore, quantum computers require a cryogenic apparatus to achieve and maintain said temperatures.

[0007] SUMMARY

[0008] Aspects of the disclosure are set out in the independent claims and optional features are set out in the dependent claims. Aspects of the disclosure may be provided in conjunction with each other, and features of one aspect may be applied to other aspects.

[0009] An aspect provides a cryogenic apparatus for a quantum computer, the cryogenic apparatus comprising: an enclosure defining an enclosed volume; a sample volume disposed within the enclosed volume; wiring for connecting to the sample volume, wherein the wiring is disposed within the enclosed volume; and, a cooling device, wherein the cooling device is disposed at least partially within the enclosed volume; a cooling frame extending in an enclosed volume, wherein the cooling frame is configured to couple the cooling device and the wiring thereby to permit conductive cooling of the wiring by the cooling device in use, wherein the cooling frame comprises: a first cooling frame portion extending, along a first axis, between the cooling device toward the sample volume; and, a second cooling frame portion extending, along a second axis, between the sample volume to the wiring; wherein the first axis is transverse to the second axis.

[0010] Advantageously, said aspect provide an apparatus which permits so-called ‘side loading’. Typical cryogenic apparatus are ‘top-loading’ whereby the wiring is inserted into the enclosure by lowering the wiring, perpendicular to the floor of a room, into the enclosure which means that typical apparatus require relatively tall rooms. The apparatus provided herein can be ‘side-loaded’ whereby the wiring is inserted into the enclosure, parallel to the second axis (e.g. parallel to the floor of a room). Therefore, for example, the apparatus provided herein may be disposed in standard rooms.

[0011] The cooling device may have a longitudinal axis arranged parallel to the first axis; and, the wiring is removably couplable to the sample volume in a direction substantially parallel to the second axis.

[0012] In examples, the apparatus may comprise a series of plates arranged transverse to the second axis; wherein each of the plates is coupled to the second cooling frame portion.

[0013] The apparatus may comprise: a wiring cassette configured to support the wiring; wherein the wiring cassette is removably couplable to the sample volume in a direction substantially parallel to the second axis; the wiring cassette comprising a plurality of wiring plates; wherein each wiring plate is configured to thermally couple to a corresponding one of the plates when the wiring cassette is coupled to the sample volume. For example, the wiring may conveniently be supported and / or coupled by the cassette, which may facilitate simplified loading and / or unloading of the wiring.

[0014] The enclosure may comprises: a sample module, wherein the sample volume is disposed within the sample module; a cooling module, wherein the cooling device is connected to the cooling module and is disposed at least partially within the cooling module; and, a wiring module, wherein the wiring is disposed within the wiring module; wherein the sample module, cooling module and wiring module are interconnected to provide the enclosed volume. An aspect provides a cryogenic apparatus for a quantum computer, the cryogenic apparatus comprising: an enclosure defining an enclosed volume, wherein the enclosure comprises: a sample module comprising a sample volume disposed within the sample module; a cooling module comprising a cooling device, wherein the cooling device is connected to the cooling module and is disposed at least partially within the cooling module; and, a wiring module, comprising wiring disposed within the wiring module, the wiring for connecting to the sample volume; wherein the sample module, cooling module and wiring module are interconnected to provide the enclosed volume.

[0015] Advantageously, providing a cryogenic apparatus of modular construction may allow for easier fabrication and / or transportation of the apparatus. For example, the modules (also referred to herein as module units) may be more convenient to manufacture and transport (e.g. in comparison to a similar apparatus of similar construction and size which is not modular). A cryogenic apparatus of modular construction may allow scalability, for example, more modules may be added to increase the capacity of the enclosure provided by the modules.

[0016] In examples, the apparatus may be configured (e.g. sized) to fit within the space provided by a standard server rack (e.g. ’19-inch racks’) which have a width of approximately 600 mm. In such examples, the width of the apparatus (e.g. its physical extent in along a third axis orthogonal to the first and second axes W & U) may be sized to be held in a standard server rack and / or in the place within which a standard server rack would normally be provided (e.g. in a server room).

[0017] The cooling module may be connected to the sample module, wherein the cooling module and the sample module are arranged along a first axis; and, the wiring module may be connected to the sample module, wherein the wiring module and the sample module are arranged along a second axis; wherein the first axis is transverse to the second axis.

[0018] The cooling device may have a longitudinal axis arranged parallel to the first axis; and, the wiring may be removably couplable to the sample volume in a direction substantially parallel to the second axis.

[0019] The cryogenic apparatus may comprise: a cooling frame extending in the enclosed volume, wherein the cooling frame is configured to couple the cooling device and the wiring thereby to permit conductive cooling of the wiring by the cooling device in use, wherein the cooling frame comprises: a first cooling frame portion extending, along the first axis, between the cooling device toward the sample volume; and, a second cooling frame portion extending, along the second axis, between the sample volume to the wiring.

[0020] The first cooling frame portion may extend within the cooling module and the sample module; and, the second cooling frame portion may extend within the sample module and the wiring module.

[0021] The wiring module may comprise a series of cooling wherein each of the plates is coupled to the second cooling frame portion.

[0022] Each of the plates may be disposed transverse to the second axis.

[0023] The cryogenic apparatus may comprise: a wiring cassette configured to support the wiring; wherein the wiring cassette is removably couplable to the sample volume in a direction substantially parallel to the second axis; the wiring cassette comprising a plurality of wiring plates; wherein each wiring plate is configured to thermally couple to a corresponding one of the plates when the wiring cassette is coupled to the sample volume. For example, the wiring may conveniently be supported and / or coupled by the cassette, which may facilitate simplified loading and / or unloading of the wiring.

[0024] Each of the sample module; cooling module; and, the wiring module; may comprise a module unit, wherein each module unit may comprise: a module frame defining an interior volume, the module frame comprising: one or more apertures configured to permit access to the interior of the module frame.

[0025] The module frame may be configured to engage: a module panel, wherein the module panel is removably engageable with the module frame thereby to cover one of the one or more apertures.

[0026] The module frame may be configured to engage: a joining member, wherein the joining member is configured to connect the module frame to another module frame. The joining members may conveniently comprise a sealing member thereby simplifying the construction of the module frame (e.g. because no sealing member need be provided on the module frame).

[0027] The cooling device may comprise: a plurality of primary heat exchangers, wherein: the plurality of primary heat exchangers are arranged in series thereby to provide successive cooling of a sample volume; in use, the sample volume is thermally coupled to a final primary heat exchanger in said series; and, a plurality of secondary heat exchanger corresponding in number to the plurality of primary heat exchangers, wherein for each of the primary heat exchanger, a secondary heat exchanger is configured to extract heat from coolant entering the first heat exchanger. The series of primary heat exchangers may be arranged along the first axis.

[0028] The cryogenic apparatus may comprise a secondary cooling module comprising a secondary cooling device, wherein the secondary cooling device is connected to the wiring thereby to extract heat from the wiring. Advantageously, by providing more cooling devices to cool the same enclosed volume, the size and / or efficiency of each of the cooling devices may be reduced.

[0029] An aspect provides a module unit for providing a modular cryogenic apparatus, the module unit comprising: a module frame (e.g. polyhedral module frame) defining an interior volume, the module frame comprising: one or more apertures configured to permit access to the interior of the module frame.

[0030] Advantageously, providing a cryogenic apparatus of modular construction may allow for easier fabrication and / or transportation of the apparatus. For example, the modules (also referred to herein as module units) may be more convenient to manufacture and transport (e.g. in comparison to a similar apparatus of similar construction and size which is not modular). The module unit may be configured to engage another module unit such that one of the one or more apertures of the module unit is arranged opposite one of the one or more apertures of the other module unit. A cryogenic apparatus of modular construction may allow scalability, for example, more modules may be added to increase the capacity of the enclosure provided by the modules.

[0031] The module unit may comprise: one or more module panels, wherein each of the one or more module panels is removably engageable with the module frame thereby to cover one of the one or more apertures thereby to hermetically seal the aperture.

[0032] Each of the one or more module panels may comprise a sealing member configured to provide a seal between the module panel and the module frame when the module panel covers said aperture. The one or more module panels may conveniently comprise a sealing member thereby simplifying the construction of the module frame (e.g. because no sealing member need be provided on the module frame).

[0033] The module unit is configured to engage a joining member, wherein the joining member is configured to connect the module frame to another module frame. The joining member may comprise: a first side comprising a first sealing member; and, a second side comprising a second sealing member.

[0034] An aspect provides a kit of parts for providing a cryogenic apparatus, the kit comprising: a first module unit for providing a sample module; a second module unit for providing a cooling module; a third module unit for providing a wiring module; wherein the first module unit, the second module unit, and the third module unit are configured to be interconnected thereby to provide an enclosed volume. Advantageously, a cryogenic apparatus of modular construction may be provided.

[0035] The first module unit may be configured to connect to the second module unit, such that the first module unit and the second module unit are arranged along a first axis; and, the first module unit may be configured to connect to the third module unit, wherein the first module unit and the third module unit are arranged along a second axis; wherein the first axis is transverse to the second axis. The kit may comprise: a sample volume configured to be disposed within the first module unit; a cooling device configured to connect to the second module unit and configured to be disposed at least partially within the second module unit; wiring configured to be disposed within the third module unit and configured to connect to the sample volume when the sample volume is disposed within the first module unit; wherein, the cooling device has a longitudinal axis configured to be arranged parallel to the first axis; and, the wiring is removably couplable to the sample volume in a direction substantially parallel to the second axis.

[0036] The kit may further comprise: one or more joining members, wherein the joining member is configured to connect the module frame to another module frame.

[0037] An aspect provides a pump line for a cryogenic apparatus, the pump line comprising: a plurality of primary heat exchangers, wherein: the plurality of primary heat exchangers are arranged in series thereby to provide successive cooling of a sample volume; in use, the sample volume is thermally coupled to a final primary heat exchanger in said series; and, a plurality of secondary heat exchangers wherein for each of the primary heat exchanger, a secondary heat exchanger is configured to extract heat from coolant flowing from a heating side to a cooling side of the primary heat exchanger.

[0038] The cryogenic apparatus provided herein may be used for other purposed in addition to or instead of, quantum computers. For example, the cryogenic apparatus provided herein may be used to cool electronics (e.g. classical computers) and / or to store materials (e.g. to store liquid helium, liquid nitrogen, or biological samples). The cryogenic apparatus herein may be a cryogenic apparatus for cryogenic research (e.g. other than quantum computing).

[0039] In examples, a cooling module may comprise: a first circulation module provided by the first pump line and a first coldhead; and a second circulation module provided by a second pump line and a second coldhead 123. Advantageously, redundancy may be provided whereby one of the circulation modules can be operated at any given time thereby to permit maintenance and / or cleaning of the other circulation module. For examples, one or more sorption pumps may be cleaned and / or blockages may be cleared from a first circulation module whilst a second circulation module maintains the temperature of the sample volume.

[0040] Any apparatus feature as described herein may also be provided as a method feature, and vice versa.

[0041] Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method aspects may be applied to apparatus aspects, and vice versa. Furthermore, any, some and / or all features in one aspect can be applied to any, some and / or all features in any other aspect, in any appropriate combination.

[0042] It should also be appreciated that particular combinations of the various features described and defined in any aspects can be implemented and / or supplied and / or used independently.

[0043] BREIF DESCRIPTION OF THE DRAWINGS

[0044] Some embodiments will now be described, by way of example only, with reference to the figures, in which:

[0045] Figure 1A illustrates a perspective cut-away view of a cryogenic apparatus for a quantum computer;

[0046] Figure 1 B illustrates a top-down plan view of the cryogenic apparatus shown in Figure 1A;

[0047] Figure 1C illustrates a cross-sectional view of the cryogenic apparatus along plane A-A shown in Figure 1 B;

[0048] Figure 2 illustrates a cross-sectional view of the pump line 150 shown in Figures 1A - 1C;

[0049] Figure 3A illustrates a perspective view of a wiring cassette of the cryogenic apparatus shown in Figure 1A;

[0050] Figure 3B illustrates a top-down plan view of a wiring cassette shown in Figure 3A;

[0051] Figure 3C illustrates a cross-sectional view of a wiring cassette along plane A-A shown in Figure 3B;

[0052] Figure 4 illustrates a perspective view of three module unit frames connected together;

[0053] Figure 5 illustrates a plan view of module panel of a module unit;

[0054] Figure 6 illustrates a cross-sectional view of a portion of two module panels connected to a module frame;

[0055] Figure 7 illustrates a plan view of joining member for joining together two module units;

[0056] Figure 8A illustrates a side plan view of three module frames joined together by two joining member;

[0057] Figure 8B illustrates an enlarged view of a portion of Figure 8A;

[0058] Figure 9 illustrates a cross sectional view of a portion of alternative joining member, a first module frame, and a second module frame;

[0059] Figure 10 illustrates a perspective view of a portion of a cryogenic apparatus.

[0060] SPECIFIC DESCRIPTION

[0061] Figure 1A illustrates a perspective cut-away of a cryogenic apparatus 100 for a quantum computer; Figure 1 B illustrates a top-down plan view of the cryogenic apparatus 100 shown in Figure 1A; Figure 1C illustrates a cross-sectional view of the cryogenic apparatus 100 along plane A-A shown in Figure 1 B.

[0062] The cryogenic apparatus 100 comprises: a sample module 110; a wiring module 130; a cooling module 120; and, a cooling frame 140.

[0063] The sample module 110 comprises: a sample volume 111.

[0064] The cooling module 120 comprises: a cooling device 121. The cooling device 121 comprises: coldheads 122 & 123; and, a pump line 150.

[0065] The wiring module 130 comprises: wiring 131 (only shown in Figure 1A); and, a wiring cassette 160, which will be described in more detail below with reference to Figures 3A - 3C. In Figures 1A - 1C, the coldheads 122 & 123 are thermally coupled to the cooling frame 140. In particular, the coldheads 122 & 123 are connected directly (e.g. bolted) to the cooling frame 140. The coldheads 122 & 123 may be connected directly to the cooling frame 140 using flexible copper braids. The pump line 150 is thermally coupled to the sample volume 111.

[0066] The sample module 110, cooling module 120, and wiring module 130 are interconnected to provide an enclosure defining an enclosed volume. The sample module 110, the wiring module 130, and the cooling module 120 each comprises a module unit 200. Module units are described herein more detail (e.g. with reference to Figures 4 to 9), but in brief, these are housings which can be joined together to provide an enclosure defining an enclosed volume. In use the enclosure is sealed (e.g. hermetically sealed) and evacuated of air (or the air pressure therein is reduced relative to atmospheric pressure) thereby to reduce conductive heat transfer from the environment to the enclosed volume.

[0067] The sample module 110 is connected to the cooling module 120. The sample module 110 and cooling module 120 are arranged along a first axis W e.g. so that at least a portion of the sample module 110 and the cooling module 120 intersect the first axis W.

[0068] The sample module 110 is connected to the wiring module 130. The sample module 110 and wiring module 130 are arranged along a second axis U e.g. so that at least a portion of the sample module 110 and the wiring module 130 intersect the second axis U.

[0069] Generally the first axis W is arranged transverse to the second axis U. In the example described herein, the first axis W is perpendicular to the second axis U.

[0070] In use, the cryogenic apparatus may be arranged on a surface (e.g. a floor of a building, for example, in a server room) such that a bottom side of the sample module 110 and a bottom side of the wiring module 130 are disposed horizontally parallel to the surface. For example, the bottom side of the sample module 110 and the bottom side of the wiring module 130 are disposed on the floor of a building thereby to support the cryogenic apparatus. In such examples, the second axis U may be considered a horizontal ‘X’-axis and the first axis W may be considered a vertical ‘Y’-axis orthogonal to the X-axis.

[0071] The apparatus is configured to fit within the space provided by a standard server rack. Standard server racks (e.g. ’19-inch racks’) have a width of approximately 600 mm. The width of the apparatus (e.g. its physical extent in along a third axis orthogonal to the first and second axes W & U) is sized to be held in a standard server rack and / or in the place within which a standard server rack would normally be provided (e.g. in a server room). The example apparatus 100 shown in Figures 1A-1C has a width of under 600 mm. Accordingly, the example apparatus 100 is configured to fit in a standard ’19-inch’ server rack.

[0072] The sample volume 111 is configured to hold a sample e.g. the sample volume 111 may be provided by a vessel configured to hold the sample. The sample comprises a substance which can be configured to exhibit one or more quantum mechanical effects thereby to provide a plurality of qubits. In more detail, at least one of the ways in which the sample is configured to exhibit one or more quantum mechanical effects thereby to provide a plurality of qubits is to cool the sample to a temperature below a critical temperature value. In examples, the sample may comprise niobium and / or aluminium and, in such examples, the critical temperature may be approximately 1 K. In examples, the sample volume may have a volume of approximately 1 x 10'3m3. The sample volume 111 may comprise one or more magnets disposed around the sample e.g. to confine the material which provides the plurality of qubits.

[0073] When the wiring is provided (e.g. when the wiring cassette 160 is inserted into the cryogenic apparatus) the sample volume 111 is coupled to the wiring. Accordingly, inputs may be provided to the sample volume and / or outputs may be received from the sample volume using the wiring (described in more detail below).

[0074] As set out above the cooling device 121 comprises the coldheads 122 & 123 and the pump line 150.

[0075] The pump line 150 is removably disposed within the cryogenic apparatus 100, therefore, the pump line 150 is thermally couplable to the sample volume 111. In the arrangement shown in Figure 1A, wherein the sample volume 111 , cooling device 121 , and wiring 131 are all present because the apparatus 100 is assembled for use, the pump line 150 is thermally coupled to the sample volume 111. Thermally coupled means that the heat is exchangeable between the sample volume 111 and the pump line 150.

[0076] In the present example, two coldheads 122 & 123 are provided but any number may be provided, such as one coldhead or three cold heads. One or more of the coldheads may be coupled to the wiring thereby to provide dedicated cooling thereto. In examples, a secondary cooling module can be provided. The secondary cooling module may comprise a secondary cooling device (e.g. coldheads). The secondary cooling device (i.e. in addition to the coldhead(s) provided by the ‘primary’ cooling module) may be dedicated to cooling the wiring 131 (e.g. by thermal coupling, such as by direct connection (e.g. bolting), to one or more of the plates 141-144). The secondary cooling module may comprise a module unit (as described in detail herein) which is connected to the wiring module 130 and the ‘primary’ cooling module 110 e.g. so that the assembly comprises two connected columns of module units wherein each column has a height of two module units.

[0077] The cooling frame 140 is thermally coupled to the coldheads 122 & 123 so that the when the coldheads 122 & 123 are operated, they act to extract heat from the cooling frame 140.

[0078] The cooling frame 140 is configured to extract heat from the enclosed volume. The cooling frame 140 comprises: a plurality of plates 141-144; and a plurality of cooling subframes 147-149.

[0079] As shown in Figure 1C, the plurality of cooling subframes 147-149 are nested e.g. arranged in the manner of Russian dolls thereby to provide a sequence of nested enclosed volumes each configured to hold elements therein at successively lower temperatures. In the particular example shown in Figure 1C, the cooling frame 140 comprises: an inner cooling subframe 147; a middle cooling subframe 148; and, an outer cooling subframe 149. The inner cooling subframe 147 encloses the sample volume. In use, the interior of the inner cooling subframe 147 has the lowest temperature of any of the cooling subframes. In examples, in use, the interior of the inner cooling subframe 147 is approximately 1 K or temperatures below 1 K e.g. temperatures of approximately 300 mK (e.g. with the use of additional cooling units such as a Helium-3 pot) or temperatures of approximately 10 mK (e.g. with the use of a dilution unit).

[0080] The middle cooling subframe 148 encloses the inner cooling subframe 147. In use, the interior of the middle cooling subframe 148 has the second lowest temperature of the cooling subframes, the inner cooling subframe 147 having an interior the lowest temperature. In examples, in use, the interior of the middle cooling subframe 148 is approximately 4 K.

[0081] The outer cooling subframe 149 encloses the middle cooling subframe 148. In use, the interior of the outer cooling subframe 149 has the highest temperature of the cooling subframes. In examples, in use the interior of the outer cooling subframe 149 is approximately 50 K.

[0082] As shown in Figure 1C, each of the cooling subframes 147-149 is a prism with a cross- sectional shape of a gnomon or rectangular gnomon (i.e. it is ‘L-shaped’, that is resembling the shape of a capital letter ‘L’). The part of each cooling subframe 147-149 which extends from the sample volume 111 along the first axis W is referred to collectively as the first cooling frame portion 145. The part of each cooling subframe 147- 149 which extends from the sample volume 111 along the second axis W is referred to collectively as the second cooling frame portion 146.

[0083] The fourth plate 144 is connected to the inner cooling subframe 147. The third plate 143 is connected to the middle cooling subframe 148. The second plate 143 is connected to the outer cooling subframe 149. The first plate 141 forms part of the housing of the wiring module 130.

[0084] Each plate 141-144 comprises an aperture through which the wiring cassette 160 can be inserted and removed from the apparatus 100. The aperture of each plate 141-144 is configured to engage (e.g. be disposed into thermal contact with) a respective wiring plate 161-164 (described in more detail herein, but in brief, first wiring plate 161 engages the first plate 141 and so on).

[0085] Figure 2 illustrates a cross-sectional view of the pump line 150 shown in Figures 1A - 1C.

[0086] The pump line 150 is shown in more detail in Figure 2. The pump line 150 comprises a plurality of primary heat exchangers arranged in series thereby to provide successive cooling along the series of primary heat exchangers. In examples, the pump line may be referred to as a condensing cassette.

[0087] In the present example, there are three primary heat exchangers provided: first primary heat exchanger 152; second primary heat exchanger 154; and, third primary heat exchanger 156. These primary heat exchangers are arranged in series such that, when the cryogenic apparatus is arranged for use (as shown in Figures 1A-1C), the third primary heat exchanger 156 is the final primary heat exchanger in said series, and the third primary heat exchanger 156 is configured to the extract heat from the sample volume 111. In other words, when the apparatus is arranged for use, the third primary heat exchanger 156 is thermally coupled to the sample volume 111 and operable to extract heat from the sample volume.

[0088] The primary heat exchangers can be any suitable heat exchanger. In general terms, the primary heat exchangers comprise: a cooling side; a heating side; and, one or more refrigerant fluids to permit heat exchange between the cooling side and the heating side. The cooling side is configured to extract heat from an element thermally coupled thereto. The heating side is configured to discharge heat to an element thermally coupled thereto. In examples, the primary heat exchangers one or more coolants comprising any of: liquid nitrogen and / or liquid helium, for example, Helium-4 or Helium-3 or a mixture thereof (e.g. using a dilution unit).

[0089] In the present example shown in Figure 2: the heating side of the first primary heat exchanger 152 is disposed in thermal contact with the environment; the cooling side of the first primary heat exchanger 152 is disposed in thermal contact with the heating side of the second primary heat exchanger 154 (e.g. to achieve a temperature on the cooling side of 50 K or less); the cooling side of the second primary heat exchanger 154 is disposed in thermal contact with the heating side of the third primary heat exchanger 156 (e.g. to achieve a temperature on the cooling side of 4 K or less); the cooling side of the third primary heat exchanger 156 is disposed in thermal contact with the sample volume 111 (e.g. to achieve a temperature on the cooling side of 1 K or less).

[0090] One or more secondary heat exchangers are provided. In the present example there is a secondary heat exchanger provided for each of the primary heat exchanger but it will be appreciated that one or more of the primary heat exchangers may not be paired with one or more of the primary heat exchangers.

[0091] In the example shown in Figure 2 there are three secondary heat exchangers provided: first secondary heat exchanger 151 ; second secondary heat exchanger 153; and, third secondary heat exchanger 155. The secondary heat exchangers are arranged pairwise with the primary heat exchangers: the first secondary heat exchanger 151 is paired with the first primary heat exchanger 152; the second secondary heat exchanger 153 is paired with the second primary heat exchanger 154; the third secondary heat exchanger 155 is paired with the third primary heat exchanger 156. In this way (and as can be seen in Figure 2) the secondary heat exchangers are interposed between the primary heat exchangers.

[0092] Each secondary heat exchanger can be any suitable heat exchanger (such as any of the primary heat exchangers described in detail herein or indeed any other suitable heat exchanger not described herein). Functionally, each second heat exchanger is configured to extract heat from coolant of the primary heat exchanger flowing from a heating side of the primary heat exchanger to a cooling side of the primary heat exchanger (e.g. this may be referred to as pre-cooling in the art). In the present example shown in Figure 2: the first secondary heat exchanger 151 is arranged to extract heat from coolant flowing from a heating side to a cooling side of the first primary heat exchanger 152; the second secondary heat exchanger 153 is arranged to extract heat from coolant flowing from a heating side to a cooling side of the second primary heat exchanger 154; the third secondary heat exchanger 155 is arranged to extract heat from coolant flowing from a heating side to a cooling side of the third primary heat exchanger 156.

[0093] The parts of the pump line 150 are assembled to be top loadable into the cooling module e.g. to be loaded along the first axis W.

[0094] By providing the secondary heat exchangers in the manner described herein, coolant entering the cooling side of the respective primary heat exchangers has a lower temperature (e.g. compared to if no secondary heat exchangers were provided). Accordingly, the cooling side of the primary heat exchangers may accept comparably more heat (e.g. compared to if no secondary heat exchangers were provided), thereby providing sample volume with a lower temperature and / or an overall more efficient pump line 150 and / or cooling device 121.

[0095] In examples, the pump line 150 may comprise one or more sorption pumps. In examples comprising one or more sorption pumps, a sorption pump may be provided at the 50 K region (e.g. at or within the outer cooling subframe 149) and / or a sorption pump may be provided at a region at around 20 K (e.g. at or within or between the middle cooling subframe 148 and the outer cooling subframe 149). Advantageously, the sorption pumps have no moving parts meaning they are not a source of noise in the system.

[0096] One or more of the secondary heat exchangers may be produced by a method of additive manufacture, such as three-dimensional printing (e.g. the secondary heat exchangers may comprise or consist essentially of aluminium, and may be manufactured by direct metal laser sintering (DMLS)).

[0097] A first pump line 150 is shown in the drawing (e.g. in Figure 1A). However, a second pump line 150-2 can be provided as shown in Figure 10. In examples, a cooling module 120 may comprise a first circulation module, provided by the first pump line 150 and a first coldhead 122, and a second circulation module, provided by the second pump line 150-2 and a second coldhead 123. Each circulation module may comprise a diagnostic wiring stack e.g. an individual diagnostic wiring stack is provided for each of the circulation modules. Advantageously, redundancy may be provided whereby one of the circulation modules can be operated at any given time thereby to permit maintenance and / or cleaning of the other circulation module. For example, a limp mode may be provided whereby a first circulation module is warmed (e.g. to approximately 200 K) thereby to clean one or more parts thereof, whilst a second circulation module continues to cool the sample volume.

[0098] Figure 10 also shows an arrangement comprising additional coldheads. In particular, a third coldhead 1003 and a fourth coldhead 1004 are provided. The third coldhead 1003 and the fourth coldhead 1004 may be disposed on (e.g. directly coupled to) the wiring module as shown in Figure 10. In the present example, two additional coldheads are provided but any number may be provided, such as one coldhead or three coldheads.

[0099] The third coldhead 1003 and the fourth coldhead 1004 may be coupled to the wiring thereby to provide dedicated cooling thereto. The third coolhead 1003 and the fourth coolhead 1004 may be dedicated to cooling the wiring 131 (e.g. by thermal coupling, such as by direct connection (e.g. bolting), to one or more of the plates 141-144). In examples, the additional coldhead(s) may be provided in a secondary cooling module (not shown in Figure 10).

[0100] Figure 3A illustrates a perspective view of a wiring cassette 160 of the cryogenic apparatus shown in Figure 1A; Figure 3B illustrates a top-down plan view of a wiring cassette 160 shown in Figure 3A; Figure 3C illustrates a cross-sectional view of a wiring cassette 160 along plane A-A shown in Figure 3B.

[0101] The wiring cassette 160 comprises: a plurality of wiring plates 161-164; a plurality of wire sockets 165; a wiring plate frame 166. The wiring cassette 160 is configured to support the wiring. The wiring cassette 160 is configured to be moved into the cryogenic apparatus to an inserted configuration wherein the wiring in the wiring cassette is coupled to the sample volume.

[0102] The wiring comprises wires which, when the apparatus is configured for use, extend generally along the second axis U. The wiring permits communication between an exterior of the apparatus (e.g. with a user of the quantum computer) and the sample volume. As such, inputs may be provided to the sample volume and / or outputs may be received from the sample volume using the wiring. For example, the wiring may connect to devices which control conditions in the sample volume (e.g. temperature, electric field, magnetic field etc.) and / or the wiring may connect to devices which measure conditions in the sample volume (e.g. temperature, electric field, magnetic field etc.).

[0103] In Figures 3A - 3C, there are four wiring plates provided, namely: a first wiring plate 161 ; a second wiring plate 162; a third wiring plate 163; a fourth wiring plate 164. The wiring plates 161 - 164 are mounted on the wiring plate frame 166. In the present example, the wiring plate frame 166 comprises a plurality of parallel rods which connect the wiring plates in series. The first wiring plate 161 is connected to the second wiring plate 162, that is by rods of the wiring plate frame 166 and the remaining plates are connected in a like manner. In particular, the second wiring plate 162 is connected to the third wiring plate 163, and the third wiring plate 163 is connected to the fourth wiring plate 164. In examples, additional wiring plates may be provided, for example, in arrangements examples comprising a dilution unit.

[0104] Each wiring plate 161-164 has a plurality of wire sockets 165. Each wire socket 165 is configured to hold (e.g. it is engageable with) one or more wires of the wiring. For example, each wire socket 165 may comprise a plurality of sockets (e.g. arranged in an array) configured to receive the end of a wire of the wiring. In this manner, wires of the wiring are held by the wire sockets 165. In this manner, the wiring cassette supports the wiring in a direction parallel to the second axis . Whilst in the present example, each wiring plate 161-164 comprises three wire sockets 165 it will be appreciated by those of skill in the art that any number of wire sockets may be provided, for example, one wire socket per wiring plate, two wire sockets per wiring plate, or more than three wire sockets per wiring plate.

[0105] The wiring plates 161-164 are removably engageable with the plates 141-144. In other words, the wiring plates 161-164 can be brought into and out of engagement with the plates. Specifically, the first wiring plate 161 is engageable with the first plate 141 , the second wiring plate 162 is engageable with the second plate 142, the third wiring plate 163 is engageable with the third plate 143, the fourth wiring plate 164 is engageable with the fourth plate 144. Each of the wiring plates 161-164 comprises an aperture configured to receive the wiring plates 161-162.

[0106] When the wiring plates 161-164 are engaged with the plates 141-144, each wiring plate thermally coupled to a corresponding one of the plates 141-144.

[0107] The wiring cassette 160 is configured to be moved into the cryogenic apparatus 100 to an inserted configuration wherein the wiring in the wiring cassette is coupled to the sample volume. In the present example, the wiring cassette 160 is insertable into the apparatus 100 via an opening in the wiring module 130, into the inserted configuration.

[0108] The wiring cassette 160 is movable approximately along the second axis U with the fourth wiring plate 164 entering the enclosed volume of the apparatus 100 first, followed by the third wiring plate 163, then the second wiring plate 162. The first plate 141 forms a portion of the housing of the wiring module 130.

[0109] When the first wiring plate 161 engages with the first plate 141 simultaneously, the second wiring plate 162 engages with the second plate 142, the third wiring plate 163 engages with the third plate 143, the fourth wiring plate 164 engages with the fourth plate 144. Furthermore, the wiring in the wiring cassette 160 couples to the sample volume 111.

[0110] By moving the wiring cassette 160 in the opposite direction along the second axis U (i.e., in a “side-loading” arrangement), the wiring cassette 160 can be brought out of the inserted configuration (e.g. so that the wiring is no longer coupled to the sample volume 111) and by further continuance of said movement the wiring cassette 160 can be removed from the apparatus 100.

[0111] Figure 4 illustrates a perspective view of three module unit frames connected together;

[0112] Each of the sample module 110, cooling module 120, and the wiring module 130 comprises a module unit 200. Each module unit 200 comprises: a module frame 210; one or more module panels 220.

[0113] Each module unit 200 is configured to engage one or more other module units 200 thereby to provide an enclosure for the apparatus 100. To engage a first module unit with a second module unit, a joining member 230 is provided therebetween. Each joining member 230 is configured to engage two module units thereby to join (that is, engage) the two module units. The module units 200, the joining members 230 are described in more detail herein.

[0114] Three module frames 210 are shown in Figure 4. In Figure 4 each module frame 210 has a cubic shape defining an interior volume 211 and six module apertures 212-218. Each of the module apertures 212-218 configured to permit access to the interior 211 of the module frame. Each of the six module apertures 212-218 fills most of each face of module frame 210 e.g. each aperture occupies over 80% of each face of the frame 210. It is preferable to increase the relative size of the aperture of each face to permit access therethrough whilst keeping a suitable thickness of the frame to maintain structural integrity of the frame. Put another way, the frame 210 is essentially a wireframe of a cube.

[0115] The frame 210 comprises a plurality of engagement features 219 around each of the module apertures 212-218. The engagement features 219 around a given module aperture 212-218 are configured to engage either a module panel 220 or a joining member 230. In the present example, the engagement features 219 are threaded blind holes each configured to receive a screw thereby to join the frame 220 and the module panel 220 / joining member 230. It will be appreciated by those skilled in the art that any other suitable engagement features may be provided. The module apertures 212-218 are each the same size which thereby allows a module panel 220 of standard size to be provided, suitable for covering said apertures.

[0116] Figure 5 illustrates a plan view of module panel 220 of a module unit 200.

[0117] The module panels comprise a seal member 221 and plurality of engagement features 229. The seal member 221 comprises a groove and an O-ring disposed therein. The O- ring stands proud of the top of the groove thereby to provide a seal between the module panel and the module frame 210 in use. Each module panel 220 is sized to cover off (e.g. completely cover) the module apertures 212-218.

[0118] Each module panel 220 is removably engageable with the module frame thereby to cover one of the one or more module apertures thereby to hermetically seal the module aperture. Therefore, a module panel 220 is engageable (e.g. joinable) with a side of the module frame to close off (e.g. cover) the module aperture on that side of the module frame and also disengageable therewith thereby to leave the aperture open.

[0119] Figure 6 illustrates a cross-sectional view of a portion of two module panels connected to a module frame.

[0120] In more detail, the module panel 220 engagement features 229 are configured to permit reversible (e.g. removable) engagement between the module panel engagement features 229 and the module frame engagement features 219. In the example shown in Figure 5, the each engagement feature 229 is a through hole configured to receive a screw such that the shank and / or thread fit through said through hole and to prevent the head of the screw passing therethrough.

[0121] Accordingly, the module panel engagement features 229 may be aligned with the module frame engagement features 219 thereby to form a plurality of pairs wherein each pair comprises one module panel engagement feature 229 and one module frame engagement feature. A screw S is provided for each pair and said screw is first disposed through the through hole (module panel engagement feature 229) and then disposed in the threaded blind hole (module frame engagement feature 219) and tightened in the latter such that the head of the screw S presses against a periphery of the through hole on the panel to thereby push the panel 220 toward the frame 210. Together the panel 220 and frame 210 act to hermitically seal aperture. By hermitically sealing each aperture 212-218 of the module units in a given apparatus, a hermitically sealed enclosure can be provided.

[0122] It will be appreciated by those of skill in the art that other suitable module frames may have the shape of any other polyhedrons, and in particular, polyhedrons which can honeycomb (i.e. tessellate in 3 dimensions) 3 dimensional space. It will also be appreciated that other suitable module frames polyhedrons may be those which have a footprint (e.g. top-down cross-section in use) which is a 2 dimensional shape which tessellates two dimensional space (e.g. tessellates the floor of the room in which the module units are provided. The advantage with such shapes is that the apparatus may be easily expandable (e.g. by adding further modules which fit together with the existing modules) and / or the storage of apparatuses formed of such shapes is more space efficient.

[0123] Figure 7 illustrates a plan view of a joining member for detachably joining together two module units, as shown for example in Figures 8A and 8B. The joining member 230 is a band of material (e.g. metal) comprising: a first joining member side 231 ; a second joining member side 232 opposite the first joining member side 231 ; a joining member aperture 233 delimited by the band of material; a first sealing member 235; a second sealing member 236; and, a plurality of joining member engagement features 239.

[0124] The first sealing member 235 is disposed on the first joining member side 231. The first sealing member 235 comprises a groove in the first joining member side 231 and an O- ring disposed therein. The O-ring stands proud of the top of the groove thereby to provide a seal between the first joining member side 231 and a first module frame 210 connected thereto in use. Similarly, the second sealing member 236 is disposed on the second joining member side 232. The second sealing member 236 comprises a groove in the second joining member side 232 and an O-ring disposed therein. The O-ring stands proud of the top of the groove thereby to provide a seal between the second joining member side 232 and a second module frame 210 connected thereto in use. There are joining member engagement features 229 on the first joining member side 231 configured to engage a first module unit. There are joining member engagement features 229 on the second joining member side 232 configured to engage a second module unit. The joining member engagement features 239 on a given side of the joining member 230 are configured to engage the module frame engagement features 219 of a module unit. Accordingly, the joining member engagement features 239 on a given side thereof may be aligned with the module frame engagement features 219 thereby to form a plurality of pairs wherein each pair comprises one joining member engagement feature 239 and one module frame engagement feature 219.

[0125] In more detail, the joining member engagement features 239 are configured to permit reversible (e.g. removable) engagement between the joining member engagement features 239 and the module frame engagement features 219. In the example shown in Figures 8A & 8B, each engagement feature 239 on the first joining member side 231 comprises: a hole disposed in the first joining member side 231 ; a screw R disposed in the hole such that the shank and / or thread project from the hole and the head of the screw is disposed within the hole and the head of the screw comprises a groove; a transverse hole arranged transverse to a longitudinal direction of the hole disposed in the first joining member side 231 ; and a transverse screw T disposed in the transverse hole wherein a portion of the transverse screw is disposed within the groove in the head of the screw.

[0126] To join first module unit 200A to the first joining member 230A, an aperture of the first module unit 200A is arranged with the aperture 233 of the first joining member 230, then screws R are screwed into the module frame engagement features 219 on a side of the first module 200A. The heads of each screw stands proud of the side of the first module 200A. The first joining member 230A and the first module unit 200A are moved together and the heads of the screws R protruding from the side of the first module 200A are located into the holes in the first side 231 A of the first joining member 230A. Together the module frame 210 and the joining member 230 act to hermitically seal aperture. Next the transverse screws T are screwed into the transverse holes so that for each screw R protruding from the module frame 230A has part of a transverse screw T is located in the groove in the head thereof. This process is repeated for the second module unit 200B and the second joining member 230B.

[0127] Figure 9 illustrates a cross sectional view of a portion of alternative joining member 230’, a first module frame 210A’, and a second module frame 21 OB’.

[0128] The first module frame 210A’ and joining member 230’ are brought together (e.g. so that their respective apertures are arranged opposite one another) and then first screws (only one first screw is shown in Figure 9) 291 pass through a through hole in the joining member 230’ and engage a thread in the first module frame 210A’ thereby to secure the first module frame 210A’ to the joining member 230’.

[0129] Brackets 293 are connected to the second module frame 21 OB’ by second screws 292 (only one bracket and one second screw are shown in Figure 9). The second module frame 21 OB’ and brackets 293 are brought together and then second screws 292 pass through a through hole in the bracket 293 and engage a thread in the second module frame 21 OB’ thereby to secure the brackets 293 to the second module frame 21 OB’.

[0130] Next the second module frame 21 OB’ and the combined first module frame 210A’ and joining member 230’ are brought together (e.g. so that their respective apertures are arranged opposite one another) and then third screws 294 pass through another through hole in the bracket 293 and engage a thread in the joining member 230’ thereby to secure the second module frame 210B’ to the joining member 230’.

[0131] It will be appreciated from the discussion above that the embodiments shown in the figures are merely exemplary, and include features which may be generalised, removed or replaced as described herein and as set out in the claims. With reference to the drawings in general, it will be appreciated that schematic functional block diagrams are used to indicate functionality of systems and apparatus described herein. In addition the processing functionality may also be provided by devices which are supported by an electronic device. It will be appreciated however that the functionality need not be divided in this way, and should not be taken to imply any particular structure of hardware other than that described and claimed below. The function of one or more of the elements shown in the drawings may be further subdivided, and / or distributed throughout apparatus of the disclosure. In some embodiments the function of one or more elements shown in the drawings may be integrated into a single functional unit.

[0132] As will be appreciated by the skilled reader in the context of the present disclosure, each of the examples described herein may be implemented in a variety of different ways. Any feature of any aspects of the disclosure may be combined with any of the other aspects of the disclosure. For example method aspects may be combined with apparatus aspects, and features described with reference to the operation of particular elements of apparatus may be provided in methods which do not use those particular types of apparatus. In addition, each of the features of each of the embodiments is intended to be separable from the features which it is described in combination with, unless it is expressly stated that some other feature is essential to its operation. Each of these separable features may of course be combined with any of the other features of the embodiment in which it is described, or with any of the other features or combination of features of any of the other embodiments described herein. Furthermore, equivalents and modifications not described above may also be employed without departing from the invention.

[0133] Other examples and variations of the disclosure will be apparent to the skilled addressee in the context of the present disclosure.

Claims

CLAIMS1. A cryogenic apparatus for a quantum computer, the cryogenic apparatus comprising: an enclosure defining an enclosed volume; a sample volume disposed within the enclosed volume; wiring for connecting to the sample volume, wherein the wiring is disposed within the enclosed volume; and, a cooling device, wherein the cooling device is disposed at least partially within the enclosed volume; a cooling frame extending in an enclosed volume, wherein the cooling frame is configured to couple the cooling device and the wiring thereby to permit conductive cooling of the wiring by the cooling device in use, wherein the cooling frame comprises: a first cooling frame portion extending, along a first axis, between the cooling device toward the sample volume; and, a second cooling frame portion extending, along a second axis, between the sample volume to the wiring; wherein the first axis is transverse to the second axis.

2. The cryogenic apparatus of claim 1 , wherein: the cooling device has a longitudinal axis arranged parallel to the first axis; and, the wiring is removably couplable to the sample volume in a direction substantially parallel to the second axis.

3. The cryogenic apparatus of any of claims 1 to 2 comprising: a series of plates arranged transverse to the second axis; wherein each of the plates is coupled to the second cooling frame portion.

4. The cryogenic apparatus of claim 3, comprising: a wiring cassette configured to support the wiring; wherein the wiring cassette is removably couplable to the sample volume in a direction substantially parallel to the second axis; the wiring cassette comprising a plurality of wiring plates; wherein each wiring plate is configured to thermally couple to a corresponding one of theplates when the wiring cassette is coupled to the sample volume.

5. The cryogenic apparatus of any of claims 1 to 4, wherein: the enclosure comprises: a sample module, wherein the sample volume is disposed within the sample module; a cooling module, wherein the cooling device is connected to the cooling module and is disposed at least partially within the cooling module; and, a wiring module, wherein the wiring is disposed within the wiring module; wherein the sample module, cooling module and wiring module are interconnected to provide the enclosed volume.

6. A cryogenic apparatus for a quantum computer, the cryogenic apparatus comprising: an enclosure defining an enclosed volume, wherein the enclosure comprises: a sample module comprising a sample volume disposed within the sample module; a cooling module comprising a cooling device, wherein the cooling device is connected to the cooling module and is disposed at least partially within the cooling module; and, a wiring module, comprising wiring disposed within the wiring module, the wiring for connecting to the sample volume; wherein the sample module, cooling module and wiring module are interconnected to provide the enclosed volume.

7. The cryogenic apparatus of claim 6, wherein: the cooling module is connected to the sample module, wherein the cooling module and the sample module are arranged along a first axis; and, the wiring module is connected to the sample module, wherein the wiring module and the sample module are arranged along a second axis; wherein the first axis is transverse to the second axis.

8. The cryogenic apparatus of claim 7, wherein:the cooling device has a longitudinal axis arranged parallel to the first axis; and, the wiring is removably couplable to the sample volume in a direction substantially parallel to the second axis.

9. The cryogenic apparatus of any of claims 6 to 8, comprising: a cooling frame extending in the enclosed volume, wherein the cooling frame is configured to couple the cooling device and the wiring thereby to permit conductive cooling of the wiring by the cooling device in use, wherein the cooling frame comprises: a first cooling frame portion extending, along the first axis, between the cooling device toward the sample volume; and, a second cooling frame portion extending, along the second axis, between the sample volume to the wiring.

10. The cryogenic apparatus of claim 9, wherein: the first cooling frame portion extends within the cooling module and the sample module; and, the second cooling frame portion extends within the sample module and the wiring module.11 . The cryogenic apparatus of any of claims 6 to 10, wherein: the wiring module comprises a series of cooling wherein each of the plates is coupled to the second cooling frame portion.

12. The cryogenic apparatus of claim 11 , wherein: each of the plates is disposed transverse to the second axis.

13. The cryogenic apparatus of claim 12, comprising: a wiring cassette configured to support the wiring; wherein the wiring cassette is removably couplable to the sample volume in a direction substantially parallel to the second axis; the wiring cassette comprising a plurality of wiring plates; wherein each wiring plate is configured to thermally couple to a corresponding one of the plates when the wiring cassette is coupled to the sample volume.

14. The cryogenic apparatus of any of claims 5 to 13, wherein: each of the sample module; cooling module; and, the wiring module; comprises a module unit, wherein each module unit comprises: a module frame defining an interior volume, the module frame comprising: one or more apertures configured to permit access to the interior of the module frame.

15. The cryogenic apparatus of claim 14, wherein: the module frame is configured to engage: a module panel, wherein the module panel is removably engageable with the module frame thereby to cover one of the one or more apertures;16. The cryogenic apparatus of any of claims 14 to 15, wherein: the module frame is configured to engage: an joining member, wherein the joining member is configured to connect the module frame to another module frame.

17. The cryogenic apparatus of any of claims 1 to 16, wherein: the cooling device comprises: a plurality of primary heat exchangers, wherein: the plurality of primary heat exchangers are arranged in series thereby to provide successive cooling of a sample volume; in use, the sample volume is thermally coupled to a final primary heat exchanger in said series; and, a plurality of secondary heat exchanger corresponding in number to the plurality of primary heat exchangers, wherein for each of the primary heat exchanger, a secondary heat exchanger is configured to extract heat from coolant entering the first heat exchanger.

18. The cryogenic apparatus of any of claims 5 to 17, comprising: a secondary cooling module comprising a secondary cooling device, wherein the secondary cooling device is connected to the wiring thereby to extract heat from thewiring.

19. A module unit for providing a modular cryogenic apparatus, the module unit comprising: a polyhedral module frame defining an interior volume, the polyhedral module frame comprising: one or more apertures configured to permit access to the interior of the module frame.

20. The module unit of claim 19, comprising: one or more module panels, wherein each of the one or more module panels is removably engageable with the module frame thereby to cover one of the one or more apertures thereby to hermetically seal the aperture.21 . The module unit of claim 20, wherein: each of the one or more module panels comprises a sealing member configured to provide a seal between the module panel and the module frame when the module panel covers said aperture.

22. The module unit of any of claims 19 to 21 , wherein: the module unit is configured to engage another module unit such that one of the one or more apertures of the module unit is arranged opposite one of the one or more apertures of the other module unit.

23. The module unit of any of claims 19 to 22, wherein: the module unit is configured to engage a joining member, wherein the joining member is configured to connect the module frame to another module frame.

24. The module unit of claim 23, wherein: the joining member comprises: a first side comprising a first sealing member; and, a second side comprising a second sealing member.

25. A kit of parts for providing a cryogenic apparatus, the kit comprising: a first module unit for providing a sample module; a second module unit for providing a cooling module; a third module unit for providing a wiring module; wherein the first module unit, the second module unit, and the third module unit are configured to be interconnected thereby to provide an enclosed volume.

26. The kit of claim 25, wherein: the first module unit is configured to connect to the second module unit, such that the first module unit and the second module unit are arranged along a first axis; and, the first module unit is configured to connect to the third module unit, wherein the first module unit and the third module unit are arranged along a second axis; wherein the first axis is transverse to the second axis.

27. The kit of claim 26, the kit comprising: a sample volume configured to be disposed within the first module unit; a cooling device configured to connect to the second module unit and configured to be disposed at least partially within the second module unit; wiring configured to be disposed within the third module unit and configured to connect to the sample volume when the sample volume is disposed within the first module unit; wherein, the cooling device has a longitudinal axis configured to be arranged parallel to the first axis; and, the wiring is removably couplable to the sample volume in a direction substantially parallel to the second axis.

28. The kit of any of claims 25 to 27, the kit comprising: one or more joining members, wherein the joining member is configured to connect the module frame to another module frame.

29. A pump line for a cryogenic apparatus, the pump line comprising: a plurality of primary heat exchangers, wherein: the plurality of primary heat exchangers are arranged in series thereby to provide successive cooling of a sample volume;in use, the sample volume is thermally coupled to a final primary heat exchanger in said series; and, a plurality of secondary heat exchangers wherein for each of the primary heat exchanger, a secondary heat exchanger is configured to extract heat from coolant flowing from a heating side to a cooling side of the primary heat exchanger.

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