Cryogenic system including integrated cryocooler and dilution refrigerator

Abstract

The present invention relates to a regenerative cryogenic system, the system comprising a pulse tube assembly having one or more stages configured to generate cryogenic temperatures below 4.2 Kelvin, and one or more flanges configured to provide a vacuum interface or thermal equilibrium, the one or more flanges being coupled to the pulse tube assembly, and further comprising a still exhaust line integrated into at least one of the one or more flanges, the still exhaust line being configured to provide a passage for still gas of a dilution refrigerator.

Description

[Technical Field]

[0001] This relates to a cryogenic system including an integrated cryocooler and dilution refrigerator. [Background technology]

[0002] Cryogenic systems may include cryocoolers (e.g., pulse tube assemblies) and dilution refrigerators. Such cryogenic systems may be used to achieve low temperatures in a variety of scientific and industrial applications, including quantum computing applications. [Overview of the Initiative]

[0003] According to aspects of the present disclosure, a regenerative cryogenic system is provided. The regenerative cryogenic system comprises a cryocooler configured to generate cryogenic temperatures, one or more flanges coupled to the cryocooler, and a still exhaust line integrated with one or more flanges. The still exhaust line is configured to provide a passage for still gas from a dilution refrigerator.

[0004] In some embodiments, the cryocooler is configured to generate extremely low temperatures below 4.2 Kelvin (K). For example, the cryocooler may be configured to cool in a temperature range from over 300 K to about 2 K. In some embodiments, the cryocooler may be configured to cool down to about 2.5 K.

[0005] In some embodiments, one or more flanges are configured to provide a vacuum interface and / or thermal equilibrium (thermalization). In some embodiments, the regenerative cryogenic system further includes a dilution refrigerator condenser line integrated to exchange heat with a cryocooler and a still exhaust line, wherein the dilution refrigerator condenser line is configured to condense the still gas of the dilution refrigerator, and the cryocooler is configured to cool the dilution refrigerator condenser line. In some embodiments, the gas does not have to be completely condensed in the cryocooler. Rather, some of the gas may be condensed in the cryocooler, and most of the gas may be condensed for the first time at other locations in the system. In a steady state, most of the gas may be condensed in the cryocooler.

[0006] In some embodiments, the condensing line of the dilution refrigerator is integrated with the cryocooler and the still exhaust line by winding, brazing, or arranging the conduit of the still exhaust line within the gas flow path or a heat-conducting block.

[0007] In some embodiments, the still exhaust line is configured to cool the condensing line of the dilution refrigerator. In some embodiments, the regenerative cryogenic system further comprises one or more heat exchangers integrated with the cryocooler, the one or more heat exchangers configured to perform heat exchange between the dilution refrigerator and the cryocooler. The cryocooler, such as a pulse tube, may include a heat exchanger for a fluid different from the working fluid of the pulse tube.

[0008] In some embodiments, the cryocooler includes one or more pulse tubes. In some embodiments, the cryocooler further includes a 4K helium compressor, and the regenerative cryogenic system further includes an adsorbent exchange system integrated with the 4K helium compressor, the adsorbent exchange system being configured to replace its adsorbent without stopping the 4K helium compressor.

[0009] In some embodiments, the regenerative cryogenic system further comprises a helium battery integrated with the cryocooler, which is configured to store and release helium gas to maintain the operation of the regenerative cryogenic system. In some embodiments, batteries other than helium batteries, such as other types of batteries made of high specific heat materials, may be used.

[0010] A part of the present disclosure provides a method for operating a cryogenic system comprising a cryocooler, a still exhaust line for a dilution refrigerator, and a condensing line for a dilution refrigerator. The method includes generating a cryogenic temperature using the cryocooler, performing heat exchange between the condensing line and the cryocooler, and further performing heat exchange between the condensing line and the still exhaust line.

[0011] In some embodiments, generating cryogenic temperatures using a cryocooler includes generating cryogenic temperatures below 4.2 Kelvin. In some embodiments, the method further includes condensing the still gas of a dilution refrigerator using a condensation line.

[0012] In some embodiments, heat exchange between the condensation line and the cryocooler includes cooling the condensation line using the cryocooler. In some embodiments, heat exchange between the condensing line and the still exhaust line includes using the still exhaust line to cool the condensing line.

[0013] In some embodiments, the cryogenic system further comprises one or more flanges configured to provide a vacuum interface and / or thermal equilibrium, the one or more flanges being coupled to the cryocooler, and a still exhaust line being integrated into one or more flanges.

[0014] According to aspects of the present disclosure, a cryogenic system is provided comprising means for generating cryogenic temperatures, one or more flanges configured to provide a vacuum interface and / or thermal equilibrium, the one or more flanges being coupled to the means for generating cryogenic temperatures, and a still exhaust line integrated with the one or more flanges. The still exhaust line is configured to provide a passage for still gas of a dilution refrigerator.

[0015] In some embodiments, the cryogenic system further includes a dilution refrigerator condenser line, which is configured to exchange heat with means for generating cryogenic temperatures and a still exhaust line, and to condense the still gas of the dilution refrigerator.

[0016] In some embodiments, the condensing line of a dilution refrigerator includes a first part and a second part, the first part being integrated with a still exhaust line and configured to exchange heat with the still exhaust line, the second part being integrated with means for generating cryogenics and configured to exchange heat with the cryogenics generating means and the still exhaust line, the still exhaust line being configured to cool the condensing line of the dilution refrigerator.

[0017] In some embodiments, the condensing line of the dilution refrigerator is integrated with the means for generating cryogenic temperatures and the still exhaust line by winding, brazing, or arranging the conduit of the still exhaust line within the gas flow path or a heat-conducting block.

[0018] According to aspects of the present disclosure, a regenerative cryogenic system is provided comprising a pulse tube assembly having one or more stages configured to generate cryogenic temperatures below 4.2 Kelvin, one or more flanges configured to provide a vacuum interface or thermal equilibrium, coupled to the pulse tube assembly, and a still exhaust line integrated to one or more flanges. The still exhaust line is configured to provide a passage for still gas of a dilution refrigerator.

[0019] In some embodiments, the still exhaust line is configured to provide a passage for the still gas of the dilution refrigerator to be exhausted from the regenerative cryogenic system. In some embodiments, the regenerative cryogenic further comprises a dilution refrigerator condenser line integrated with a pulse tube assembly and a still exhaust line, configured to exchange heat with them, the dilution refrigerator condenser line being configured to condense the still gas of the dilution refrigerator, and the pulse tube assembly being configured to cool the dilution refrigerator condenser line.

[0020] In some embodiments, the condensing line of the dilution refrigerator is integrated with the pulse tube assembly and the still exhaust line by winding, brazing, or placement within the gas flow path.

[0021] In some embodiments, the condensing line of a dilution refrigerator includes a first part and a second part, the first part being integrated with a still exhaust line and configured to exchange heat with the still exhaust line, and the second part being integrated with a pulse tube assembly and configured to exchange heat with the pulse tube assembly.

[0022] In some embodiments, the still exhaust line is configured to cool the condensing line of the dilution refrigerator. In some embodiments, the condensing line of the dilution refrigerator is integrated with the pulse tube assembly and the still exhaust line by winding, brazing, or placement within the gas flow path.

[0023] In some embodiments, the regenerative cryogenic system further comprises one or more heat exchangers integrated with the pulse tube assembly, the one or more heat exchangers configured to perform heat exchange between the dilution refrigerator and the pulse tube assembly.

[0024] In some embodiments, the pulse tube assembly includes a 4K helium compressor, and the regenerative cryogenic system further comprises an adsorbent exchange system integrated with the 4K helium compressor, the adsorbent exchange system being configured to replace its adsorbent without stopping the 4K helium compressor.

[0025] In some embodiments, the regenerative cryogenic system further comprises a helium battery integrated with a pulse tube assembly, the helium battery configured to store and release helium gas to maintain the operation of the regenerative cryogenic system.

[0026] According to aspects of the present disclosure, a cryogenic system is provided comprising a cryocooler having one or more stages configured to generate cryogenic temperatures; one or more flanges configured to provide a vacuum interface or thermal equilibrium, coupled to the cryocooler; and a still exhaust line integrated with one or more flanges. The still exhaust line is configured to provide a passage for still gas from a dilution refrigerator.

[0027] In some embodiments, the cryocooler is configured to generate extremely low temperatures below 4.2 Kelvin. In some embodiments, the cryogenic system further comprises a cryocooler and a dilution refrigerator condenser line configured to exchange heat with a still exhaust line, the dilution refrigerator condenser line being configured to condense the still gas of the dilution refrigerator, and the cryocooler being configured to supply the dilution refrigerator condenser line.

[0028] In some embodiments, the condensing line of the dilution refrigerator includes a first part and a second part, the first part being integrated with the still exhaust line and configured to exchange heat with the still exhaust line, and the second part being integrated with the cryocooler and configured to exchange heat with the cryocooler.

[0029] In some embodiments, the still exhaust line is configured to cool the condensing line of the dilution refrigerator. In some embodiments, the condensing line of the dilution refrigerator is integrated with the cryocooler and still exhaust line by winding, brazing, or placement within the gas flow path.

[0030] According to aspects of the present disclosure, a cryogenic system is provided comprising one or more flanges configured to provide a vacuum interface or thermal equilibrium, the one or more flanges being coupled to the cryogenic means, and a still exhaust line integrated with the one or more flanges. The still exhaust line is configured to provide a passage for still gas of a dilution refrigerator. In some embodiments, the cryogenic means is configured to produce a cryogenic temperature of less than 4.2 Kelvin.

[0031] In some embodiments, the cryogenic system further comprises means for generating cryogenic temperatures and a dilution refrigerator condenser line configured to exchange heat with a still exhaust line, wherein the dilution refrigerator condenser line is configured to condense the still gas of the dilution refrigerator, and the means for generating cryogenic temperatures is configured to cool the dilution refrigerator condenser line.

[0032] In some embodiments, the condensing line of a dilution refrigerator includes a first part and a second part, the first part being integrated with a still exhaust line and configured to exchange heat with the still exhaust line, and the second part being integrated with means for generating cryogenics and configured to exchange heat with means for generating cryogenics, the still exhaust line being configured to cool the condensing line of the dilution refrigerator.

[0033] In some embodiments, the condensing line of the dilution refrigerator is integrated with the means for generating cryogenic temperatures and the still exhaust line by winding, brazing, or placement within the gas flow path.

[0034] According to aspects of this disclosure, a method for manufacturing a cryogenic system is provided, which includes coupling one or more flanges to a cryocooler and integrating a still exhaust line to one or more flanges.

[0035] The attached drawings are not necessarily drawn to scale. In the drawings, identical or nearly identical components shown in each drawing are indicated by the same reference number. For convenience, not all components in all drawings are assigned reference numbers. [Brief explanation of the drawing]

[0036] [Figure 1] This is a schematic diagram of a cryogenic system including a cryocooler integrated with a dilution refrigerator, according to some embodiments described herein. [Figure 2A] This figure shows exemplary components of a cryogenic system (such as the cryogenic system in Figure 1) that includes a cryocooler integrated with a dilution refrigerator, according to some embodiments described herein. [Figure 2B] This figure shows exemplary components of a cryogenic system (such as the cryogenic system in Figure 1) that includes a cryocooler integrated with a dilution refrigerator, according to some embodiments described herein. [Figure 2C] This figure shows exemplary components of a cryogenic system (such as the cryogenic system in Figure 1) that includes a cryocooler integrated with a dilution refrigerator, according to some embodiments described herein. [Figure 2D] This figure shows exemplary components of a cryogenic system (such as the cryogenic system in Figure 1) that includes a cryocooler integrated with a dilution refrigerator, according to some embodiments described herein. [Figure 3] This is a schematic diagram of a closed-cycle dilution refrigerator according to some embodiments described herein. [Figure 4] This is a schematic diagram of a helium purification device in the dilution refrigerator shown in Figure 3, according to some embodiments described herein. [Figure 5]This is a schematic diagram of a cool-down turbocharger device in a dilution refrigerator, as described in this specification, according to some embodiments. [Figure 6] This is a schematic diagram of a still equipped with a device for separating 3He and 4He using a second sonic action, according to some embodiments described herein. [Figure 7A] This figure shows exemplary components of a removable dilution insert in the dilution refrigerator of Figure 3, according to some embodiments described herein. [Figure 7B] This figure shows an example of a thermal equilibrium plate insert in the removable dilution insert of Figure 7A, according to some embodiments described herein. [Figure 7C] This is an exemplary cross-sectional view of an integrated heat exchanger showing a helium channel, according to some embodiments described herein. [Figure 7D] These are images of high specific surface area materials used in integrated heat exchangers according to some embodiments described herein. [Figure 7E] This figure shows examples of a continuous heat exchanger and individual heat exchangers in the dilution refrigerator shown in Figure 3, according to some embodiments described herein. [Figure 8A] This is a schematic diagram of an exemplary 4He membrane separation apparatus according to some embodiments described herein. [Figure 8B] This is a schematic diagram of an exemplary 4He membrane separation apparatus according to some embodiments described herein. [Figure 8C] This is a schematic diagram of an exemplary 4He membrane separation apparatus according to some embodiments described herein. [Figure 8D] This is a schematic diagram of an exemplary 4He membrane separation apparatus according to some embodiments described herein. [Figure 8E] This is a schematic diagram of an exemplary 4He membrane separation apparatus according to some embodiments described herein. [Figure 8F] This is a schematic diagram of an exemplary 4He membrane separation apparatus according to some embodiments described herein. [Figure 9A]This is an image of sintered metal particles used in heat exchangers. [Figure 9B] These are images of nanowires used in heat exchangers according to some embodiments described herein. [Figure 9C] These are images of nanoclusters used in heat exchangers according to some embodiments described herein. [Figure 9D] This figure includes images of various nanopellets used in heat exchangers according to some embodiments described herein. [Figure 10A] This is a schematic diagram of an exemplary vibration isolation system used in the dilution refrigerator shown in Figure 3, according to some embodiments described herein. [Figure 10B] This figure shows an exemplary spring used in the vibration isolation system of Figure 10A, according to some embodiments described herein. [Figure 11] This is a side view of an external support rack and integrated lift configured to raise and lower a portion of a vacuum chamber, according to some embodiments described herein. [Figure 12A] Figure 3 is a side view of an example of a dilution refrigerator, including components that enable toolless assembly of a vacuum chamber and access to the experimental space, according to some embodiments described herein. [Figure 12B] This figure shows, respectively, an integrated latch in the open and closed positions that enables toolless assembly of a vacuum chamber, according to some embodiments described herein. [Figure 12C] This figure shows, respectively, an integrated latch in the open and closed positions that enables toolless assembly of a vacuum chamber, according to some embodiments described herein. [Figure 13] This is an external view of a housing configured to support a dilution refrigerator according to some embodiments described herein. [Figure 14A] This is a schematic diagram of an inversion type dilution refrigerator according to some embodiments described herein. [Figure 14B]This is a schematic diagram of exemplary components of an inversion dilution refrigerator according to some embodiments described herein. [Figure 14C] This is a schematic diagram of exemplary components of an inversion dilution refrigerator according to some embodiments described herein. [Figure 15] This is a schematic diagram of a distributed cooling system according to some embodiments described herein. [Figure 16] This figure schematically shows an exemplary computing device capable of carrying out the technology described herein, according to some embodiments described herein. [Modes for carrying out the invention]

[0037] Aspects of this disclosure relate to the field of cryogenic engineering. In some embodiments, this disclosure provides pulse-tube cryogenic systems and related methods integrated with a dilution refrigerator. Aspects of this disclosure include pulse-tube cryogenic systems and related methods integrated with a dilution refrigerator, which overcome the limitations associated with the configuration of conventional cryogenic systems and methods. Furthermore, aspects of this disclosure provide more efficient, effective, and miniaturized cryogenic systems and methods for achieving low temperatures. In some embodiments, low temperatures may include temperatures below 300 mK, including temperatures suitable for scientific and industrial applications, such as quantum computing applications. Embodiments of this disclosure described herein provide more efficient, effective, and miniaturized systems and methods, for example, through better integration of a 4.2 Kelvin pulse-tube cooler and a sub-Kelvin dilution unit.

[0038] Pulse tube cryogenic systems and dilution refrigerators are two technologies for achieving low temperatures in various scientific and industrial applications. A pulse tube cryogenic system may include a type of specially modified Stirling engine, which operates by compressing and expanding helium gas through a series of valves, heat exchangers, and regenerators, ultimately producing intermediate low temperatures. For example, intermediate low temperatures may include temperatures of about 2 to 4.2 Kelvin. In other embodiments, intermediate low temperatures may be about 7 Kelvin, about 10 Kelvin, or about 50 Kelvin.

[0039] Dilution refrigerators are 3 He and 4 Low temperatures are achieved using a mixture of He isotopes. For example, low temperatures may include temperatures down to a few millikelvins. In some embodiments, this mixture is first liquefied by another cooling system. For example, this liquefied mixture is initially cooled through a Joule-Thomson expander and a subsequent series of heat exchangers until it reaches a critical temperature. In some embodiments, this critical temperature may be about 870 mK. At this critical temperature, spontaneous phase separation occurs, 3 The first phase contains a lot of He and 4 The second phase, which is rich in He, may separate into two fractions. The lean phase is exhausted under sufficient pressure and at an appropriate temperature. Once the lean phase is exhausted, 3 Due to the high vapor pressure of helium, the natural ratio within the dilute phase may be disrupted. 3 The heat of mixing generated when he crosses the phase boundary to correct this ratio allows the cryogenic system to be cooled to temperatures as low as a few millikelvins. This cooling capacity obtained by the cryogenic system can be used for the cooling and study of various materials and phenomena, such as superconductivity and quantum mechanics.

[0040] In some embodiments, for operation, the dilution refrigerator 3 He and 4The He mixture is first cooled to an intermediate low temperature, for example, about 4.2 Kelvin or lower. According to various embodiments, techniques for achieving this intermediate low temperature or temperature initialization include helium baths, stepwise nitrogen-helium baths, Gifford-McMahon (GM) cryocoolers, GM pulse tubes, or Stirling pulse tubes (collectively referred to as "pulse tubes"). In some conventional systems, using a dilution unit in combination with a GM pulse tube may be preferred for various reasons.

[0041] However, conventional pulse-tube cryogenic systems and dilution refrigerators have several limitations, including a large system footprint, low thermal equilibrium efficiency of the introduced helium gas, and the return of cooled gas to room temperature through the still exhaust line. These limitations reduce the overall efficiency of conventional cryogenic systems.

[0042] Aspects of this disclosure overcome the limitations of conventional cryogenic systems by integrating a pulse tube or other 4K cryogenic system with a dilution refrigerator. For example, the still exhaust line of the dilution refrigerator is integrated within the same flange as the pulse tube or other 4K cryogenic system. A cryogenic system configured in this way improves the thermal equilibrium of the introduced helium gas, enhances cooling performance, and improves energy efficiency. Furthermore, the means for generating sub-Kelvin cryogenic temperatures are significantly smaller compared to conventional cryogenic systems.

[0043] Furthermore, the inventors recognized that conventional pulse tubes can sometimes be unnecessarily large. They also found that integrating a dilution refrigerator with the pulse tube or other 4K cryogenic systems, for example, by integrating the still exhaust line with the pulse tube's vacuum interface, yields several significant advantages, including miniaturization and improved thermal performance. Additionally, the inventors discovered several other improvements for the 4.2 Kelvin system.

[0044] The contents of U.S. Patent Application No. 17 / 860,909 (title "INTEGRATED DILUTION REFRIGERATORS"), filed on 8 July 2022, are incorporated herein by reference in their entirety. U.S. Patent Application No. 17 / 860,909 describes several embodiments of cryogenic systems, including dilution refrigerators, pulse tubes, and other cryocoolers or 4K cryogenic systems.

[0045] I. Integration of cryocooler and dilution refrigerator Figure 1 shows a schematic diagram of the cryogenic system 2000, which includes a cryocooler 2054 integrated with a dilution refrigerator 2052. In some embodiments, the cryocooler 2054 may include a pulse tube or another type of cryocooler. Figures 2A to 2D show exemplary components of the cryogenic system 2000, including an integrated configuration of a cryocooler (e.g., cryocooler 2054) and a dilution refrigerator (e.g., dilution refrigerator 2052).

[0046] Figure 2A shows an overall view of the cryogenic system 2100, and Figure 2B shows a detailed view thereof. The cryogenic system 2100 is an example of the cryogenic system 2000 according to various embodiments. In the example shown in Figures 2A to 2D, the cryogenic system 2100 includes a cryocooler 2154 integrated with a dilution refrigerator 2152, where the cryocooler 2154 may include a pulse tube, but cryogenic systems according to other embodiments may include a different type of cryocooler.

[0047] As shown in Figure 2C, the cryogenic system 2100 includes a cryocooler 2154. The cryocooler 2154 may include a pulse tube cryocooler. In the embodiment shown in Figure 2C, the pulse tube cryocooler may include a pulse tube assembly that includes one or more pulse tubes and one or more pulse tube regenerators. In the embodiment shown in Figure 2C, the cryocooler 2154 includes a primary pulse tube 2154a, a secondary pulse tube 2154b, a primary pulse tube regenerator 2154c, and a secondary pulse tube regenerator 2154d.

[0048] The dilution refrigerator 2152 is configured to provide cooling down to cryogenic temperatures. The dilution refrigerator may include a condensation line 2102a, a return 2102b, and one or more flanges 2156a - 2156c in addition to other components described in relation to other figures. According to aspects of the present disclosure, the dilution refrigerator 2152 of the cryogenic system 2100 may be implemented in the same or substantially the same manner as other dilution refrigerators described herein, such as dilution refrigerator 100 or dilution refrigerator 1200 (described later).

[0049] The cryogenic system 2100 includes a condensation line 2102a. As described later, 3 He / 4 The He / He gas mixture may be introduced into the vacuum chamber of the cryogenic system 2100 through one or more inlets and then pass through some internal thermal stages of the cryogenic system 2100 via the condensation line 2102a. 3 He / 4 After performing the cooling function, the He / He mixture returns to the pump system via the return 2102b. The return 2102b may include a still exhaust line.

[0050] The condensation line 2102a may include a first condensation line portion 2102a - 1 and a second condensation line portion 2102a - 2. The condensation line may further include an outlet 2102a - 3, which may include an outlet to the dilution unit of the enriched 3 He condensation line. The first condensation line portion 2102a - 1 may include an enriched 3 He condensation line winding portion. For example, the first condensation line portion 2102a - 1 may be thermally coupled to the return 2102b by being wound around the second still exhaust line portion 2102b - 2. The second condensation line portion 2102a - 2 may include an enriched 3The He condensation line may include a winding section. For example, the second condensation line section 2102a-2 may be thermally coupled to the cryocooler 2154 by being wound around the secondary pulse tube regenerator 2154d. Furthermore, in some embodiments, the condensation line 2102a may include three or more sections. For example, in some embodiments, the condensation line 2102a may include a third section, thereby configuring the condensation line to exchange heat with the return 2102b (e.g., a still exhaust line) at two locations. For example, heat exchange with the return 2102b may occur before and after heat exchange with the cryocooler 2154.

[0051] The cryogenic system 2100 may further include a return 2102b. The return 2102b may include a still exhaust line. The return 2102b may include a first return section 2102b-1 and a second return section 2102b-2. The return 2102b may be connected to a return inlet 2102b-3. The return inlet 2102b-3 may be an inlet from a still (not shown in Figure 2C) to a still exhaust line. The connected still may include still 114, which will be detailed later. The return 2102b may be connected to a return outlet 2102b-4. The return outlet 2102b-4 may be an outlet from the still exhaust line to a pump (not shown in Figure 2C). The connected pump may include a pump system 102 (detailed later) and / or a turbomolecular pump.

[0052] The dilution refrigerator may include one or more flanges 2156a to 2156c. Flanges 2156a to 2156c may be held to allow for a gradual decrease in temperature and may provide multiple different heat stages (e.g., thermal equilibrium plates). As will be detailed later, the cryogenic system may include various heat stages (e.g., thermal equilibrium plates) 108a to 108f, which may be held to allow for a gradual decrease in temperature (for example, about 50K, 9-10K, 3K, etc.). Each of the one or more flanges 2156 may include a heat stage (e.g., thermal equilibrium plate). Furthermore, one or more flanges 2156a to 2156c may be configured to perform heat exchange between the cryocooler 2154 and the dilution refrigerator 2152 in order to improve the efficiency of the cryogenic system 2100.

[0053] Each of the one or more flanges of the cryogenic system 2100 may be configured to exchange heat between the cryocooler 2154 and the components of the dilution refrigerator 2152. The one or more flanges may include a first flange 2156a, a second flange 2156b, and a third flange 2156c. The first flange 2156a may include a vacuum flange. The second flange 2156b and the third flange 2156c may each include a thermal equilibrium / vacuum flange. Other stages, not shown in Figure 2C (and described in detail later), may constitute even lower-temperature cryogenic stages.

[0054] The first flange 2156a may include a vacuum flange configured to seal the cryocooler 2154 at the boundary of a vacuum chamber (for example, the vacuum chamber 106 described later). In some embodiments, the first flange 2156a may be configured to perform heat exchange between the cryocooler 2154 and the dilution refrigerator 2152 by thermally coupling two or more of the following: for example, the first condensation line section 2102a-1, the second return section 2102b-2, the primary pulse tube 2154a, and the secondary pulse tube regenerator 2154c.

[0055] As an example, the second flange 2156b may include a thermal equilibrium / vacuum flange of about 50K. In some embodiments, the second flange 2156b may be configured to perform heat exchange between the cryocooler 2154 and the dilution refrigerator 2152 by thermally coupling two or more of the following: a first condensation line section 2102a-1, a second return section 2102b-2, a primary pulse tube 2154a, a primary pulse tube regenerator 2154c, a second condensation line section 2102a-2, a first return section 2102b-1, a secondary pulse tube 2154b, and a secondary pulse tube regenerator 2154d.

[0056] As an example, the third flange 2156c may include a thermal equilibrium / vacuum flange of about 4K. In some embodiments, the second flange 2156b may be configured to perform heat exchange between the cryocooler 2154 and the dilution refrigerator 2152 by thermally coupling two or more of the following: for example, the second condensation line section 2102a-2, the first return section 2102b-1, the secondary pulse tube 2154b, and the secondary pulse tube regenerator 2154d.

[0057] In various embodiments, thermal coupling of components of the cryogenic system (e.g., thermal coupling of one or more flanges 2156a-2156c with components of either the cryocooler 2154 or the dilution refrigerator 2152 (i.e., first condensation line section 2102a-1, second return section 2102b-2, primary pulse tube 2154a, primary pulse tube regenerator 2154c, second condensation line section 2102a-2, first return section 2102b-1, secondary pulse tube 2154b, secondary pulse tube regenerator 2154d), or thermal coupling of condensation line 2102a with return 2102b) can be achieved by any suitable method. Suitable methods include winding, brazing, soldering, placing components within a gas flow path, installing 3D printed components within a wall, or placing conduits within a thermally conductive block (e.g., a copper block for the pulse tube flanges) and other heat exchange techniques.

[0058] Figure 2C further shows the housing 2109. The housing 2109 may house a switching system, such as the switching system 109 (described in detail later). The housing 2109 may also include a valve manifold housing. In some embodiments, the housing 2109 may house valves or other components of a turbocharger device (such as the turbocharger device 111 described later).

[0059] The inventors found that the thermal equilibrium of the introduced helium gas could be improved by integrating the return (e.g., return 2102b including a still exhaust line) with other components of the cryogenic system 2100.

[0060] In low-efficiency cryogenic systems, a method for cooling helium may involve thermally coupling the condensation line 2102a with components of the cryocooler 2154. An example of such a low-efficiency configuration is the inlet side (i.e., condensation side) of the dilution unit. 3 In some cases, a He line is wound around the first regenerator to cool the helium. However, the inventors have found that such an inefficient configuration has drawbacks, and therefore, 3 It was recognized that winding the He line around the first regenerator would divert cooling capacity from the cryogenic system, as it would be used to cool the helium rather than the system wiring.

[0061] Therefore, the inventors have found that by thermally coupling the components of the cryocooler 2154 with the return 2102b, the condensation line 2102a can be thermally coupled with the return 2102b (rather than directly thermally coupling it with a cryocooler such as a regenerator). By thermally coupling the condensation line 2102a with the return 2102b, the cryogenic system 2100 can utilize the cooling capacity from the cryogenic (e.g., about 700 mK) gas without letting it escape to the room temperature side. A particular configuration according to this disclosure integrates the primary pulse tube with the still exhaust line of the dilution unit (e.g., using a flange), and the condensation on the introduction side 3This includes winding the helium line around the still exhaust line. This improved configuration facilitates the integration of regeneration and light-shielding baffles within the cryogenic system. These integrated configurations and associated features improve the cooling performance and overall efficiency of the cryogenic system.

[0062] The inventors recognize further advantages with respect to the integrated cryocooler and dilution refrigerator described herein. For example, by integrating the still exhaust line and pulse tube, 3 The He condensation line is routed from the regenerator line located below the primary stage of the pulse tube (e.g., approximately 40 Kelvin) to the secondary stage regenerator line, removing excess amounts from the system. 3 The transition can be easily carried out without introducing He. In various embodiments, the condensing line of the dilution refrigerator is integrated with the pulse tube assembly and the still exhaust line and can perform heat exchange by any suitable method. This includes other heat exchange techniques such as winding, brazing, soldering, inserting the tube into the gas flow path, 3D printing the tube into the wall, or placing the conduit in a heat-conducting block (e.g., a copper block in the pulse tube flange).

[0063] Conventional methods may involve completely separate configurations of the pulse tube and dilution unit, resulting in the need for a large space and a large footprint for the cryogenic system. The operating part of the pulse tube requires considerable space in the range from room temperature to approximately 3K. The dilution unit requires a large space in the range from below 3K to the base temperature, and a relatively limited space in the range from 3K to room temperature. The inventors recognized that integrating the still exhaust line into the pulse tube assembly significantly reduces the footprint of the cryogenic system. Reducing the footprint of the cryogenic system is advantageous for several reasons. For example, reducing the footprint reduces the excess radiant heat load and the system's heat capacity, and also allows for additional space for non-operating elements of the cryogenic system, such as wiring, electronics, experimental equipment, or objects being processed.

[0064] Therefore, in cryogenic systems, integrating a dilution refrigerator with a pulse tube or other 4K cryogenic system, for example, integrating a still exhaust line with a pulse tube assembly, offers several significant advantages compared to conventional systems, including improved cooling performance, increased energy efficiency, and reduced footprint. These are particularly useful effects in the field of cryogenic technology.

[0065] In various embodiments, performance is improved by thermally coupled cryocoolers and dilution refrigerators. For example, a cryogenic system incorporating thermally coupled cryocoolers and dilution refrigerators has a base temperature of less than 10 mK, a sample volume of more than 130 liters, a total internal volume of at least 600 liters, and a volume of 4000 cm³. 2 When the mixing chamber plate area exceeds a certain size, a cooling capacity of 1000 μW at 100 mK can be provided. Furthermore, the cryogenic system described herein has a compact system footprint, and compared to other systems, the cooling capacity can be doubled and the experimental space quadrupled with only a 50% increase in footprint. Such system performance is made possible by the efficient thermal equilibrium and attenuation layout and improved integrated pulse tube described herein. Thermally coupled cryocooler and dilution refrigerator significantly improve the shape of the cryogenic system, enabling a substantial reduction in footprint, thermal mass, and radiant heat load. Conventional cylindrical dilution refrigerators allocate at least 10-25% of the plate area for user wiring, but the cryogenic system described herein allows at least 50% of the plate area to be allocated for user wiring, thereby reducing unnecessary heat load. This larger allocated area allows multiple experiments to be performed simultaneously, resulting in a more efficient system. Furthermore, the cryogenic system can be equipped with parallel-insertable wiring inserts, which allows large samples to be wired outside the cryogenic system and incorporated as a single assembly.

[0066] Furthermore, in alternative or additional embodiments, the temperatures in the embodiments described herein may be replaced with approximate temperatures. For example, "4.2 Kelvin" may be "about 4.2 Kelvin" in alternative or additional embodiments.

[0067] II. Closed-cycle dilution refrigerator Dilution refrigerators are 3 He and 4 This is a cryogenic device that uses the heat of mixing of helium isotopes to cool temperatures in the range of approximately 2 mK to 1 K. Older dilution refrigerators, so-called "wet" dilution refrigerators, 3 He / 4 He mixed gas and liquid nitrogen and 4 Pre-cooling is performed using a helium bath, followed by further cooling to a temperature below 4K. On the other hand, newer dilution refrigerators, so-called "dry" dilution refrigerators, use devices such as cryocoolers instead of cryogenic liquid baths. 3 He / 4 Pre-cool the He gas mixture.

[0068] Dilution refrigerators are cryogenic devices capable of cooling to temperatures ranging from approximately 2 mK to 1 K, and are used in a variety of applications requiring these extremely low temperatures. For example, dilution refrigerators may be used to support quantum computing (e.g., superconducting quantum computing technology and qubits) or in research on low-temperature condensed matter physics.

[0069] As mentioned above, the dilution refrigerator is 3 He and 4 Cooling is performed using the heat of mixing of He isotopes. When cooled to below approximately 870 mK, 3 He / 4 The He mixture undergoes spontaneous phase separation. 3 The phase containing a large amount of helium ("concentrated phase") and 3 He forms a phase with less helium ("dilute phase"). These two phases are maintained in equilibrium in the mixing chamber, which is the coldest part of the dilution refrigerator, and are separated by a phase boundary. In the mixing chamber, 3He diffuses from the enriched phase through the phase boundary to the dilute phase. The heat required for this endothermic dilution process generates the cooling capacity of the dilution refrigerator.

[0070] However, conventional dilution refrigerators have numerous drawbacks and potential failure points. For example, wet dilution refrigerators require large amounts of liquid refrigerant, resulting in high maintenance and supply costs. On the other hand, dry dilution refrigerators are unnecessarily affected by mechanical vibrations from the cryocooler system and / or may consume a large amount of electricity to drive the cryocooler.

[0071] Conventional dilution refrigerators generally require a large installation area, making them unsuitable for applications requiring multiple units. For example, a single conventional dry dilution refrigerator typically requires approximately 300 square feet of floor space and a ceiling height of about 12-14 feet. This space is needed not only for the refrigerator itself but also to support auxiliary equipment such as pumps, compressors, water cooling systems, and / or cryocooler systems.

[0072] The inventors recognized and understood that a reliable, easy-to-use, easy-to-maintain, and compact dilution refrigerator is needed in the quantum technology industry to facilitate measurements in quantum computing and other quantum technologies. In response, the inventors developed a dilution refrigerator and distributed cooling system that can be integrated with commercially available server rack structures (e.g., 19-inch server racks). Furthermore, the inventors developed several functions that facilitate maintenance of the dilution refrigerator, enable high-speed cooling without the use of mechanical pumps, and reduce the transmission of mechanical vibrations from the dilution refrigerator to the experimental space, as described below.

[0073] Some embodiments relate to a dilution refrigerator comprising a plurality of thermal equilibration plates configured to be cooled to a plurality of temperatures. The first thermal equilibration plate of the plurality of thermal equilibration plates includes an integrated heat exchanger, the integrated heat exchanger includes a flow path formed within the first thermal equilibration plate, the flow path configured to allow helium to pass through the first thermal equilibration plate during the operation of the dilution refrigerator.

[0074] In some embodiments, the integrated heat exchanger is formed by additive manufacturing. In some embodiments, the first thermal equilibrium plate further includes a removable portion, the removable portion including an integrated heat exchanger.

[0075] In some embodiments, the dilution refrigerator further includes a replaceable dilution insert that is detachably coupled to a detachable portion of the first thermal equilibrium plate. In some embodiments, the dilution insert is detachably coupled to the condensing line of the dilution refrigerator and to three of the multiple thermal equilibrium plates.

[0076] In some embodiments, the dilution insert is 3 He and 4 From a mixture of He 3 It includes a still configured to distill and cool He vapor. In some embodiments, the dilution refrigerator further includes an experimental space thermally coupled to the lowest temperature thermal equilibration plate among a plurality of thermal equilibration plates, and a still coupled to a second thermal equilibration plate that is hotter than the lowest temperature thermal equilibration plate. The still is 3 He and 4 From a mixture of He 3 The dilution refrigerator is configured to cool the He vapor by distillation. The dilution refrigerator further includes a continuous heat exchanger positioned between the second heat equilibrium plate and the lowest temperature heat equilibrium plate.

[0077] In some embodiments, the dilution refrigerator further comprises at least one heat exchanger thermally coupled to one of a plurality of thermal equilibration plates, the at least one heat exchanger comprising a nanomaterial.

[0078] In some embodiments, the nanomaterial includes at least one of nanowires, nanoforms, nanopellets, and / or nanotubes. In some embodiments, the nanomaterial includes nanowires comprising one or more of the following: copper nanowires, silver nanowires, gold nanowires, platinum nanowires, polymer nanowires, carbon nanowires, and / or carbon fiber nanowires.

[0079] In some embodiments, at least one heat exchanger includes either an individual heat exchanger and / or a heat exchanger located in the mixing chamber of a dilution refrigerator. In some embodiments, the dilution refrigerator further comprises a condensation line configured to transport helium to the lowest temperature of a plurality of equilibration plates; a still positioned upstream of the lowest temperature equilibration plate along the condensation line; a heat exchanger positioned along the condensation line between the still and the lowest temperature equilibration plate; and a heat exchange line configured to transport the helium mixture back from the heat exchanger to the still and to lower the temperature of the helium mixture in the condensation line above the still.

[0080] In some embodiments, the dilution refrigerator further includes a Joule-Thomson expander positioned upstream of the still along the condensation line, and the heat exchange line is configured to lower the temperature of the helium mixture in the condensation line upstream of the Joule-Thomson expander.

[0081] In some embodiments, the dilution refrigerator further comprises a condensation line configured to transport helium to the lowest temperature of a plurality of thermal equilibration plates, and a high specific surface area material arranged along the condensation line, which is configured to adsorb helium transported during the cooling cycle.

[0082] In some embodiments, a first end of a high-specific-surface-area material is thermally coupled to a higher-temperature thermal equilibration plate among a plurality of thermal equilibration plates by a first thermal switch, and a second end of the high-specific-surface-area material opposite to the first end is thermally coupled to a lower-temperature thermal equilibration plate among a plurality of thermal equilibration plates by a second thermal switch.

[0083] In some embodiments, the dilution refrigerator further comprises at least one heater thermally coupled to a high surface area material, the heater being configured to heat the high surface area material, thereby releasing helium adsorbed on the high surface area material, and cooling the helium while moving it from a higher temperature thermal equilibration plate to a lower temperature thermal equilibration plate among a plurality of thermal equilibration plates.

[0084] In some embodiments, the dilution refrigerator further comprises a first valve positioned along a condensation line between a higher temperature equilibration plate and a high specific surface area material, and a second valve positioned along a condensation line between the high specific surface area material and a lower temperature equilibration plate, wherein the first and second valves are configured to transport helium adsorbed on the high specific surface area material from the higher temperature equilibration plate to the lower temperature equilibration plate when the first valve is closed and the second valve is open.

[0085] In some embodiments, the high specific surface area material includes either activated carbon or metal powder. In some embodiments, the dilution refrigerator further comprises a condensation line configured to transport helium from a helium inlet to the lowest temperature of a plurality of thermal equilibration plates; a first helium filter positioned along the condensation line; a second helium filter positioned in parallel with the first helium filter along the condensation line; and at least one valve configured to switch the helium flow along the condensation line between the first and second helium filters.

[0086] In some embodiments, the first helium filter and / or the second helium filter include a charcoal trap. In some embodiments, the dilution refrigerator further comprises a first counterflow heat exchanger positioned between a first helium filter and a helium inlet, and a second counterflow heat exchanger positioned between a second helium filter and a helium inlet.

[0087] In some embodiments, the dilution refrigerator further comprises a condensation line configured to transport helium to the lowest temperature of a plurality of thermal equilibration plates, a Joule-Thomson expander positioned along the condensation line, and a bypass positioned in parallel with the Joule-Thomson expander along the condensation line, wherein the bypass is configured to allow the transported helium to bypass the Joule-Thomson expander when the temperature of the transported helium is above a threshold and below 300K.

[0088] In some embodiments, the bypass includes a material configured to allow the transported helium to diffuse through the material when the temperature of the transported helium is above a threshold but below 300K. In some embodiments, the material includes a polymer material.

[0089] Figure 3 is a schematic diagram of a dry closed-cycle dilution refrigerator 100 according to some embodiments described herein. In some embodiments, the dilution refrigerator 100 includes an external vacuum chamber 106 at room temperature (e.g., about 300K) and a number of heat stages 108a to 108f (e.g., thermal equilibrium plates) whose temperatures decrease in stages (e.g., about 50K, 9-10K, 3K, etc.). For example, the first heat stage 108a may be about 50K, the second heat stage 108b about 9-10K, the third heat stage 108c about 3-4K, the fourth heat stage 108d about 800mK, the fifth heat stage 108e about 100mK, and the sixth heat stage 108f about 10mK.

[0090] In some embodiments, the dilution refrigerator 100 is 3 He / 4 The system may include a pump system 102 for pressurizing the He mixed gas (for example, to a pressure of about 1 bar). 3 He / 4 The He mixed gas is introduced into the external vacuum chamber 106 through one or more inlets, and may then pass through the condensation line 102a to the inside of the heat stages 108a-108f. After performing its cooling function, 3 He / 4 The He mixture may be returned to the pump system via return 102b.

[0091] In some embodiments, 3 He / 4 The He mixture may be purified before moving through the condensation line 102a, passing through heat stages 108a–108f. Contaminants in the helium passing through the dilution refrigerator can clog certain components, such as the Joule-Thomson expander and capillaries in the heat exchanger, potentially leading to performance degradation or system failure. Conventionally, to reduce the risk of contaminants entering the system, helium is first passed through an external "cleaning trap" filled with activated carbon before being introduced into the dilution unit of the dilution refrigerator. These external traps require maintenance and operation by the user, as they need to be covered with liquid nitrogen and frequently refilled.

[0092] The inventors recognized and understood that by using a passive helium filter that does not require liquid nitrogen replenishment, usability can be improved and the maintenance frequency of the dilution refrigeration system can be reduced. Accordingly, in some embodiments, the dilution refrigerator 100 comprises one or more helium purifiers 110. In some embodiments, if the dilution refrigerator 100 includes two or more helium purifiers 110, the dilution refrigerator 100 may further include a switching system 109 configured to direct the helium flow to a single helium purifier 110.

[0093] Figure 4 shows a schematic diagram of a helium purifier 110 according to some embodiments described herein. The helium purifier 110 may be connected to the pump system 102 via a switching system 109 located outside the external vacuum chamber 106. The switching system 109 may include one or more helium-compatible valves. The switching system 109 may be configured to switch the flow of helium between each helium purifier 110. In this way, while the dilution refrigerator is operating, helium can be actively filtered using one helium purifier 110 and the other helium purifier can be purified (e.g., heated and impurity removed). This enables near-indefinite continuous operation of the dilution refrigerator 100.

[0094] In some embodiments, the helium purifier 110 includes a counterflow heat exchanger 110a, a trap 110b, and a low-temperature contact area 110c (e.g., a gas gap heat exchanger, a low-thermal-conductivity joint, etc.). The counterflow heat exchanger 110a and the low-temperature contact area 110c reduce the heat load that the helium purifier 110 imposes on the dilution refrigerator 100 and eliminate the need for cryogenic valves within the helium purifier 110. The trap 110b may include, for example, a high-surface-area material (e.g., charcoal, activated carbon, and / or metal powder) that captures non-helium-based impurities in the dilution refrigerator 100.

[0095] Returning to Figure 3, in some embodiments, the dilution refrigerator 100 may include a cool-down turbocharger device 111. Conventional dry dilution refrigerators use an auxiliary compressor to generate a flow of warm helium. This warm helium initially has a high impedance and resists flow. The additional pressure from the auxiliary compressor pressurizes the helium to a pressure that initiates isenthalpic expansion and cooling at a higher temperature. However, such auxiliary mechanical compressor pumps are expensive, prone to reliability issues, often leak, and can lead to performance degradation over time. The inventors recognized and understood that a faster and more efficient cool-down process could be achieved by pulsed helium through the dilution refrigerator during the cooling process without using an auxiliary mechanical pump.

[0096] Figure 5 shows a schematic diagram of a cool-down turbocharger device 111 according to several embodiments described herein. The cool-down turbocharger device 111 may include a high specific surface area material 111a, a heater 111b, a first valve 111c, and a second valve 111d. The first valve 111c and the second valve 111d may be, for example, cryogenic valves located within a vacuum chamber 106. Alternatively, as another example, the first valve 111c and the second valve 111d may be room temperature valves located outside the vacuum chamber 106. In some embodiments, the heater 111b and the first valve 111c and the second valve 111d may be communicated with a control unit 330. The control unit 330 may be, for example, a computer as described in relation to Figure 16 herein.

[0097] In some embodiments, the cool-down turbocharger device 111 may be thermally coupled to a heat stage (e.g., a thermal equilibrium plate). In the example in Figure 5, the high specific surface area material 111a is thermally coupled to the second heat stage 108b, but in other embodiments, the high specific surface area material 111a may be thermally coupled to another heat stage (e.g., the first heat stage 108a).

[0098] Furthermore, in some embodiments, the cool-down turbocharger device 111 may be thermally coupled to multiple heat stages (e.g., across two or more heat stages 108a to 108f). In such embodiments, the sequential heating and cooling of the high-surface-area material 111a can be controlled by a thermal switch. For example, the cool-down turbocharger device 111 may be switchably thermally coupled between a higher-temperature heat stage and a lower-temperature heat stage, and the device 111 may be configured to selectively thermally couple to either the higher-temperature or lower-temperature heat stage. When the cool-down turbocharger device 111 is thermally coupled to the higher-temperature heat stage, the high-surface-area material 111a may release adsorbed helium. On the other hand, when the cool-down turbocharger device 111 is thermally coupled to the lower-temperature heat stage, helium may begin to adsorb onto the high-surface-area material 111a. In this way, helium can be sequentially flowed through the condensation line 102a.

[0099] In some embodiments, the high specific surface area material 111a may include a material having a porous and / or textured surface. This allows helium to be adsorbed onto the high specific surface area material 111a during the cooling process. For example, the high specific surface area material 111a may include a material composite formed from activated carbon, metal powders (e.g., copper or silver powder) and / or nanostructures (e.g., nanowires, nanoparticles, etc.).

[0100] In some embodiments, the cool-down turbocharger device 111 may be operated by sequentially opening and closing a first valve 111c and a second valve 111d in conjunction with the operation of the heater 111b. For example, the first valve 111c may be closed to prevent helium from flowing to the lower stage of the dilution refrigerator 100, and the second valve 111d may be opened to allow helium to reach the high-surface-area material 111a, thereby adsorbing the helium onto the high-surface-area material 111a. The operation of closing the first valve 111c and opening the second valve 111d may be performed by the control unit 330 in response to measured pressure or temperature, or to timing signals generated by the control unit 330.

[0101] In some embodiments, after sufficient helium has been adsorbed onto the high-specific-surface-area material 111a, the second valve 111d may be closed and the first valve 111c may be opened. The first valve 111c and the second valve 111d may be opened and closed in response to the measured temperature or pressure and / or timing signals generated by the control unit 330.

[0102] In some embodiments, when the second valve 111d is closed and the first valve 111c is opened, the heater 111b may operate simultaneously or nearly simultaneously in response to a signal generated by the control unit 330 to heat the high surface area material 111a. For example, the heater 111b may be a resistance heater that heats the high surface area material 111a by the flow of current through the heater 111b. In response to the heat from the heater 111b, helium adsorbed on the high surface area material 111a may act as a reserve and then be released from the high surface area material 111a. This release of adsorbed helium may increase the pressure in the rest of the condensation line 102a, and this pressure increase may initiate isenthalpic expansion, accelerating the cooling of the dilution refrigerator 100.

[0103] In some embodiments, after helium is released from the high surface area material 111a, the first valve 111c may be closed, the second valve 111d may be opened, and the control unit 330 may be stopped to stop the heater 111b. This allows new helium to be adsorbed onto the high surface area material 111a. The control unit 330 may be configured to periodically open and close the valves 111c and 111d (for example, at fixed time intervals, irregular time intervals, time intervals based on the temperature of the experimental space, or time intervals based on the pressure of the experimental space) and to activate the heater 111b to flush the helium introduction path. In some embodiments, the control unit 330 may be configured to "pulse" helium from the high surface area material 111a through the condensation line 102a to cool the dilution refrigerator.

[0104] Returning to Figure 3, while the dilution refrigerator is in operation, 3 He / 4The He mixture may be cooled stepwise as it moves from the first heat stage 108a to the mixing chamber 122 along the condensation line 102a. In the first heat stage, the helium may be initially cooled to about 50K. After being discharged from the cool-down turbocharger device, 3 He / 4 The He mixture may then be cooled by a cryocooler 104. In some embodiments, a portion of the cryocooler 104 may be partially located outside the external vacuum chamber 106. The cryocooler 104 is vibrationally isolated from the external vacuum chamber 106 by a vibration isolation stage 105, which may include padding and / or other suitable vibration isolation techniques.

[0105] In some embodiments, the cryocooler 104 may be coupled to the cryocooler support 103. The cryocooler support 103 may be, for example, a compressor and / or compression system. The cryocooler support 103 may include a cooling member 103a. In some embodiments, the cooling member 103a is configured to provide air cooling to the dilution refrigerator 100. The cooling member 103a may include, in some, cooling fins, fans and / or heat pipes configured to remove waste heat generated by the cryocooler support 103 and / or the cryocooler 104.

[0106] Cooling component 103a is in contrast to conventional closed-cycle dilution refrigerators. Conventional closed-cycle dilution refrigerators typically remove waste heat generated by an integrated cryocooler using a water-cooling system. However, in the case of a water-cooled cryocooler, a large and / or expensive water-cooling system must be installed alongside the dilution refrigerator. Furthermore, such water-cooling systems are generally not integrated in typical commercial computing facilities. Such facilities often employ air-cooling, which is less expensive and does not pose risks such as coolant leaks or water ingress to electronic equipment. The inventors recognized that by using air cooling as a means of removing heat from the cryocooler of a dilution refrigerator, the manufacturing cost of the dilution refrigerator can be reduced, making it suitable for use in commercial computing facilities.

[0107] In some embodiments, the dilution refrigerator 100 may be positioned above a plenum (not shown) located under the floor that supports the dilution refrigerator. The plenum may generate airflow over the cooling member 103a and provide air cooling. In some embodiments, the cooling member 103a may include an inlet and / or louvers for taking in air from the plenum. Alternatively or additionally, in some embodiments, the dilution refrigerator 100 may be installed in a facility that includes ducts and / or heat pipes (not shown) arranged to remove heat from the cooling member 103a, the cryocooler support 103 and / or the cryocooler 104 and to minimize vibrations experienced by the dilution refrigerator 100.

[0108] In some embodiments, 3 He / 4 The He mixture may be cooled in two stages by the cryocooler 104. The condensation line 102a is wound around the two parts of the cryocooler 104, and within the condensation line 102a 3 He / 4 Heat exchange may be performed between the He mixture and the cryocooler 104. In the first step, 3 He / 4The He mixture may be cooled to approximately 10K by the cryocooler 104. In the second step, 3 He / 4 The He mixture may be cooled to approximately 3-4K by the cryocooler 104.

[0109] In some embodiments, after being cooled by the cryocooler 104, 3 He / 4 The He mixture may pass through the third heat stage 108c. The third heat stage 108c may, in some embodiments, be mechanically isolated from the cryocooler 104 while still being thermally coupled, in order to provide vibration isolation from the subsequent heat stages 108d-108f. In some, non-limiting embodiments, the third heat stage 108c may be mechanically isolated from the cryocooler 104 by a copper blade, a heat strap, or other suspension member configured to maintain the thermal coupling between the third heat stage 108c and the cryocooler 104.

[0110] In some embodiments, after passing through the third heat stage 108c, 3 He / 4 The He mixture may enter the primary impedance stage 112. The primary impedance stage 112 is 3 He / 4 A Joule-Thomson expander may be configured to reduce the temperature and / or pressure of the He mixture. For example, in some embodiments, 3 He / 4 The He mixture may be about 3-5K before entering the primary impedance stage 112 and about 1K after being discharged from the primary impedance stage 112.

[0111] In some embodiments, the primary impedance stage 112 may be a Joule-Thomson expander formed from an optical fiber cable. Conventional Joule-Thomson expanders may be formed as metal tubes manufactured by stretching. However, such metal Joule-Thomson expanders have irregularities and / or large diameters, which can reduce the cooling capacity of the device. By using a hollow-core optical fiber cable, the narrow opening required for the Joule-Thomson expander can be reliably and reproducibly provided.

[0112] In some embodiments, the dilution refrigerator 100 may include a bypass device 113a configured to improve the cooling rate of the dilution refrigerator 100. For example, during the initial cooling of the dilution refrigerator, the helium flow rate may decrease due to the high impedance of the Joule-Thomson expander within the dilution refrigerator and the circulation of low-density, high-viscosity warm helium. This decrease in flow rate contributes to a reduction in the cooling rate of the lower part of the refrigerator. To mitigate this effect, a needle valve may conventionally be provided on the condensation line upstream of the Joule-Thomson expander to reduce the impedance of the warm helium gas in the initial stages. However, since the needle valve contains mechanical components, it may fail over time. The inventors have found that the helium flow rate can be improved without relying on mechanical components such as a needle valve.

[0113] In some embodiments, the bypass device 113a may be located in parallel with the primary impedance stage 112 along the condensation line 102a and provided on the bypass line 113b that bypasses the primary impedance stage 112 (i.e., 3 He / 4(Allowing the He mixture to flow around the primary impedance stage 112). The bypass device 113a may include a sheet of vacuum-compatible material and may be configured to allow helium to diffuse through the vacuum-compatible material at temperatures above the threshold temperature. For example, the bypass device 113a may be in the range of about 40K to 300K, about 50K to 300K, about 80K to 300K, about 100K to 300K, or about 150K to 300K, or any range within these ranges. 3 He / 4 The He mixture may be diffused through the bypass device 113a. In some embodiments, the bypass device 113a may include a sheet of vacuum-compatible polymer material. For example, in non-limiting examples, the bypass device 113a may be formed from a sheet of Kapton, PEEK, and / or Mylar. Thus, the bypass device 113a is 3 He / 4 This avoids the high impedance of the primary impedance stage 112 when the He mixture is warm, allowing for an increase in the helium flow rate and the cooling rate of the dilution refrigerator 100. Once the dilution refrigerator 100 has cooled sufficiently (e.g., to below the threshold temperature), 3 He / 4 The He mixture no longer diffuses through the bypass device 113a and instead passes through the primary impedance stage 112.

[0114] In some embodiments, after being discharged from the primary impedance stage 112 or the bypass device 113a, 3 He / 4 The He mixture flows into still 114 via the fourth heat stage 108d. Still 114 is different 3 He / 4 The He liquid mixture is introduced as the condensation line 102a passes through the still 114. 3 He / 4 The He mixture may be cooled in some embodiments. 3 He / 4 The He mixture may be cooled to approximately 400-900 mK by still 114.

[0115] In some embodiments, the still 114 may include a membrane configured to utilize a second sound wave to improve He evaporation within the still. The second sound wave is a superfluid phenomenon present in superfluid helium and may be generated, for example, by vibrating a porous membrane or periodically operating a heated wire in a superfluid helium bath. In the two-fluid model, while the superfluid helium component in the mixture passes through the membrane, the non-superfluid component of the helium bath cannot easily pass through the porous membrane. As a result, an entropy wave or temperature wave occurs in the superfluid helium. Similarly, in the helium mixture system, the non-superfluid 3 He is preferentially pushed out by the vibrating membrane, and the superfluid 3 He may remain relatively stationary. The inventors have recognized and understood that by generating this second sound wave phenomenon within the still 114, the evaporation rate of 4 He at low temperatures can be improved, and the 3 He concentration in the vapor contained in the upper part of the liquid helium mixture within the still can be reduced. 4 He concentration in the vapor contained in the upper part of the liquid helium mixture within the still can be reduced.

[0116] FIG. 6 shows a schematic diagram of a still 400 including a device for separating 3 He and 4 He using the second sound wave effect, according to some embodiments described herein. The still 400 may be implemented as the still 114 of the dilution refrigerator 100 in some embodiments. The still 400 may include a stationary surface 402 and a porous movable membrane 404. The porous membrane 404 is vibrated in the Z direction to form a standing concentration wave of 3 He within the still, and 3 regions 406 with low 3 He concentration and 3 regions 408 with high 3 He concentration may be generated. This standing wave is adjusted so that the region 408 with high

[0117] Returning to Figure 3, in some embodiments, after being discharged from still 114, 3 He / 4 The He mixture may flow to the secondary impedance stage 116 via the condensation line 102a. The secondary impedance stage 116 is a liquid 3 He / 4 The system may be configured so that only He proceeds downstream of the dilution refrigerator 100, and to prevent gas cavitation in the still 114 (for example, by maintaining the pressure in the still 114 above a threshold). Therefore, the secondary impedance stage 116 is configured 3 He / 4 This can reduce the downstream cooling load caused by the latent heat of He gas.

[0118] In some embodiments, after being discharged from the secondary impedance stage 116, 3 He / 4 The He mixture may flow into the first heat exchanger 118. The first heat exchanger 118 may be a continuous heat exchanger. For example, the first heat exchanger 118 may be a counterflow type (e.g., a tube-tube heat exchanger), a cross-counterflow type and / or a parallel flow type heat exchanger. At the outlet of the first heat exchanger 118, in the condensation line 102a 3 He / 4 The He mixture may be cooled to a temperature of approximately 20 mK.

[0119] In conventional closed-cycle dilution refrigerators, before entering the still, in the condensation line 3 He / 4 He mixtures typically need to pass through a primary impedance stage. This primary impedance stage generally functions as an independent refrigeration stage, i.e., a Joule-Thomson refrigerator. 3 He / 4 The He mixture is cooled by isenthalpic expansion. 3 He / 4 To control the cooling capacity due to the expansion of the He mixture, in the condensation line 3 He / 4 The pressure of the helium mixture is usually increased by an external compressor.

[0120] The inventors, 3 He / 4 By cooling the He mixture before it enters the primary impedance stage, an equivalent cooling effect is achieved (i.e., 3 He / 4 It was recognized and understood that the He mixture (which reaches the same base temperature after passing through the primary impedance stage) could be obtained with a lower pressure difference. This configuration improves the efficiency of the dilution refrigerator and allows it to pass through the primary impedance stage. 3 He / 4 The need to pressurize the He mixture can be reduced or eliminated. Furthermore, the inventors have found that before entering the primary impedance stage... 3 He / 4 It was recognized that the heat removed from the He mixture can be returned to the still, thus eliminating or reducing the need for an auxiliary heater to increase the vapor pressure and promote evaporation within the still.

[0121] Therefore, in some embodiments, the dilution refrigerator 100 may include a heat exchange line 117 configured to transfer heat from the condensation line 102a to the return helium mixture transported from the first heat exchanger 118 to the still 114. The heat exchange line 117 may cool the condensation line 102a above the primary impedance stage 112. The heat exchange line 117 then cools the condensation line 102a before entering the primary impedance stage 112. 3 He / 4 The He mixture is cooled. The heated mixture in the heat exchange line 117 is then transported to the still 114.

[0122] 3 He / 4 By cooling the He mixture before it enters the primary impedance stage 112, the output obtained from the primary impedance stage 112 is obtained. 3 He / 4 He mixtures are more liquid than gaseous. 3The mixture will contain a higher proportion of He. Therefore, the primary impedance stage 112 can be made more efficient by providing an additional heat exchange line 117. Furthermore, this improved efficiency reduces or eliminates the need for auxiliary pressurization (e.g., an external compressor) and lowers the flow impedance of the circulating helium mixture. This is particularly useful in reducing the size and complexity of small dilution refrigerators that feature smaller (i.e., lower-power) pulse tubes or other cryocoolers.

[0123] In some embodiments, after being discharged from the first heat exchanger 118, 3 He / 4 The He mixture passes through the fifth heat stage 108e and enters the continuous heat exchanger 119. The continuous heat exchanger 119 may be a counterflow type (e.g., a tube-tube heat exchanger), a cross-counterflow type, and / or a parallel flow type heat exchanger. The continuous heat exchanger 119 is located below the fifth heat stage 108e. The fifth heat stage 108e may be an intercooling plate (ICP) configured to cool to about 100–200 mK. Generally, continuous heat exchangers are more efficient than discrete heat exchangers, but their efficiency decreases below about 80 mK. However, by adding the continuous heat exchanger 119 below the fifth heat stage 108e, the fifth heat stage 108e can operate at a greater cooling capacity during the cooling process of the dilution refrigerator.

[0124] In some embodiments, 3 He / 4 The He mixture, after exiting the continuous heat exchanger 119, enters the discrete heat exchanger 120. In some embodiments, the discrete heat exchanger 120 may be formed from sintered nanoparticles. Alternatively or additionally, in some embodiments, the discrete heat exchanger 120 may be formed from sintered nanowires, as described in relation to Figures 9A-9D of this specification. The discrete heat exchanger 120 is 3 He / 4 The He mixture may be configured to be further cooled to a temperature of approximately 10-20 mK or less.

[0125] The inventors further recognized and understood that usability would be improved if users could easily replace parts inside and outside the dilution refrigerator 100 (for example, during maintenance, for changes in the characteristics of the dilution refrigerator 100, and / or for upgrades to the dilution refrigerator 100 due to technological innovations). Based on this recognition, the inventors developed a swappable dilution insert that can be easily removed and replaced. Figure 7A shows an example configuration of the detachable dilution insert 540 in the dilution refrigerator 100 of Figure 3, according to some embodiments described herein.

[0126] In some embodiments, the removable dilution insert 540 includes removable plates 540a, 540b, and 540c that are removablely coupled to the heat stages 108d, 108e, and 108f, respectively. As shown in the example in Figure 7A, the removable plates 540a, 540b, and 540c may be removablely coupled using mechanical fasteners (e.g., bolts and / or screws). In some embodiments, the removable dilution insert 540 further includes removable connectors 540d to the top of the still (e.g., flanges) and to the condensation line 102a, which further simplifies the replacement of the dilution insert 540.

[0127] Figure 7B shows a magnified view of the removable plate 540b of the removable dilution insert of Figure 7A, according to some embodiments described herein. The removable plate 540b may include an inlet A and an outlet B configured to allow helium to pass through the plate.

[0128] In some embodiments, the removable plates 540a, 540b and / or 540c may include an integrated heat exchanger. In some embodiments, the integrated heat exchanger may be a channel 542 formed within the removable plates 540a and / or 540b, as shown in Figure 7C. Figure 7C shows a cross-sectional view of the removable plate 540b of Figure 7B. The channel 542 may be configured to have a high specific surface area. The cooling rate of helium can be increased by flowing helium through the channel 542 in the removable plates 540a and / or 540b. In some embodiments, the channel 542 may be formed by machining, welding, and / or additive manufacturing techniques (e.g., 3D printing techniques).

[0129] In some embodiments, the integrated heat exchanger may be a high specific surface area material structure formed within the detachable plate 540c. For example, the integrated heat exchanger may have a lattice structure as shown in Figure 7D. As a non-limiting example, the lattice structure may be a tetragonal lattice structure having a periodicity of about 400 μm to about 1000 μm, or for example, a periodicity of about 600 μm.

[0130] In some embodiments, the lattice structure may be manufactured using additive manufacturing techniques (e.g., 3D printing techniques). The lattice structure may be manufactured to have a rough surface texture in order to increase the surface area of ​​the material that comes into contact with the helium mixture passing through the integrated heat exchanger. This improves heat exchange performance. In some embodiments, the lattice structure may be formed from metal. As a non-limiting example, the lattice structure may be formed from copper, silver, and / or aluminum.

[0131] In some embodiments, the dilution insert 540 includes one or more heat exchangers as described in relation to the dilution refrigerator 100 in Figure 3. Figure 7E shows an exemplary configuration of a continuous heat exchanger 119 and a discrete heat exchanger 120 according to some embodiments described herein. As shown in Figure 7E, helium flows into the continuous heat exchanger 119 from a detachable plate 540b coupled to the fifth heat stage 108e, and then passes through the discrete heat exchanger 120 and the detachable plate 540c.

[0132] In cryogenic refrigeration cycles, techniques are generally used to control the heat flow throughout the system. This control is achieved by thermally connecting or disconnecting components within the system through superconductors, gas gaps, or other mechanisms (i.e., thermal switches). A common example of a thermal switch is a gas gap, which consists of two high-surface-area bodies with a small gap between them, filled with gas. When the system temperature drops below a certain threshold, the thermally conductive gas is adsorbed onto the surfaces within the thermal switch, creating a vacuum and reducing heat transfer between the surfaces. Another common thermal switch is a superconducting switch, which involves a material undergoing a superconducting transition to reduce its thermal conductivity.

[0133] In some embodiments, the dilution refrigerator 100 may further include a combined gas gap and / or superconducting thermal switch between the heat stages of the dilution refrigerator 100. In the example of Figure 7E, such a combined gas gap and superconducting thermal switch 550 is thermally coupled between heat stages 108e and 108f. The combined gas gap and superconducting thermal switch 550 includes a superconducting material (e.g., aluminum, titanium) that becomes superconducting at a temperature higher than the target temperature of the heat stage to which the switch is thermally coupled, and a gas gap thermal switch for improving thermal insulation between the heat stages.

[0134] Returning to Figure 3, after the heat is discharged from the discrete heat exchanger 120, 3 He / 4 The He mixture passes through the sixth heat stage 108f and enters the mixing chamber 122. Inside the mixing chamber 122, 3He atoms move from the enriched phase to the dilute phase (i.e.) 4 It may be pumped into the phase mixed with He. 3 He is cooled during the phase transition from the enriched phase to the dilute phase, and this endothermic phase transition provides the final cooling capacity of the dilution refrigerator 100.

[0135] In some embodiments, the experimental space 124 (e.g., a sample stage or plate) may be thermally coupled to the mixing chamber 122 and configured to support the sample and / or quantum device. Because the experimental space 124 is thermally coupled to the mixing chamber 122, the sample and / or quantum device is maintained at a temperature equal to or approximately equal to the temperature of the mixing chamber.

[0136] In some embodiments, when the dilution refrigerator 100 is not operating, the user can access the experimental space 124 through an opening and door 125 in the vacuum chamber 106. In some embodiments, the door 125 may be a removable panel secured with mechanical fasteners, or a hinged door that can be opened and closed with a clamp-type handle (see, for example, the example shown in Figure 12A of this specification).

[0137] As shown in the example in Figure 3, certain components of the dilution refrigerator 100 may be thermally coupled to a heat stage and located on one side (e.g., the upper or lower side) of the heat stage. For example, the still 114 is located on the lower side of the fourth heat stage 108d. However, in some embodiments, the component can be located on either side of the corresponding heat stage, and the technical scope of the present invention is not limited thereto. For example, in some embodiments, the still 114 may be located on the upper side of the fourth heat stage 108d. In another example, the helium purifier 110 may be located on the lower side of the first heat stage 108a.

[0138] In some embodiments, after entering the dilute phase, 3 He / 4The He mixture may be pumped out of the mixing chamber 122, returned via the dilution refrigerator 100, and discharged from the external vacuum chamber 106 through return 102b. Under low temperature and low pressure conditions, 4 Helium forms thick, highly mobile films that can travel long distances on surfaces, including against gravity. This helium creep phenomenon allows for... 4 He may enter unwanted areas within the dilution refrigeration system (e.g., gaps between thermally insulated regions). Figures 8A to 8F show some embodiments described herein, for example, provided at the outlets of the mixing chamber 122 and / or still 114. 4 This is a schematic diagram of a hemolysis device.

[0139] Figure 8A shows a cooling stage 600 (e.g., a still or mixing chamber) in several embodiments, the cooling stage 600 is a dilute phase helium mixture (e.g., 3 He / 4 The bath 602 contains a He mixture. 4 He travels up the outlet pipe (e.g., the still pumping outlet pipe or the mixing chamber outlet pipe) and is discharged from the cooling stage 600 if the barrier 606 is not present. In the example in Figure 8A, the barrier 606 has sharp edges formed on a right-angled surface and is configured to prevent helium from leaving the cooling stage 600 through the low-pressure pumping outlet.

[0140] 4 Other embodiments of the barrier configured to prevent creep of He are shown in examples in Figures 8B, 8C, 8D and 8E. In the example in Figure 8B, a ring 608 having a knife edge 609 4 His 3 He is configured to prevent outflow through the outlet. In some embodiments, ring 608 is 4 To suppress He creep, 4 The heating device may include a heating device (e.g., a resistance heater or other suitable heater) configured to separate He from the superfluid phase.

[0141] In the examples in Figures 8C, 8D, and 8E, the vertical knife edge is 3 He went through the exit 4 It is used to prevent the outflow of He. In some embodiments, as shown in the example in Figure 8C, the knife edge 610 is provided on the outer circumference of the outlet pipe. Alternatively, as shown in the example in Figure 8D, the knife edge 611 may be provided on the inner circumference of the outlet pipe with a chamfer. Furthermore, as shown in the example in Figure 8E, the knife edge 612 may be provided at an angle on both the outer and inner circumferences of the outlet pipe.

[0142] In some embodiments, as shown in the example in Figure 8F, 3 The outlet includes P-trap 621. 4 He 622 may be configured to collect on the lower surface of the P trap 621. 3 The He outlet may include a normal leak or superleak 624 configured to discharge normal helium or superfluid helium from the P-trap 621. Also, a pump 626 (e.g., a fountain pump) may be provided. 4 The system may be configured to transport He to a location away from the P-trap 621. In some embodiments, a further barrier 627 may be provided on the inner surface of the outlet pipe. For example, the barrier 627 may be configured in a ring shape. In some embodiments, the barrier 627 is 4 The device may also include a heating element to further prevent He from leaking out of the outlet.

[0143] The inventors recognized and understood that nanomaterials offer advantages over conventional typical discrete heat exchangers, such as sintered metal powders (e.g., silver and / or copper powders). Based on this, the inventors developed a nanomaterial heat exchanger that achieves efficient heat exchange due to the large specific surface area, high mechanical contact strength, and good neck growth between nanowires of the nanomaterials.

[0144] Conventional discrete heat exchangers are generally constructed from sintered metal powders (e.g., silver and / or copper powders). An example of such sintered particles is shown in Figure 9A. However, in order to achieve efficient heat exchange at sub-Kelvin temperatures, the heat exchange material must meet several requirements. Specifically, the heat exchange material must have a large surface area, provide high mechanical and / or thermal contact between the liquid helium and the heat exchange material, allow for good neck growth, and have space for the liquid helium to pass through the heat exchanger.

[0145] Figure 9B shows an image of nanomaterials, including nanowires, used in a heat exchanger. Figure 9C shows an image of nanomaterials, including nanoclusters, used in a heat exchanger. Figure 9D shows images of nanomaterials in different nanopellet shapes used in a heat exchanger according to some embodiments described herein. These nanomaterials may be implemented in the discrete heat exchanger 120 and / or block-type heat exchanger (e.g., located in the mixing chamber 122) in the dilution refrigerator 100. Figures 9B to 9D show examples of nanomaterial shapes, and the embodiments of nanomaterials used in the discrete heat exchanger are not limited to these. For example, the nanomaterial may be a nanoform, a nanotube, and / or other suitable nanoform.

[0146] In some embodiments, such nanomaterial-based heat exchangers may be formed by bonding nanomaterials by sintering. For example, the nanomaterials may be formed by chemical precipitation and / or electron deposition or electroplating techniques. A substrate having a rough surface (e.g., including nucleation sites) may be provided for growing or bonding the nanomaterials. In some embodiments, the heat exchanger may be manufactured under heating and / or pressure. The nanomaterials are held in a compressed state during the sintering process to form a nanowire heat exchanger. In some embodiments, the substrate may be patterned with a macroscopic structure (e.g., a grid or post row). In some embodiments, the substrate is a tube, and the nanomaterials may be bonded to the inner or outer surface of the tube. In some embodiments, the substrate may be formed of a material with a lower thermal conductivity than the nanomaterials bonded to the substrate.

[0147] In some embodiments, the nanomaterial may be formed from one of the vacuum-compatible materials, including but not limited to copper, silver, vacuum-compatible polymers, carbon, and / or carbon fibers. For example, the nanomaterial may be a nanowire comprising at least one of copper nanowires, silver nanowires, gold nanowires, platinum nanowires, polymer nanowires, carbon nanowires, and / or carbon fiber nanowires.

[0148] III. Vibration isolation Many experiments conducted at sub-Kelvin temperatures are highly sensitive to vibration noise originating from the ambient environment and the cooling system pumps and components of the dilution refrigerator. Furthermore, at sub-Kelvin temperatures, mechanical vibrations can generate thermal loads, reducing the cooling capacity of the dilution refrigerator or introducing triboelectric noise (frictional electrostatic noise) into the electrical input and / or output of the dilution refrigerator. The inventors recognized and understood that improving vibration isolation could improve the cooling capacity and other performance characteristics (e.g., magnetic flux disturbance) of the dilution refrigerator. Therefore, the inventors developed a vibration isolation component configured to mechanically isolate the lower heat stages 108d-108f from the upper heat stages 108a-108c.

[0149] Figure 10A shows another schematic diagram of a dilution refrigerator 100 including mechanical elements configured to provide vibration isolation, according to some embodiments described herein. The vibration isolation elements include a first suspension system 832, at least one second suspension system 840, and a third suspension system 834.

[0150] In some embodiments, the first suspension system 832 may be configured to suspend the first heat stage 108a, the second heat stage 108b, and / or the third heat stage 108c from the upper surface of the external vacuum chamber 106. The first suspension system 832 may include one or more rods configured to rigidly connect the first, second, and / or third heat stages 108a-108c to the upper surface of the external vacuum chamber 106. The rods may be formed of a material having a high spring constant. For example, the rods may be formed of carbon fiber and / or stainless steel.

[0151] In some embodiments, the second suspension system 840 may be configured to independently suspend the fourth heat stage 108d, the fifth heat stage 108e, and / or the sixth heat stage 108f from the upper surface of the external vacuum chamber 106. This independent suspension of the lower heat stages 108d-108f vibratively isolates them from the upper heat stages 108a-108c, improving the vibration isolation performance of the lower heat stages 108d-108f.

[0152] In some embodiments, the second suspension system 840 may include one or more springs 842, rods 843 and / or connectors 844. In the example in Figure 10A, only one second suspension system 840 is shown, but in some embodiments, multiple second suspension systems 840 may be used to suspend the lower thermal stages 108d-108f. For example, in some embodiments, two, three, or four second suspension systems 840 may be provided.

[0153] In some embodiments, the spring 842 may be configured to provide a constant spring tension under different loads (e.g., different damped masses suspended from the spring 842). An example of the spring 842 is shown in Figure 10B. In some embodiments, the spring 842 may be a leaf suspension spring and may include an upper flexible portion 842a and a lower flexible portion 842b separated by a rigid portion 842c. The spring 842 may vibrate-isolate the lower heat stages 108d-108f in the Z-axis direction (e.g., perpendicular to the plane of the floor supporting the dilution refrigerator 100) by the elastic deformation of the upper flexible portion 842a and the lower flexible portion 842b. In some embodiments, the spring constant of the spring 842 may be determined by pre-tensioning the upper flexible portion 842a and / or the lower flexible portion 842b. Alternatively or additionally, the spring constant of spring 842 may be determined by changing the lengths of the upper flexible portion 842a and / or the lower flexible portion 842b (for example, lengthening the flexible portions 842a and 842b will result in a lower spring constant).

[0154] In some embodiments, the spring 842 may be coupled to the third heat stage 108d via a rod 843. The rod 843 may be a soft rod having a low spring constant. For example, the rod 843 may be formed from a polymer material (e.g., DELRIN). Due to its flexibility, the rod 843 may provide vibration isolation for the lower heat stages 108d-108f in the XY plane (i.e., in a plane parallel to the floor supporting the dilution refrigerator 100 and perpendicular to the Z axis).

[0155] In some embodiments, the connector 844 may be arranged in a triangular structure to ensure the suspension stability of the fourth heat stage 108d. The connector 844 may be formed from a material configured to have a high spring constant. For example, the connector 844 may be formed from stainless steel and / or carbon fiber.

[0156] In some embodiments, the third suspension system 834 may be configured to suspend the fourth to fifth heat stages 108d, 108e, and 108f. In this configuration, the three lower heat stages 108d-108f are all suspended from the top surface of the external vacuum chamber 106 via the second suspension system 840. The third suspension system 834 may include one or more rods configured to rigidly couple the fifth heat stage 108e and / or the sixth heat stage 108f to the fourth heat stage 108d. The rods may be made of a material having a high spring constant. For example, the rods may be made of carbon fiber and / or stainless steel.

[0157] In the example shown in Figure 10A, the first suspension system 832 and the third suspension system 834 are formed by rods, but in some embodiments, the first suspension system 832 and / or the third suspension system 834 may be formed by flexible springs, and the technical scope of this disclosure is not limited thereto. Similarly, in the example shown in Figure 10A, the second suspension system 840 is formed by springs, but in some embodiments, the second suspension system 840 may be formed by rods. This disclosure is not limited to these configurations.

[0158] IV. Integrated Dilution Refrigeration Unit Conventional dilution refrigerator technology often requires large installation space and expensive support structures (e.g., custom vibration-isolating foundations, high ceilings, and / or pit access). Such structural requirements can limit the scalability of quantum technologies operating at low temperatures. As a non-limiting example, the adoption of certain quantum computing technologies may be restricted by the necessity of using large dilution refrigerators. The inventors recognized and understood that scalability of quantum technologies could be achieved by reducing the size and structural requirements of dilution refrigerators. The inventors further found that the scalability of dilution refrigerators and the quantum technologies that depend on them can be further improved by integrating dilution refrigerators with commercial computing structures (e.g., commercial server structures). Such integrated dilution refrigerators are easily integrated into communication networks, can utilize existing thermal removal structures in the communications field, and can further be integrated with fiber optic networks and related systems.

[0159] Figure 11 shows a side view of an external support rack 950 according to some embodiments described herein. In some embodiments, the external support rack 950 may be configured to support a dilution refrigerator 100 by suspending the dilution refrigerator 100 from the floor. As shown in the example in Figure 11, the external support rack 950 may include arms 952 coupled to the upper portion of an external vacuum chamber 106, these arms 952 connected via vibration isolation members 954 to suspend the dilution refrigerator 100 from the floor. In some embodiments, the vibration isolation members 954 may be air pistons, electromagnetic dampers and / or springs.

[0160] In some embodiments, the external support rack 950 may include casters (not shown) configured to assist in the movement of the dilution refrigerator 100. The casters are retractable so that when the dilution refrigerator 100 is not being transported and / or during operation, the wheels of the casters do not come into contact with the floor surface supporting the external support rack 950.

[0161] In some embodiments, the external support rack 950 further includes a floor support 958. The floor support 958 may be configured to protrude from the external support rack 950 when the dilution refrigerator 100 is not being moved. The floor support 958 can extend from the external support rack 950, for example, using a screw mechanism. The floor support 958 may be used to lift and / or level the external support rack 950 from the floor and / or to lift the casters of the external support rack 950 off the floor. In some embodiments, the floor support 958 may be used to adjust the position of the external support rack 950 when the floor surface is uneven.

[0162] In some embodiments, the external support rack 950 may support additional components located outside the external vacuum chamber 106 of the dilution refrigerator 100. For example, the external support rack 950 may house a compressor, pump, and / or cooling equipment configured to assist the operation of the dilution refrigerator 100. Alternatively, in some embodiments, these external components may be housed in a separate, adjacent (e.g., different) server rack container and / or support rack 950 from the dilution refrigerator 100.

[0163] In some embodiments, the external support rack 950 may include components that provide tool-free assembly and / or disassembly of the vacuum chamber 106, as well as access to the experimental space. As shown in the example in Figure 11, the vacuum chamber 106 comprises three sections: a first section 106a, a second section 106b suspended from the first section 106a, and a third section 106c suspended from the second section 106b. The art of the present invention is not limited to a three-section structure, and in some embodiments, the vacuum chamber may have one, two, four, five, or six sections.

[0164] In some embodiments, the vacuum chamber 106 may have one or more substantially flat surfaces. In some embodiments, at least one of these substantially flat surfaces may be located in a plane perpendicular to the plane of the floor supporting the dilution refrigerator. As shown in the example in Figure 11, each section 106a-106c may have at least four substantially flat surfaces, and the vacuum chamber 106 may be configured as a rectangular parallelepiped when assembled. In some embodiments, the vacuum chamber 106 may include two substantially flat surfaces located in a plane parallel to the plane of the floor, and these surfaces may be configured to close the rectangular parallelepiped formed by the surfaces of sections 106a-106c. In some embodiments, as described below, the vacuum chamber 106 may have an opening accessible by a door 1070 in at least one substantially flat surface.

[0165] In some embodiments, three sections 106a to 106c of the vacuum chamber 106 are partially or completely removable to provide access to the internal parts of the dilution refrigerator 100. For example, the three sections 106a to 106c of the vacuum chamber 106 may include removable panels (e.g., side panels, frame-mounted panels, etc.). The three sections 106a to 106c may be configured so that the user can remove the vacuum chamber 106 from the dilution refrigerator 100 without requiring a large clearance above or below the dilution refrigerator 100 (e.g., without a high ceiling or a pit below the dilution refrigerator 100).

[0166] In some embodiments, the external support rack 950 may include an integrated lift 956a configured to support three sections 106a-106c of the vacuum chamber during assembly, disassembly, and / or maintenance of the dilution refrigerator 100. The integrated lift 956a may be configured to raise and lower sections 106a-106c of the vacuum chamber. For example, the integrated lift 956a may be configured to raise and lower an arm 956b configured to support a portion (e.g., flange) of the three sections 106a-106c. In some embodiments, the integrated lift 956a may be operated manually (e.g., using a screw mechanism and / or cable). Alternatively, in some embodiments, the integrated lift 956a may be actuated by an electronically operated mechanical device (e.g., a pneumatic or hydraulic device).

[0167] In some embodiments, the external support rack 950 may include one or more carts 957. The carts 957 may be configured to receive one or more sections 106a-106c when lowered using an integrated lift 956a or manually. For example, the integrated lift 956a may be used to lower the third section 106c onto the cart 957. The third section 106c may then be moved along direction C using the cart 957 to provide working space below the internal components of the dilution refrigerator 100.

[0168] In some embodiments, the integrated lift 956a may be detachably coupled to the external support rack 950. For example, the integrated lift 956a may be slidably removed from the external support rack 950 (e.g., by sliding horizontally outward along direction C). It may be desirable to remove the integrated lift 956a to provide the user with additional workspace (e.g., during maintenance of the dilution refrigerator 100).

[0169] In some embodiments, the three sections 106a to 106c of the vacuum chamber 106 may be suspended from one another by an integrated clamp and / or cam. Such an integrated clamp and / or cam may be configured to allow the user to clamp or release any two of the three sections 106a to 106c without the use of additional tools. Figures 12A to 12C show an example of an integrated cam 1060. Figure 12B shows the integrated cam 1060 in the open position. Figure 12C shows the integrated cam 1060 in the closed position.

[0170] In some embodiments, the integrated cam 1060 includes a handle 1062 that allows the user to clamp or release two of the three sections 106a-106c. The handle 1062 is coupled to two latches 1064 configured to connect to a bar 1066. The handle 1062 and latches 1064 are supported by a cam 1068 that is hinged to a portion of the vacuum chamber 106, and the cam 1068 provides the required range of motion for clamping and releasing.

[0171] In some embodiments, compression layers may be provided at the connection points of the three sections 106a to 106c of the vacuum chamber 106 to ensure a seal suitable for a vacuum environment. For example, rubber O-rings, copper or indium gaskets, or other vacuum-compatible compression layers may be placed between sections 106a to 106c.

[0172] Returning to Figure 12A, in some embodiments, the vacuum chamber 106 may include an external opening to provide access to the internal space of the dilution refrigerator 100. For example, the opening may provide access to the sample stage or experimental space of the dilution refrigerator 100, or to other internal components of the dilution refrigerator 100. In some embodiments, the opening may be sealed by an airtight seal. In some embodiments, the opening may be sealed by a door 1070, as shown in the example in Figure 12A. The door 1070 may be sealed using, for example, manually removable hinges and / or clamps. In some embodiments, the door 1070 may be coupled to the opening via a load lock.

[0173] In some embodiments, the door 1070 may allow the user to access the experimental space of the dilution refrigerator 100 through all internal radiation shields (not shown, which may be thermally coupled to one or more heat stages 108a-108f). For example, a portion of the internal radiation shields (not shown) may be coupled to the door 1070, and when the user opens the door 1070, the shields may slide or otherwise move to allow access to the inside of the dilution refrigerator. In some embodiments, a portion of the internal radiation shields may be removable and / or slideable through the door 1070.

[0174] In some embodiments, the external support rack 950 may be configured to integrate with a server rack type container. For example, the external support rack 950 may be configured to integrate the dilution refrigerator 100 with a commercial server rack structure (e.g., a server rack). In some embodiments, the external support rack 950 may be configured to integrate the dilution refrigerator 100 with a 19-inch server rack.

[0175] In some embodiments, the external support rack 950 and the dilution refrigerator 100 may be housed within an external housing. An example of the external housing 1100 is shown in Figure 13. In some embodiments, the external housing 1100 may include an integrated horizontal surface 1110. For example, the integrated horizontal surface 1110 may be used as a desk or support surface when the user is operating with the dilution refrigerator. The integrated horizontal surface 1110 may be configured to be folded (as shown in the example in Figure 13) or slid into storage when not in use. In some embodiments, the external housing 1100 may further include one or more storage compartments (e.g., drawers, shelves, etc.) for storing parts and / or tools related to the maintenance of the dilution refrigerator 100.

[0176] In some embodiments, the external housing 1100 may further include a door 1125 that allows access to the experimental space of the dilution refrigerator 100 through an opening 1120. For example, the door 1125 may open through the vacuum chamber 106 and the radiation shield inside it to allow access to the experimental space. In some embodiments, the vacuum chamber exterior and / or radiation shield may be coupled to the door 1125, and when the user opens the door 1125, the vacuum chamber exterior 106 and / or radiation shield may also open. Also in some embodiments, the radiation shield may be movable by sliding and / or hinge so as not to obstruct the user's access to the experimental space as needed.

[0177] In some embodiments, the housing 1100 may be configured to further provide sound insulation. For example, the housing 1100 may include sound insulation material to achieve passive sound insulation. Alternatively or additionally, the housing 1100 may include an acoustic device (e.g., a speaker) configured to provide active sound insulation by generating an interference wave with the opposite phase to the sound generated by the functional components of the system.

[0178] V. Reversal Dilution Refrigerator Conventionally, dilution refrigerators have heat stages arranged so that the temperature increases as you move towards the top of the system. 3 He / 4 The He mixture is configured such that its temperature decreases as it moves towards the bottom of the dilution refrigerator. The inventors recognized and understood that by adopting an inverted structure in which the lowest temperature stage is located at the top of the system (i.e., furthest from the floor), it is possible to improve the thermodynamic properties and facilitate user access to the experimental space compared to conventional dilution refrigerators. Therefore, the inventors developed a dry dilution refrigerator with an inverted structure.

[0179] Figure 14A is a schematic diagram of an inverted dilution refrigerator 1200 according to some embodiments described herein. The inverted dilution refrigerator 1200 is 3 He / 4 The inverting dilution refrigerator 1200 may also include a pump system 1202 configured to circulate the He mixture within the dilution refrigerator 1200. The inverting dilution refrigerator 1200 may also include a cryocooler 1204. The cryocooler may be coupled to a cryocooler support structure (not shown) as described herein in relation to the cryocooler support 103.

[0180] In some embodiments, the inverted dilution refrigerator 1200 may include an external vacuum chamber 1206 and a series of heat stages 1208a to 1208f located inside it. These heat stages 1208a to 1208f may be maintained at the same or substantially the same temperature as the heat stages 108a to 108f described in relation to Figure 3.

[0181] In some embodiments, the inverting dilution refrigerator 1200 may include an opening through an external vacuum chamber 1206 and / or an internal radiation shield to facilitate access to the lowest temperature stage. In some embodiments, the opening is provided with an open / close mechanism 1225 that can withstand an airtight seal and / or a vacuum condition in the external vacuum chamber during operation of the inverting dilution refrigerator 1200. For example, the open / close mechanism 1225 may include a hinged door and / or a removable panel.

[0182] In some embodiments, the inverting dilution refrigerator 1200 may include a plurality of components arranged along the longitudinal direction of the dilution refrigerator (e.g., from the inside of the vacuum chamber 1206 to the sixth heat stage 1208f). These components may be configured such that the mixing chamber 1224, which is the lowest temperature heat stage, is located above the higher temperature heat stages (e.g., still 1214, impedance stages 1212 and 1216, heat exchangers 1218, 1219, 1220, etc.).

[0183] In some embodiments, the inverting dilution refrigerator 1200 includes a demixing chamber 1222 coupled to a mixing chamber 1224. In some embodiments, the demixing chamber 1222 may be thermally coupled to the mixing chamber 1224 by a heat exchanger 1223 (e.g., a co-flow heat exchanger). The demixing chamber 1222 is fluidly connected to the mixing chamber 1224. 3 He may be transported from the demixing chamber 1222 to the mixing chamber 1224, and the chamber may be configured to provide additional cooling to the mixing chamber 1224. Furthermore, the demixing chamber 1222 may contain 4 He was injected, 3 He and 4 It may be configured to generate He co-flow and reduce the formation of a concentration gradient between the still 1214 and the mixing chamber 1224.

[0184] Figures 14B and 14C are schematic diagrams of internal components of an inverting dilution refrigerator according to some embodiments described herein. The exemplary components in Figures 14B and 14C may be implemented in the inverting dilution refrigerator 1200 shown in Figure 14A (for example, within the third heat stage 1208c).

[0185] As shown in the example in Figure 14B, in some embodiments, the inverted dilution refrigerator is connected from still 1214 to demixing chamber 1222. 4 Configured to transport He 4 It may also include He line 1226, 4 He line 1226 is 4The system may include a pump 1228 configured to assist in transporting He to the demixing chamber 1222. In some embodiments, the pump 1228 may be a fountain pump. Alternatively or additionally, 4 He line 1226 is 4 When He moves to demixing chamber 1222 4 It may also include an additional heat exchanger to cool He.

[0186] As shown in the example in Figure 14C, in some embodiments, the inverting dilution refrigerator is located before the main impedance stage 1212. 3 He / 4 A heat exchange stage 1230 configured to cool the He mixed gas may be included. As can be understood from the description of Figure 3, such a configuration improves the efficiency of the primary impedance stage and / or 3 He / 4 The need to pressurize the He mixed gas can be reduced or eliminated.

[0187] VI. Distributed cooling Dilution refrigerators are generally, 3 He / 4 The system includes an integrated cryocooler (e.g., a pulse tube or Gifford-McMahon type cryocooler) for pre-cooling a He mixed gas to below 5K. Conventionally, dilution refrigerators are used in combination with at least one of these cryocoolers, and dilution refrigerators do not share a cooling system with each other. Such small-scale dilution refrigerator systems generally rely on low-power cryogenic cooling systems, which have the challenge of being relatively inefficient compared to large, high-power cryogenic cooling systems (e.g., requiring more power per watt of cooling output at 4K). The inventors recognized and understood that a single high-efficiency cooling system can be thermally coupled to multiple cryogenic systems (e.g., dilution refrigerators), and that the first stage of cooling can be distributed among these multiple cryogenic systems. Such distributed cooling can improve the overall cooling efficiency of the multiple cryogenic systems.

[0188] Figure 15 is a schematic diagram of a distributed cooling system 1300 according to some embodiments described herein. The distributed cooling system 1300 may include a plurality of housings 1305. In some embodiments, the housings 1305 may be server rack type containers (e.g., commercial server rack structures, 19-inch server racks, etc.).

[0189] As shown in the example in Figure 15, each housing 1305 may include a cooling system 1310 or a cryogenic device 1320. In some embodiments, the cryogenic devices 1320 and / or the cooling system 1310 may be grouped within the housing 1305. Furthermore, although three cryogenic devices 1320 are coupled to the cooling system 1310 in Figure 15, the disclosure is not limited thereto. In some embodiments, two, four, ten, or several dozen cryogenic devices 1320 may be coupled to the cooling system 1310.

[0190] In some embodiments, the cooling system 1310 may be a cryogenic cooling system configured to cool the first stage of the cryogenic device 1320 to at least 5K and / or about 4-5K. In some embodiments, the cooling system 1310 may be a pulse tube. For example, the cooling system 1310 may be a pulse tube, a helium liquefaction system and / or a Brayton type cryocooler.

[0191] In some embodiments, the cooling system 1310 may be thermally coupled to a plurality of cryogenic devices 1320. Cooling may be distributed from the cooling system 1310 to the cryogenic devices 1320 via cooling lines 1312. Heat may also be returned from the cryogenic devices 1320 to the cooling system 1310 via returns 1314. The cooling lines 1312 and / or returns 1314 may be lines configured to transport liquid and / or gaseous helium. For example, the cooling lines 1312 and / or returns 1314 may be vacuum-insulated pipes to maintain the temperature of the helium being transported. In some embodiments, the cooling lines 1312 and / or returns 1314 may be filling lines, heat pipes (e.g., conventional and / or pulsed heat pipes) and / or superfluid loops.

[0192] In some embodiments, the cryogenic device 1320 may include any suitable refrigeration system configured to reach temperatures below 5K. In some embodiments, the cryogenic device 1320 may include one or more dilution refrigerators (e.g., dilution refrigerator 100 described herein) configured to reach temperatures below 1K. Alternatively or additionally, the cryogenic device 1320 may include cryogenic systems other than dilution refrigerators, such as microscopy systems such as scanning tunneling microscopes or atomic force microscopes. 3 This may include systems such as helium refrigeration systems and superconducting CMOS systems.

[0193] In the embodiment shown in Figure 16, the computer 1400 includes a processing unit 1401 having one or more processors and a non-volatile computer-readable storage medium 1402. The non-volatile computer-readable storage medium 1402 may include, for example, volatile memory and / or non-volatile memory. The memory 1402 stores instructions for programming the processing unit 1401 and may perform any of the functions described herein. In addition to the system memory 1402, the computer 1400 may also include other types of non-volatile computer-readable media, such as storage 1405 (e.g., one or more disk drives). The storage 1405 may store one or more application programs and / or resources used by the application programs (e.g., software libraries), which may be loaded into the memory 1402.

[0194] The computer 1400 may include one or more input and / or output devices, such as devices 1406 and 1407 shown in Figure 16. These devices are used for various purposes, such as presenting a user interface. Examples of output devices that provide a user interface include a printer or display screen for visual output and a speaker or other sound-generating device for audible output. Examples of input devices for the user interface include pointing devices such as a keyboard, mouse, touchpad, or digitizer tablet. Furthermore, input device 1407 may include a microphone for acquiring audio signals, and output device 1406 may include a display screen for visually displaying recognized text and / or a speaker for audible playback.

[0195] As shown in Figure 16, the computer 1400 may further include one or more network interfaces (e.g., network interface 1410) that enable communication over various networks (e.g., network 1420). Examples of networks include local area networks (LANs) or wide area networks (WANs), and include enterprise networks or the internet. These networks may operate based on any suitable technology and according to any suitable protocol, and may include wireless networks, wired networks or fiber optic networks. These networks may include analog and / or digital networks.

[0196] VII. Definition The various embodiments described above can be used individually, in combination, or in various configurations not specifically described above. Therefore, the present invention is not limited to the details and arrangements of the configurations shown in the above description or drawings. For example, an embodiment described in one embodiment can be combined in any way with an embodiment described in another embodiment.

[0197] All definitions defined and used herein should be understood to take precedence over dictionary definitions, definitions in citations, and / or the ordinary meanings of terms. In this specification and in the claims, the indefinite articles "a" and "an" should be understood to mean "at least one" unless otherwise explicitly indicated.

[0198] As used herein and in the claims, the phrase "and / or" should be understood to mean "either one or both" of the elements listed together; that is, the elements may exist simultaneously or individually. Multiple elements listed with "and / or" are similarly interpreted as meaning "one or more" of the listed elements. There may also be elements other than those specified in the "and / or" phrase (which may or may not be related to these elements). Therefore, as a non-restrictive example, when "A and / or B" is used with an open expression such as "equipped with," in one embodiment it may mean only A (which may also include elements other than B), in another embodiment it may mean only B (which may also include elements other than A), and in yet another embodiment it may mean both A and B (which may also include other elements).

[0199] As used herein and in the claims, the phrase “at least one,” when used in relation to a list of one or more elements, should be understood to mean at least one element selected from any one or more elements in the list. However, this does not necessarily mean that every element in the list is included at least once, nor does it exclude other elements (relevant or irrelevant) that are not explicitly identified in the list. As a non-limiting example, “at least one of A and B” (equivalent to “at least one of A or B” or “at least one of A and / or B”) means, in one embodiment, at least one of A and not B (but other elements may be included); in another embodiment, at least one of B and not A (but other elements may be included); and in yet another embodiment, at least one of A and at least one of B (and other elements may be included).

[0200] When claim elements are modified using ordinal numbers such as "first," "second," and "third" in a claim, they do not in themselves imply priority, order, or temporal order of actions in the method among the claim elements, but are simply used as labels to distinguish them from other elements of the same name.

[0201] In this specification and in the claims, the terms "equipped with," "containing," "mounted with," "having," "containing," "involving," "holding," and "composed of" are all used in an open sense and are interpreted as not being limited to the enumerated elements. In contrast, only the terms "consisting of" and "substantially consisting of" are used in a closed and semi-closed sense, respectively.

[0202] The terms “approximately,” “about,” and “substantially” are used in some embodiments to mean within ±20% of the target value, within ±10% of the target value in other embodiments, within ±5% of the target value in yet another embodiment, or within ±2% of the target value in yet another embodiment. These terms “approximately,” “about,” and “substantially” shall include the target value itself.

[0203] Although several aspects of at least one embodiment have been described above, those skilled in the art will understand that various changes, modifications, and improvements are readily conceivable. These changes, modifications, and improvements constitute part of this disclosure and are intended to be within the spirit and scope of the principles described herein. Accordingly, the above description and drawings are illustrative and not limiting to the invention.

Claims

1. A regenerative cryogenic system, A cryocooler configured to generate extremely low temperatures, One or more flanges coupled to the cryocooler, The system comprises a still exhaust line integrated with one or more flanges, The still exhaust line is configured to provide a passage for still gas from the dilution refrigerator. Regenerative cryogenic system.

2. The cryocooler is configured to generate extremely low temperatures of less than 4.2 Kelvin. The regenerative cryogenic system according to claim 1.

3. The regenerative cryogenic system according to claim 1, wherein one or more flanges are configured to provide a vacuum interface and / or thermal equilibrium.

4. The aforementioned dilution refrigerator further comprises a condensing line, The condensing line is integrated with the cryocooler and the still exhaust line, and is configured to exchange heat with the cryocooler and the still exhaust line. The condensing line of the dilution refrigerator is configured to condense the still gas of the dilution refrigerator, The regenerative cryogenic system according to claim 1, wherein the cryocooler is configured to cool the condensation line of the dilution refrigerator.

5. The regenerative cryogenic system according to claim 4, wherein the condensing line of the dilution refrigerator is integrated with the cryocooler and the still exhaust line by winding, brazing, or arranging the conduit of the still exhaust line within a gas flow path or a heat-conducting block.

6. The regenerative cryogenic system according to claim 4, wherein the still exhaust line is configured to cool the condensing line of the dilution refrigerator.

7. The cryocooler further comprises one or more heat exchangers integrated into it, The regenerative cryogenic system according to claim 1, wherein one or more heat exchangers are configured to perform heat exchange between the dilution refrigerator and the cryocooler.

8. The regenerative cryogenic system according to claim 1, wherein the cryocooler includes one or more pulse tubes.

9. The cryocooler further includes a 4K helium compressor, The regenerative cryogenic system further comprises an adsorbent replacement system integrated with the 4K helium compressor, The regenerative cryogenic system according to claim 8, wherein the adsorbent replacement system is configured to replace the adsorbent in the 4K helium compressor without stopping the 4K helium compressor.

10. The aforementioned cryocooler is further equipped with an integrated helium battery, The regenerative cryogenic system according to claim 8, wherein the helium battery is configured to store and release helium gas to maintain the operation of the regenerative cryogenic system.

11. A method for operating a cryogenic system including a cryocooler, a still exhaust line for a dilution refrigerator, and a condensation line for the dilution refrigerator, A step of generating extremely low temperatures using the aforementioned cryocooler, A step of performing heat exchange between the condensation line and the cryocooler, A step of performing heat exchange between the condensing line and the still exhaust line, A method for operating a cryogenic system, comprising the following features.

12. The method for operating a cryogenic system according to claim 11, wherein the step of generating a cryogenic temperature using the cryocooler includes generating a cryogenic temperature of less than 4.2 Kelvin.

13. The method for operating a cryogenic system according to claim 11, further comprising the step of condensing the still gas of the dilution refrigerator using the condensation line.

14. The process of performing heat exchange between the condensation line and the cryocooler is, A method for operating a cryogenic system according to claim 11, comprising cooling the condensation line using the cryocooler.

15. The method for operating a cryogenic system according to claim 11, wherein the step of performing heat exchange between the condensation line and the still exhaust line includes cooling the condensation line using the still exhaust line.

16. The cryogenic system further comprises one or more flanges configured to provide a vacuum interface and / or thermal equilibrium, One or more flanges are coupled to the cryocooler, The method for operating a cryogenic system according to claim 11, wherein the still exhaust line is integrated with one or more flanges.

17. A cryogenic generating means, which is a means for generating cryogenic temperatures, One or more flanges configured to provide a vacuum interface and / or thermal equilibrium and coupled to the cryogenic generating means, A still exhaust line, integrated with one or more flanges and configured to provide a passage for still gas from a dilution refrigerator, A cryogenic system equipped with the following features.

18. The dilution refrigerator is further equipped with a condensation line, The condensing line of the dilution refrigerator, The cryogenic generating means and the still exhaust line perform heat exchange, The cryogenic system according to claim 17, configured to condense the still gas of the dilution refrigerator.

19. The condensing line of the dilution refrigerator, A first portion is integrated with the aforementioned still exhaust line and configured to exchange heat with the still exhaust line, A second part is integrated with the cryogenic generating means and configured to exchange heat with the cryogenic generating means, Includes, The cryogenic system according to claim 18, wherein the still exhaust line is configured to cool the condensation line of the dilution refrigerator.

20. The condensing line of the dilution refrigerator is integrated with the cryogenic generating means and the still exhaust line by winding, brazing, or arranging the conduit of the still exhaust line within the gas flow path or a heat-conducting block. The cryogenic system according to claim 18.

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