Deep hypothermia cold accumulation device and manufacturing, cold accumulation and refrigeration method

Abstract

The invention discloses a deep hypothermia cold storage device and a manufacturing method, a cold storage method and a refrigeration method, and belongs to the field of low-temperature refrigeration and inertial confinement fusion. A plurality of metal particles and a plurality of hollow glass balls; the gaseous heat transfer medium can permeate into and seep out of the glass balls, and exchanges heat with the metal particles after permeating out of the glass balls. The manufacturing method comprises the steps that the heat conduction metal material piece is machined into the containing cavity; loading a plurality of metal particles therein; filling a plurality of glass balls with a gaseous heat transfer medium and loading the glass balls into the accommodating cavity; and sealing the heat-conducting metal cavity. The cold accumulation and refrigeration method comprises the following steps: firstly storing cold energy by using the metal particles, and releasing the cold energy when the refrigerator is shut down. On the basis of excellent low-temperature cold storage capacity and refrigeration effect, the low-temperature cold storage device does not generate vibration, the problem of serious heat leakage caused by a traditional mode is avoided, and the low-temperature cold storage device is suitable for in-situ high-resolution imaging of low-temperature samples, high in safety, convenient to implement and wide in application prospect.

Description

Technical Field

[0001] The present application belongs to the technical field of low-temperature refrigeration and inertial confinement fusion, and in particular relates to a deep-low temperature cold storage device and its manufacturing, cold storage and refrigeration methods. Background Art

[0002] Deep cryogenic temperature refers to a temperature range far below that of ordinary refrigeration engineering, usually from 120K (about -153℃) to near absolute zero (0K, -273.15℃). At this temperature, the structure and properties of many materials will undergo significant changes, leading to the development of many cutting-edge scientific research and engineering technologies. Obtaining an excellent deep cryogenic environment is a prerequisite for conducting deep cryogenic scientific and technological research. A cryogenic refrigerator is a device that can provide cooling effects at low temperatures. It is widely used in scientific research, industrial production, medical treatment, inertial confinement fusion and other fields, such as in superconducting magnets, quantum computing, and mechanical refrigeration and other low-temperature devices. With the development of microelectronics, micro heat exchangers, bioengineering, cryogenic engineering, aerospace, fusion energy and other fields, the requirements for the deep cryogenic cold storage capacity of cryogenic refrigerators are getting higher and higher.

[0003] Existing cryogenic refrigerators are difficult to use for in-situ high-resolution imaging of cryogenic samples. This is because current cryogenic refrigerators, such as GM refrigerators and pulse tube refrigerators, inevitably generate vibrations during operation. In-situ high-resolution imaging of cryogenic samples requires high stability at the sub-nanometer level, and current cryogenic refrigerators do not meet the requirements for high-resolution imaging. Summary of the Invention

[0004] The present application aims to solve the technical problem of in-situ high-resolution imaging of low-temperature samples. To this end, the present application provides a deep-low temperature cold storage device and a manufacturing, cold storage and refrigeration method. On the basis of excellent low-temperature cold storage capacity and refrigeration effect, it avoids vibration when the refrigerator is working, thereby being suitable for in-situ high-resolution imaging of low-temperature samples.

[0005] In a first aspect, an embodiment of the present application provides a deep-low temperature cold storage device for use in temperature conditions less than 20K, comprising:

[0006] A heat-conducting metal cavity, one end of which is used to connect to the cold head of the refrigerator and the other end of which is used to connect to the object to be refrigerated. The interior of the heat-conducting metal cavity is provided with a receiving cavity;

[0007] A plurality of metal particles are arranged in the accommodating cavity, and are used to receive the cold energy of the cold head of the refrigerator, and transfer the received cold energy to the heat-conducting metal cavity and the object to be refrigerated through the accommodating cavity and the gaseous heat transfer medium after the refrigerator is shut down;

[0008] A plurality of hollow glass balls are arranged in the accommodating cavity, and the interior of the glass balls has a hollow cavity for storing a gaseous heat transfer medium;

[0009] Among them, all metal particles and all glass balls fill the containing cavity; the glass balls can be filled with gaseous heat transfer medium by diffusion and penetration, and the gaseous heat transfer medium can penetrate out of the glass balls in the heat-conducting metal cavity and spread in the containing cavity to exchange heat with the metal particles.

[0010] In some embodiments, the gaseous heat transfer medium is helium.

[0011] In some embodiments, under the condition of less than 20K, the preset pressure of the gaseous heat transfer medium in the containing cavity is P1: 0.1 kPa to 1 kPa.

[0012] In some embodiments, under normal temperature conditions, the preset pressure of the gaseous heat transfer medium in the accommodating cavity is P2: 1 kPa to 10 kPa.

[0013] In some embodiments, the metal particles have a specific heat capacity greater than 0.1 J / gK at a temperature less than 20 K.

[0014] In some embodiments, the outer diameter of the metal particles is in the range of [100 μm, 300 μm].

[0015] In some embodiments, the material of the thermally conductive metal cavity includes at least one of copper and aluminum.

[0016] In some embodiments, when the material of the heat-conducting metal cavity is a single metal, the metal purity of the heat-conducting metal cavity is greater than 99.9%.

[0017] In a second aspect, an embodiment of the present application provides a method for manufacturing a cryogenic cold storage device, which uses the above-mentioned cryogenic cold storage device, and the manufacturing method includes:

[0018] A heat-conducting metal material is used to machine a receiving cavity at one end;

[0019] A plurality of metal particles are used and placed into the receiving cavity;

[0020] Using multiple glass balls, and using the diffusion and penetration method to fill the glass balls with gaseous heat transfer medium;

[0021] A plurality of glass balls filled with a gaseous heat transfer medium are placed into the receiving cavity;

[0022] The end of the heat-conducting metal cavity is sealed to separate the accommodating cavity from the outside.

[0023] In a third aspect, an embodiment of the present application provides a cold storage and cooling method for a cryogenic cold storage device, which is applied to a refrigerator shutdown condition. The cryogenic cold storage device is installed between the refrigerator cold head and the sample holder. The cold storage and cooling method includes:

[0024] Before the above-mentioned method of manufacturing the deep-low temperature cold storage device, the size of the accommodating cavity, the total amount of metal particles and gaseous heat transfer medium are determined according to the refrigeration demand, and the metal particles and glass balls are able to fill the accommodating cavity completely;

[0025] The deep-cold storage device manufactured by the manufacturing method of the deep-cold storage device is installed at one end on the cold head of the refrigerator and at the other end on the sample holder provided with the sample;

[0026] The refrigerator is first started, and the cold energy generated is stored through metal particles. When imaging the sample, the refrigerator connected to the cold head of the refrigerator is stopped, and the metal particles, gaseous heat transfer medium and heat-conducting metal cavity in the deep low-temperature cold storage device are used to transfer the stored cold energy to the sample, so that the sample is always in a deep low-temperature environment of less than 20K.

[0027] It can be seen from the above technical solution that the beneficial effects of this application are:

[0028] 1. The cold storage device of the present application forms a heat transfer structure with a heat-conducting metal cavity, internal metal particles, and a gaseous heat transfer medium, achieving efficient cold storage and vibration-free low-temperature refrigeration at deep low temperatures (<20K): the glass ball serves as a carrier for transferring the gaseous heat transfer medium, first storing the gaseous heat transfer medium under a certain preset pressure and transferring it to the accommodating cavity. The gaseous heat transfer medium diffuses out of the glass ball, enters and spreads in the accommodating cavity, and multiple metal particles can receive cold energy in the accommodating cavity. After the refrigerator is shut down, the received cold energy is transferred to the heat-conducting metal cavity through the gaseous heat transfer medium, which can dynamically release cold energy and maintain the cooling effect and temperature stability. Since the gaseous heat transfer medium in the glass ball enters the accommodating cavity and transfers heat with the metal particles through gas-solid coupling, and the refrigerator is in a shut-down state, no mechanical vibration will be generated. Therefore, the present application has excellent low-temperature cold storage capacity and cooling effect, and avoids vibration when the refrigerator is working, making it suitable for in-situ high-resolution imaging of low-temperature samples.

[0029] 2. The manufacturing method of the present application processes a receiving cavity in a heat-conducting metal material to provide space for loading metal particles and glass balls. The gaseous heat transfer medium is first filled into the glass balls based on the thermal diffusion permeation diffusion method, and then the glass balls are mixed with the metal particles and loaded into the receiving cavity. Then, the end of the heat-conducting metal cavity is sealed. When the gaseous heat transfer medium penetrates the glass balls, it can fully contact with the metal particles and transfer cold energy, finally forming an overall deep-low temperature cold storage device, which can still provide cold energy for the object to be refrigerated when the refrigerator is shut down, avoiding the serious heat leakage problem caused by the gas filling pipe in the traditional high-pressure gas cold storage, and facilitating implementation and large-scale production.

[0030] 3. The cold storage and refrigeration method of the present application determines the size of the accommodating cavity, the total amount of metal particles and gaseous heat transfer medium according to the refrigeration demand, can meet the refrigeration demand, is applicable to different refrigeration parameter conditions, and the refrigeration effect is adjusted as needed, and the metal particles and glass balls fully fill the accommodating cavity; the deep low temperature cold storage device is connected between the cold head of the refrigerator and the sample holder, and can store the cold energy generated by the refrigerator when it is working. When the refrigerator is stopped, the stored cold energy is released through the gaseous heat transfer medium and the heat-conducting metal cavity, providing cold energy for the sample for a period of time, keeping the sample in a deep low temperature environment of less than 20K. The above method can maintain the deep low temperature environment of the sample and maintain high stability during sample imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments one by one. Obviously, the drawings described below are some embodiments of the present application. For those of ordinary skill in the art, other embodiments and drawings can be obtained based on these drawings without inventive work. Various schematic diagrams according to the embodiments of the present application are shown in the drawings. These drawings are not necessarily drawn to scale. For the purpose of clarity, some details are magnified and some details may be omitted.

[0032] Figure 1 A schematic diagram of an embodiment of a deep-low temperature cold storage device according to the present invention is shown;

[0033] Figure 2 A schematic diagram showing the implementation process of the deep low temperature cold storage device method of the present invention is shown;

[0034] Figure 3 A schematic diagram showing the steps of an embodiment of a method for producing a deep-low temperature cold storage device according to the present invention is shown;

[0035] Figure numerals: 10, deep-low temperature cold storage device; 11, heat-conducting metal cavity; 111, accommodating cavity; 12, metal particles; 13, glass balls; 14, gaseous heat transfer medium; 20, cold head; 30, sample holder. DETAILED DESCRIPTION

[0036] The following will be combined with the accompanying drawings corresponding to the specific embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. The following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection. The described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, various different configurations can be arranged and designed. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0037] The present application is described below with reference to specific embodiments and with reference to the accompanying drawings:

[0038] Please refer to Figure 1 In the first embodiment of the present application, there is provided a deep-low temperature cold storage device 10, which is used in temperature conditions less than 20K, and includes: a heat-conducting metal cavity 11, a plurality of metal particles 12, a plurality of glass balls 13 and a gaseous heat transfer medium 14. The heat-conducting metal cavity 11 is made of heat-conducting metal, taking copper as an example. One end of the heat-conducting metal cavity 11 is used to connect with the cold head 20 of the refrigerator, and the other end is used to connect with the object to be refrigerated. After the connection, the heat-conducting metal cavity 11 can transfer cold energy to the object to be refrigerated for cooling. The interior of the heat-conducting metal cavity 11 is provided with a closable accommodating cavity 111, such as forming a copper cavity, so as to accommodate the metal particles 12, the glass balls 13 and the gaseous heat transfer medium 14; the plurality of metal particles 12 are arranged in the accommodating cavity 111, which is used to receive the cold energy of the cold head 20 of the refrigerator, and transfer the received cold energy to the heat-conducting metal cavity 11 through the gaseous heat transfer medium 14 and the accommodating cavity 111 after the refrigerator is shut down; the plurality of glass particles 12 are provided in the accommodating cavity 111, which is used to receive the cold energy of the cold head 20 of the refrigerator, and transfer the received cold energy to the heat-conducting metal cavity 11 through the gaseous heat transfer medium 14 and the accommodating cavity 111 after the refrigerator is shut down; The glass balls 13 are arranged in the accommodating cavity 111. The gaseous heat transfer medium 14 is stored in the glass balls 13 in advance and transferred to the accommodating cavity 111. The metal particles 12 and the glass balls 13 are all placed in the accommodating cavity 111. All the metal particles 12 and all the glass balls 13 fill the accommodating cavity 111. The gaseous heat transfer medium 14 seeps out of the glass balls 13. The heat-conducting metal cavity 11 is a closed structure and can be sealed after the metal particles 12 and the glass balls 13 are loaded. For example, by welding, bolting or other sealing methods, the metal particles 12, the glass balls 13 and the gaseous heat transfer medium 14 are confined inside the heat-conducting metal cavity 11, and the gaseous heat transfer medium 14 is released from the glass balls 13 into the accommodating cavity 111.

[0039] Within the containment chamber 111, the heat transfer process and principle between the glass balls 13, the gaseous heat transfer medium 14, and the metal particles 12 are as follows: The gaseous heat transfer medium 14 is first filled into the glass balls 13 at room temperature using the thermal diffusion permeation method; the glass balls 13 filled with the gaseous heat transfer medium 14 and the metal particles 12 are quickly transferred into the containment chamber 111, which is then sealed; the gaseous heat transfer medium 14 within the glass balls 13 permeates out of the glass balls 13, disseminate throughout the containment chamber 111, and exchange heat with the metal particles 12. The cold energy generated during the operation of the refrigerator is first stored by the metal particles 12 in the cryogenic cold storage device; when imaging the sample, the refrigerator connected to the refrigerator cold head 20 is shut down, and the stored cold energy is transferred to the sample using the metal particles 12, the gaseous heat transfer medium 14, and the heat-conducting metal cavity 11 in the cryogenic cold storage device, ensuring that the sample remains in a cryogenic environment of less than 20K.

[0040] Existing cryogenic refrigerators are difficult to use for in situ high-resolution imaging of cryogenic samples. This is because current cryogenic refrigerators, especially regenerative cryogenic refrigerators with regenerative refrigerants, inevitably generate vibrations of tens of microns during operation. In situ high-resolution imaging of cryogenic samples requires high sample stability, reaching sub-nanometer levels. Solutions to this problem include developing vibration reduction / isolation technologies to reduce or eliminate sample vibrations caused by refrigerator operation, which current cryogenic refrigerators do not meet. Alternatively, the refrigerator can be shut down during high-resolution imaging. However, this requires a novel device with excellent deep-cold storage capabilities to maintain the sample's low temperature during this period. Conventional high-pressure gas regenerative refrigerants, however, face extreme operating conditions, including high pressure and low temperature, and significant heat leakage from the gas piping. This poses significant risks and poses a significant safety risk. Therefore, the development of a novel device with excellent deep-cold storage capabilities is urgently needed.

[0041] The cold storage device of the present application forms a heat transfer structure through the heat-conducting metal cavity 1111, the internal metal particles 1212, and the gaseous heat transfer medium 1414, and realizes efficient cold storage and vibration-free low-temperature refrigeration at deep low temperatures (<20K): the glass ball 13 serves as a carrier for transferring the gaseous heat transfer medium 14, and the gaseous heat transfer medium 14 is first stored under a certain preset pressure and transferred to the accommodating cavity 111. The gaseous heat transfer medium 14 diffuses out of the glass ball 13, enters and spreads in the accommodating cavity 111, and multiple metal particles 12 can receive cold energy in the accommodating cavity 111, and after the refrigerator is shut down, the received cold energy is transferred to the heat-conducting metal cavity 11 through the gaseous heat transfer medium 14, which can dynamically release cold energy to maintain the cooling effect and temperature stability. Because the gaseous heat transfer medium 14 in the glass ball 13 enters the accommodating cavity 111 and transfers heat to the metal particles 12 through gas-solid coupling, and the refrigerator is in a shutdown state, no mechanical vibration is generated. Therefore, the present application, while having excellent low-temperature cold storage capacity and refrigeration effect, avoids vibration when the refrigerator is operating, making it suitable for in-situ high-resolution imaging of low-temperature samples. The low-temperature cold storage device of the present application is easy to engineer and apply, is easy to implement, can be mass-produced, and has broad application prospects.

[0042] In some embodiments, to enhance the cold storage capacity of the cold storage device, the total volume of the storage space occupied by the plurality of metal particles 12 is greater than the volume of the storage space occupied by the plurality of glass balls 13. The larger the space occupied by the metal particles 12, the smaller the space occupied by the glass balls 13. As the space occupied by the metal particles 12 increases, the cold storage capacity gradually increases, and then decreases as the space occupied by the glass balls 13 increases. To ensure excellent cold storage and cooling capacity, the size of the storage space, the metal particles 12, and the glass balls 13 can be determined through experiments. The size of the metal particles 12 and the glass balls 13 can also be determined as needed.

[0043] In some embodiments, the gaseous heat transfer medium 14 stored in the glass balls 13 is helium. Helium remains in a gaseous state at temperatures below 20K, ensuring that the helium can penetrate into and out of the glass balls 13. The helium is mixed with the metal particles 12 and enclosed within the heat-conducting metal cavity 11. As a heat transfer medium, helium can quickly transfer the cooling energy provided by the refrigerator to the metal particles 12, and also quickly transfer the cooling energy released by the metal particles 12 to the heat-conducting metal cavity 11 and the sample holder 30.

[0044] In some embodiments, at temperatures below 20K, the preset pressure of the gaseous heat transfer medium 14 within the accommodating cavity 111 is P1: 0.1 kPa to 1 kPa, such as 1 kPa, 0.6 kPa, or 1 kPa. In some embodiments, at room temperature, the preset pressure of the gaseous heat transfer medium 14 within the accommodating cavity 111 is P2: 1 kPa to 10 kPa, such as 1 kPa, 5 kPa, or 10 kPa. Under these pressure conditions, the glass balls 13 are able to permeate the gaseous heat transfer medium 14, ensuring the operation of the cold storage device.

[0045] In some embodiments, the metal particles 12 have a specific heat capacity greater than 0.1 J / gK at a temperature less than 20 K. The metal particles 12 can be made of pure metal or alloys, such as erbium nickel or holmium copper. In this way, the helium gas and the metal particles 12 with a larger specific heat capacity are both sealed in the copper cavity, achieving mutual coupling.

[0046] In some embodiments, the outer diameter of the metal particles 12 is in the range of [100 μm, 300 μm], such as 100 μm, 200 μm, or 300 μm. Using metal particles 12 of this particle size allows for a larger contact area between the metal particles 12 and the gaseous heat transfer medium 14, enhancing the cold storage effect. The cold energy from the gaseous heat transfer medium 14 and the cold head 20 can be quickly transferred to the metal particles 12. The metal particles 12, acting as a low-temperature cold storage medium, effectively store the cold energy provided by the refrigerator during operation, and when needed, supply it to the sample holder 30 as a cold source to cool the sample.

[0047] In some embodiments, the material of the heat-conducting metal cavity 11 includes at least one of copper and aluminum. In some embodiments, when the heat-conducting metal cavity 11 is made of a single metal, the metal purity of the heat-conducting metal cavity 11 is greater than 99.9%, such as a high-purity copper cavity with a purity greater than 99.9%. Using high-purity metal, the heat-conducting metal cavity 11 can have excellent thermal conductivity, allowing cold air to be effectively transferred to the object to be cooled.

[0048] Please refer to Figure 2 and Figure 3The second embodiment of the present application provides a method for manufacturing a cryogenic cold storage device, which uses the above-mentioned cryogenic cold storage device 10. The manufacturing method includes:

[0049] S1. Use a heat-conducting metal material to process a receiving cavity 111 at one end. A columnar heat-conducting metal material, such as a copper column, can be selected and processed at one end by turning, boring, or electric spark processing to form a copper cavity. The copper cavity is the above-mentioned receiving cavity 111. One end of the copper cavity is open to facilitate the loading of metal particles 12 and glass balls 13.

[0050] S2. Use multiple metal particles 12 and load them into the accommodating cavity 111; directly select the material of the metal particles 12, which can be prepared by electromagnetic induction heating, plasma rotating electrode atomization or ultrasonic atomization; load the required number of metal particles 12 into the copper cavity.

[0051] S3. Use multiple glass balls 13 and fill the glass balls 13 with gaseous heat transfer medium 14 by diffusion and penetration. The glass balls 13 are hollow glass balls 13. Place the glass balls 13 in a high-pressure helium environment and fill the glass balls 13 with high-pressure helium by thermal diffusion and penetration. The high pressure is determined according to needs and is greater than 10 MPa at room temperature. The helium penetrates into and is stored in the glass balls 13.

[0052] S4, multiple glass balls 13 filled with gaseous heat transfer medium 14 are placed into the accommodating cavity 111; the glass balls 13 filled with helium are transferred into the copper cavity, and the copper cavity is completely filled with metal particles 12 and glass balls 13. After the copper cavity is sealed, the helium in the glass balls 13 penetrates the glass balls 13 and diffuses throughout the copper cavity. Figure 2 In steps 3 and 4, it can be seen that the helium in the glass ball 13 is dispersed in the receiving cavity 111 .

[0053] S5. Close the end of the heat-conducting metal cavity 11 to separate the accommodating cavity 111 from the outside. Different methods can be used to close the end of the heat-conducting metal cavity 11, but it is necessary to ensure that the copper cavity is closed and the metal particles 12 and glass balls 13 are placed in a copper cavity environment that is completely separated from the outside of the heat-conducting metal cavity 11. For example, the end of the copper cavity can be sealed by welding. Figure 2 It can be seen from steps 3 and 4 that the top of the heat-conducting metal cavity 11 is sealed after the glass balls 13 and metal particles 12 are loaded.

[0054] The manufacturing method of the present application processes a receiving cavity 111 in a heat-conducting metal material to provide space for loading metal particles 12 and glass balls 13; first, a gaseous heat transfer medium 14 is filled into the glass balls 13 based on the thermal diffusion permeation diffusion method, and then the glass balls 13 are mixed with the metal particles 12 and loaded into the receiving cavity 111, and then the end of the heat-conducting metal cavity 11 is sealed. After the gaseous heat transfer medium 14 penetrates the glass balls 13, it can fully contact with the metal particles 12 and transfer cold energy, finally forming an overall deep low-temperature cold storage device 10, which can still provide cold energy for the object to be refrigerated when the refrigerator is shut down, avoiding the traditional high-pressure gas cold storage method, which has serious heat leakage problems caused by the existence of the filling pipe, and is easy to implement and large-scale production.

[0055] Please refer to Figure 2 and Figure 3 In a third embodiment of the present application, a cold storage and refrigeration method for a cryogenic cold storage device is provided, which is applied to a refrigerator shutdown condition. The cold storage and refrigeration method is based on the cryogenic cold storage device 10 manufactured as described above. The cryogenic cold storage device 10 is installed between the refrigerator cold head 20 and the sample holder 30. The method adds steps to the manufacturing method, and the sequence of the steps can be continuous. The cold storage and refrigeration method includes:

[0056] S0. Before manufacturing the cryogenic cold storage device described above, the dimensions of the accommodating cavity 111, the total amount of metal particles 12 and the gaseous heat transfer medium 14, and the amount of metal particles 12 and glass balls 13 required to completely fill the accommodating cavity 111 are determined based on the cooling requirements. The desired cryogenic cold storage device can be obtained by adjusting the inner diameter and height of the copper cavity, adjusting the dimensions of the accommodating cavity 111, and determining the total amount of metal particles 12 and glass balls 13 required to fill the cavity, as well as the helium pressure within the cavity.

[0057] S6. The deep low-temperature cold storage device 10 manufactured by the manufacturing method of the deep low-temperature cold storage device is installed at one end on the cold head 20 of the refrigerator and at the other end on the sample holder 30 provided with the sample. When connected to the cold head 20 of the refrigerator, the metal particles 12 can absorb cold energy and store cold. Taking the copper cavity as an example, one end of the copper cavity is installed on the cold head 20 of the refrigerator by tightening screws, and the other end of the copper cavity is fixed to the sample holder 30 in the same way.

[0058] S7. First, the refrigerator is started to store the cold energy generated by the metal particles 12. When imaging the sample, the refrigerator connected to the refrigerator cold head 20 is stopped, and the metal particles 12, the gaseous heat transfer medium 14 and the heat-conducting metal cavity 11 in the deep low-temperature cold storage device 10 are used to transfer the stored cold energy to the sample, so that the sample is always in a deep low-temperature environment of less than 20K. When the refrigerator is stopped, the cold energy received by the metal particles 12 can be quickly released and transferred to the sample holder 30, and finally the refrigeration temperature of the sample is maintained.

[0059] Experiments were conducted using the cold storage and refrigeration method of the present application. For example, 500 grams of Er3Ni metal particles 12 with an average particle size of 150 microns and 100 Pa of helium were mixed in a copper chamber. After the refrigerator was shut down, the sample holder 30 maintained a temperature rise of less than 1 mK at each temperature point within the temperature range of 10K to 20K for 2 minutes, making it fully suitable for cryo-X-ray and high-resolution electron microscopy imaging.

[0060] The cold storage and refrigeration method of the present application determines the size of the accommodating cavity 111, the total amount of metal particles 12 and the gaseous heat transfer medium 14 according to the refrigeration demand, can meet the refrigeration demand, is applicable to different refrigeration parameter conditions, and adjusts the refrigeration effect as needed. The metal particles 12 and glass balls 13 fully fill the accommodating cavity 111. The deep low-temperature cold storage device 10 is connected between the refrigerator cold head 20 and the sample holder 30, and can store the cold energy generated when the refrigerator is working. When the refrigerator is stopped, the stored cold energy is released through the gaseous heat transfer medium 14 and the heat-conducting metal cavity 11, providing cold energy for the sample for a period of time, keeping the sample in a deep low-temperature environment of less than 20K. The above method can maintain the deep low-temperature environment of the sample and maintain a high degree of stability when the sample is imaged.

[0061] Regarding the specific implementation of this application, it should be noted that:

[0062] In the description of this application, unless otherwise clearly specified and limited, the terms "connect", "fixed", "connected", etc. should be understood in a broad sense. For example, "fixed" can be a fixed connection, a detachable connection, or an integral molding; "connection" can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly limited; "connected" can be the internal connection of two parts and between two parts, or the spatial connection between the two, and the two are directly or indirectly connected through the part that forms the space. The terms "set", "install", "provided with", "configured", etc. should also be understood in a broad sense. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0063] In the description of this application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are only used to facilitate the description of this application and simplify the description. They do not indicate or imply that the system or component referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting this application. All directional indications are only used to explain the relative positional relationships, movement conditions, etc. between the components in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0064] In the description of this application, reference to the terms "some embodiments", "optional embodiments", "examples", "specific examples", "optional examples" or "optional embodiments" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of this application, but does not mean that these embodiments illustrate and describe all possible forms of the invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0065] The present invention has been described in detail above with reference to specific embodiments and exemplary examples. The above description is illustrative, not exhaustive, and is not limited to the disclosed embodiments; the above description cannot be understood as a limitation of the present invention. The technical solutions between the various embodiments can be combined with each other, but must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application. Although the embodiments of the present application have been shown and described, these embodiments can be subjected to various changes, modifications, substitutions and variations without departing from the principles and purposes of the present application. Ordinary technicians in this field can understand that various other specific changes and combinations of embodiments that do not depart from the essence of the present application are made according to the technical inspirations disclosed in this application, and are still within the scope of protection defined by the claims of the present invention and its equivalent technical solutions.

Claims

1. A deep low temperature cold storage device (10), characterized in that: Applicable to temperature conditions below 20K, including: A heat-conducting metal cavity (11), one end of which is used to be connected to a cold head (20) of a refrigerator, and the other end of which is used to be connected to an object to be refrigerated (30), wherein a closable accommodating cavity (111) is provided inside the heat-conducting metal cavity (11); A plurality of metal particles (12) are arranged in the accommodating cavity (111) and are used to receive cold energy from the cold head (20) of the refrigerator and transfer the received cold energy to the heat-conducting metal cavity (11) and the object to be refrigerated (30) through the accommodating cavity (111) and the gaseous heat transfer medium (14) after the refrigerator is shut down; A plurality of hollow glass balls (13) are arranged in the accommodating cavity (111), wherein the glass balls (13) have hollow cavities inside for storing a gaseous heat transfer medium (14); All the metal particles (12) and all the glass balls (13) fill the accommodating cavity (111); the glass balls (13) can be filled with the gaseous heat transfer medium (14) by diffusion and penetration, and the gaseous heat transfer medium (14) can penetrate out of the glass balls (13) in the heat-conducting metal cavity (11) and be dispersed in the accommodating cavity (111) to perform heat exchange with the metal particles (12).

2. The deep-low temperature cold storage device (10) according to claim 1, characterized in that: The gaseous heat transfer medium (14) is helium.

3. The deep low temperature cold storage device (10) according to claim 2, characterized in that: Under the condition of less than 20K, the preset pressure of the gaseous heat transfer medium (14) in the accommodating cavity (111) is P1: 0.1 kPa to 1 kPa.

4. The deep-low temperature cold storage device (10) according to claim 2, characterized in that: Under normal temperature conditions, the preset pressure of the gaseous heat transfer medium (14) in the accommodating cavity (111) is P2: 1 kPa to 10 kPa.

5. The deep-low temperature cold storage device (10) according to claim 1, characterized in that: The specific heat capacity of the metal particles (12) at a temperature less than 20K is greater than 0.1 J / gK.

6. The deep-low temperature cold storage device (10) according to claim 1, characterized in that: The outer diameter of the metal particles (12) ranges from [100 μm to 300 μm].

7. The deep-low temperature cold storage device (10) according to any one of claims 1 to 6, characterized in that: The material of the heat-conducting metal cavity (11) includes at least one of copper and aluminum.

8. The deep-low temperature cold storage device (10) according to claim 7, characterized in that: When the material of the heat-conducting metal cavity (11) is a single metal, the metal purity of the heat-conducting metal cavity (11) is greater than 99.9%.

9. A method for manufacturing a deep-low temperature cold storage device (10), characterized in that: The deep-low temperature cold storage device (10) according to any one of claims 1 to 8 is used, and the manufacturing method comprises: A heat-conducting metal material is used to form the accommodating cavity (111) at one end; Using a plurality of the metal particles (12) and placing them into the accommodating cavity (111); A plurality of the glass balls (13) are used, and a gaseous heat transfer medium (14) is filled into the glass balls (13) by a diffusion-infiltration method; Loading a plurality of the glass balls (13) filled with a gaseous heat transfer medium (14) into the accommodating cavity (111); The end of the heat-conducting metal cavity (11) is sealed to separate the accommodating cavity (111) from the outside.

10. A cold storage and refrigeration method for a deep low temperature cold storage device, characterized in that: Applied to a refrigerator shutdown condition, the deep low temperature cold storage device (10) is installed between a refrigerator cold head (20) and a sample holder (30), and the cold storage and refrigeration method includes: Before the method for manufacturing the deep-low temperature cold storage device (10) according to claim 9 is carried out, the size of the accommodating cavity (111), the total amount of the metal particles (12) and the gaseous heat transfer medium (14) are determined according to the refrigeration demand, and the metal particles (12) and the glass balls (13) are able to completely fill the accommodating cavity (111); The deep-cold storage device (10) manufactured by the method for manufacturing the deep-cold storage device (10) is mounted on a cold head (20) of a refrigerator at one end and on a sample holder (30) provided with a sample at the other end; The refrigerator is first started to operate, and the generated cold energy is stored through the metal particles (12); when imaging the sample, the refrigerator connected to the refrigerator cold head (20) is stopped, and the stored cold energy is transferred to the sample by using the metal particles (12), the gaseous heat transfer medium (14) and the heat-conducting metal cavity (11) in the deep low-temperature cold storage device (10), so that the sample is always in a deep low-temperature environment of less than 20K.

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