Low-temperature molecular beam device

Abstract

The invention provides a low-temperature molecular beam device, which relates to the field of low-temperature physical chemistry and comprises a refrigeration assembly, a primary shielding cover and a buffer cooling structure. The refrigeration assembly comprises a first-stage cold head and a second-stage cold head; the first-stage shielding cover is provided with a first-stage shielding inner cavity; the first-stage cold head is connected with the first-stage shielding cover and is used for cooling the first-stage shielding cover; the second-stage cold head is accommodated in the first-stage shielding inner cavity; the buffer cooling structure is connected to the second-stage cold head and is accommodated in the first-stage shielding inner cavity; the buffer cooling structure is provided with a buffer cooling inner cavity, and the buffer cooling inner cavity is used for introducing buffer gas and target molecules. According to the low-temperature molecular beam device in the embodiment of the invention, the temperature of the buffer gas can be further reduced.

Description

Technical Field

[0001] This invention relates to the field of low-temperature physical chemistry, and more specifically to low-temperature molecular beam devices. Background Technology

[0002] In related technologies, molecular beam sources are widely used in the field of cold atom molecular physics and are a crucial starting step in almost any atomic and molecular physics experiment. Low-temperature molecular beams, in particular, are beneficial for researchers to further study molecular properties.

[0003] For molecular bundles composed of target molecules, some techniques dissipate the energy of the target molecules through collisions with a low-temperature inert gas, thereby reducing the energy of the molecular bundle and achieving cooling. However, the buffer gas used in these techniques also needs to be cooled to a lower temperature so that it can further cool the target molecules after collision. Existing technologies directly utilize the cold head of a refrigerator to cool the buffer gas, but the temperature of the buffer gas remains relatively high, resulting in a high temperature for the cooled molecular bundle as well. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a cryogenic molecular beam device that can further reduce the temperature of the buffer gas.

[0005] A cryogenic molecular beam apparatus according to a first aspect of the present invention comprises: Refrigeration components, including primary and secondary cold heads; A primary shielding cover has a primary shielding cavity; a primary cold head is connected to the primary shielding cover and is used to cool the primary shielding cover; a secondary cold head is housed within the primary shielding cavity; A buffer cooling structure is connected to the secondary cold head and housed within the primary shielding cavity; the buffer cooling structure has a buffer cooling cavity for introducing buffer gas and target molecules.

[0006] The cryogenic molecular beam apparatus according to embodiments of the present invention has at least the following beneficial effects: the primary cold head can reduce the temperature of the primary shield by cooling the primary shield, and the primary shield itself can block external heat radiation from entering the primary shield cavity, resulting in a lower temperature in the primary shield cavity. Furthermore, since the secondary cold head is housed within the primary shield cavity, it can further reduce the temperature of the buffer cooling structure, thereby lowering the temperature of the buffer cooling cavity and the buffer gas. This facilitates a further decrease in the temperature of the target molecules after collision with the buffer gas, resulting in a better molecular beam cooling effect.

[0007] According to some embodiments of the present invention, the cryogenic molecular beam device further includes a secondary shield, which is housed within the primary shield cavity; a secondary cold head is connected to the secondary shield and is used to cool the secondary shield; the secondary shield has a secondary shield cavity; and a buffer cooling structure is connected to the secondary cold head through the secondary shield and is housed within the secondary shield cavity.

[0008] According to some embodiments of the present invention, the cryogenic molecular beam device further includes a vacuum chamber; the secondary shield is connected to the primary shield, and the primary shield is connected to the vacuum chamber; The refrigeration assembly further includes a first heat-conducting component and a second heat-conducting component; the primary cold head and the secondary cold head are non-rigidly connected to the vacuum cavity; the primary cold head is flexibly connected to the primary shielding cover through the first heat-conducting component; the secondary cold head is flexibly connected to the secondary shielding cover through the second heat-conducting component.

[0009] According to some embodiments of the present invention, the cryogenic molecular beam device further includes a gas pipeline connected to the vacuum cavity, the gas pipeline including a gas inlet, a transport section and a gas outlet; the gas inlet, the transport section and the gas outlet are connected in sequence, the interior of the gas inlet is used to introduce buffer gas and / or molecular beam; the buffer cooling cavity has a buffer cooling inlet end and a buffer cooling outlet end, the gas outlet extends into the buffer cooling cavity from the buffer cooling inlet end; The refrigeration assembly further includes a fourth heat-conducting element, which includes a third heat-conducting part and a fourth heat-conducting part connected together. The first-stage cold head is flexibly connected to the fourth heat-conducting part through the third heat-conducting part, and the fourth heat-conducting part is accommodated in the first-stage shielding cavity. The transport section is accommodated in the first-stage shielding cavity and connected to the fourth heat-conducting part.

[0010] According to some embodiments of the present invention, the cryogenic molecular beam device further includes a gas pipeline, the gas pipeline including a gas outlet extending along the extension direction of the buffer cooling cavity; the buffer cooling cavity has a buffer cooling inlet and a buffer cooling outlet, the gas outlet communicating with the buffer cooling inlet for providing target molecules to the buffer cooling cavity, and the buffer cooling outlet communicating with the secondary shielding cavity; The primary shield has a primary through hole that extends through the primary shield along the extending direction of the buffer cooling cavity; the secondary shield has a secondary through hole that extends through the secondary shield along the extending direction of the buffer cooling cavity. The cryogenic molecular beam device has a projection plane perpendicular to the extension direction of the buffer cooling cavity. The buffer cooling cavity has a first projection, the secondary through hole has a second projection, and the primary through hole has a third projection. The third projection is contained within the second projection, and the second projection is contained within the first projection.

[0011] According to some embodiments of the present invention, the cryogenic molecular beam device further includes a vacuum chamber and a vacuum pump. The vacuum chamber has a vacuum inner cavity, and the cooling component, the primary shield, the secondary shield, and the buffer cooling structure are housed in the vacuum inner cavity. The vacuum pump is internally connected to the vacuum inner cavity and is used to evacuate the vacuum inner cavity.

[0012] According to some embodiments of the present invention, the inner wall surface of the secondary shielding cavity is coated with activated carbon particles; And / or, the cryogenic molecular beam device further includes a secondary extender connected to the inner wall of the secondary shielding cavity, the surface of which is coated with activated carbon particles.

[0013] According to some embodiments of the present invention, the cryogenic molecular beam device further includes a gas pipeline, the gas pipeline including a gas inlet, a transport section and a gas outlet; the gas inlet, the transport section and the gas outlet are connected in sequence, the interior of the gas inlet is used to introduce buffer gas and / or molecular beam; the buffer cooling cavity has a buffer cooling inlet end and a buffer cooling outlet end, the gas outlet extends from the buffer cooling inlet end into the buffer cooling cavity; The refrigeration assembly further includes a third heat-conducting component, which includes a first heat-conducting part and a second heat-conducting part connected to each other; the first heat-conducting part is connected to the first-stage cold head, and the second heat-conducting part is housed in the first-stage shielding cavity; the transport section is housed in the first-stage shielding cavity.

[0014] According to some embodiments of the present invention, the transport section is wound around the second heat-conducting part.

[0015] According to some embodiments of the present invention, the cooling assembly further includes a temperature sensor and a heating element. The temperature sensor is disposed within the buffer cooling cavity, and the heating element is configured to heat the buffer cooling structure when the temperature sensor detects that the temperature of the buffer cooling cavity is lower than a preset temperature.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is an overall schematic diagram of a cryogenic molecular beam apparatus according to some embodiments of the first aspect of the present invention; Figure 2 for Figure 1 A schematic diagram of part of the structure of a medium- and low-temperature molecular beam device; Figure 3 for Figure 2 A diagram from another perspective; Figure 4 This is a schematic diagram of a cryogenic molecular beam apparatus according to a second aspect embodiment of the present invention.

[0018] Figure label: First-stage cold head 110, second-stage cold head 120, first heat-conducting component 130, second heat-conducting component 140, third heat-conducting component 150, first heat-conducting section 151, second heat-conducting section 152, fourth heat-conducting component 160, third heat-conducting section 161, and fourth heat-conducting section 162; Primary shielding cover 200, primary shielding inner cavity 210, primary through hole 220; Buffer cooling structure 300, buffer cooling inner cavity 310, buffer cooling inlet end 311, buffer cooling outlet end 312; Secondary shielding cover 400, secondary shielding inner cavity 410, secondary through hole 420; Vacuum cavity 500, vacuum inner cavity 510; Gas pipeline 600, gas inlet 610, transport section 620, gas outlet 630; Secondary expansion component 700; First connector 800; Second connector 900; 1000 activated carbon granules. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0021] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0022] In the description of this invention, unless otherwise explicitly defined, terms such as "setting," "installing," and "connecting" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0023] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0024] In existing technologies, to achieve molecular beam cooling, some techniques pre-cool the buffer gas using a refrigerator's cold head. The inventors discovered in practice that, limited by the cooling efficiency of existing refrigerators, the molecular beam cooled by the buffer gas reaches a relatively high temperature.

[0025] In view of this, please refer to Figures 1 to 4 As shown, the present invention proposes a cryogenic molecular beam device, including a cooling component, a primary shield 200, and a buffer cooling structure 300.

[0026] The refrigeration assembly of the present invention includes a primary cold head 110 and a secondary cold head 120. Both the primary cold head 110 and the secondary cold head 120 can cool the structure through their connection during operation.

[0027] The primary shield 200 of the present invention has a primary shielding cavity 210, and a secondary cold head 120 is housed within the primary shielding cavity 210. The primary cold head 110 is connected to the primary shield 200 and is used to cool the primary shield 200. By cooling the primary shield 200, the primary cold head 110 can reduce the temperature environment of the primary shielding cavity 210. Since the secondary cold head 120 is housed within the primary shielding cavity 210, the temperature of the secondary cold head 120 can also decrease along with the temperature environment of the primary shielding cavity 210. Furthermore, the primary shield 200 can prevent heat radiation from outside the primary shielding cavity 210 from entering the primary shielding cavity 210, further enabling the secondary cold head 120 to maintain a relatively stable low temperature state.

[0028] The buffer cooling structure 300 of the present invention is connected to the secondary cold head 120 and housed in the primary shielding cavity 210. The buffer cooling structure 300 has a buffer cooling cavity 310, which is used to introduce buffer gas and target molecules. Through the above scheme, since the ambient temperature of the primary shielding cavity 210 has been reduced by the primary cold head 110, the secondary cold head 120 housed in the primary shielding cavity 210 can further cool the buffer cooling structure 300 based on the ambient temperature of the primary shielding cavity 210, making the temperature of the buffer cooling cavity 310 even lower. Consequently, the buffer gas located in the buffer cooling cavity 310 will have a lower temperature, and after the target molecules collide with the lower-temperature buffer gas, the temperature of the molecular beam can also be further reduced.

[0029] Specifically, when a lower target cooling temperature is set, since the secondary cold head 120 of the present invention is housed in the primary shielding cavity 210, the secondary cold head 120 can further cool the buffer cooling structure 300 while the primary shielding cover 100 blocks external heat radiation from entering the primary shielding cavity 210. After cooling by the primary cold head 110, the ambient temperature of the primary shielding cavity 210 is lower than the ambient temperature of the cryogenic molecular beam device. Therefore, the difference between the ambient temperature of the primary shielding cavity 210 and the target cooling temperature is smaller. The secondary cold head 120 requires less power to cool the buffer cooling structure 300 and is less prone to heat leakage. The secondary cold head 120 can cool the buffer gas to a lower temperature, and the molecular beam temperature cooled by the buffer gas is even lower.

[0030] Without departing from the inventive concept of this invention, those skilled in the art can further select the material of the primary shielding layer. As a preferred embodiment, the primary shielding layer is made of 6061 aluminum alloy. 6061 aluminum alloy can better isolate external heat radiation, further reduce the ambient temperature of the first shielding cavity, and is conducive to further reducing the temperature of the buffer gas.

[0031] It should be noted that the present invention does not limit the manner in which target molecules and buffer gas are introduced into the buffer cooling cavity 310. In some embodiments, the primary shield 200 is provided with a primary through hole 220, and the buffer cooling cavity 310 has a first buffer opening, with the primary through hole 220 and the first buffer opening arranged sequentially in a straight line. Through the above scheme, buffer gas and target molecules can enter the buffer cooling cavity 310 through the primary through hole 220.

[0032] As a preferred option, please refer to Figure 1 , Figure 2 , Figure 3 As shown, where Figure 1 , Figure 2 Gas line 600 not shown. Figure 3 It shows Figure 1 , Figure 2 In some embodiments of the cryogenic molecular beam apparatus, which includes a gas conduit 600, the gas conduit 600 further comprises a gas inlet 610, a transport section 620, and a gas outlet 630. The gas inlet 610, transport section 620, and gas outlet 630 are sequentially connected to a buffer cooling cavity 310 having a buffer cooling inlet end 311 and a buffer cooling outlet end 312. The gas outlet 630 extends into the buffer cooling cavity 310 from the buffer cooling inlet end 311. When buffer gas and / or target molecules are introduced into the gas inlet 610, the buffer gas and / or target molecules can enter the buffer cooling cavity 310 via the gas inlet 610, transport section 620, gas outlet 630, and buffer cooling inlet end 311.

[0033] Based on the above embodiments, the cooling assembly further includes a third heat-conducting element 150, which includes a first heat-conducting part 151 and a second heat-conducting part 152 connected to each other. The first heat-conducting part 151 is connected to the first-stage cold head 110, and the second heat-conducting part 152 is housed in the first-stage shielding cavity 210. The transport section 620 is also housed in the first-stage shielding cavity 210. Through the above scheme, the first-stage cold head 110 can absorb the heat from the second heat-conducting part 152 through the first heat-conducting part 151, thereby reducing the temperature of the second heat-conducting part 152. Since the second heat-conducting part 152 is housed in the first-stage shielding cavity 210, it can better maintain a lower temperature. The heat from the transport section 620 can radiate to the second heat-conducting part 152 and then be transferred out through the first heat-conducting part 151, thereby reducing the temperature of the buffer gas and / or target molecules passing through the transport section 620. This is beneficial for accelerating the cooling rate of the buffer gas or target molecules after entering the buffer cooling cavity 310.

[0034] Further, please refer to Figure 3As shown, in some embodiments, the transport segment 620 is wound around the second heat-conducting part 152. The transport segment 620 wound around the second heat-conducting part 152 can further increase the contact area with the second heat-conducting part 152, and can more fully cool the buffer gas and / or target molecules.

[0035] Please refer to Figure 1 , Figure 2 As shown, in some embodiments, the cryogenic molecular beam device further includes a secondary shield 400, which is housed within the primary shield cavity 210. A secondary cold head 120 is connected to the secondary shield 400 and is used to cool the secondary shield 400. The secondary shield 400 has a secondary shield cavity 410. A buffer cooling structure 300 is connected to the secondary cold head 120 through the secondary shield 400 and is housed within the secondary shield cavity 410. Through the above scheme, the buffer cooling structure 300 is indirectly connected to the secondary cold head 120 through the secondary shield 400. The secondary cold head 120 can reduce the temperature of the buffer cooling structure 300 by cooling the secondary shield 400. Since the buffer cooling structure 300 is housed in the secondary shield cavity 410, the secondary shield 400 can further reduce the heat radiation entering the secondary shield cavity 410 from the primary shield cavity 210. The temperature of the buffer cooling structure 300 is lower than that of the secondary shield 400, which is beneficial to lower the temperature of the buffer gas and / or target molecules in the buffer cooling cavity 310 and reduce the temperature of the molecular beam.

[0036] Without departing from the inventive concept of this invention, those skilled in the art can adjust the connection method between the primary shield 200 and the primary cold head 110, and the connection method between the secondary shield 400 and the secondary cold head 120. In some embodiments, the cryogenic molecular beam device further includes a vacuum chamber 500, and both the primary cold head 110 and the secondary cold head 120 are connected to the vacuum chamber 500. The primary shield 200 and the primary cold head 110 are rigidly connected, and the secondary shield 400 and the secondary cold head 120 are rigidly connected.

[0037] As a preferred option, please refer to Figure 1 , Figure 2 , Figure 3 As shown, where Figure 3The image shows a cross-section of the first heat-conducting element 130. In some embodiments, the cryogenic molecular beam device further includes a vacuum chamber 500; a secondary shield 400 is connected to a primary shield 200, and the primary shield 200 is connected to the vacuum chamber 500. The cooling assembly also includes a first heat-conducting element 130 and a second heat-conducting element 140; a primary cold head 110 and a secondary cold head 120 are elastically connected to the vacuum chamber 500; the primary cold head 110 is flexibly connected to the primary shield 200 via the first heat-conducting element 130; and the secondary cold head 120 is flexibly connected to the secondary shield 400 via the second heat-conducting element 140.

[0038] Through the above scheme, both the secondary shield 400 and the primary shield 200 can be fixed to the vacuum cavity 500. Since the primary cold head 110 and the secondary cold head 120 are elastically connected to the vacuum cavity 500, and the primary cold head 110 is flexibly connected to the primary shield 200 via the first heat-conducting element 130, and the secondary cold head 120 is flexibly connected to the secondary shield 400 via the second heat-conducting element 140, the elastic connection between the primary cold head 110 and the vacuum cavity 500, and the flexible connection between the primary cold head 110 and the primary shield 200 via the first heat-conducting element 130, can jointly reduce the vibration directly transferred from the primary cold head 110 to the primary shield 200. The heat from the primary shield 200 can be transferred through the first heat-conducting element 130. The heat transfer from the heat transfer element 130 to the primary cold head 110, the elastic connection between the secondary cold head 120 and the vacuum cavity 500, and the flexible connection between the secondary cold head 120 and the secondary shield 400 via the second heat-conducting element 140, can jointly reduce the vibration directly transferred from the secondary cold head 120 to the secondary shield 400. The heat from the secondary shield 400 can be transferred to the secondary cold head 120 via the second heat-conducting element 140. The above solution can reduce the vibration of the shield while achieving the cooling of the cold head shield, thereby reducing the vibration of the buffer cooling structure 300, reducing the collision of the buffer cooling structure 300 with the target molecules and buffer gas, and improving the stability of the target molecules and buffer gas located in the buffer cooling cavity 310.

[0039] In some embodiments, please refer to Figure 1 , Figure 2 As shown, the primary shield 200 is connected to the vacuum chamber 500 via multiple first connectors 800, and the secondary shield 400 is connected to the primary shield 200 via multiple second connectors 900. As a preferred embodiment, both the first connectors 800 and the second connectors 900 are made of 316 stainless steel. 316 stainless steel has low thermal conductivity, which helps reduce heat transfer from the vacuum chamber 500 to the primary shield 200 and the secondary shield 400, thereby improving the stability of the target molecules and buffer gas located in the buffer cooling cavity 310.

[0040] The embodiments for introducing buffer gas and / or target molecules through gas pipeline 600 have been described above. Please refer to the following for further details. Figure 4 As shown, where Figure 4 The vacuum chamber 500 is not shown. In some embodiments, the cryogenic molecular beam device further includes a gas conduit 600 connected to the vacuum chamber 500, comprising a gas inlet 610, a transport section 620, and a gas outlet 630. The gas inlet 610, transport section 620, and gas outlet 630 are connected sequentially. The interior of the gas inlet 610 is used to introduce buffer gas and / or target molecules. The buffer cooling cavity 310 has a buffer cooling inlet end 311 and a buffer cooling outlet end 312. The gas outlet 630 extends into the buffer cooling cavity 310 from the buffer cooling inlet end 311. The gas conduit 600 is fixed by its connection to the vacuum chamber 500, thereby maintaining its stability. When buffer gas and / or target molecules are introduced into the interior of the gas inlet 610, the buffer gas and / or target molecules can enter the buffer cooling cavity 310 via the gas inlet 610, transport section 620, gas outlet 630, and buffer cooling inlet end 311.

[0041] Based on the above embodiments, the refrigeration assembly further includes a fourth heat-conducting element 160, which includes a third heat-conducting part 161 and a fourth heat-conducting part 162 connected to each other; the first-stage cold head 110 is flexibly connected to the fourth heat-conducting part 162 through the third heat-conducting part 161, and the fourth heat-conducting part 162 is accommodated in the first-stage shielding cavity 210; the transport section 620 is accommodated in the first-stage shielding cavity 210 and connected to the fourth heat-conducting part 162. Through the above scheme, the first-stage cold head 110 can absorb the heat of the fourth heat-conducting part 162 through the third heat-conducting part 161, thereby reducing the temperature of the second heat-conducting part 152. Since the fourth heat-conducting part 162 is housed in the first-stage shielding cavity 210, the fourth heat-conducting part 162 can better maintain a lower temperature. The transport section 620 connected to the fourth heat-conducting part 162 can transfer heat out through the fourth heat-conducting part 162 and the third heat-conducting part 161 in sequence, thereby reducing the temperature of the buffer gas and / or target molecules in the transport section 620. This is beneficial to accelerate the cooling rate of the buffer gas and / or target molecules when entering the buffer cooling cavity 310, and accelerate the manufacturing efficiency of the molecular beam.

[0042] On the other hand, since the first-stage cold head 110 is flexibly connected to the fourth heat-conducting part 162 through the third heat-conducting part 161, the elastic connection between the first-stage cold head 110 and the vacuum chamber 500, as well as the flexible connection between the first-stage cold head 110 and the fourth heat-conducting part 162 through the third heat-conducting part 161, can jointly reduce the vibration directly transmitted from the first-stage cold head 110 to the gas pipeline 600, reduce the collision of the gas pipeline 600 with the internal target molecules and buffer gas, and improve the stability of the target molecules and buffer gas inside the gas pipeline 600.

[0043] Without departing from the inventive concept of this invention, those skilled in the art can adjust the method for forming molecular beams using the cryogenic molecular beam apparatus of this invention. Please refer to... Figure 3 As shown, in some embodiments, the cryogenic molecular beam apparatus further includes a gas conduit 600 and an outlet pipe. The gas conduit 600 includes a gas outlet 630 extending along the extension direction of the buffer cooling cavity 310. The buffer cooling cavity 310 has a buffer cooling inlet end 311 and a buffer cooling outlet end 312. The gas outlet 630 is connected to the buffer cooling inlet end 311 for providing target molecules to the buffer cooling cavity 310. The buffer cooling outlet end 312 is connected to the secondary shielding cavity 410. The cryogenic molecular beam apparatus also includes an outlet pipe connected to the buffer cooling outlet end 312 of the buffer cooling cavity 310. With the above scheme, after the target molecules are introduced into the buffer cooling cavity 310 through the gas outlet 630, the target molecules can flow from the buffer cooling outlet end 312 into the outlet pipe and be rectified into a molecular beam through the outlet pipe for subsequent processing.

[0044] As a preferred option, please refer to Figure 3 As shown, the cryogenic molecular beam apparatus also includes a gas conduit 600, which includes a gas outlet 630 extending along the extension direction of the buffer cooling cavity 310. The buffer cooling cavity 310 has a buffer cooling inlet 311 and a buffer cooling outlet 312. The gas outlet 630 is connected to the buffer cooling inlet 311 and is used to provide target molecules to the buffer cooling cavity 310. The buffer cooling outlet 312 is connected to the secondary shielding cavity 410. After the target molecules are introduced into the buffer cooling cavity 310 through the gas outlet 630, the target molecules can flow into the secondary shielding cavity 410 from the buffer cooling outlet 312.

[0045] In the above embodiments, the primary shield 200 also has a primary through hole 220, which penetrates the primary shield 200 along the extending direction of the buffer cooling cavity 310; the secondary shield 400 has a secondary through hole 420, which penetrates the secondary shield 400 along the extending direction of the buffer cooling cavity 310. The cryogenic molecular beam device has a projection plane perpendicular to the extending direction of the buffer cooling cavity 310. The buffer cooling cavity 310 has a first projection, the secondary through hole 420 has a second projection, and the primary through hole 220 has a third projection. The third projection is accommodated within the second projection, and the second projection is accommodated within the first projection.

[0046] Through the above scheme, after the target molecules from the gas outlet 630 enter the buffer cooling cavity 310, they will diffuse within the buffer cooling cavity 310. Since the third projection is contained within the second projection, and the second projection is contained within the first projection, some target molecules moving along the extension direction of the buffer cooling cavity 310 can sequentially pass through the secondary through-hole 420 and the primary through-hole 220 in the same direction, forming a molecular beam. The above scheme utilizes the structure of the primary shield 200 and the secondary shield 400 to screen the target molecules inside the buffer cooling cavity 310 to form a molecular beam, further reducing the overall space occupied by the cryogenic molecular beam device and improving the spatial integration of the cryogenic molecular beam device.

[0047] Existing cryogenic molecular beam devices require a vacuum pump to create a vacuum environment. Those skilled in the art can choose their own method for creating a vacuum environment within the cryogenic molecular beam device of this invention.

[0048] Further, please refer to Figure 1 As shown, in some embodiments, the cryogenic molecular beam device further includes a vacuum chamber 500 and a vacuum pump (not shown). The vacuum chamber 500 has a vacuum inner cavity 510, in which a cooling assembly, a primary shield 200, a secondary shield 400, and a buffer cooling structure 300 are housed. The vacuum pump is internally connected to the vacuum inner cavity 510 and is used to evacuate the vacuum inner cavity 510. With this design, since the buffer cooling outlet 312 of the buffer cooling inner cavity 310 is connected to the secondary shield inner cavity 410, the secondary shield inner cavity 410 is connected to the primary shield inner cavity 210 through a secondary through-hole 420, and the primary shield inner cavity 210 is connected to the vacuum inner cavity 510 through a primary through-hole 220, the vacuum pump can further increase the vacuum level of the primary shield inner cavity 210, the secondary shield inner cavity 410, and the buffer cooling inner cavity 310 by evacuating the vacuum inner cavity 510, thereby creating a vacuum environment. The above solution uses a single vacuum pump to create a vacuum environment for the cryogenic molecular beam apparatus, effectively saving the number of vacuum pumps, further reducing the overall space occupied by the cryogenic molecular beam apparatus, and improving the spatial integration of the cryogenic molecular beam apparatus.

[0049] Based on the above plan, please refer to Figure 1 , Figure 2 As shown, in some embodiments, the inner wall surface of the secondary shield 400 is coated with activated carbon particles 1000. The activated carbon particles 1000 coated on the inner surface of the secondary shield cavity 410 can further absorb gas molecules participating inside the secondary shield cavity 410, thereby improving the vacuum level of the secondary shield cavity 410, as well as the vacuum level of the buffer cooling cavity 310, the primary shield cavity 210, and the vacuum cavity 510 connected to the secondary shield cavity 410.

[0050] In some embodiments, the cryogenic molecular beam apparatus further includes a secondary extender 700, which is connected to the inner wall of the secondary shielding cavity 410. The surface of the secondary extender 700 is coated with activated carbon particles 1000. The activated carbon particles 1000 coated on the surface of the secondary extender 700 can further absorb gas molecules participating inside the secondary shielding cavity 410, thereby increasing the vacuum level of the secondary shielding cavity 410, as well as the vacuum level of the buffer cooling cavity 310, the primary shielding cavity 210, and the vacuum cavity 510 connected to the secondary shielding cavity 410.

[0051] Furthermore, in some embodiments, the cooling assembly further includes a temperature sensor and a heating element. The temperature sensor is disposed outside the buffer cooling cavity 310, and the heating element is configured to heat the buffer cooling structure 300 when the temperature sensor detects that the temperature of the buffer cooling cavity 310 is lower than a preset temperature. Through this scheme, the heating element can heat the buffer cooling structure 300 based on the data monitored by the temperature sensor, reducing the difference between the ambient temperature of the buffer cooling cavity 310 and the preset temperature, thus facilitating precise control of the cooling effect of the buffer gas.

[0052] It should be noted that the cryogenic molecular beam device of the present invention can further cool the buffer gas. Therefore, by adjusting the temperature of the buffer cooling structure 300 through the heating element, the temperature control range of the buffer gas can be further expanded, making it easier for researchers to set up multiple sets of experiments using the cryogenic molecular beam device of the present invention.

[0053] To facilitate understanding by those skilled in the art, some preferred embodiments of the present invention and their corresponding beneficial effects are further described below.

[0054] Please refer to Figures 1 to 4 As shown, the cryogenic molecular beam device includes a cooling component, a primary shield 200, a secondary shield 400, a buffer cooling structure 300, a vacuum chamber 500, a gas pipeline 600, a secondary extension component 700, a first connector 800, a second connector 900, and activated carbon particles 1000.

[0055] The cooling assembly includes a primary cold head 110 and a secondary cold head 120. The primary cold head 110 is connected to and used to cool the primary shield 200. The primary shield 200 has a primary shielding cavity 210, within which both the secondary cold head 120 and the secondary shield 400 are housed. The secondary cold head 120 is connected to and used to cool the secondary shield 400. The secondary shield 400 has a secondary shielding cavity 410. A buffer cooling structure 300 is connected to the secondary cold head 120 via the secondary shield 400 and is housed within the secondary shielding cavity 410. The buffer cooling structure 300 has a buffer cooling cavity 310, which is used to introduce buffer gas and target molecules.

[0056] The secondary shield 400 is connected to the primary shield 200 via multiple second connectors 900, and the primary shield 200 is connected to the vacuum chamber 500 via multiple first connectors 800. The cooling assembly also includes a first heat-conducting element 130 and a second heat-conducting element 140; the primary cold head 110 and the secondary cold head 120 are elastically connected to the vacuum chamber 500; the primary cold head 110 is flexibly connected to the primary shield 200 via the first heat-conducting element 130; and the secondary cold head 120 is flexibly connected to the secondary shield 400 via the second heat-conducting element 140.

[0057] The gas pipeline 600 includes a gas inlet 610, a transport section 620, and a gas outlet 630. The gas inlet 610, the transport section 620, and the gas outlet 630 are sequentially connected to a buffer cooling cavity 310, which has a buffer cooling inlet end 311 and a buffer cooling outlet end 312. The gas outlet 630 extends into the buffer cooling cavity 310 from the buffer cooling inlet end 311. The refrigeration assembly also includes a third heat-conducting element 150, which includes a first heat-conducting part 151 and a second heat-conducting part 152 connected to each other. The first heat-conducting part 151 is connected to the first-stage cold head 110, and the second heat-conducting part 152 is accommodated in the first-stage shielding cavity 210. The transport section 620 is accommodated in the first-stage shielding cavity 210.

[0058] The gas outlet 630 extends along the extension direction of the buffer cooling cavity 310. The buffer cooling cavity 310 has a buffer cooling inlet end 311 and a buffer cooling outlet end 312. The gas outlet 630 communicates with the buffer cooling inlet end 311 to provide target molecules to the buffer cooling cavity 310, and the buffer cooling outlet end 312 communicates with the secondary shielding cavity 410. The primary shield 200 also has a primary through hole 220, which penetrates the primary shield 200 along the extension direction of the buffer cooling cavity 310. The secondary shield 400 has a secondary through hole 420, which penetrates the secondary shield 400 along the extension direction of the buffer cooling cavity 310. The cryogenic molecular beam device has a projection plane perpendicular to the extension direction of the buffer cooling cavity 310. The buffer cooling cavity 310 has a first projection, the secondary through hole 420 has a second projection, and the primary through hole 220 has a third projection. The third projection is accommodated within the second projection, and the second projection is accommodated within the first projection.

[0059] The secondary expansion component 700 is connected to the inner wall of the secondary shield cavity 410. The surface of the secondary expansion component 700 and the inner wall of the secondary shield 400 are coated with activated carbon particles 1000.

[0060] The cooling assembly also includes a temperature sensor and a heating element. The temperature sensor is located outside the buffer cooling cavity 310, and the heating element is configured to heat the buffer cooling structure 300 when the temperature sensor detects that the temperature of the buffer cooling cavity 310 is lower than a preset temperature.

[0061] The cryogenic molecular beam apparatus of the above embodiments has the following effects: First, the primary shield 200 can block external heat radiation, allowing the primary shield cavity 210 to be cooled by the primary cold head 110. This, in turn, allows the secondary cold head 120 to further cool the secondary shield 400. The secondary cold head 120 can reduce the temperature of the buffer cooling structure 300 by cooling the secondary shield 400. Since the buffer cooling structure 300 is housed in the secondary shield cavity 410, the secondary shield 400 can further reduce the heat radiation entering the secondary shield cavity 410 from the primary shield cavity 210. The temperature of the buffer cooling structure 300 is lower than that of the secondary shield 400, which helps to lower the temperature of the buffer gas and / or target molecules in the buffer cooling cavity 310, thereby reducing the temperature of the molecular beam.

[0062] Second, the primary cold head 110 is flexibly connected to the primary shield 200 via the first heat-conducting element 130, and the secondary cold head 120 is flexibly connected to the secondary shield 400 via the second heat-conducting element 140. The elastic connection between the primary cold head 110 and the vacuum chamber 500, and the flexible connection between the primary cold head 110 and the primary shield 200 via the first heat-conducting element 130, can jointly reduce the vibration directly transmitted from the primary cold head 110 to the primary shield 200. Heat from the primary shield 200 can be conducted to the primary cold head 110 via the first heat-conducting element 130. Similarly, the elastic connection between the secondary cold head 120 and the vacuum chamber 500, and the flexible connection between the secondary cold head 120 and the secondary shield 400 via the second heat-conducting element 140, can jointly reduce the vibration directly transmitted from the secondary cold head 120 to the secondary shield 400. Heat from the secondary shield 400 can be conducted to the secondary cold head 120 via the second heat-conducting element 140. The above solution can reduce the vibration of the shield while achieving the cooling shield of the cold head, thereby reducing the vibration of the buffer cooling structure 300, reducing the collision of the buffer cooling structure 300 with the target molecules and buffer gas, and improving the stability of the target molecules and buffer gas located in the buffer cooling cavity 310.

[0063] Third, when buffer gas and / or target molecules are introduced into the gas inlet 610, the buffer gas and / or target molecules can enter the buffer cooling inner cavity 310 through the gas inlet 610, the transport section 620, the gas outlet 630, and the buffer cooling inlet end 311. The heat from the transport section 620 can radiate to the second heat-conducting part 152, and then transfer the heat out through the first heat-conducting part 151, thereby reducing the temperature of the buffer gas and / or target molecules passing through the transport section 620, which helps to accelerate the cooling rate of the buffer gas or target molecules after entering the buffer cooling inner cavity 310.

[0064] Fourth, by utilizing the structure of the primary shield 200 and the secondary shield 400, the target molecules inside the buffer cooling cavity 310 are screened to form a molecular beam, which further reduces the overall space occupied by the cryogenic molecular beam device and improves the spatial integration of the cryogenic molecular beam device.

[0065] Fifth, the activated carbon particles 1000 coated on the surface can further absorb the gas molecules inside the secondary shielding cavity 410, thereby improving the vacuum level of the secondary shielding cavity 410, as well as the vacuum level of the buffer cooling cavity 310, the primary shielding cavity 210 and the vacuum cavity 510 connected to the secondary shielding cavity 410.

[0066] Sixth, the heating element can heat the buffer cooling structure 300 based on the data monitored by the temperature sensor, reducing the difference between the ambient temperature of the buffer cooling cavity 310 and the preset temperature, and facilitating precise control of the cooling effect of the buffer gas.

[0067] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A cryogenic molecular beam device, characterized in that, include: Refrigeration components, including primary and secondary cold heads; A primary shielding cover has a primary shielding cavity; a primary cold head is connected to the primary shielding cover and is used to cool the primary shielding cover; a secondary cold head is housed within the primary shielding cavity; A buffer cooling structure is connected to the secondary cold head and housed within the primary shielding cavity; the buffer cooling structure has a buffer cooling cavity for introducing buffer gas and target molecules.

2. The cryogenic molecular beam device according to claim 1, characterized in that, The cryogenic molecular beam device further includes a secondary shield, which is housed within the primary shield cavity. The secondary cold head is connected to the secondary shield and is used to cool the secondary shield. The secondary shielding cover has a secondary shielding cavity; The buffer cooling structure is connected to the secondary cold head through the secondary shield and is housed within the secondary shield cavity.

3. The cryogenic molecular beam device according to claim 2, characterized in that, The cryogenic molecular beam device further includes a vacuum chamber; the secondary shield is connected to the primary shield, and the primary shield is connected to the vacuum chamber; The refrigeration assembly further includes a first heat-conducting component and a second heat-conducting component; the primary cold head and the secondary cold head are elastically connected to the vacuum cavity; the primary cold head is flexibly connected to the primary shielding cover through the first heat-conducting component; the secondary cold head is flexibly connected to the secondary shielding cover through the second heat-conducting component.

4. The cryogenic molecular beam device according to claim 3, characterized in that, The cryogenic molecular beam device further includes a gas pipeline connected to the vacuum chamber, comprising a gas inlet, a transport section, and a gas outlet; the gas inlet, the transport section, and the gas outlet are connected in sequence, and the interior of the gas inlet is used to introduce buffer gas and / or molecular beams; the buffer cooling cavity has a buffer cooling inlet end and a buffer cooling outlet end, and the gas outlet extends into the buffer cooling cavity from the buffer cooling inlet end; The refrigeration assembly further includes a fourth heat-conducting element, which includes a third heat-conducting part and a fourth heat-conducting part connected together. The first-stage cold head is flexibly connected to the fourth heat-conducting part through the third heat-conducting part, and the fourth heat-conducting part is accommodated in the first-stage shielding cavity. The transport section is accommodated in the first-stage shielding cavity and connected to the fourth heat-conducting part.

5. The cryogenic molecular beam device according to claim 2, characterized in that, The cryogenic molecular beam device further includes a gas pipeline, which includes a gas outlet extending along the extension direction of the buffer cooling cavity. The buffer cooling cavity has a buffer cooling inlet and a buffer cooling outlet. The gas outlet is connected to the buffer cooling inlet and is used to provide target molecules to the buffer cooling cavity. The buffer cooling outlet is connected to the secondary shielding cavity. The primary shield has a primary through hole that extends through the primary shield along the extending direction of the buffer cooling cavity; the secondary shield has a secondary through hole that extends through the secondary shield along the extending direction of the buffer cooling cavity. The cryogenic molecular beam device has a projection plane perpendicular to the extension direction of the buffer cooling cavity. The buffer cooling cavity has a first projection, the secondary through hole has a second projection, and the primary through hole has a third projection. The third projection is contained within the second projection, and the second projection is contained within the first projection.

6. The cryogenic molecular beam device according to claim 5, characterized in that, The cryogenic molecular beam device further includes a vacuum chamber and a vacuum pump. The vacuum chamber has a vacuum inner cavity, in which the cooling components, the primary shield, the secondary shield, and the buffer cooling structure are housed. The vacuum pump is internally connected to the vacuum inner cavity and is used to evacuate the vacuum inner cavity.

7. The cryogenic molecular beam apparatus according to claim 6, characterized in that, The inner wall of the secondary shield is coated with activated carbon particles; And / or, the cryogenic molecular beam device further includes a secondary extender connected to the inner wall of the secondary shield, the surface of which is coated with activated carbon particles.

8. The cryogenic molecular beam device according to claim 1, characterized in that, The cryogenic molecular beam device further includes a gas pipeline, which includes a gas inlet, a transport section, and a gas outlet; the gas inlet, the transport section, and the gas outlet are connected in sequence, and the interior of the gas inlet is used to introduce buffer gas and / or molecular beams; the buffer cooling cavity has a buffer cooling inlet end and a buffer cooling outlet end, and the gas outlet extends into the buffer cooling cavity from the buffer cooling inlet end; The refrigeration assembly further includes a third heat-conducting component, which includes a first heat-conducting part and a second heat-conducting part connected to each other; the first heat-conducting part is connected to the first-stage cold head, and the second heat-conducting part is housed in the first-stage shielding cavity; the transport section is housed in the first-stage shielding cavity.

9. The cryogenic molecular beam device according to claim 8, characterized in that, The transport section is wound around the second heat-conducting part.

10. The cryogenic molecular beam apparatus according to claim 1, characterized in that, The cooling assembly also includes a temperature sensor and a heating element. The temperature sensor is disposed outside the buffer cooling structure, and the heating element is configured to heat the buffer cooling structure when the temperature sensor detects that the temperature of the buffer cooling cavity is lower than a preset temperature.

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