A system and method for obtaining ultra-high vacuum

Abstract

This invention relates to the field of particle accelerators, and more particularly to an ultra-high vacuum acquisition system and method. The vacuum acquisition system includes a vacuum acquisition device and a vacuum temperature control device. The vacuum acquisition device includes a ceramic vacuum chamber, a sandwiched vacuum chamber, a main pump chamber, a first vacuum pumping assembly, and a second vacuum pumping assembly. The main vacuum chamber is formed inside the ceramic vacuum chamber, which is located inside the sandwiched vacuum chamber, forming a sandwich space between them. By placing the ceramic vacuum chamber inside the sandwiched vacuum chamber, and forming a sandwich space between them, heating the sandwiched vacuum chamber with heating elements achieves uniform heating through non-contact thermal radiation. This ensures uniform heating of the ceramic vacuum chamber, completely eliminating the thermal stress concentration problem caused by direct conduction heating of the ceramic vacuum chamber, preventing leakage or cracking of the ceramic-metal joint due to thermal stress, and ensuring the structural integrity of the dissimilar material connection area.

Description

Technical Field

[0001] This invention relates to the field of particle accelerators, and more particularly to an ultra-high vacuum acquisition system and method. Background Technology

[0002] In high-energy particle accelerator systems, an ultra-high vacuum environment must be maintained inside the vacuum pipes to ensure stable beam operation and extend their lifespan. To achieve this ultra-high vacuum, a high-temperature baking process is necessary to thoroughly remove physically and chemically adsorbed gas molecules, especially water vapor, from the inner walls of the pipes. Ceramic vacuum chambers, as a key component of accelerator vacuum systems, are widely used in the internal vacuum channels of magnetic components such as dipole magnets, quadrupole magnets, BUMP magnets, and scanning magnets due to their excellent insulation and complete absence of eddy current effects. They serve the dual functions of precise beam control and vacuum maintenance. However, the significant difference in thermal expansion coefficients between the ceramic and metal brazed parts makes them prone to leakage, cracking, or even rupture during traditional baking processes due to uneven heating. This severely restricts the safe application of ceramic vacuum chambers in ultra-high vacuum environments.

[0003] Currently, ceramic vacuum chambers are generally heated by directly wrapping heating tape around the outer wall or by adding an external baking jacket. While these methods are suitable for metal pipes such as stainless steel and oxygen-free copper, they pose serious safety hazards when used in vacuum chambers with ceramic-metal composite structures. Existing technologies lack uniform heating and temperature control methods for heat-sensitive structures in ceramic vacuum chambers, making it difficult to avoid thermal stress damage during baking and thus unable to safely and reliably achieve ultimate vacuum.

[0004] As a crucial component of vacuum systems, ceramic vacuum tubing also undergoes rigorous baking processes to reduce surface gas escape rates and enhance vacuum levels. However, due to the unique manufacturing process, ceramic vacuum chambers require vacuum brazing at both ends to connect with dissimilar materials such as Kovar alloy and stainless steel flanges. The significant differences in thermal expansion coefficients between ceramics, Kovar, and stainless steel, coupled with the presence of multiple dissimilar weld seams, make it difficult to achieve a uniform temperature distribution using traditional heating methods. This can easily lead to serious malfunctions such as ceramic cracking and leaks in the brazed areas due to localized overheating. This not only poses significant safety hazards but also limits the reliable application of ceramic vacuum chambers in extremely high vacuum environments, failing to meet the stringent ultimate vacuum requirements of next-generation accelerator devices. Summary of the Invention

[0005] This invention provides an ultra-high vacuum acquisition system to solve the problems of existing technologies, which have difficulty in achieving a uniform temperature field distribution and are prone to serious failures such as ceramic cracking and leakage in the brazing area due to local overheating.

[0006] This invention provides an ultra-high vacuum acquisition system, comprising:

[0007] A vacuum acquisition device includes a ceramic vacuum chamber, a sandwiched vacuum chamber, a main pump chamber, a first vacuum pumping assembly, and a second vacuum pumping assembly. The main vacuum chamber is formed inside the ceramic vacuum chamber, which is located inside the sandwiched vacuum chamber. A sandwiched space is formed between the ceramic vacuum chamber and the sandwiched vacuum chamber, and the sandwiched vacuum chamber is fixedly connected to the main pump chamber. The first vacuum pumping assembly communicates with the sandwiched space and is used to evacuate the sandwiched space. The second vacuum pumping assembly and the main vacuum chamber are both communicated with the interior of the main pump chamber. The second vacuum pumping assembly is used to evacuate both the ceramic vacuum chamber and the main pump chamber.

[0008] A vacuum temperature control device includes a heating element for heating the jacketed vacuum chamber, the main pump chamber, and the second vacuum pumping assembly, so as to make the ceramic vacuum chamber uniformly heated by the thermal radiation of the jacketed vacuum chamber.

[0009] According to the ultra-high vacuum acquisition system provided by the present invention, the vacuum temperature control device further includes:

[0010] The control unit is electrically connected to the heating element and the temperature measuring element. The temperature measuring element is disposed on the outer surface of the ceramic vacuum chamber and is used to detect the temperature of the ceramic vacuum chamber and send the detected temperature value to the control unit. The control unit is used to compare the temperature value with a preset value and adjust the output power of the heating element according to the comparison result.

[0011] According to the present invention, an ultra-high vacuum acquisition system is provided, wherein a first interface is provided on the top of the main pump chamber, and the ceramic vacuum chamber is connected to the first interface through a flange.

[0012] According to the present invention, an ultra-high vacuum acquisition system is provided, wherein the second vacuum pumping component includes a titanium sublimation pump, a sputtering ion pump, a valve, and a molecular pump. A second interface is provided at the bottom of the main pump chamber, and the sputtering ion pump is connected to the second interface via a flange. A third interface is provided at the front of the main pump chamber, and a first interface of the valve is connected to the third interface via a flange. The inlet of the molecular pump is connected to the second interface of the valve. A fourth interface is provided at the rear of the main pump chamber, and the titanium sublimation pump is connected to the fourth interface via a flange.

[0013] According to the ultra-high vacuum acquisition system provided by the present invention, the second vacuum pumping component further includes a first mechanical pump, the inlet of which is connected to the outlet of the molecular pump through a first connecting pipe.

[0014] According to the present invention, an ultra-high vacuum acquisition system is provided, wherein a first blind flange is provided on the left side of the main pump chamber.

[0015] The ultra-high vacuum acquisition system provided by the present invention further includes:

[0016] The vacuum gauge is provided with a first adapter flange on the right side of the main pump chamber, and the vacuum gauge communicates with the interior of the main pump chamber through the first adapter flange.

[0017] According to the present invention, an ultra-high vacuum acquisition system is provided, wherein the first vacuum pumping component includes:

[0018] The second mechanical pump is provided with a top flange at the top of the interlayer vacuum chamber, which communicates with the interlayer space. The inlet of the second mechanical pump is connected to the top flange through a second connecting pipe.

[0019] According to the present invention, an ultra-high vacuum acquisition system is provided, wherein an electrode flange is provided on the top of the sandwich vacuum chamber, and the electrode flange is used to connect the temperature measuring element and the control unit.

[0020] The present invention also provides a method for obtaining ultra-high vacuum, the method being based on the ultra-high vacuum acquisition system described in any of the preceding claims, comprising:

[0021] Install the ceramic vacuum chamber inside the jacketed vacuum chamber, connect the second vacuum pumping assembly to the main pump chamber, and ensure that all interfaces are leak-free after helium mass spectrometry testing, with a leak rate <5×10⁻⁶. -10 mbarl / s; meanwhile, the temperature measuring element is placed on the outer surface of the ceramic vacuum chamber and connected to the control unit through an electrode flange; the heating element is placed outside the jacketed vacuum chamber, the main pump chamber and the second vacuum assembly;

[0022] The molecular pump and the first mechanical pump were started to initially evacuate the main vacuum chamber to 10. -6 -10 -8 mbar, and simultaneously start the second mechanical pump to evacuate the jacketed vacuum chamber to 10 mbar. -1 -10 -3 mbar;

[0023] The heating element heats the interlayer vacuum chamber, and the thermal radiation from the interlayer vacuum chamber ensures uniform heating of the ceramic vacuum chamber. The ceramic vacuum chamber is slowly heated to 160℃-300℃ at a rate of 0.5℃ / min and held at that temperature for 40-60 hours. The surface temperature distribution of the ceramic vacuum chamber is monitored by the temperature value detected by the temperature sensing element to ensure that the temperature uniformity deviation does not exceed ±2°C.

[0024] During the heat preservation process, a vacuum gauge and a titanium sublimation pump are used for circulating degassing, with a degassing cycle of 1-4 hours.

[0025] After the heat preservation stage, the temperature is reduced at a rate of 0.5℃ / min. When the temperature drops to 180℃, the gas is evacuated by a titanium sublimation pump, while the valve, molecular pump and first mechanical pump are closed, and the temperature is reduced to room temperature.

[0026] The ultra-high vacuum acquisition system provided by this invention, by placing a ceramic vacuum chamber inside a sandwiched vacuum chamber, forming a sandwich space between the ceramic vacuum chamber and the sandwiched vacuum chamber, and heating the sandwiched vacuum chamber through heating elements, achieves non-contact thermal radiation uniform heating, ensuring uniform heating of the ceramic vacuum chamber. This completely eliminates the problem of thermal stress concentration caused by direct conduction heating of the ceramic vacuum chamber, avoids leakage or cracking of ceramic-metal joints due to thermal stress, and ensures the structural integrity of the heterogeneous material connection area. By employing multi-zone independent temperature control and high-precision sensing technology, the uniformity of the surface temperature of the ceramic vacuum chamber during heating and cooling is controlled within ±2℃, significantly improving process reliability and repeatability. The combination of a titanium sublimation pump and a sputtering ion pump is used for efficient pumping of different gas types, especially H2, which has an extremely high pumping speed, achieving 10 -12 Extremely high vacuum at the mbar level; the metal-clad vacuum chamber can withstand baking at 300℃, has strong system compatibility, and is easy to integrate into accelerator vacuum systems; it also has online monitoring and automatic protection functions, reducing the risk of human intervention. This technology completely avoids electrical safety hazards that may be caused by heating belt aging and insulation damage, significantly improving the reliability and service life of the ceramic vacuum chamber. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a three-dimensional structural diagram of the ultra-high vacuum acquisition system provided by the present invention.

[0029] Figure 2 This is a side view cross-sectional structural diagram of the ultra-high vacuum acquisition system provided by the present invention.

[0030] Figure 3 This is a top view of the ultra-high vacuum acquisition system provided by the present invention.

[0031] Figure label:

[0032] 1. Main pump chamber; 2. Titanium sublimation pump; 3. Jacketed vacuum chamber; 4. Second connecting pipe; 5. Electrode flange; 6. First transition flange; 7. Valve; 8. Vacuum gauge; 9. Molecular pump; 10. First connecting pipe; 11. First mechanical pump; 12. Second mechanical pump; 13. Sputter ion pump; 14. First blind flange; 15. Ceramic vacuum chamber; 16. Second blind flange. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0034] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present 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 limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0036] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0037] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "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 present 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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0038] like Figures 1 to 3 As shown, the ultra-high vacuum acquisition system includes a vacuum acquisition device and a vacuum temperature control device. The vacuum acquisition device includes a ceramic vacuum chamber 15, a sandwiched vacuum chamber 3, a main pump chamber 1, a first vacuum pumping assembly, and a second vacuum pumping assembly. The main vacuum chamber is formed inside the ceramic vacuum chamber 15, which is located inside the sandwiched vacuum chamber 3, forming a sandwich space. The sandwiched vacuum chamber 3 is fixedly connected to the main pump chamber 1. The first vacuum pumping assembly communicates with the sandwiched space and is used to evacuate the sandwiched space. The second vacuum pumping assembly and the main vacuum chamber are both communicated with the interior of the main pump chamber 1. The second vacuum pumping assembly is used to evacuate both the ceramic vacuum chamber 15 and the main pump chamber 1. The vacuum temperature control device includes a heating element, which is used to heat the sandwiched vacuum chamber 3, the main pump chamber 1, and the second vacuum pumping assembly, so that the ceramic vacuum chamber 15 is heated uniformly through the thermal radiation of the sandwiched vacuum chamber 3. Preferably, the heating element is a baking jacket with built-in heating wires for heating.

[0039] The ultra-high vacuum acquisition system provided by this invention, by placing a ceramic vacuum chamber 15 inside a sandwiched vacuum chamber 3, forming a sandwich space between the ceramic vacuum chamber 15 and the sandwiched vacuum chamber 3, and heating the sandwiched vacuum chamber 3 through heating elements, achieves uniform heating of the ceramic vacuum chamber 15 through non-contact thermal radiation, completely eliminating the problem of thermal stress concentration caused by direct conduction heating of the ceramic vacuum chamber 15, avoiding leakage or cracking of the ceramic-metal joint due to thermal stress, and ensuring the structural integrity of the heterogeneous material connection area; by adopting multi-zone independent temperature control and high-precision sensing technology, the uniformity of the surface temperature of the ceramic vacuum chamber 15 during heating and cooling is controlled within ±2℃, significantly improving process reliability and repeatability; the combination of a titanium sublimation pump 2 and a sputtering ion pump 13 is used for efficient pumping of different gas types, especially H2, which has an extremely high pumping speed, achieving 10 -12The ultra-high vacuum level is in the mbar range; the metal-clad vacuum chamber can withstand high-temperature baking at 300℃, has strong system compatibility, and is easy to integrate into accelerator vacuum systems; it also has online monitoring and automatic protection functions, reducing the risk of human intervention. This technology completely avoids electrical safety hazards that may be caused by heating belt aging and insulation damage, significantly improving the reliability and service life of the ceramic vacuum chamber 15.

[0040] In one embodiment of the present invention, such as Figure 2 As shown, the sandwich vacuum chamber 3 is vertically arranged and is made of stainless steel, specifically 304, 316L, or 316LN. It has an inner diameter of 200mm, a wall thickness of 2.5mm, and a total length of 630mm. Two CF35 flange interfaces are provided on the end face, used to connect the second connecting pipe to the electrode flange 5, respectively. Because a sandwich space is formed between the ceramic vacuum chamber 15 and the sandwich vacuum chamber 3, a vacuum environment is created after the sandwich space is evacuated, effectively insulating heat and enabling heat radiation transfer.

[0041] A ceramic vacuum chamber 15 is vertically mounted within the interlayer vacuum chamber 3. Made of ceramic, such as alumina, zirconium oxide, or other ceramic materials, the ceramic vacuum chamber 15 is the primary component for achieving ultimate vacuum. The flange interface of the ceramic vacuum chamber 15 is CF100, the pipe inner diameter is ф100mm, and the wall thickness is 6mm. The lower end of the ceramic vacuum chamber 15 connects to the interior of the main pump chamber 1, and the upper end of the ceramic vacuum chamber 15 is sealed with a second blind flange 16. The second blind flange 16 is CF100 and made of 304 stainless steel.

[0042] In one embodiment of the present invention, the vacuum temperature control device further includes a control unit and a temperature sensing element. The control unit is electrically connected to the heating element and the temperature sensing element. The temperature sensing element is disposed on the outer surface of the ceramic vacuum chamber 15 and is used to detect the temperature of the ceramic vacuum chamber 15 and send the detected temperature value to the control unit. By disposing the temperature sensing element on the outer surface of the ceramic vacuum chamber 15, the temperature information of the ceramic vacuum chamber 15 can be directly and accurately obtained, providing real-time feedback to the control unit and ensuring the accuracy of temperature control. The control unit is used to compare the temperature value with a preset value and adjust the output power of the heating element according to the comparison result. By comparing the detected temperature value with the preset value, the power output of the heating element can be adjusted in real time to maintain the temperature of the ceramic vacuum chamber 15 within the target range, achieving precise temperature control. When the temperature value is less than the preset value, the control unit adjusts the heating element to increase the output power. By increasing the output power of the heating element, the temperature of the ceramic vacuum chamber 15 can be quickly increased, shortening the heating time and improving working efficiency. When the temperature value is greater than the preset value, the control unit adjusts the heating element to decrease the output power. By decreasing the output power of the heating element, the temperature of the ceramic vacuum chamber 15 can be prevented from becoming too high, avoiding safety hazards caused by overheating. The control unit uses a PID algorithm to calculate the control quantity based on the deviation, and then adjusts the power output of the heating element to form a closed-loop feedback control loop. By using the PID algorithm, the power of the heating element can be automatically adjusted according to the temperature deviation, achieving precise and stable temperature control, reducing manual intervention, and improving the automation level of the system.

[0043] In one embodiment of the present invention, such as Figure 1 and Figure 3 As shown, the top of the main pump chamber 1 is equipped with a first interface, and the ceramic vacuum chamber 15 is connected to the first interface via a flange. The main pump chamber 1 is made of stainless steel, specifically 304, 316L, or 316LN. Each interface of the main pump chamber 1 is equipped with a CF series flange interface for connecting various vacuum pumps and measuring elements. The inner diameter of the pipe in the main pump chamber 1 is ф250mm. Of the six interfaces in the main pump chamber, one is a CF100 interface, two are CF150 interfaces, one is a CF200 interface, and two are CF250 interfaces. The CF100 interface is connected to the lower end of the ceramic vacuum chamber, the two CF150 interfaces are connected to the first interface of the sputtering ion pump 13 and the valve 7, respectively, the CF200 interface is connected to the titanium sublimation pump, and the two CF250 interfaces are connected to the blind flange and the transition flange, respectively.

[0044] In one embodiment of the present invention, such as Figure 1 and Figure 3As shown, the second vacuum pumping assembly includes a titanium sublimation pump 2, a sputtering ion pump 13, a valve 7, and a molecular pump 9. By combining different types of vacuum pumps, staged pumping can be achieved, fully utilizing the advantages of each pump within different pressure ranges to efficiently obtain an ultra-high vacuum environment. A second interface is located at the bottom of the main pump chamber 1, and the sputtering ion pump 13 is connected to this second interface via a flange. The sputtering ion pump 13 is mainly used to extract inert gases such as Ar and CH4 from the system. Since the titanium sublimation pump 2 is less effective at removing inert gases like Ar and CH4, the dedicated sputtering ion pump 13 can specifically and efficiently remove these residual gases, which is crucial for obtaining and maintaining an ultra-high vacuum. The sputtering ion pump 13 uses a CF150 interface and has a pumping speed of 330 L / s. The large-size CF150 interface and high pumping speed of 330 L / s ensure that gas molecules can quickly enter the pump and be captured, providing powerful pumping capabilities. This significantly shortens the time to reach the target vacuum level and effectively maintains vacuum stability during the process.

[0045] The first port of valve 7 is connected to the third port via a flange, and the inlet of molecular pump 9 is connected to the second port of valve 7. By setting valve 7 between molecular pump 9 and main pump chamber 1, molecular pump 9 can be isolated, facilitating system maintenance or starting / stopping of molecular pump 9 without disrupting the vacuum in main pump chamber 1, greatly improving operational flexibility and system maintainability. Valve 7 is an all-metal manual valve that can withstand vacuum baking at 300℃ and below. The use of an all-metal valve 7 capable of withstanding high-temperature baking ensures that valve 7 will not release gas or be damaged due to high temperature when baking and degassing the entire vacuum system to obtain ultra-high vacuum, which is a key guarantee for achieving an ultra-high vacuum environment. The interface of molecular pump 9 is CF150, and the pumping speed is 700L / s. As the main pump of the system, molecular pump 9 can quickly extract gas from the chamber, establishing a high vacuum environment in a short time, laying the foundation for obtaining ultra-high vacuum later.

[0046] A fourth port is located at the rear of the main pump chamber 1, and the titanium sublimation pump 2 is connected to this fourth port via a flange. By independently positioning the titanium sublimation pump 2 at the rear of the main pump chamber 1, it can work in conjunction with the molecular pump 9 and the sputtering ion pump 13 to specifically handle certain gases, achieving complementary pump group functions and thus more efficiently improving the ultimate vacuum. The titanium sublimation pump 2 uses a CF200 port with a pumping speed of 3000 L / s for H2. The large diameter of the CF200 port ensures a sufficiently large flow channel for gas molecules to enter the pump, allowing the titanium sublimation pump 2 to fully utilize its high pumping speed of up to 3000 L / s. Titanium sublimation pumps have high pumping speeds. They achieve chemical adsorption of gases by depositing a titanium film onto the inner wall of the pump through sublimation of titanium wires. H2 is a major residual gas in ultra-high and very high vacuum systems, and a CF200 caliber titanium sublimation pump can pump H2 at a speed of 3000 L / s. Hydrogen is the most significant residual gas in ultra-high vacuum systems and is difficult to remove effectively with conventional pumps. By configuring a titanium sublimation pump with extremely high chemical adsorption pumping speed for hydrogen, hydrogen molecules can be captured specifically and efficiently. This is a crucial component for overcoming high vacuum bottlenecks and raising the system vacuum level to ultra-high and even very high vacuum levels.

[0047] In one embodiment of the present invention, such as Figure 1 As shown, the second vacuum pumping assembly also includes a first mechanical pump 11. The inlet of the first mechanical pump 11 is connected to the outlet of the molecular pump 9 through a first connecting pipe 10. By providing a vacuum to the molecular pump 9, it ensures that the molecular pump 9 can start normally and operate stably under high pressure differential, which is a necessary condition for the entire high vacuum-ultra-high vacuum pump group to achieve relay pumping. The molecular pump 9 and the first mechanical pump 11 are combined to form a rough pumping unit, which discharges a large amount of gas released during the system baking process through combined pumping. This combination can efficiently handle the large gas load generated during system baking and degassing, prevent the main chamber pressure from rising excessively and affecting the degassing effect, thereby effectively shortening the time required to obtain the target vacuum level. The interface of the first mechanical pump 11 is KF25, and the pumping speed is 4L / s. The pumping speed of 4L / s matches the exhaust volume of the backing molecular pump 9, achieving an economical and efficient configuration that meets the backing pressure requirements of the molecular pump 9 while avoiding waste of energy and cost.

[0048] In one embodiment of the present invention, a first blind flange 14 is provided on the left side of the main pump chamber 1. The specification of the first blind flange 14 is CF250, and the material of the first blind flange 14 is 304 stainless steel.

[0049] In one embodiment of the present invention, such as Figure 1 and Figure 3 As shown, the ultra-high vacuum acquisition system also includes a vacuum gauge 8. A first adapter flange 6 is provided on the right side of the main pump chamber 1, and the vacuum gauge 8 is connected to the interior of the main pump chamber 1 through the first adapter flange 6. Figure 2The interface on the left side of the transition flange is CF250, which connects to the main pump chamber 1. The interface on the right side of the transition flange is CF35, which connects to the vacuum gauge 88. The vacuum gauge 88 is a measuring element; it uses the IE514 specification for ultra-high vacuum measurement, and its measuring range is 1×10⁻⁶. -4 mbar-2×10 -12 mbar is used to monitor the vacuum level obtained by the system.

[0050] In one embodiment of the present invention, by evacuating the interlayer space, gas convection and heat conduction between the inner and outer walls can be effectively reduced, thereby forming a highly efficient heat insulation layer, providing excellent heat preservation for the internal main vacuum chamber and reducing energy loss. The top of the interlayer vacuum chamber 3 is provided with a top flange communicating with the interlayer space, and the inlet of the second mechanical pump 12 is connected to the top flange through a second connecting pipe 4; this connection method ensures unobstructed air extraction path, enabling rapid extraction of air from the interlayer and establishing an effective heat-insulating vacuum environment in a short time.

[0051] In one embodiment of the present invention, such as Figure 1 and Figure 3 As shown, an electrode flange 5 is also provided on the top of the interlayer vacuum chamber 3. The electrode flange 5 is used to connect the temperature measuring element and the control unit. The electrode flange 5 is a vacuum through-wall component. The specification of the electrode flange 5 is CF35, etc. The inner core of the electrode flange 5 is oxygen-free copper, and the insulating material is alumina ceramic.

[0052] The present invention also provides a method for obtaining ultra-high vacuum, the method being based on the ultra-high vacuum acquisition system described in any of the above embodiments, comprising:

[0053] Install the ceramic vacuum chamber 15 inside the jacketed vacuum chamber 3, connect the second vacuum pumping assembly to the main pump chamber 1, and ensure that all interfaces are leak-free after helium mass spectrometry leak detection, with a leak rate <5×10⁻⁶. -10 mbarl / s; meanwhile, the temperature measuring element is placed on the outer surface of the ceramic vacuum chamber 15, and the temperature measuring element is connected to the control unit through the electrode flange 5; the heating element is placed outside the jacketed vacuum chamber 3, the main pump chamber 1 and the second vacuum assembly;

[0054] Molecular pump 9 and first mechanical pump 11 are started to initially evacuate the main vacuum chamber to 10. -6 -10 -8 mbar, and simultaneously start the second mechanical pump to evacuate the jacketed vacuum chamber to 10 mbar. -1 -10 -3 mbar;

[0055] The jacketed vacuum chamber 3 is heated by heating elements, and the ceramic vacuum chamber 15 is heated uniformly by the thermal radiation of the jacketed vacuum chamber 3. The ceramic vacuum chamber 15 is slowly heated to 160℃-300℃ at a rate of 0.5℃ / min and kept at that temperature for 40-60h. The surface temperature distribution of the ceramic vacuum chamber 15 is monitored by temperature measuring elements to ensure that the temperature uniformity deviation does not exceed ±2°C.

[0056] During the heat preservation process, vacuum gauge 8 and titanium sublimation pump 2 are used for circulating degassing, with a degassing cycle of 1-4 hours.

[0057] After the heat preservation stage is completed, the temperature is reduced at a rate of 0.5℃ / min. When the temperature drops to 180℃, the gas is evacuated by the titanium sublimation pump 2, and at the same time, the valve 7, the molecular pump 9 and the first mechanical pump 11 are closed to continue cooling to room temperature.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for obtaining ultra-high vacuum, the method being based on an ultra-high vacuum acquisition system, characterized in that, The ultra-high vacuum acquisition system includes: A vacuum acquisition device includes a ceramic vacuum chamber (15), a sandwich vacuum chamber (3), a main pump chamber (1), a first vacuum pumping assembly, and a second vacuum pumping assembly. The ceramic vacuum chamber (15) forms a main vacuum chamber inside the sandwich vacuum chamber (3). The ceramic vacuum chamber (15) is disposed inside the sandwich vacuum chamber (3). A sandwich space is formed between the ceramic vacuum chamber (15) and the sandwich vacuum chamber (3). The sandwich vacuum chamber (3) is fixedly connected to the main pump chamber (1). The first vacuum pumping assembly is connected to the sandwich space and is used to evacuate the sandwich space. The second vacuum pumping assembly and the main vacuum chamber are both connected to the interior of the main pump chamber (1). The second vacuum pumping assembly is used to evacuate the ceramic vacuum chamber (15) and the main pump chamber (1). A vacuum temperature control device includes a heating element, which is used to heat the jacketed vacuum chamber (3), the main pump chamber (1) and the second vacuum assembly so that the ceramic vacuum chamber (15) is heated evenly by the thermal radiation of the jacketed vacuum chamber (3). The vacuum temperature control device also includes: The control unit is electrically connected to the heating element and the temperature measuring element. The temperature measuring element is disposed on the outer surface of the ceramic vacuum chamber (15) and is used to detect the temperature of the ceramic vacuum chamber (15) and send the detected temperature value to the control unit. The control unit is used to compare the temperature value with a preset value and adjust the output power of the heating element according to the comparison result. The second vacuum assembly includes a titanium sublimation pump (2), a sputtering ion pump (13), a valve (7), and a molecular pump (9). The bottom of the main pump chamber (1) is provided with a second interface, and the sputtering ion pump (13) is connected to the second interface through a flange. The front side of the main pump chamber (1) is provided with a third interface, and the first interface of the valve (7) is connected to the third interface through a flange. The inlet of the molecular pump (9) is connected to the second interface of the valve (7). The rear side of the main pump chamber (1) is provided with a fourth interface, and the titanium sublimation pump (2) is connected to the fourth interface through a flange. The second vacuum assembly also includes a first mechanical pump (11), the inlet of which is connected to the outlet of the molecular pump (9) via a first connecting pipe (10); The ultra-high vacuum acquisition system also includes: Vacuum gauge (8), a first transition flange (6) is provided on the right side of the main pump chamber (1), and the vacuum gauge (8) is connected to the interior of the main pump chamber (1) through the first transition flange (6); The first vacuum pumping component includes: The second mechanical pump (12) is provided with a top flange that communicates with the interlayer space at the top of the interlayer vacuum chamber (3), and the inlet of the second mechanical pump (12) is connected to the top flange through a second connecting pipe (4). An electrode flange (5) is provided on the top of the interlayer vacuum chamber (3), and the electrode flange (5) is used to connect the temperature measuring element and the control unit; The method includes: The ceramic vacuum chamber (15) is installed inside the sandwich vacuum chamber (3), and the second vacuum pumping assembly is connected to the main pump chamber (1). All interfaces are checked for leaks by helium mass spectrometry and found to be leak-free with a leak rate of <5×10⁻⁶. -10 mbarl / s; Meanwhile, the temperature measuring element is placed on the outer surface of the ceramic vacuum chamber (15), and the temperature measuring element is connected to the control unit through the electrode flange (5); the heating element is placed outside the jacketed vacuum chamber (3), the main pump chamber (1) and the second vacuum assembly; The molecular pump (9) and the first mechanical pump (11) are started to initially evacuate the main vacuum chamber to 10. -6 -10 -8 mbar, and simultaneously start the second mechanical pump (12) to evacuate the jacketed vacuum chamber to 10 mbar. -1 -10 -3 mbar; The jacketed vacuum chamber (3) is heated by the heating element, and the ceramic vacuum chamber (15) is heated evenly by the thermal radiation of the jacketed vacuum chamber (3); the ceramic vacuum chamber (15) is slowly heated to 160℃-300℃ at a rate of 0.5℃ / min, and kept at that temperature for 40-60h; the surface temperature distribution of the ceramic vacuum chamber (15) is monitored by the temperature value detected by the temperature measuring element to ensure that the temperature uniformity deviation does not exceed ±2℃; During the heat preservation process, a vacuum gauge (8) and a titanium sublimation pump (2) are used for circulating degassing, with a degassing cycle of 1-4 hours. After the heat preservation stage is completed, the temperature is reduced at a rate of 0.5℃ / min. When the temperature drops to 180℃, the gas is pumped out by the titanium sublimation pump (2), and the valve (7), molecular pump (9) and first mechanical pump (11) are closed at the same time to continue cooling to room temperature.

2. The method for obtaining ultra-high vacuum according to claim 1, characterized in that, The top of the main pump chamber (1) is provided with a first interface, and the ceramic vacuum chamber (15) is connected to the first interface through a flange.

3. The method for obtaining ultra-high vacuum according to claim 1, characterized in that, The main pump chamber (1) is provided with a first blind flange (14) on the left side.

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