Vacuum keeping system capable of keeping ultrahigh vacuum for ultra-long time

Abstract

The invention discloses a vacuum keeping system capable of keeping ultrahigh vacuum for an ultra-long time. The vacuum keeping system comprises a special-shaped vacuum cavity, an ultrahigh vacuum multifunctional sealing valve assembly and an adsorption assembly, the ultrahigh vacuum multifunctional sealing valve assembly is connected to the first connecting opening of the special-shaped vacuum cavity through a bolt. The first connecting port and the ultrahigh vacuum multifunctional sealing valve assembly are sealed by extruding the sealing assembly; the adsorption assembly is connected to the second connecting port of the special-shaped vacuum cavity through a bolt and then extrudes the sealing assembly for sealing. The vacuum keeping system for keeping the ultrahigh vacuum for the ultra-long time can get rid of a traditional vacuum pump set obtaining mode; and the pressure intensity of 10 <-6 > Pa can be kept for an ultra-long time through single activation.

Description

Technical Field

[0001] The present invention relates to a vacuum maintaining system, in particular to a vacuum maintaining system capable of maintaining ultra-high vacuum for an ultra-long period of time. Background Art

[0002] In physics, vacuum refers to a state where the gas pressure in a space is lower than a standard atmospheric pressure. The vacuum state is divided into four levels according to the pressure, namely low vacuum (10 5 Pa~10 2 Pa), medium vacuum (10 2 Pa~10 0 Pa), high vacuum (10 0 Pa-10 -3 Pa), ultra-high vacuum (10 -3 Pa or less). Vacuum maintenance technology utilizes specialized methods or measures to maintain a specific vacuum state within a container system. Different vacuum devices have varying vacuum requirements, and high-power microwave vacuum devices have extremely stringent vacuum requirements, requiring ultra-high vacuum conditions during operation. Otherwise, lower vacuum pressures will affect the microwave's normal output. Vacuum maintenance is a complex and important technology, involving key technologies such as material degassing, vacuum sealing, adsorption methods, and topological layout.

[0003] Currently, vacuum pressure is traditionally maintained using an external mechanical pump system. However, these systems have significant advantages and disadvantages. Advantages include: First, achieving vacuum pressure is relatively easy, requiring only one pump system; Second, the sealing requirements for the anisotropic vacuum chamber are less stringent; as long as there are no major leaks, a certain vacuum pressure can be achieved; Third, there are virtually no requirements for the materials used to construct the anisotropic vacuum chamber, and outgassing is largely irrelevant; Fourth, the vacuum seal structure is simple, and rubber rings can be used as the sealing material. Disadvantages include: First, the vacuum pressure achieved by the mechanical pump system is limited, with a limit vacuum of the order of -4 Pa; Second, the mechanical pump system is bulky and heavy, resulting in poor plasticity and difficulty in conformality and integration; Third, its poor environmental adaptability, such as resistance to high and low temperatures, vibration and shock, and electromagnetic compatibility, makes it unsuitable for use in specialized environments. With the rapid development of high-power microwave technology in recent years, the power levels and repetition rates of vacuum devices have continued to increase, expanding their application scenarios. Simultaneously, requirements for the system size, lifespan, stability, reliability, and environmental adaptability of vacuum devices have also become increasingly stringent. The normal output of high-power microwave vacuum devices is inseparable from the maintenance of ultra-high vacuum. When the vacuum deteriorates to a certain extent, it can lead to shortened microwave pulse width, decreased power, and even anode and cathode creep, affecting the normal operation of the system. Vacuum pressure is not only one of the main core issues of vacuum microwave sources, but also a necessary working condition for generating microwaves. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology. Therefore, based on technical problems such as maintaining ultra-high vacuum pressure for an ultra-long time, and according to actual application needs, and breaking away from the traditional vacuum pump group acquisition method, a vacuum maintenance system is proposed that can be activated once and maintain an ultra-high vacuum pressure of -6Pa for an ultra-long time of more than ten years.

[0005] In order to solve the above technical problems, the technical solution proposed in the present invention is: a vacuum maintenance system for maintaining ultra-high vacuum for an ultra-long time, comprising a heterogeneous vacuum chamber, an ultra-high vacuum multifunctional sealing valve assembly and an adsorption assembly; the ultra-high vacuum multifunctional sealing valve assembly is connected to the first connection port of the heterogeneous vacuum chamber by bolts; the first connection port and the ultra-high vacuum multifunctional sealing valve assembly are sealed by squeezing the sealing assembly; the adsorption assembly is connected to the second connection port of the heterogeneous vacuum chamber by bolts, and then squeezes the sealing assembly to seal.

[0006] The above-mentioned vacuum maintenance system for maintaining ultra-high vacuum for an ultra-long time, preferably, a third connecting port is provided on the anisotropic vacuum chamber, a high-voltage excitation vacuum pressure detector is connected to the third connecting port by bolts, and the high-voltage excitation vacuum pressure detector and the third connecting port are sealed by an extrusion sealing component.

[0007] The above-mentioned vacuum maintenance system for maintaining ultra-high vacuum for an ultra-long time, preferably, the sealing component includes an oxygen-free sealing copper ring and an extrusion structure, the extrusion structure is arranged on the first connection port, the ultra-high vacuum multifunctional sealing valve assembly, the second connection port, the adsorption assembly, the third connection port and the high-pressure excitation vacuum pressure detector; the extrusion structure includes a stepped knife-edge structure; the oxygen-free sealing copper ring is squeezed and deformed by the stepped knife-edge structure to thereby seal.

[0008] The above-mentioned vacuum maintenance system that maintains ultra-high vacuum for an ultra-long time, preferably, the adsorption component includes a gas adsorption material component and a ceramic-packaged vacuum-maintaining activation aviation plug; the gas adsorption material component is connected to the ceramic-packaged vacuum-maintaining activation aviation plug, and the outer shell and the second connection port of the ceramic-packaged vacuum-maintaining activation aviation plug are sealed by bolts squeezing an oxygen-free sealing copper ring.

[0009] In the above-mentioned vacuum maintenance system that maintains ultra-high vacuum for an ultra-long time, preferably, the gas adsorption material component has a columnar porous structure or a columnar grid structure, and the preparation material of the gas adsorption material component includes one or more of zirconium, vanadium, titanium and their alloys.

[0010] In the aforementioned vacuum maintenance system for maintaining an ultra-high vacuum for an extremely long period of time, the ultra-high vacuum multifunctional sealing valve assembly preferably includes a contraction member, a sealing member, and a structural member. The contraction member and the sealing member are disposed within the structural member, which serves as the outer shell of the ultra-high vacuum multifunctional sealing valve assembly 2. The sealing member includes a limiting rod and a sealing portion. The limiting rod is disposed on the sealing portion and is in extrusion-sealed connection with the gas passage at the bottom of the structural member. The limiting rod extends through the central hole of the contraction member and out of the structural member, where it is connected to a fastener.

[0011] Compared with the prior art, the advantages of the present invention are: the vacuum maintaining system of the present invention can get rid of the traditional vacuum pump group acquisition method; a single activation can achieve ultra-long-term maintenance of 10 -6 Pa pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the structure of the vacuum maintenance system for maintaining ultra-high vacuum for an ultra-long time in Example 1.

[0013] Figure 2 This is a schematic cross-sectional structural diagram of the vacuum maintenance system for maintaining ultra-high vacuum for an ultra-long period of time in Example 1.

[0014] Figure 3 Schematic diagram of the structure of the heterogeneous vacuum chamber in Example 1.

[0015] Figure 4 for Figure 3 Schematic diagram of the enlarged structure at point A in the middle.

[0016] Figure 5 This is a schematic diagram of the structure of the oxygen-free sealing copper ring in Example 1.

[0017] Figure 6 Schematic diagram of the structure of the adsorption component in Example 1.

[0018] Figure 7 This is a structural diagram of the ceramic package vacuum activation aviation plug in Example 1.

[0019] Figure 8 Schematic diagram of the high-voltage excitation vacuum pressure detector in Example 1.

[0020] Figure 9 This is a schematic structural diagram of the ultra-high vacuum multifunctional sealing valve assembly in Example 1.

[0021] Figure 10 This is a schematic structural diagram of the ultra-high vacuum multifunctional sealing valve assembly in Example 1 during vacuuming.

[0022] Figure 11 The vacuum pressure values measured annually for the past 12 years are for the vacuum maintenance system in Example 1 that maintains ultra-high vacuum for an ultra-long period of time.

[0023] Legend 1. Heterogeneous vacuum chamber; 11. First connection port; 12. Second connection port; 13. Third connection port; 2. Ultra-high vacuum multifunctional sealing valve assembly; 21. Contraction part; 22. Sealing part; 221. Limit rod; 222. Sealing part; 23. Structural part; 24. Fastener; 3. Adsorption assembly; 31. Gas adsorption material assembly; 32. Ceramic package vacuum activation aviation plug; 4. Sealing assembly; 41. Receiving groove; 42. Oxygen-free sealing copper ring; 43. Step-type knife-edge structure; 5. High-voltage excitation vacuum pressure detector. DETAILED DESCRIPTION

[0024] In order to facilitate understanding of the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with preferred embodiments, but the protection scope of the present invention is not limited to the following specific embodiments.

[0025] It should be noted that when an element is described as being "fixed, fixed, connected or communicated with" another element, it can be directly fixed, fixed, connected or communicated with the other element, or it can be indirectly fixed, fixed, connected or communicated with the other element through other intermediate connectors.

[0026] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention. Example

[0027] like Figure 1 and Figure 2 The illustrated vacuum maintenance system for maintaining an ultra-high vacuum for an extremely long period of time includes a non-uniform vacuum chamber 1, an ultra-high vacuum multifunctional sealing valve assembly 2, and an adsorption assembly 3. The ultra-high vacuum multifunctional sealing valve assembly 2 is bolted to a first connection port 11 of the non-uniform vacuum chamber 1. The first connection port 11 and the ultra-high vacuum multifunctional sealing valve assembly 2 are sealed by squeezing a sealing assembly 4. The adsorption assembly 3 is bolted to a second connection port 12 of the non-uniform vacuum chamber 1 and then squeezes the sealing assembly 4 to seal the connection. In this embodiment, the non-uniform vacuum chamber 1 is provided with a third connection port 13, to which a high-voltage excitation vacuum pressure detector 5 is bolted. The high-voltage excitation vacuum pressure detector 5 and the third connection port 13 are sealed by squeezing the sealing assembly 4.

[0028] In this embodiment, in a vacuum system under ultra-low vacuum leakage rate, material degassing of components in the heterogeneous vacuum cavity 1 includes natural degassing under static conditions and pulsed degassing, thermal degassing, chemical gas production, etc. under dynamic conditions, which will lead to the deterioration of the vacuum pressure and increase the vacuum pressure. The adsorption component 3 is used for adsorption to reduce the vacuum pressure, thereby achieving the maintenance of ultra-high vacuum pressure for an ultra-long time.

[0029] In this embodiment, if Figure 3 As shown, the first connection port 11, the second connection port 12, and the third connection port 13 on the heterogeneous vacuum chamber 1 need to be sealed by the sealing component 4 when they are respectively connected to the ultra-high vacuum multifunctional sealing valve assembly 2, the adsorption assembly 3, and the high-pressure excitation vacuum pressure detector 5. In this embodiment, the sealing component 4 includes an oxygen-free sealing copper ring 42 and an extrusion structure. The extrusion structure is provided on the first connection port 11, the ultra-high vacuum multifunctional sealing valve assembly 2, the second connection port 12, the adsorption assembly 3, the third connection port 13, and the high-pressure excitation vacuum pressure detector 5; as shown in FIG. Figure 4 As shown, the extrusion structure includes a stepped blade structure 43; the oxygen-free sealing copper ring 42 is squeezed and deformed by the stepped blade structure 43 to seal. Figure 5 As shown. In this embodiment, the outer shells of the ultra-high vacuum multifunctional sealing valve assembly 2, the adsorption assembly 3 and the high-pressure excitation vacuum pressure detector 5 are all made of metal materials, such as titanium alloy. A receiving groove 41 for the oxygen-free sealing copper ring 42 is provided on the outer shells of the ultra-high vacuum multifunctional sealing valve assembly 2, the adsorption assembly 3 and the high-pressure excitation vacuum pressure detector 5, and a stepped blade structure 43 is provided in the receiving groove 41. When the ultra-high vacuum multifunctional sealing valve assembly 2, the adsorption assembly 3 and / or the high-pressure excitation vacuum pressure detector 5 are connected to the heterogeneous vacuum chamber 1 with bolts, the oxygen-free sealing copper ring 42 is provided in the receiving groove 41 of each outer shell, and the outer shell squeezes the oxygen-free sealing copper ring 42 so that the oxygen-free sealing copper ring 42 is deformed to achieve sealing.

[0030] In this embodiment, if Figure 6 As shown, the adsorption assembly 3 includes a gas adsorption material assembly 31 and a ceramic-encapsulated vacuum-maintaining activation plug 32. The gas adsorption material assembly 31 is connected to the ceramic-encapsulated vacuum-maintaining activation plug 32. The outer shell of the ceramic-encapsulated vacuum-maintaining activation plug 32 and the second connection port 12 are sealed by bolts squeezing an oxygen-free sealing copper ring 42. The gas adsorption material assembly 31 has a columnar porous structure or a columnar grid structure and is made of one or more of zirconium, vanadium, titanium, and their alloys.

[0031] In this embodiment, the main function of the gas adsorption material is to adsorb the gas and vacuum activate the material in the heterogeneous vacuum chamber 1 by degassing the material; its working principle is to desorb the surface of the adsorption material through different voltage excitations. The surface after desorption has adsorption capacity, and the gas in the heterogeneous vacuum chamber 1 is adsorbed and captured, thereby reducing the vacuum pressure. The structure of the ceramic package vacuum activation aviation plug 32 is as follows Figure 7 As shown, it mainly provides vacuum activation excitation for the gas adsorption material component 31 and provides a carrier for the gas adsorption material component 31 so as to be sealed and connected with the heterogeneous vacuum chamber 1.

[0032] In this embodiment, the high-voltage excitation vacuum pressure detector 5 detects and reads the vacuum pressure in the heterogeneous vacuum chamber. It uses high voltage to excite the gas molecules in the vacuum to ionize them, thereby generating an ion flow. The ion flow is extracted by the corresponding control circuit under the constraint of the magnetic field; that is, the size of the ion flow can reflect the size of the vacuum pressure. The structure of the high-voltage excitation vacuum pressure detector is as follows: Figure 8 shown.

[0033] In this embodiment, the structure of the ultra-high vacuum multifunctional sealing valve assembly 2 is as follows: Figure 2 and Figure 9 As shown, it provides an exhaust channel for obtaining the background pressure of the heterogeneous vacuum chamber 1. In this embodiment, the ultra-high vacuum multifunctional sealing valve assembly 2 includes a contraction part, a sealing part and a structural part. The contraction part and the sealing part are arranged in the structural part, and the structural part is the outer shell of the ultra-high vacuum multifunctional sealing valve assembly 2. The sealing part includes a limiting rod and a sealing part. The limiting rod is arranged on the sealing part, and the sealing part is squeezed and sealed with the gas channel at the bottom of the structural part; the limiting rod extends through the center hole of the contraction part and is connected to the structural part and the fastener. In this embodiment, the fastener can be a nut, which is fixed to the top of the structural part; the upper part of the limiting rod is provided with a thread matching the nut, and a hexagonal groove is provided at the top of the limiting rod.

[0034] In this embodiment, when the air is pumped out, Figure 10 As shown, a hexagonal rod is first used to twist the limit rod on the fastener, raising the limit rod and allowing the seal to open the gas passage below the structural component. This allows an air pump to pump air through the gas extraction port of the structural component, achieving a vacuum within the heterogeneous vacuum chamber. When the air pump is finished pumping air, the air pump continues to operate, and the limit rod descends, causing the seal to press against the extrusion structure on the gas passage at the bottom of the structural component. The fastener secures the limit rod to the structural component, closing the gas passage and ensuring the vacuum level within the heterogeneous vacuum chamber.

[0035] In this embodiment, when assembling a vacuum maintenance system that maintains ultra-high vacuum for an ultra-long period of time, the following specific steps can be used: 1) Assemble all components to complete the integration of the vacuum system.

[0036] 2) The external vacuum pump group opens the ultra-high vacuum multifunctional sealing valve assembly 2 to pump air, so that the heterogeneous vacuum chamber can obtain 10 -3 Background vacuum pressure of the order of Pa.

[0037] 3) Use a vacuum leak detector to test the vacuum system for vacuum leakage rate, and ensure that the vacuum leakage rate of the vacuum system of this embodiment is 5.0×10 -13 Pa.m 3 / s.

[0038] 4) High temperature vacuum exhaust baking: The baking time is 10 to 24 hours at 100 to 300 degrees Celsius, and vacuum exhaust is performed during the baking process.

[0039] 5) The vacuum system is cooled naturally.

[0040] 6) Vacuum activation: The adsorption material is excited with a power of several hundred watts for 3 to 5 hours.

[0041] 7) Vacuum cooling.

[0042] 8) Ultra-high vacuum multifunctional sealing valve assembly 2 closes the valve seal.

[0043] 9) Vacuum pressure test.

[0044] The vacuum maintenance system of this embodiment can maintain ultra-high vacuum for a long time without the traditional vacuum pump group acquisition method; a single activation can achieve an ultra-long time of ten years to maintain 10 -6 Pa vacuum pressure.

[0045] The vacuum maintaining system of this embodiment can maintain ultra-high vacuum for an ultra-long time at 5.0×10 -13 Pa.m 3 Under the condition of vacuum leakage rate of 0.01% / s, the leakage of the system can be ignored. Then the only factor affecting the drop of vacuum pressure is the natural outgassing of the material in the heterogeneous vacuum chamber. In this embodiment, the surface area S of the heterogeneous vacuum chamber is about 1100 cm 2 The total outgassing rate Q of special-shaped vacuum chamber materials within 10 years is about 1.33×10 -11 Pa.m 3 / s, and T in 10 years is 3.15×10 8 s, then the total gas load is Q×S×T≈4.6Pa.m 3 It is known that the gas extraction rate V of the adsorption material is about 0.1L / s=10 -4 m 3 / s, mass m is about 10g, and suction capacity H is about 500Pa.m 3 / g, the maximum amount of gas that can be adsorbed in 10 years is H×m=5000Pa.m 3 Based on the above data, the maximum gas volume that the adsorption material can adsorb in 10 years is much greater than the natural outgassing value of the material in the heterogeneous vacuum chamber, and the calculated system vacuum pressure P=Q / V is about 1.33×10 -7 Pa and the measured data in the past 10 years (10 -7 ~10 -6 Therefore, the vacuum system designed by the present invention can get rid of the traditional vacuum pump group to obtain the vacuum for a long time. Once activated, it can achieve a long-term maintenance of 10 -6 Pa pressure. Figure 11 The vacuum pressure values measured annually for the past 12 years are for the vacuum maintenance system in Example 1 that maintains ultra-high vacuum for an ultra-long period of time.

Claims

1. A vacuum maintenance system for maintaining ultra-high vacuum for an extremely long time, characterized by: It includes a heterosexual vacuum chamber, an ultra-high vacuum multifunctional sealing valve assembly and an adsorption assembly; the ultra-high vacuum multifunctional sealing valve assembly is connected to the first connecting port of the heterosexual vacuum chamber by bolts; the first connecting port and the ultra-high vacuum multifunctional sealing valve assembly are sealed by squeezing the sealing assembly; the adsorption assembly is connected to the second connecting port of the heterosexual vacuum chamber by bolts and then squeezed to seal.

2. The vacuum maintaining system for maintaining ultra-high vacuum for an ultra-long period of time according to claim 1, characterized in that: The anisotropic vacuum chamber is provided with a third connection port, the third connection port is connected to a high-voltage excitation vacuum pressure detector via bolts, and the high-voltage excitation vacuum pressure detector and the third connection port are sealed by extruding a sealing component.

3. The vacuum maintaining system for maintaining ultra-high vacuum for an ultra-long period of time according to claim 1 or 2, characterized in that: The sealing assembly includes an oxygen-free sealing copper ring and an extrusion structure, and the extrusion structure is arranged on the first connection port, the ultra-high vacuum multifunctional sealing valve assembly, the second connection port, the adsorption assembly, the third connection port and the high-pressure excitation vacuum pressure detector; the extrusion structure includes a stepped knife-edge structure; the oxygen-free sealing copper ring is squeezed and deformed by the stepped knife-edge structure to achieve sealing.

4. The vacuum maintaining system for maintaining ultra-high vacuum for an ultra-long period of time according to claim 1, characterized in that: The adsorption assembly includes a gas adsorption material assembly and a ceramic packaged vacuum-maintaining activated aviation plug; the gas adsorption material assembly is connected to the ceramic packaged vacuum-maintaining activated aviation plug, and the outer shell and the second connection port of the ceramic packaged vacuum-maintaining activated aviation plug are sealed by bolts squeezing an oxygen-free sealing copper ring.

5. The vacuum maintaining system for maintaining ultra-high vacuum for an ultra-long period of time according to claim 4, characterized in that: The gas adsorption material component has a columnar porous structure or a columnar grid structure, and the preparation material of the gas adsorption material component includes one or more of zirconium, vanadium, titanium and alloys thereof.

6. The vacuum maintaining system for maintaining ultra-high vacuum for an ultra-long period of time according to claim 1, characterized in that: The ultra-high vacuum multifunctional sealing valve assembly comprises a contraction member, a sealing member, and a structural member. The contraction member and sealing member are disposed within the structural member, which serves as the outer shell of the ultra-high vacuum multifunctional sealing valve assembly 2. The sealing member comprises a limiting rod and a sealing portion. The limiting rod is disposed on the sealing portion and is extruded and sealed with the gas passage at the bottom of the structural member. The limiting rod extends through the central hole of the contraction member and out of the structural member to connect to the fastener.

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