High-vacuum low-gas-permeation glass ceramic cavity and preparation method thereof

Abstract

The invention discloses a high-vacuum low-gas-permeation glass ceramic cavity and a preparation method thereof, and belongs to the field of vacuum technology and quantum precision measurement equipment. The high-vacuum low-gas-permeation glass ceramic cavity comprises a glass ceramic vacuum cavity (1), an ion pump part (2), a getter pump part (3) and an atom preparation area part (4), wherein the glass ceramic vacuum cavity (1) comprises a cavity body (11), an ion pump interface (12), a getter pump interface (13), an exhaust interface (14), an experiment interface (15) and a cover plate (16); the ion pump interface (12), the getter pump interface (13), the exhaust interface (14) and the experiment interface (15) are arranged on each side wall of the cavity body (11); the cover plate (16) is used for covering the exhaust interface (14); the glass ceramic vacuum cavity (1) is connected with the ion pump part (2), the getter pump part (3) and the atom preparation area part (4) through optical cement bonding or low-temperature bonding and is communicated with the ion pump part (2), the getter pump part (3) and the atom preparation area part (4) through an ion pump interface (12), a getter pump interface (13) and an experiment interface (15).

Description

Technical Field

[0001] This invention belongs to the field of vacuum technology and quantum precision measurement equipment, specifically relating to a high-vacuum, low-permeability microcrystalline glass cavity suitable for cold atom quantum sensors (such as atomic clocks and atomic interferometers) and quantum computers, and its preparation method. Background Technology

[0002] In the field of cold atom quantum technology, maintaining a long-term stable ultra-high vacuum environment is crucial for the success of quantum sensing and quantum computing experiments. The core component of a cold atom system is the ultra-high vacuum chamber, which provides the necessary vacuum environment for laser cooling, confinement, and manipulation of atoms, typically requiring a vacuum level on the order of 10⁻⁷ Pa. In existing technologies, vacuum chambers are mostly made of non-magnetic stainless steel or titanium and connected to an external ion pump via flanges. While such metal chambers can meet the vacuum requirements, they have the following inherent drawbacks: 1. Mismatch in thermal expansion coefficients of materials: The thermal expansion coefficients of the metal cavity and the glass window are significantly different, which can easily generate thermal stress when the temperature changes, leading to sealing failure or a decrease in vacuum. 2. High gas permeability: Metal materials (especially stainless steel) have poor barrier properties against small molecule gases such as hydrogen. Over long-term use, gas permeation will cause the vacuum level to decrease slowly, especially in the area of ​​metal vacuum pipelines where the vacuum level decreases more significantly. 3. Complex structure and large size: The metal cavity needs to be connected to the ion pump and optical system through complex connectors, resulting in a large system size and weight, making it difficult to meet the requirements of miniaturization and integration.

[0003] To overcome the aforementioned problems, technical solutions employing glass vacuum chambers have emerged in recent years to reduce weight and improve light transmittance. However, these solutions still utilize traditional metal-cased ion pumps, and the sealing interface between the glass and metal can still become a weak point for gas permeation. Other solutions utilize low thermal expansion coefficients to improve stability, but these do not address the material mismatch between the ion pump casing and the chamber. Therefore, there is an urgent need for an all-glass integrated vacuum system to fundamentally reduce gas permeability and achieve a long-term stable ultra-high vacuum environment. Summary of the Invention

[0004] Purpose of the invention: This invention provides a high-vacuum, low-permeability microcrystalline glass cavity and its preparation method, in order to solve the problems of high gas permeability and short vacuum life caused by material mismatch in the prior art.

[0005] Technical solution: A high-vacuum, low-permeability microcrystalline glass cavity includes: a microcrystalline glass vacuum cavity 1, an ion pump section 2, a getter pump section 3, and an atomic preparation region section 4; wherein, the microcrystalline glass vacuum cavity 1 includes: a cavity body 11, an ion pump interface 12, a getter pump interface 13, an exhaust interface 14, an experimental interface 15 disposed on each side wall of the cavity body 11, and a cover plate 16 for covering the exhaust interface 14; the microcrystalline glass vacuum cavity 1 is connected to the ion pump section 2, the getter pump section 3, and the atomic preparation region section 4 by photopolymer bonding or cryogenic bonding and is connected to the ion pump interface 12, the getter pump interface 13, and the experimental interface 15.

[0006] Furthermore, the ion pump interface 12, getter pump interface 13, exhaust interface 14, and experimental interface 15 are circular holes machined on the cavity 11, with a diameter of 4-20 mm.

[0007] Furthermore, the outer surface of the cavity 11 is within a 5mm area adjacent to each of the interfaces: the ion pump interface 12, the getter pump interface 13, the exhaust interface 14, and the experimental interface 15. The outer edge 5mm area is polished without scratches.

[0008] Furthermore, the contact area between the outer surface of the cavity 11 and the cover plate 16 is a glossy adhesive area, and the outer edge 5mm area is polished without scratches.

[0009] Furthermore, the microcrystalline glass is lithium aluminum silicon microcrystalline glass or magnesium aluminum silicon microcrystalline glass, with a crystalline phase content of not less than 50% and a coefficient of thermal expansion of less than 5 × 10⁻⁶. -6 / K.

[0010] Further, the ion pump part 2 includes: an ion pump housing 21, multiple anode cylinders 22, two cathode plates 23, two magnet supports 24, two magnets 25, and electrodes 26; wherein, the two cathode plates 23 are arranged in parallel inside the ion pump housing 21, the array of anode cylinders 22 is located between the two cathode plates 23, and magnets 25 are provided on the outside of the ion pump housing 21 in the area corresponding to the two cathode plates 23 through the magnet supports 24; a static magnetic field is formed between the two magnets; The ion pump housing 21 is made of microcrystalline glass, which is either formed by integral molding or by photopolymer bonding or low-temperature bonding of multiple single microcrystalline glass elements, and the inner wall is chemically polished. The magnet support 24 is a detachable structure; The electrode 26 is made of a metal material with a low outgassing rate, including oxygen-free copper or platinum, and is installed on the ion pump housing 21 by ceramic metallization sealing technology. The anode cylinder 22 is placed between two cathode plates 23. A high voltage of 1kV-10kV is applied through the electrode 26, and high vacuum preparation is achieved under the magnetic field of 0.1-0.5T formed by the magnet 25.

[0011] Furthermore, the getter pump section 3 includes: a getter pump housing 31 and a getter 32 disposed inside the getter pump housing 31; The getter pump housing 31 is made of microcrystalline glass and is formed by integral molding or by photopolymer bonding or low-temperature bonding of multiple individual microcrystalline glass elements. The inner wall is chemically polished. The getter 32 is a non-evaporative getter that can continuously adsorb gas molecules after being activated at high temperature.

[0012] Furthermore, the atom preparation region 4 includes: a preparation region shell 41 and a gaseous atom releasing agent 42 disposed within the preparation region shell 41; The shell 41 of the preparation area is made of microcrystalline glass and is obtained by integral molding or by photopolymer bonding or low-temperature bonding of multiple single microcrystalline glass elements. The inner wall is chemically polished. The gaseous atom releasing agent 42 is a metal compound that can release adsorbed gases or undergo a reduction reaction to release elemental metal vapors when heated.

[0013] Furthermore, the high-vacuum, low-permeability microcrystalline glass cavity is used for quantum sensors and quantum computers based on cold atom systems.

[0014] A method for preparing a high-vacuum, low-permeability microcrystalline glass cavity includes the following steps: S1: Assemble the cavity: Except for magnet 25, assemble and install ion pump part 2, getter pump part 3, atomic preparation region part 4, and vacuum pre-preparation part 5 respectively; connect cavity 11 with ion pump part 2, getter pump part 3, and atomic preparation region part 4, using photopolymer bonding or low-temperature bonding; place cover plate 16 at the center of the platform of vacuum threaded rod 53, connecting cavity 11 with vacuum pre-preparation part 5 using indium sealing, leaving a 3-7mm gap between cover plate 16 and cavity 11; wherein, vacuum pre-preparation part 5 includes metal shell 51, flange interface 52, and vacuum threaded rod 53; the metal shell 51 is made of titanium alloy with a thermal expansion coefficient similar to that of microcrystalline glass; the metal shell 51 is sealed to cavity 11 by indium sealing; the top of vacuum threaded rod 53 is provided with a flat platform to support cover plate 16 and realize relative movement between cover plate 16 and cavity 11; S2: Vacuum pre-evacuation: Connect the vacuum leak detector to the flange interface 52 to check the leak and verify the sealing of the chamber 11 with the ion pump part 2, the getter pump part 3, and the atom preparation area part 4; after the sealing is complete, connect the molecular pump group to the flange interface 52 and start it. Place the assembled structure in an environment below 100°C for low-temperature baking for 3-7 days. S3: High-temperature baking of components: Induction heating coils are surrounded around the ion pump section 2, getter pump section 3, and atom preparation area section 4 respectively. Each coil is turned on alternately to perform local high-temperature treatment on the internal metal or metal compound material. The baking lasts for 3-7 days. S4: Sealing the vent hole: Rotate the threaded rod 53 to bring the cover plate 16 close to the cavity 11 until it contacts, and achieve a sealed connection between the cover plate 16 and the cavity 11 by light adhesive bonding; S5: Remove vacuum pre-preparation part 5: Remove the molecular pump group, surround the metal shell 51 with an induction heating coil, heat to 100-150°C and maintain until the indium sealing area falls off, so as to separate the vacuum pre-preparation part 5 from the cavity 11. S6: Start the vacuum chamber components: Install the magnet bracket 24 and magnet 25 to the periphery of the ion pump housing 21 of the ion pump part 2, and connect the electrode 26 to the high voltage to start the ion pump; activate the getter 32 by laser irradiation to start the getter pump; activate the gaseous atom releasing agent 42 by laser irradiation to achieve gaseous atom preparation.

[0015] Beneficial effects: The present invention achieves and maintains an extremely clean and stable high vacuum environment through the synergistic effect of the following four technical features: 1. Adhesive-free vacuum sealing: The entire system (including the main cavity and pump component interface) is made of microcrystalline glass and sealed entirely through optical adhesive bonding or low-temperature bonding technology. This technology eliminates the need for any intermediate adhesives, achieving direct fusion of atomically flat surfaces at the molecular level to form a monolithic all-microcrystalline glass vacuum system, fundamentally eliminating the outgassing pollution from organic adhesives and traditional solders.

[0016] 2. High-Temperature Baking Degassing: Thanks to the excellent thermal stability and all-inorganic structure of the microcrystalline glass, the entire cavity system can withstand prolonged baking degassing (step S3). By using an induction coil to locally heat-treat the metal components such as the electrodes and getter inside the ion pump, adsorbed gas molecules can be thoroughly and quickly removed, significantly accelerating the exhaust process and achieving an ultimate vacuum level that is difficult to reach with traditional methods. At the same time, the directional heating method avoids excessive temperature rise in other areas of the cavity, which could cause vacuum failure (such as the indium-sealed interface in the vacuum pre-preparation section). The detachable magnet structure in the ion pump prevents the magnet from demagnetizing due to overall heating.

[0017] 3. No metal piping for additional venting: During the core vacuum maintenance phase, after initial vacuuming and baking are completed via the detachable vacuum pre-preparation section 5, this section is completely removed, and the vent is permanently sealed using a movable cover plate 16 bonded with photoresist. This ensures that the final working chamber contains no internal metal connecting pipes, metal flanges, or metal housings, eliminating the largest source of venting within the vacuum chamber—metal—and achieving a fully microcrystalline glass environment inside the chamber.

[0018] 4. Composite Pump Unit Pumping: The system integrates two high-vacuum maintenance pump units using low-permeability microcrystalline glass pump housings: ion pump section 2 and getter pump section 3. The ion pump ionizes and adsorbs gas molecules through electric and magnetic fields, achieving high pumping speeds for reactive gases; the non-evaporative getter pump has extremely high adsorption capacity for small molecule gases such as hydrogen. Both work collaboratively within a clean chamber free of metal venting, enabling long-term, active maintenance of the required ultra-high vacuum. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of a high-vacuum, low-permeability microcrystalline glass cavity according to the present invention.

[0021] Among them, there are microcrystalline glass vacuum chamber 1, ion pump section 2, getter pump section 3, atom preparation region section 4, and vacuum pre-preparation section 5; Chamber 11, ion pump interface 12, getter pump interface 13, exhaust interface 14, experimental interface 15, and cover plate 16; Ion pump housing 21, anode cylinder 22, cathode plate 23, magnet support 24, magnet 25, electrode 26; Getter pump housing 31, getter 32; Preparation zone shell 41, gaseous atom releasing agent 42; Metal housing 51, flange interface 52, vacuum threaded rod 53. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.

[0024] In the description of this invention, it should be noted that the directions or positional relationships indicated by terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing and simplifying the invention, and should not be construed as limiting the invention. Furthermore, the use of ordinal numbers (e.g., "first and second," etc.) is for distinguishing objects and is not limited to this order, and should not be construed as indicating or implying relative importance.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly, encompassing both direct connection and indirect connection via an intermediate medium. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0026] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited in each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0028] This invention discloses a high-vacuum, low-permeability microcrystalline glass cavity and its vacuum preparation method, belonging to the fields of vacuum technology and quantum precision measurement equipment. The structure includes a fully microcrystalline glass vacuum cavity, an ion pump section, a getter pump section, and an atom preparation region, all sealed together by photopolymer bonding or low-temperature bonding technology, forming an integral, glue-free vacuum sealing system. A detachable magnet structure is used to realize the ion pump within the microcrystalline glass shell, replacing the traditional metal shell ion pump, and it can withstand high-temperature baking. The method utilizes the detachable vacuum pre-preparation section for vacuum pre-evacuation and low-temperature baking, followed by high-temperature baking and degassing of the internal metal components through induction heating. Then, a movable cover plate is used to permanently seal the cavity using photopolymer bonding, and the vacuum pre-preparation section is removed, thereby completely eliminating additional gas release from the metal pipelines within the core working cavity. Finally, the composite pump group consisting of the internal ion pump and getter pump is activated to maintain a high vacuum for a long period. The method significantly reduces the permeation rate and outgassing rate of the gas inside the cavity, achieving an ultra-high vacuum environment (10⁻⁶). -8 The long-term stability of Pa) is maintained.

[0029] This invention achieves a clean, stable, and high-vacuum environment suitable for cold atom quantum technology through the synergistic effect of four key features: glue-free sealing, high-temperature baking, metal-free piping, and a composite pump assembly. By employing an ion pump with a microcrystalline glass shell and integrating it with the microcrystalline glass vacuum chamber, long-term stability of the ultra-high vacuum environment is maintained, while simultaneously meeting the miniaturization and integration requirements of cold atom interferometers.

[0030] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are intended to explain the present invention, but not to limit its scope.

[0031] The present invention provides a high-vacuum, low-permeability microcrystalline glass cavity, comprising: a microcrystalline glass vacuum cavity 1, an ion pump section 2, a getter pump section 3, and an atomic preparation region section 4; wherein, the microcrystalline glass vacuum cavity 1 comprises: a cavity body 11, an ion pump interface 12, a getter pump interface 13, an exhaust interface 14, an experimental interface 15 disposed on each side wall of the cavity body 11, and a cover plate 16 for covering the exhaust interface 14; the microcrystalline glass vacuum cavity 1 is connected to the ion pump section 2, the getter pump section 3, and the atomic preparation region section 4 by photopolymer bonding or low-temperature bonding and is connected to the ion pump interface 12, the getter pump interface 13, and the experimental interface 15.

[0032] In one possible embodiment, the cavity 11 is formed by integral molding or by splicing multiple microcrystalline glass windows through photopolymer bonding or low-temperature bonding to form a polyhedral structure.

[0033] In one possible embodiment, the inner wall of the cavity 11 is chemically polished to keep it smooth, thereby removing surface microcracks and reducing the amount of venting.

[0034] In one possible embodiment, the ion pump interface 12, getter pump interface 13, exhaust interface 14, and experimental interface 15 are circular holes machined on the cavity 11, with a diameter of 4-20 mm.

[0035] In one possible embodiment, the outer surface of the cavity 11 is within a 5mm area adjacent to each of the interfaces: the ion pump interface 12, the getter pump interface 13, the exhaust interface 14, and the experimental interface 15. The outer edge of the 5mm area is polished without scratches.

[0036] In one possible embodiment, the contact area between the outer surface of the cavity 11 and the cover plate 16 is a glossy adhesive area, and the outer edge 5mm area is polished without scratches.

[0037] In one possible embodiment, the glass-ceramic is lithium aluminum silicon glass-ceramic or magnesium aluminum silicon glass-ceramic, with a crystalline phase content of not less than 50% and a coefficient of thermal expansion of less than 5 × 10⁻⁶. -6 / K.

[0038] In one possible embodiment, the ion pump section 2 includes: an ion pump housing 21, a plurality of anode cylinders 22, two cathode plates 23, two magnet supports 24, two magnets 25, and electrodes 26; wherein, the two cathode plates 23 are arranged in parallel inside the ion pump housing 21, the array of anode cylinders 22 is located between the two cathode plates 23, and magnets 25 are provided on the outer side of the ion pump housing 21 in the region corresponding to the two cathode plates 23 via the magnet supports 24; a static magnetic field is formed between the two magnets; The ion pump housing 21 is made of microcrystalline glass, which is either formed by integral molding or by photopolymer bonding or low-temperature bonding of multiple single microcrystalline glass elements, and the inner wall is chemically polished. The magnet support 24 is a detachable structure; The electrode 26 is made of a metal material with a low outgassing rate, including oxygen-free copper or platinum, and is installed on the ion pump housing 21 by ceramic metallization sealing technology. The anode cylinder 22 is placed between two cathode plates 23. A high voltage of 1kV-10kV is applied through the electrode 26, and high vacuum preparation is achieved under the magnetic field of 0.1-0.5T formed by the magnet 25.

[0039] In one possible embodiment, the getter pump section 3 includes: a getter pump housing 31 and a getter 32 disposed inside the getter pump housing 31; The getter pump housing 31 is made of microcrystalline glass and is formed by integral molding or by photopolymer bonding or low-temperature bonding of multiple individual microcrystalline glass elements. The inner wall is chemically polished. The getter 32 is a non-evaporative getter that can continuously adsorb gas molecules after being activated at high temperature.

[0040] In one possible embodiment, the atom preparation region portion 4 includes: a preparation region housing 41 and a gaseous atom releasing agent 42 disposed within the preparation region housing 41; The shell 41 of the preparation area is made of microcrystalline glass and is obtained by integral molding or by photopolymer bonding or low-temperature bonding of multiple single microcrystalline glass elements. The inner wall is chemically polished. The gaseous atom releasing agent 42 is a metal compound that can release adsorbed gases or undergo a reduction reaction to release elemental metal vapors when heated.

[0041] In one possible embodiment, the high-vacuum, low-permeability microcrystalline glass cavity is used for quantum sensors and quantum computers based on cold atom systems.

[0042] A method for preparing a high-vacuum, low-permeability microcrystalline glass cavity includes the following steps: S1: Assemble the cavity: Except for magnet 25, assemble and install ion pump part 2, getter pump part 3, atomic preparation region part 4, and vacuum pre-preparation part 5 respectively; connect cavity 11 with ion pump part 2, getter pump part 3, and atomic preparation region part 4, using photopolymer bonding or low-temperature bonding; place cover plate 16 at the center of the platform of vacuum threaded rod 53, connecting cavity 11 with vacuum pre-preparation part 5 using indium sealing, leaving a 3-7mm gap between cover plate 16 and cavity 11; wherein, vacuum pre-preparation part 5 includes metal shell 51, flange interface 52, and vacuum threaded rod 53; the metal shell 51 is made of titanium alloy with a thermal expansion coefficient similar to that of microcrystalline glass; the metal shell 51 is sealed to cavity 11 by indium sealing; the top of vacuum threaded rod 53 is provided with a flat platform to support cover plate 16 and realize relative movement between cover plate 16 and cavity 11; S2: Vacuum pre-evacuation: Connect the vacuum leak detector to the flange interface 52 to check the leak and verify the sealing of the chamber 11 with the ion pump part 2, the getter pump part 3, and the atom preparation area part 4; after the sealing is complete, connect the molecular pump group to the flange interface 52 and start it. Place the assembled structure in an environment below 100°C for low-temperature baking for 3-7 days. S3: High-temperature baking of components: Induction heating coils are surrounded around the ion pump section 2, getter pump section 3, and atom preparation area section 4 respectively. Each coil is turned on alternately to perform local high-temperature treatment on the internal metal or metal compound material. The baking lasts for 3-7 days. S4: Sealing the vent hole: Rotate the threaded rod 53 to bring the cover plate 16 close to the cavity 11 until it contacts, and achieve a sealed connection between the cover plate 16 and the cavity 11 by light adhesive bonding; S5: Remove vacuum pre-preparation part 5: Remove the molecular pump group, surround the metal shell 51 with an induction heating coil, heat to 100-150°C and maintain until the indium sealing area falls off, so as to separate the vacuum pre-preparation part 5 from the cavity 11. S6: Start the vacuum chamber components: Install the magnet bracket 24 and magnet 25 to the periphery of the ion pump housing 21 of the ion pump part 2, and connect the electrode 26 to the high voltage to start the ion pump; activate the getter 32 by laser irradiation to start the getter pump; activate the gaseous atom releasing agent 42 by laser irradiation to achieve gaseous atom preparation. Example 1: Detailed Construction of a High-Vacuum, Low-Permeability Microcrystalline Glass Cavity Construction of the microcrystalline glass vacuum cavity 1: Material preparation: The preferred coefficient of thermal expansion is 10. -6 Microcrystalline glass with a K value below 1000 K is used as the raw material. After nucleation and crystallization treatment, the crystalline phase content of this material can reach more than 70%, ensuring that it has near-zero thermal expansion characteristics, thus possessing extremely high thermal stability and structural stability.

[0043] Cavity 11 molding: Two optional options are available: Option A (Integrated Molding): Using precision CNC grinding and ultrasonic machining technology, a single piece of microcrystalline glass blank is processed into the designed polyhedral structure (such as a cube or hexagonal prism). This option offers the highest structural strength and is seamless.

[0044] Option B (Assembly Forming): First, multiple planar microcrystalline glass windows are prepared. The bonding surfaces of each window require ultra-precision polishing to achieve an optical level surface roughness Ra < 0.5 nm. Then, in a cleanroom environment, the windows are bonded together in pairs using photoadhesive bonding or low-temperature bonding techniques. Photoadhesive bonding involves initial alignment and adsorption at room temperature using van der Waals forces, followed by rearranging the silicon-oxygen bonds at the contact interface under specific temperature and pressure (e.g., 300°C, slight pressure) to form strong Si-O-Si covalent bonds, thus achieving a permanent molecular-level seal. Low-temperature bonding involves pre-treating the window surface at room temperature using an alkaline solution, followed by dehydration of the hydroxyl groups on both sides of the contact interface under room temperature and slight pressure, achieving strong Si-O-Si covalent bonds.

[0045] Interface processing and treatment: On the formed cavity 11, an ion pump interface 12, a getter pump interface 13, an exhaust interface 14, and an experimental interface 15 are machined using a diamond drill bit. The diameter of the circular holes is preferably 8 mm. After processing, the 5 mm wide annular area on the outer edge of all interfaces is finely polished to form a gluing area. This area must be free of any scratches or defects in preparation for subsequent bonding with other microcrystalline glass components.

[0046] Inner wall treatment: All surfaces inside cavity 11 must be chemically polished. For example, etching with a mixed solution of hydrofluoric acid and nitric acid can effectively remove subsurface microcracks introduced by machining, making the inner wall atomically smooth, thereby minimizing surface area and potential sources of venting.

[0047] Optical thin film deposition: Based on the optical path design, antireflection films (for specific laser wavelengths, such as 780nm for rubidium atomic systems or 852nm for cesium atomic systems) or high reflectivity films are deposited on the outer surface of specific cavity windows using ion beam sputtering technology to meet the requirements of different modulated laser incident cavities in cold atom experiments.

[0048] Construction of Ion Pump Part 2: Ion pump housing 21: Its manufacturing process is similar to that of cavity 11, preferably integral molding to ensure strength. The shape of the internal cavity must match the anode cylinder 22 and cathode plate 23.

[0049] Electrode and Seal: Electrode 26 is made of ultra-high purity oxygen-free copper. Its sealing with the microcrystalline glass ion pump housing 21 is a key technical challenge. We employ ceramic metallization sealing technology: first, a chromium-copper composite film is formed on the area to be sealed on the microcrystalline glass using magnetron sputtering; then, the oxygen-free copper electrode is brazed to this metallized area using silver-copper eutectic solder in a vacuum furnace at approximately 800°C. This connection is an inorganic seal with an extremely low outgassing rate and can withstand subsequent high-temperature baking.

[0050] Construction of getter pump section 3 and atom preparation region section 4: The getter pump housing 31 and the preparation zone housing 41 are constructed in the same manner as the ion pump housing 21.

[0051] Getter 32: A non-evaporable getter tablet made of zirconium-vanadium-iron alloy (Zr-V-Fe). This getter is in a passivated state before activation.

[0052] Gaseous atom release agent 42: High-purity rubidium chromium salt (Rb2CrO4) or similar alkali metal / alkaline earth metal chloride particles are selected as solid source.

[0053] Construction of vacuum pre-preparation section 5 Metal casing 51: Made of national standard TC4 titanium alloy, whose coefficient of thermal expansion is similar to that of the selected microcrystalline glass in the range of room temperature to 300°C, which can reduce thermal stress.

[0054] Indium sealing design: A shallow groove with a depth of approximately 0.2 mm is machined on the contact surface between the titanium alloy flange and cavity 11 to accommodate a high-purity indium wire (purity > 99.99%). When the flange is tightened by bolts, the indium undergoes plastic deformation, filling all microscopic imperfections to form a reliable vacuum seal.

[0055] Example 2: Detailed Flowchart of Vacuum Preparation Method S1: Assemble the cavity In a Class 10,000 cleanroom, the anode cylinder 22 and cathode plate 23 are installed inside the ion pump housing 21, and the electrodes 26 are welded on to form an ion pump assembly (excluding magnets). Similarly, the getter 32 is loaded into the getter pump housing 31, and the gaseous atom release agent 42 is loaded into the preparation area housing 41.

[0056] Align the interface surfaces of the ion pump section 2, the getter pump section 3, and the atom preparation region section 4 with the corresponding interfaces of the cavity 11: ion pump interface 12, getter pump interface 13, and experimental interface 15, and connect them one by one using photopolymer bonding technology to form an integrated all-glass subsystem.

[0057] Place the cover plate 16 on the platform at the top of the vacuum threaded rod 53. Using bolts and indium wire, seal the metal housing 51 to the exhaust port 14 of the cavity via the flange interface 52 of the vacuum pre-fabrication section 5. At this time, precisely adjust the threaded rod 53 to maintain a distance of approximately 5 mm between the cover plate 16 and the exhaust port 14, forming an exhaust channel.

[0058] S2: Vacuum pre-extraction and low-temperature baking Connect the helium mass spectrometer leak detector to the auxiliary port of flange interface 52 to perform leak detection on the entire system and confirm that there is no leakage at the indium seal and other bonding points.

[0059] Remove the leak detector and connect the turbomolecular pump assembly to flange port 52. Start the molecular pump and pump the system to approximately 10... - 5 The basic vacuum degree is Pa.

[0060] Subsequently, the entire cavity system is placed in a temperature-controlled oven, or heated with heating tape wrapped around the outside of the cavity, for low-temperature baking. The temperature is controlled at 80-100°C, and baking continues for 5 days. This process effectively removes water vapor and other volatile contaminants physically adsorbed on the material surface.

[0061] S3: High-temperature baking of key components Localized high-temperature baking is performed under continuous pumping conditions. This is the key to achieving ultra-high vacuum.

[0062] High-frequency induction heating coils are tightly wound around the exterior of the shells of the ion pump section 2, the getter pump section 3, and the atom preparation region section 4, respectively.

[0063] The coils are alternately activated. By controlling the power and time of induction heating, the titanium electrodes 22 and 23 inside the ion pump can be heated to approximately 600°C, the getter 32 to approximately 400°C (in preparation for its subsequent activation), and the atom-releasing agent 42 to approximately 300°C, below its decomposition critical temperature, to expel its adsorbed gases. This localized high temperature can excite the gas within the bulk phase of the material to diffuse outward and be rapidly pumped away by the molecular pump, lasting for 3-7 days.

[0064] S4: Seal the vent and S5: Remove the vacuum pre-preparation section When the system vacuum level stabilizes at 10 -6 When the pressure (Pa) is even higher, sealing begins.

[0065] Slowly and smoothly rotate the vacuum threaded rod 53 from outside the cavity to push the cover plate 16 forward until it comes into close contact with the edge of the polished exhaust port 14 on the cavity 11. Since both surfaces are atomically smooth and clean, a permanent vacuum seal can be automatically achieved at room temperature through photopolymer bonding.

[0066] After sealing is complete, shut down and remove the molecular pump assembly.

[0067] The titanium alloy metal shell 51 is surrounded by an induction heating coil and heated to a temperature higher than the melting point of indium, such as 120°C, and maintained until the indium sealing layer melts. At this point, the vacuum pre-preparation section 5 can be cleanly separated from the main cavity under gravity or slight external force. Thus, the system becomes a completely sealed, all-microcrystalline glass vacuum cavity without any internal metal connecting pipes.

[0068] S6: Start the vacuum chamber components Magnet 25 is mounted on detachable magnet bracket 24, and then the entire bracket is fixed to the outside of ion pump housing 21 of ion pump part 2 to form a confinement magnetic field of about 0.1-0.5T.

[0069] Apply a DC high voltage of 1kV-10kV to electrode 26 and start the ion pump.

[0070] The getter 32 is irradiated with a near-infrared laser (e.g., 808nm) introduced by an optical fiber, which instantly and locally heats it to the activation temperature (~450°C), thus completing the activation and starting the getter pump.

[0071] Similarly, another laser beam is used to irradiate the gaseous atom release agent 42 to near or above the decomposition temperature, causing it to undergo a thermal decomposition reaction and release the desired alkali metal atoms or alkaline earth metal vapor.

[0072] The high-vacuum, low-permeability, low-magnetic-noise, and high-optical-flux microcrystalline glass cavity prepared by the above method is an ideal platform for constructing quantum sensors (such as atomic interferometers, gravimeters, gyroscopes, and atomic clocks) and quantum computers based on cold atom systems. Cold atoms can be confined and coherently manipulated within it for extended periods, providing the necessary physical environment for achieving high-precision quantum measurement and large-scale qubit arrays.

[0073] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A high-vacuum, low-permeability microcrystalline glass cavity, characterized in that, include: The microcrystalline glass vacuum chamber (1), the ion pump section (2), the getter pump section (3), and the atom preparation region section (4) are provided. The microcrystalline glass vacuum chamber (1) includes: a cavity (11), an ion pump interface (12), a getter pump interface (13), an exhaust interface (14), an experimental interface (15) provided on each side wall of the cavity (11), and a cover plate (16) for covering the exhaust interface (14). The microcrystalline glass vacuum chamber (1) is connected to the ion pump section (2), the getter pump section (3), and the atom preparation region section (4) by photopolymer bonding or low-temperature bonding and is connected to the ion pump interface (12), the getter pump interface (13), and the experimental interface (15).

2. The high-vacuum, low-permeability microcrystalline glass cavity according to claim 1, characterized in that, The ion pump interface (12), getter pump interface (13), exhaust interface (14) and experimental interface (15) are circular holes machined on the cavity (11), with a diameter of 4-20 mm.

3. The high-vacuum, low-permeability microcrystalline glass cavity according to claim 1, characterized in that, The outer surface of the cavity (11) is within a 5mm area adjacent to each of the interfaces: ion pump interface (12), getter pump interface (13), exhaust interface (14), and experimental interface (15). The outer edge of the 5mm area is polished without scratches.

4. The high-vacuum, low-permeability microcrystalline glass cavity according to claim 1, characterized in that, The contact area between the outer surface of the cavity (11) and the cover plate (16) is a glossy adhesive area, and the outer edge 5mm area is polished without scratches.

5. The high-vacuum, low-permeability microcrystalline glass cavity according to claim 1, characterized in that, The microcrystalline glass is lithium aluminum silicon microcrystalline glass or magnesium aluminum silicon microcrystalline glass, with a crystalline phase content of not less than 50% and a coefficient of thermal expansion of less than 5 × 10⁻⁶. -6 / K.

6. The high-vacuum, low-permeability microcrystalline glass cavity according to claim 1, characterized in that, The ion pump part (2) includes: an ion pump housing (21), multiple anode cylinders (22), two cathode plates (23), two magnet supports (24), two magnets (25), and electrodes (26); wherein, the two cathode plates (23) are arranged in parallel inside the ion pump housing (21), the array of anode cylinders (22) is located between the two cathode plates (23), and magnets (25) are provided on the outside of the ion pump housing (21) in the area corresponding to the two cathode plates (23) through the magnet supports (24); a static magnetic field is formed between the two magnets; The ion pump housing (21) is made of microcrystalline glass, which is obtained by integral molding or by photopolymer bonding or low-temperature bonding of multiple single microcrystalline glass elements, and the inner wall is chemically polished. The magnet bracket (24) is a detachable structure; The electrode (26) is made of a metal material with a low outgassing rate, including oxygen-free copper or platinum, and is installed on the ion pump housing (21) by ceramic metallization sealing technology. The anode cylinder (22) is placed between two cathode plates (23), and a high voltage of 1kV-10kV is applied through the electrode (26) to achieve high vacuum preparation under the magnetic field of 0.1-0.5T formed by the magnet (25).

7. The high-vacuum, low-permeability microcrystalline glass cavity according to claim 1, characterized in that, The getter pump section (3) includes: a getter pump housing (31) and a getter (32) disposed inside the getter pump housing (31). The getter pump housing (31) is made of microcrystalline glass and is obtained by integral molding or by light adhesive bonding or low temperature bonding of multiple single microcrystalline glass elements. The inner wall is chemically polished. The getter (32) is a non-evaporative getter that can continuously adsorb gas molecules after being activated at high temperature.

8. The high-vacuum, low-permeability microcrystalline glass cavity according to claim 1, characterized in that, The atomic preparation region (4) includes: a preparation region shell (41) and a gaseous atomic release agent (42) disposed within the preparation region shell (41). The shell (41) of the preparation area is made of microcrystalline glass and is obtained by integral molding or by photopolymer bonding or low-temperature bonding of multiple single microcrystalline glass elements. The inner wall is chemically polished. The gaseous atom release agent (42) is a metal compound that can release adsorbed gas or undergo a reduction reaction to release metal elemental vapor by heating.

9. The high-vacuum, low-permeability microcrystalline glass cavity according to claim 1, characterized in that, The high-vacuum, low-permeability microcrystalline glass cavity is used for quantum sensors and quantum computers based on cold atom systems.

10. A method for preparing a high-vacuum, low-permeability microcrystalline glass cavity, characterized in that, Includes the following steps: S1: Assemble the cavity: Except for the magnet (25), assemble and install the ion pump part (2), getter pump part (3), atomic preparation region part (4), and vacuum pre-preparation part (5) respectively; connect the cavity (11) with the ion pump part (2), getter pump part (3), and atomic preparation region part (4) by photopolymer bonding or low-temperature bonding; place the cover plate (16) at the center of the platform of the vacuum threaded rod (53), connect the cavity (11) with the vacuum pre-preparation part (5) by indium sealing, so that the cover plate (16) A 3-7mm gap is left between the vacuum pre-preparation part (5) and the cavity (11); wherein, the vacuum pre-preparation part (5) includes a metal shell (51), a flange interface (52) and a vacuum threaded rod (53); the metal shell (51) is made of titanium alloy with a thermal expansion coefficient similar to that of microcrystalline glass; the metal shell (51) is sealed to the cavity (11) by indium sealing; the top of the vacuum threaded rod (53) is provided with a flat platform for supporting the cover plate (16) and realizing the relative movement between the cover plate (16) and the cavity (11); S2: Vacuum pre-evacuation: Connect the vacuum leak detector to the flange interface (52) to perform leak detection and verify the sealing performance of the cavity (11) with the ion pump part (2), the getter pump part (3), and the atom preparation area part (4); after the sealing is complete, connect the molecular pump group to the flange interface (52) and start it. Place the assembled structure in an environment below 100°C for low-temperature baking for 3-7 days. S3: High-temperature baking of components: Induction heating coils are surrounded around the ion pump section (2), getter pump section (3), and atom preparation area section (4) respectively. Each coil is turned on alternately to perform local high-temperature treatment on the internal metal or metal compound material. The baking lasts for 3-7 days. S4: Seal the vent hole: Rotate the threaded rod (53) to bring the cover plate (16) close to the cavity (11) until it contacts, and achieve a sealed connection between the cover plate (16) and the cavity (11) by light adhesive bonding; S5: Remove the vacuum pre-preparation part (5): Remove the molecular pump group, surround the induction heating coil around the metal shell (51), heat to 100-150°C and maintain until the indium sealing area falls off, so as to separate the vacuum pre-preparation part (5) from the cavity (11); S6: Start the vacuum chamber components: Install the magnet bracket (24) and magnet (25) to the periphery of the ion pump housing (21) of the ion pump part (2), and connect the electrode (26) to the high voltage to start the ion pump; activate the getter (32) by laser irradiation and start the getter pump; activate the gaseous atom release agent (42) by laser irradiation to realize the preparation of gaseous atoms.

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