Coating atomic gas chamber and manufacturing method thereof

Abstract

The invention discloses a coated atomic gas chamber and a preparation method thereof, and particularly relates to the technical field of quantum measurement and sensing. The coating atomic gas chamber comprises an exhaust pipe, the exhaust pipe is communicated with a gas storage chamber main body, and the inner sides and the outer sides of the exhaust pipe, the gas storage chamber main body and the cover plate are all coated with protective films. The manufacturing method comprises the following steps: hermetically connecting the exhaust pipe with the gas storage chamber main body, and plating protective films on the exhaust pipe, the gas storage chamber main body and the cover plate; the coated gas storage chamber main body is hermetically connected with the cover plate to form a first atomic gas chamber; filling the first atomic gas chamber with alkali metal and other working gases, and then taking down the first atomic gas chamber from the vacuum inflation table; and cleaning the outer surface of the first atomic gas chamber, and coating the outer surface of the first atomic gas chamber to obtain a second atomic gas chamber. By adopting the technical scheme provided by the invention, the problem that the precision of the sensor is influenced as materials such as borosilicate glass are easily corroded by alkali metal or permeated by gas at a relatively high temperature is solved, and the corrosion resistance and gas permeation resistance of the atomic gas chamber are improved.

Description

Technical Field

[0001] The present invention relates to the field of quantum measurement and sensing technology, and in particular to a film-coated atomic gas chamber and a preparation method thereof. Background Art

[0002] Alkali metal atoms (such as 133Cs, 87Rb, 85Rb, 23Na, 39K) have only one valence electron outside the nucleus and a simple energy level structure. It is easy to use lasers to control and measure their quantum states, so they have been widely used in the field of quantum measurement and sensing. Typical applications are: (1) Nuclear magnetic resonance gyroscopes usually use alkali metal atoms. The spin exchange optical pumping technology is used to polarize the spins of alkali metal atoms. The polarized alkali metal atoms are used to polarize the spins of inert gas nuclei on the one hand, and on the other hand, they are used to form an embedded magnetometer to detect nuclear spin motion information. This type of nuclear magnetic resonance gyroscope has the advantages of small size and high precision, and has great application potential in the field of inertial technology. (2) Atomic magnetometers use the changes in the precession frequency of alkali metal atoms with the external magnetic field to detect magnetic fields. They have extremely high sensitivity and do not require refrigeration devices. They have been widely used in defense, medical, geology and other fields. (3) Atomic clocks use the hyperfine energy level transitions of alkali metal atoms (such as 87Rb and 85Rb) to achieve frequency standards, which have important applications in positioning and timing.

[0003] In the above applications, excess alkali metals are usually sealed in a gas chamber composed of a transparent medium and heated to a certain temperature to convert the alkali metal into saturated vapor for use. In general, borosilicate glass is widely used due to its advantages such as easy pyrotechnic operation and good quality. However, borosilicate glass also has many problems, including but not limited to: (1) Borosilicate glass is easily corroded by alkali metals at higher temperatures, consuming alkali metals and generating chemical substances on the surface that affect sensing accuracy, such as Rb2O; (2) Borosilicate glass is easily permeated by helium, and is therefore not suitable for alkali metal gas chambers filled with helium or atomic gas chambers where helium is not desired to penetrate. Summary of the invention

[0004] The present invention aims to provide a film-coated atomic gas chamber and a preparation method thereof, which solves the problem that materials such as borosilicate glass are easily corroded by alkali metals or penetrated by gases at higher temperatures, thereby affecting the sensing accuracy.

[0005] In order to achieve the above-mentioned purpose, the technical scheme of the present invention is as follows: a coated atomic gas chamber, comprising an exhaust pipe, the exhaust pipe is connected to a gas storage chamber body with an opening on one side, a cover plate is welded at the opening of the gas storage chamber body, the exhaust pipe, the gas storage chamber body and the inner and outer sides of the cover plate are coated with a protective film, the protective film prevents the alkali metal atomic vapor or alkali metal layer in the atomic gas chamber from contacting and reacting with the inner wall of the atomic gas chamber, and reduces the permeability of helium.

[0006] Furthermore, the manufacturing method of the protective film is as follows:

[0007] S1, sealingly connecting the air extraction pipe to the gas storage chamber body, and coating the inner surfaces of the air extraction pipe, the gas storage chamber body and the cover plate in the first atomic gas chamber with a protective film;

[0008] S2, the gas storage chamber body and the cover plate are sealed and connected to form a first atomic gas chamber;

[0009] S3, connecting the first atomic gas chamber to a vacuum gas filling table after cleaning, filling the first atomic gas chamber with alkali metal and other working gases, and removing the first atomic gas chamber from the vacuum gas filling table after completion;

[0010] S4, cleaning the outer surface of the first atomic gas chamber filled with alkali metal, and coating the outer surface of the first atomic gas chamber with a protective film, thereby obtaining a second atomic gas chamber.

[0011] Furthermore, the protective film is one or more of an aluminum oxide film, a zirconium oxide film, and a magnesium oxide film, which can reduce the corrosion of alkali metals on the glass and reduce the penetration of helium.

[0012] Furthermore, the thickness of the protective film is 10 nm-1 μm.

[0013] Compared with the prior art, this solution has the following beneficial effects:

[0014] This solution eliminates or reduces the contact between alkali metal and glass by coating a protective film on the inner wall of the atomic gas chamber, thereby reducing the corrosion of the glass by the alkali metal and the consumption of the alkali metal, and at the same time, separating the alkali metal from the glass surface to avoid the influence of impurities on the glass surface on the alkali metal vapor quantum state; at the same time, the inner and outer walls of the atomic gas chamber are coated with a protective film, and the coating of the outer wall is carried out after the entire gas chamber is sealed and welded. The entire outer surface of the gas chamber is filmed, and the double-layer film can effectively reduce the rate of helium penetration out of the gas chamber, eliminate or reduce the rate of external helium penetration into the gas chamber, and improve the stability of the alkali metal atomic vapor quantum state inside the gas chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is an axonometric view of an internally coated atomic gas chamber of Example 1;

[0016] Figure 2 is an exploded view of an internally coated atomic gas chamber of Example 1;

[0017] Figure 3 is an axonometric view of an internally coated atomic gas chamber of Example 2;

[0018] Figure 4 This is a picture of the inner wall of the atomic gas chamber when an internally coated atomic gas chamber of Example 1 and Example 2 is used;

[0019] Figure 5 This is a picture of the inner wall of the atomic gas chamber when an internally coated atomic gas chamber of Example 1 is used. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below through specific embodiments:

[0021] The reference numerals in the drawings of the specification include: an air extraction pipe 1 , an air storage chamber body 2 , and a cover plate 3 .

[0022] Example 1

[0023] like Figure 1 and Figure 2 As shown, an internally coated atomic gas chamber includes an exhaust pipe 1, and the exhaust pipe 1 is connected to a gas storage chamber body 2 with an opening on one side. In this embodiment, the shape of the gas storage chamber body 2 is cylindrical, and one end of the gas storage chamber body 2 is sealed, and the other end is left with an opening for cleaning and coating treatment. A cover plate 3 is welded at the opening of the gas storage chamber body 2; a vent hole is also opened at the bottom center of the gas storage chamber body 2, and the exhaust pipe 1 is connected to the vent hole. The exhaust pipe 1, the gas storage chamber body 2 and the cover plate 3 are coated with a protective film on the inside and outside, and the protective film prevents the alkali metal atomic vapor or alkali metal layer in the atomic gas chamber from contacting and reacting with the atomic gas chamber, and reduces the permeability of small molecular gas atoms such as helium and hydrogen.

[0024] The production method of the protective film is as follows:

[0025] S1. First, weld the exhaust pipe 1 to the vent hole of the gas storage chamber body 2 by pyrotechnics or laser welding, and then seal one end of the cylindrical gas storage chamber body 2 (the connection method can be laser welding, pyrotechnics, optical glue, etc.), so as to obtain a gas storage chamber body 2 with one side unsealed, and the cover plate 3 matches the opening size of the gas storage chamber body 2.

[0026] S2. Use acid, deionized water and other cleaning agents to clean the inner side of the gas storage chamber body 2 and the cover plate 3 that are sealed and connected with the exhaust pipe 1, wash away the impurities on the surface, especially the impurities on the inner surface, and then use atomic layer deposition coating to coat a layer of protective film on the inner surface of the unsealed gas storage chamber body 2 and the side of the cover plate 3 that contacts the gas storage chamber body 2. Among them, the coating method adopts the atomic layer deposition method, and the protective film adopts one of aluminum oxide film, zirconium oxide, and magnesium oxide, and the thickness of the protective film is 10nm-1μm. After the coating is completed, the gas storage chamber body 2 and the cover plate 3 that are sealed and connected with the exhaust pipe 1 are cleaned with acid and deionized water, and then sealed and connected together (for example, the connection method is assembled together by laser welding or other methods). The exhaust pipe 1, the gas storage chamber body 2 and the cover plate 3 are assembled to form a first atomic gas chamber, in which the exhaust pipe 1 can be connected to the vacuum table.

[0027] S3, connecting the first atomic gas chamber to a vacuum inflation table after cleaning, filling the first atomic gas chamber with alkali metal and other working gases, and sealing and removing it from the vacuum inflation table after completion.

[0028] S4. Since the sealing part is treated at high temperature, the protective film coated on the sealing part may be damaged. The outer surface of the first atomic gas chamber filled with alkali metal is cleaned again, and a protective film is coated on the outer surface of the first atomic gas chamber by atomic layer deposition, thereby obtaining a second atomic gas chamber.

[0029] In this embodiment, the double coating method ensures that both the inner and outer surfaces of the atomic gas chamber are covered with good protective films, wherein the inner protective film simultaneously plays a role in reducing alkali metal corrosion and helium permeation, and the outer protective film plays a role in reducing helium permeability.

[0030] Example 2

[0031] like Figure 3 As shown, an internally coated atomic gas chamber includes an exhaust pipe 1, and the exhaust pipe 1 is connected to a gas storage chamber body 2 with an opening on one side. In this embodiment, the shape of the gas storage chamber body 2 is a rectangular parallelepiped or a cube, and the opening of the gas storage chamber body 2 can be welded to the cover plate 3; a vent hole is also opened at the bottom center of the gas storage chamber body 2, and the exhaust pipe 1 is sealed and connected to the gas storage chamber body 2 and connected to the vent hole. The exhaust pipe 1, the gas storage chamber body 2 and the cover plate 3 are coated with a protective film on the inside and outside, which prevents the alkali metal atomic vapor or alkali metal layer in the gas storage chamber 2 from contacting and reacting with the inner wall of the atomic gas chamber, and reduces the permeability of small molecular gas atoms such as helium and hydrogen.

[0032] The production method of the protective film is as follows:

[0033] S1. First, the exhaust pipe 1 is welded to the vent hole of the gas storage chamber body 2 by pyrotechnics or laser welding, so as to obtain the gas storage chamber body 2 with one side not sealed.

[0034] S2. Use acid, deionized water and other cleaning agents to clean the surface of the gas storage chamber body 2 and the cover plate 3 on the side where the exhaust pipe 1 is welded and not sealed, wash away the impurities and pollutants on the surface, and then use atomic layer deposition coating to coat a layer of protective film on the side of the gas storage chamber body 2 and the cover plate 3 in contact with the gas storage chamber 2 on the side where the exhaust pipe 1 is welded and not sealed. Among them, the coating method adopts atomic layer deposition, and the protective film adopts one or more of aluminum oxide film, zirconium oxide, and magnesium oxide, and the thickness of the protective film is 10nm-1μm. After the coating is completed, the gas storage chamber body 2 and the cover plate 3 on the side where the exhaust pipe 1 is welded and not sealed are cleaned with deionized water, and then sealed and connected together (for example, assembled together by laser welding) to obtain the first atomic gas chamber.

[0035] S3, after cleaning and other treatments, the first atomic gas chamber is connected to a vacuum inflation table, and alkali metal and other working gases are filled into the first atomic gas chamber. After completion, the first atomic gas chamber is sealed and removed from the vacuum inflation table.

[0036] S4. Since the sealing part of the first atomic gas chamber is subjected to high temperature treatment, the plated protective film may be damaged. In order to enhance the coating effect, the outer surface of the first atomic gas chamber filled with alkali metal is cleaned again, and a protective film is plated on the outer surface of the first atomic gas chamber by atomic layer deposition coating, thereby obtaining a second atomic gas chamber.

[0037] In this embodiment, the double coating method ensures that both the inner and outer surfaces of the atomic gas chamber are covered with a good protective film.

[0038] Comparative Example 1

[0039] The difference between this comparative example and Example 1 or 2 is that in this comparative example, the surface of the atomic gas chamber is not subjected to coating treatment, and a protective film is not produced, and the rest of the parts are exactly the same.

[0040] The atomic gas chamber of Example 1 or 2 and the atomic gas chamber of Comparative Example 1 were sealed with an excess of alkali metal, and after a period of operation, the following was obtained: Figure 4 and Figure 5 A picture of the inner wall of the atomic chamber, where Figure 4 It is the inner wall of the coated atomic chamber. Figure 5 It is the inner wall of the uncoated atomic gas chamber. Figure 4 and Figure 5 By comparison, Figure 5 Many corrosion spots appeared on the inner wall of the atomic gas chamber in the comparative example 1 which was not coated, while no corrosion spots appeared on the inner wall of the coated atomic gas chamber described in Examples 1 and 2, which shows that the coating of the present application played a good protective role and the effect was very significant.

[0041] The above are only embodiments of the present invention, and the common knowledge such as the known specific structures and / or characteristics in the scheme are not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A film-coated atomic gas chamber, characterized in that: The invention comprises an exhaust pipe, which is connected to a gas storage chamber body with an opening on one side, a cover plate is welded at the opening of the gas storage chamber body, and the exhaust pipe, the gas storage chamber body and the inner and outer sides of the cover plate are coated with a protective film, which prevents the alkali metal atomic vapor or alkali metal layer in the atomic gas chamber from contacting and reacting with the inner wall of the atomic gas chamber and reduces the permeability of helium.

2. The film-coating atomic gas chamber according to claim 1, characterized in that: The manufacturing method of the protective film is as follows: S1, sealingly connecting the air extraction pipe to the gas storage chamber body, and then coating the inner surfaces of the air extraction pipe, the gas storage chamber body and the cover plate in the first atomic gas chamber with a protective film; S2, the gas storage chamber body and the cover plate are sealed and connected to form a first atomic gas chamber; S3, connecting the first atomic gas chamber to a vacuum gas filling table after cleaning, filling the first atomic gas chamber with alkali metal and other working gases, and removing the first atomic gas chamber from the vacuum gas filling table after completion; S4, cleaning the outer surface of the first atomic gas chamber filled with alkali metal, and coating the outer surface of the first atomic gas chamber with a protective film, thereby obtaining a second atomic gas chamber.

3. The internal film-coated atomic gas chamber according to claim 2, characterized in that: The protective film is made of one or more of aluminum oxide film, zirconium oxide and magnesium oxide.

4. The internal film-coated atomic gas chamber according to claim 3, characterized in that: The thickness of the protective film is 10 nm-1 μm.

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