A temperature gradient test system suitable for a SERF inertial device

Abstract

A temperature gradient test system suitable for SERF inertial device mainly comprises: a gas chamber temperature gradient adjusting module and a gas chamber temperature gradient real-time monitoring module. The gas chamber temperature gradient adjusting module mainly comprises a temperature sensor, a high-precision temperature control circuit board, a plurality of non-magnetic electric heating films and a sliding rheostat. The temperature control circuit board cooperates with the sliding rheostat to stabilize and shape the temperature gradient of the gas chamber in different states. The gas chamber temperature gradient real-time monitoring module mainly collects the number and density information of interference fringes under different gas chamber temperature gradients through a CCD camera in real time, so as to realize real-time monitoring of the gas chamber temperature gradient.

Description

Technical Field

[0001] This invention relates to atomic spin inertial measurement technology, and in particular to a temperature gradient testing system suitable for SERF inertial devices. Background Technology

[0002] Atomic spin inertial measurement systems based on the Spin-Exchange Relaxation-Free (SERF) effect theoretically possess the potential for higher accuracy, smaller size, and lower cost compared to traditional inertial measurement instruments. They have broad applications in marine resource exploration, aerospace and other long-endurance, high-precision inertial navigation fields, and cutting-edge technologies such as CPT (charge-parity-time) symmetry breaking. However, the accuracy of SERF atomic spin inertial measurement devices is highly susceptible to temperature effects. The SERF state requires a non-magnetic electric heating module to heat the glass gas chamber to a high temperature. Since the gas chamber is located at the center of the non-magnetic electric heating module, a certain distance from the heating film, and undergoes heat exchange with the external environment through pumping and detection light-transmitting apertures, a temperature gradient is generated inside the gas chamber. This temperature gradient affects the atomic distribution within the gas chamber, thus impacting the accuracy of the SERF inertial measurement device. Therefore, how to test the impact of the temperature gradient inside the gas chamber of a SERF atomic spin inertial measurement device on its accuracy has become a pressing engineering problem. Therefore, it is urgent to develop a temperature gradient testing system suitable for the SERF atomic inertial measurement device. The gas chamber temperature gradient testing system of this invention can create the required gas chamber temperature gradient for experiments and achieve real-time monitoring of the gas chamber temperature gradient. This enables experimental testing of different gas chamber temperature gradients, which will lay a solid foundation for the future engineering application of atomic spin inertial measurement devices. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a temperature gradient testing system suitable for SERF inertial measurement devices. This system can shape different chamber temperature gradients according to experimental requirements and achieve real-time measurement of the chamber temperature gradient. This facilitates experimental testing of SERF inertial measurement devices under different chamber temperature gradient states. This invention is of great significance and value for evaluating the impact of chamber temperature gradients on the performance of SERF inertial measurement devices and for the engineering application of next-generation SERF atomic spin inertial measurement devices.

[0004] The technical solution of the present invention is as follows:

[0005] A temperature gradient testing system for SERF inertial measurement units is characterized by comprising a chamber temperature gradient adjustment module and a chamber temperature gradient real-time monitoring module. The chamber temperature gradient adjustment module is used to stably shape the temperature gradient inside the alkali metal chamber to meet the testing requirements of the SERF inertial measurement unit. The chamber temperature gradient real-time monitoring module achieves real-time monitoring of the chamber temperature gradient by acquiring information on the number and density of interference fringes formed by the detection laser penetrating the alkali metal chamber and the reference laser bypassing the alkali metal chamber under different chamber temperature gradients.

[0006] The gas chamber temperature gradient adjustment module acts directly on the alkali metal gas chamber and consists of a temperature sensor, a temperature control circuit board, multiple heating films, and a sliding rheostat. The set temperature is input to the temperature control circuit board via a computer, and the temperature sensor attached to the gas chamber with thermally conductive silicone provides real-time temperature feedback, thereby achieving closed-loop control of the average temperature of the gas chamber. At this time, by adjusting the resistance value of the sliding rheostat connected in series with each heating film, the internal temperature gradient distribution of the gas chamber is stably shaped under the stable gas chamber temperature.

[0007] The heating film is a non-magnetic electric heating film, the temperature sensor is a platinum resistance thermometer, and the temperature control circuit board adopts PID control technology.

[0008] The real-time temperature gradient monitoring module for the gas chamber includes a first beam splitter on the incident side of the detection laser and a second beam splitter on the exit side, both located in the alkali metal gas chamber. The first beam splitter splits the laser into two beams of equal intensity: a detection laser beam and a reference laser beam. The detection laser beam passes through the alkali metal gas chamber and reaches the second beam splitter. The reference laser beam passes through a first reflector and a second reflector in sequence and reaches the second beam splitter. The interference fringes formed by the convergence of the reference laser beam and the detection laser beam at the second beam splitter are captured by a CCD camera and uploaded to a computer in real time. The computer calculates the grayscale values ​​at different positions in the image to determine the temperature gradient corresponding to a pair of adjacent bright and dark fringes. By calculating the number and density of the bright and dark fringes, the magnitude and uniformity of the temperature gradient are obtained, thereby achieving real-time monitoring and reconstruction of the temperature gradient.

[0009] The real-time monitoring module for the gas chamber temperature gradient is mainly used for real-time monitoring and reconstruction of the gas chamber temperature gradient. The first laser beam emitted by the first laser passes sequentially through the first half-wave plate, the first polarizing beam splitter, the first liquid crystal, the second polarizing beam splitter, the second half-wave plate, the third polarizing beam splitter, the first beam expander, and the first beam splitter. The first beam splitter splits the laser beam into two laser beams with the same intensity. The detection laser beam passes through the alkali metal gas chamber and exits to the second beam splitter. The other reference laser beam passes sequentially through the first reflector and the second reflector. The reference laser beam and the detection laser beam merge at the second beam splitter and then enter the CCD camera.

[0010] The reflective side of the third polarizing beam splitter is connected to the first liquid crystal via a first photoelectric converter, so as to ensure the stability of the laser intensity through closed-loop control of light intensity.

[0011] Because of the temperature gradient at different locations in the alkali metal gas chamber, the refractive index changes at different locations in the gas chamber. After the detection laser and the reference laser are combined, the CCD camera will collect the alternating bright and dark interference fringes.

[0012] For a pair of adjacent bright and dark fringes captured by a CCD camera, the refractive index corresponding to the bright fringe is σ1, and the refractive index corresponding to the dark fringe is σ2. Then... Where λ is the wavelength, L is the length of the square air cell, and the refractive index σ is a function of density n as follows:

[0013]

[0014] Where n is the atomic density inside the gas chamber, c is the speed of light, f is the oscillator intensity, v is the laser frequency, and r e Let be the classical electron radius, q can be obtained from the atomic frequency response by fitting a Voigt line, and the density n is a function of temperature T as follows:

[0015]

[0016] Where T is temperature, n A With n B For each alkali metal, there is a constant.

[0017] The CCD camera uploads the obtained interference fringe image data to the computer in real time. By calculating the gray values ​​at different positions in the image, the temperature gradient corresponding to a pair of adjacent bright and dark fringes can be obtained. The magnitude and uniformity of the temperature gradient can be obtained by the number and density of the bright and dark fringes collected by the CCD camera, thus enabling real-time monitoring and reconstruction of the temperature gradient.

[0018] The technical effects of this invention are as follows: This invention provides a temperature gradient testing system suitable for SERF inertial measurement units, also known as a gas chamber temperature gradient testing system suitable for SERF atomic spin inertial measurement units. The gas chamber temperature gradient testing system for SERF atomic spin inertial measurement units mainly comprises a gas chamber temperature gradient adjustment module and a gas chamber temperature gradient real-time monitoring module. The gas chamber temperature gradient adjustment module mainly consists of a temperature sensor, a high-precision temperature control circuit board, multiple non-magnetic electric heating films, and a sliding rheostat. The cooperation between the temperature control circuit board and the sliding rheostat stabilizes and shapes the gas chamber temperature gradient under different states. The gas chamber temperature gradient real-time monitoring module mainly uses a CCD camera to collect information on the number and density of interference fringes under different gas chamber temperature gradients in real time, thereby realizing real-time monitoring of the gas chamber temperature gradient.

[0019] A chamber temperature gradient testing system suitable for SERF atomic spin inertial measurement devices is provided. The shape of the chamber and the number and adhesion method of the heating film are not limited according to this invention. Depending on the specific SERF inertial measurement device or magnetic measurement device, the shape of the chamber and the number and adhesion method of the heating film can be adjusted. All chamber temperature gradient testing systems designed according to the concept of this invention and suitable for SERF atomic spin inertial measurement or SERF magnetic measurement devices should be within the scope of protection of this patent. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a temperature gradient testing system for a SERF inertial device, which implements the present invention.

[0021] Figure 2 This is a schematic diagram of the air chamber temperature gradient adjustment module. Figure 2 It includes a computer (computer 26), a temperature control circuit board, and a first heating film (heating film 1). Figure 1 The middle part is marked as 30) and the second heating film (heating film 2, Figure 1 The components include: (marked as 30), first platinum resistance (platinum resistance 1) and second platinum resistance (platinum resistance 2), gas chamber (alkali metal gas chamber 29), oven (non-magnetic electric heating oven 31), and sliding rheostat.

[0022] The reference numerals in the attached figures are listed below: 1-First laser; 2-First half-wave plate; 3-First polarizing beam splitter; 4-First liquid crystal; 5-Second polarizing beam splitter; 6-Second half-wave plate; 7-Third polarizing beam splitter; 8-First photoelectric converter; 9-First beam expander; 10-First beam splitter; 11-First reflector; 12-Second reflector; 13-Second beam splitter; 14-CCD camera (CCD, charge coupled) 15-Second laser; 16-Third half-wave plate; 17-Fourth polarizing beam splitter; 18-Second liquid crystal; 19-Fifth polarizing beam splitter; 20-Second beam expander; 21-Third mirror; 22-Fourth half-wave plate; 23-Sixth polarizing beam splitter; 24-First quarter-wave plate; 25-Second photoelectric converter; 26-Computer; 27-Magnetic shielding barrel; 28-Triaxial magnetic compensation coil; 29-Alkali metal gas chamber; 30-Heating film; 31-Non-magnetic electric heating oven; 32-First laser beam; 33-Second laser beam. Detailed Implementation

[0023] The following is in conjunction with the attached diagram ( Figures 1-2 The invention will be described in the following sections and examples.

[0024] Figure 1 This is a schematic diagram of the structure of a temperature gradient testing system for a SERF inertial device, which implements the present invention. Figure 2 This is a schematic diagram of the air chamber temperature gradient adjustment module. (Reference) Figures 1 to 2As shown, a temperature gradient testing system suitable for SERF inertial measurement units includes a chamber temperature gradient adjustment module and a chamber temperature gradient real-time monitoring module. The chamber temperature gradient adjustment module is used to stabilize and shape the temperature gradient inside the alkali metal chamber to meet the testing requirements of the SERF inertial measurement unit. The chamber temperature gradient real-time monitoring module achieves real-time monitoring of the chamber temperature gradient by acquiring information on the number and density of interference fringes formed by the detection laser penetrating the alkali metal chamber and the reference laser bypassing the alkali metal chamber under different chamber temperature gradients. The chamber temperature gradient adjustment module acts directly on the alkali metal chamber and consists of a temperature sensor, a temperature control circuit board, multiple heating films, and a sliding rheostat. The set temperature is input to the temperature control circuit board via a computer, and the temperature sensor, which is attached to the vicinity of the chamber with thermally conductive silicone, provides real-time temperature feedback, thereby achieving closed-loop control of the average temperature of the chamber. At this time, by adjusting the resistance value of the sliding rheostat connected in series with each heating film, the internal temperature gradient distribution of the chamber is stably shaped under the stable chamber temperature condition. The heating film is a non-magnetic electric heating film, the temperature sensor is a platinum resistance thermometer, and the temperature control circuit board adopts PID control technology (PID, Proportional Integral Derivative). The real-time temperature gradient monitoring module of the gas chamber includes a first beam splitter 10 on the incident side of the detection laser and a second beam splitter 13 on the exit side, which are set in the alkali metal gas chamber 29. The first beam splitter 10 splits the laser into two beams of the same intensity: a detection laser beam and a reference laser beam. The detection laser beam passes through the alkali metal gas chamber 29 and reaches the second beam splitter 13. The reference laser beam passes through the first reflector 11 and the second reflector 12 in sequence and reaches the second beam splitter 13. The interference fringes after the reference laser beam and the detection laser beam merge at the second beam splitter 13 are acquired by the CCD camera 14 and uploaded to the computer 26 in real time. The computer 26 calculates the gray values ​​at different positions of the image to obtain the temperature gradient corresponding to a pair of adjacent bright and dark fringes. By calculating the number and density of the bright and dark fringes, the magnitude and uniformity information of the temperature gradient are obtained, so as to realize the real-time monitoring and reconstruction of the temperature gradient.

[0025] The real-time temperature gradient monitoring module for the gas chamber is mainly used for real-time monitoring and reconstruction of the temperature gradient in the gas chamber. The first laser beam 32 emitted by the first laser 1 passes sequentially through the first half-wave plate 2, the first polarizing beam splitter 3, the first liquid crystal 4, the second polarizing beam splitter 5, the second half-wave plate 6, the third polarizing beam splitter 7, the first beam expander 9, and the first beam splitter 10. The first beam splitter 10 splits the laser beam into two laser beams with the same intensity. The detection laser beam passes through the alkali metal gas chamber 29 and exits to the second beam splitter 13. The other reference laser beam passes sequentially through the first reflector 11 and the second reflector 12. The reference laser beam and the detection laser beam merge at the second beam splitter 13 and then enter the CCD camera 14. The reflecting side of the third polarizing beam splitter 7 is connected to the first liquid crystal 4 through the first photoelectric converter 8 to ensure the stability of the laser intensity through closed-loop intensity control. Because of the temperature gradient at different locations within the alkali metal gas chamber 29, the refractive index varies at different locations within the chamber. After the detection laser and the reference laser merge, the CCD camera 14 will acquire alternating bright and dark interference fringes. For a pair of adjacent bright and dark fringes acquired by the CCD camera 14, the refractive index corresponding to the bright fringe is σ1, and the refractive index corresponding to the dark fringe is σ2. Therefore, Where λ is the wavelength, L is the length of the square air cell, and the refractive index σ is a function of density n as follows:

[0026]

[0027] Where n is the atomic density inside the gas chamber, c is the speed of light, f is the oscillator intensity, v is the laser frequency, and r e Let be the classical electron radius, q can be obtained from the atomic frequency response by fitting a Voigt line, and the density n is a function of temperature T as follows:

[0028]

[0029] Where T is temperature, n A With n B For each alkali metal, there is a constant.

[0030] The CCD camera 14 uploads the obtained interference fringe image data to the computer 26 in real time. By calculating the gray values ​​at different positions in the image, the temperature gradient corresponding to a pair of adjacent bright and dark fringes can be obtained. The magnitude and uniformity of the temperature gradient can be obtained by the number and density of the bright and dark fringes collected by the CCD camera, thereby enabling real-time monitoring and reconstruction of the temperature gradient.

[0031] This invention provides a high-precision gas cell temperature gradient testing system suitable for SERF atomic spin inertial measurement devices. This system can shape gas cell temperature gradients in different states according to experimental requirements and realize real-time measurement of the gas cell temperature gradient. It helps to test the experimental testing of SERF inertial measurement devices under different gas cell temperature gradient states. This invention is of great significance and value for evaluating the impact of gas cell temperature gradients on the performance of SERF inertial measurement devices and for the engineering application of next-generation SERF atomic spin inertial measurement devices.

[0032] This invention provides a chamber temperature gradient testing system suitable for the SERF atomic spin inertial measurement device. The system mainly comprises a chamber temperature gradient adjustment module and a chamber temperature gradient real-time monitoring module. The chamber temperature gradient adjustment module mainly consists of a non-magnetic electric heating film distributed on different surfaces of the chamber, a temperature control circuit board, an oven, a platinum resistance thermometer, and a sliding rheostat connected in series with the heating film. The power ratio of the heating film on different surfaces of the glass chamber is adjusted by the sliding rheostat, thereby creating different chamber temperature gradients. The chamber temperature gradient real-time monitoring module mainly uses a CCD camera to collect the number and density of interference fringes under different chamber temperature gradients in real time, achieving real-time monitoring and reconstruction of the chamber temperature gradient.

[0033] Furthermore, the gas chamber temperature gradient adjustment module includes a square oven (31) with a non-magnetic heating film (30) attached to each side, an atomic gas chamber (29) placed inside the oven, and a platinum resistance thermometer for temperature measurement placed inside the oven.

[0034] Furthermore, to maintain a stable temperature gradient in the air chamber, each heating film (30) is connected to the temperature control circuit board in parallel. A high-precision platinum resistance thermometer is placed at the tail of the air chamber. Based on the temperature data obtained from the platinum resistance thermometer, the total voltage across the air chamber temperature gradient adjustment module is controlled in real time by the temperature control circuit board, thereby achieving stable closed-loop control of the air chamber temperature gradient. The heating power of a single heating film can be adjusted by connecting a sliding rheostat in series with each heating film to divide the voltage.

[0035] Furthermore, the temperature gradient testing module of the SERF inertial measurement device mainly includes a first laser (1), a first laser beam (32), a first half-wave plate (2), a first polarizing beam splitter (3), a first liquid crystal (4), a second polarizing beam splitter (5), a second half-wave plate (6), a third polarizing beam splitter (7), a first photoelectric converter (8), a first beam expander (9), a first beam splitter (10), a first reflector (11), a second reflector (12), a second beam splitter (13), and a CCD camera (14). Computer (26), magnetic shielding barrel (27), triaxial magnetic compensation coil (28), non-magnetic electric heating oven (31), alkali metal gas chamber (29), second laser (15), second laser beam (33), third 1 / 2 glass slide (16), fourth polarizing beam splitter (17), second liquid crystal (18), fifth polarizing beam splitter (19), second beam expander (20), third reflector (21), fourth 1 / 2 glass slide (22), sixth polarizing beam splitter (23), second photoelectric converter (25), first 1 / 4 glass slide (24).

[0036] Furthermore, the temperature gradient testing system suitable for the SERF inertial measurement device is characterized in that the triaxial magnetic compensation coil (28), the non-magnetic electric heating oven (31), and the alkali metal gas chamber (29) are located inside a magnetic shielding barrel (27). The magnetic shielding barrel (27) is used to provide the alkali metal gas chamber (29) with the extremely weak magnetic field environment required for the operation of the SERF inertial measurement device. The triaxial magnetic compensation coil (28) applies three sinusoidal magnetic fields with different frequencies in the three orthogonal directions of x, y, and z to compensate for the residual magnetic field inside the magnetic shielding barrel. The non-magnetic electric heating oven (31) is used to heat the alkali metal gas chamber (29), heating the alkali metal atoms filled in the alkali metal gas chamber (29) from a solid state at room temperature to a gaseous state. The chamber is filled with alkali metal atoms K, Rb, inert gas helium, and quenching gas nitrogen. The second laser (15) emits the original laser beam (33), which passes through the third half-wave plate (16), the fourth polarizing beam splitter (17), the second liquid crystal (18), the fifth polarizing beam splitter (19), and enters the second beam expander (20) to expand the beam. After passing through the third mirror (21), it enters the fourth half-glass plate (22), the sixth polarizing beam splitter (23), and the first quarter-glass plate (24), and is converted into circularly polarized light. It passes through the magnetic shielding barrel and the non-magnetic electric heating oven (31) to irradiate the alkali metal gas chamber (29) to polarize the alkali metal atoms and nucleons filled in the alkali metal gas chamber, thereby realizing the SERF state. After the first laser (1) passes through the first half-wave plate (2), the first polarizing beam splitter (3), the first liquid crystal (4), the second polarizing beam splitter (5), the second half-wave plate (6), the third polarizing beam splitter (7), and the first photoelectric converter (8) for closed-loop control of light intensity, it enters the first beam expander (9) to become a surface light source. It is then split into two laser beams by the first beam splitter (10). The detection laser beam passes through the alkali metal gas chamber, and the other reference laser beam passes through two mirrors. The two laser beams merge with the detection laser beam at the second beam splitter (13) and then enter the CCD camera (14).

[0037] Furthermore, when the detection laser and the reference laser converge, the refractive index at different positions in the gas chamber changes due to the temperature gradient in the gas chamber. After the two lasers converge, the CCD camera (14) will collect the interlacing interference fringes of light and dark.

[0038] Furthermore, for a pair of adjacent bright and dark fringes acquired by the CCD camera (14), the refractive index corresponding to the bright fringe is σ1, and the refractive index corresponding to the dark fringe is σ2, then:

[0039]

[0040] Where λ is the wavelength and L is the length of the square air chamber.

[0041]

[0042] Let σ be the refractive index as a function of density n, where n is the atomic density inside the chamber, c is the speed of light, f is the oscillator intensity, v is the laser frequency, and r is the refractive index. e Where q is the classical electron radius, it can be obtained by fitting the atomic frequency response to the Voigt line shape.

[0043]

[0044] Let n be the density n as a function of temperature T, where T is the temperature and n is the density n. A With n B The constants of different alkali metals themselves

[0045] Furthermore, by solving the three equations simultaneously, the temperature gradient corresponding to a pair of adjacent bright and dark stripes can be obtained. The magnitude and uniformity of the temperature gradient can be obtained by the number and density of the bright and dark stripes. The temperature gradient distribution of the air chamber can be reconstructed in real time by a computer (26).

[0046] The present invention provides a gas chamber temperature gradient testing system suitable for atomic spin inertial measurement devices. This system has the following significant advantages: by connecting multiple heating films in parallel with a temperature control circuit board and then in series with sliding rheostats, it can not only create the temperature gradient state required for the experiment, but also maintain the stability of the gas chamber temperature gradient through closed-loop temperature control. Furthermore, by using a detection light in conjunction with a CCD camera, the distribution of the gas chamber temperature gradient can be monitored in real time, offering advantages such as high testing accuracy, ease of operation, and integrability.

[0047] like Figure 2 As shown, the gas chamber temperature gradient adjustment module of the present invention consists of a square non-magnetic electric heating oven (31), two high-precision temperature measuring platinum resistance thermometers, multiple non-magnetic electric heating films (30), a sliding rheostat, and a temperature control circuit board. The two high-precision temperature measuring platinum resistance thermometers are bonded to the non-magnetic electric heating oven (31) with thermally conductive silicone. The two platinum resistance thermometers are respectively connected to the temperature control circuit board. The temperature control circuit board is connected to the non-magnetic heating films (30) and a computer (26) through wires. The temperature of the heating films (30) can be set by the computer (26). The temperature control circuit board performs closed-loop control of the internal temperature of the oven (31) through a PID control method. Through the adjustment of the sliding rheostat and the cooperation of the temperature control circuit board, the temperature gradient required for the experiment can be stably created inside the gas chamber (29).

[0048] like Figure 1As shown, the real-time monitoring module for the air chamber temperature gradient of the present invention consists of a first laser (1), a first laser beam (32), a first half-wave plate (2), a first polarizing beam splitter (3), a first liquid crystal (4), a second polarizing beam splitter (5), a second half-wave plate (6), a third polarizing beam splitter (7), a first photoelectric converter (8), a first beam expander (9), a first beam splitter (10), a first reflector (11), a second reflector (12), a second beam splitter (13), and a CCD camera (14).

[0049] The first laser beam (32) emitted by the first laser (1) first passes through the first half-wave plate (2) and the first polarizing beam splitter (3), which can adjust the intensity and phase of the laser beam. Then it enters the first liquid crystal (4), the second polarizing beam splitter (5), the second half-wave plate (6), the third polarizing beam splitter (7), and the first photoelectric converter (8) to perform closed-loop control of the intensity, thereby ensuring the stability of the laser intensity and improving the accuracy of the temperature gradient test of the gas chamber. It then enters the first beam expander (9) to become a surface light source and is split into two laser beams with the same intensity by the first beam splitter (10). The detection laser beam passes through the alkali metal gas chamber (29), and the other reference laser beam passes through two mirrors and merges with the detection laser beam at the second beam splitter (13) before entering the CCD camera (14).

[0050] Contents not described in detail in this specification are prior art known to those skilled in the art. It is hereby indicated that the above description is intended to help those skilled in the art understand this invention, but does not limit the scope of protection of this invention. Any equivalent substitutions, modifications, improvements, and / or simplifications of the above descriptions that do not depart from the essential content of this invention fall within the scope of protection of this invention.

Claims

1. A temperature gradient test system suitable for use with a SERF inertial device, comprising: The gas chamber temperature gradient adjustment module is used for stabilizing the temperature gradient inside the alkali metal gas chamber to meet the test requirements of the SERF inertial measurement device, and the gas chamber temperature gradient real-time monitoring module realizes real-time monitoring of the gas chamber temperature gradient by collecting the number and density information of the interference fringes formed by the detection laser penetrating the alkali metal gas chamber and the reference laser bypassing the alkali metal gas chamber under different gas chamber temperature gradients. The gas chamber temperature gradient real-time monitoring module comprises a first light splitting prism arranged on the detection laser incidence side of the alkali metal gas chamber and a second light splitting prism arranged on the exit side, the first light splitting prism divides the laser into two detection laser beams and reference laser beams with the same light intensity, the detection laser beam passes through the alkali metal gas chamber to reach the second light splitting prism, the reference laser beam passes through the first mirror and the second mirror in sequence to reach the second light splitting prism, the interference fringes of the combined reference laser beam and detection laser beam at the second light splitting prism are collected by a CCD camera and uploaded to a computer in real time, the computer calculates the temperature gradient corresponding to a pair of adjacent bright and dark fringes according to the gray values of different positions of the image, and calculates the size and uniformity of the temperature gradient according to the number and density of the bright and dark fringes, so as to realize real-time monitoring and reconstruction of the temperature gradient. For a pair of adjacent bright and dark fringes captured by the CCD camera, the refractive index corresponding to the bright fringe is σ1, and the refractive index corresponding to the dark fringe is ∈2, then, where λ is the wavelength, L is the length of the square air chamber, and the refractive index ∈ is a function of the density n as follows, where n is the atomic density inside the cell, c is the speed of light, f is the oscillator strength, v is the laser frequency, r e is the electron classical radius, q can be obtained from the atomic frequency response by a Voigt profile fit, and the density n is a function of temperature T as follows, where T is the temperature, n A and n B are constants for the different alkali metals themselves.

2. The temperature gradient test system suitable for use with a SERF inertial device of claim 1, wherein, The gas chamber temperature gradient adjustment module directly acts on the alkali metal gas chamber, and is composed of a temperature sensor, a temperature control circuit board, a plurality of heating films and a sliding rheostat. The set temperature is input to the temperature control circuit board through the computer, and the temperature sensor pasted near the gas chamber by heat-conducting silica gel performs real-time temperature feedback, so as to realize closed-loop control of the average temperature of the gas chamber. At this time, the resistance value of the sliding rheostat connected in series with each heating film is adjusted to stabilize the temperature gradient distribution inside the gas chamber in the stable state of the gas chamber temperature.

3. The temperature gradient test system suitable for use with a SERF inertial device of claim 2, wherein, The heating film is a non-magnetic electric heating film, the temperature sensor is a platinum resistance, and the temperature control circuit board adopts PID control technology.

4. The temperature gradient test system suitable for use with a SERF inertial device of claim 1, wherein, The gas chamber temperature gradient real-time monitoring module is mainly used for real-time monitoring and reconstruction of the gas chamber temperature gradient. The first laser beam emitted by the first laser passes through the first 1 / 2 wave plate, the first polarization light splitting prism, the first liquid crystal, the second polarization light splitting prism, the second 1 / 2 wave plate, the third polarization light splitting prism, the first beam expander, and the first light splitting prism in sequence. The first light splitting prism divides the laser beam into two laser beams with the same light intensity. The detection laser beam passes through the alkali metal gas chamber to exit to the second light splitting prism, and the other reference laser beam passes through the first mirror and the second mirror in sequence. After the reference laser beam and the detection laser beam converge at the second light splitting prism, they enter the CCD camera.

5. The temperature gradient test system suitable for use with a SERF inertial device of claim 4, wherein, The reflection side of the third polarization light splitting prism is connected with the first liquid crystal through the first photoelectric converter, so as to ensure the stability of the laser light intensity through light intensity closed-loop control.

6. The temperature gradient test system suitable for use with a SERF inertial device of claim 1, wherein, Because the temperature gradient at different positions of the alkali metal gas chamber causes the refractive index at different positions of the gas chamber to change, the CCD camera will collect the interference fringes with alternating bright and dark stripes after the detection laser and the reference laser converge.

7. The temperature gradient test system suitable for use with a SERF inertial device of claim 1, wherein, The CCD camera uploads the obtained interference fringe image data to a computer in real time, and the temperature gradient corresponding to a pair of adjacent bright and dark fringes can be obtained by calculating the gray value of different positions of the image; the number and density of the bright and dark fringes collected by the CCD camera can be used to obtain the size and uniformity information of the temperature gradient, so that the real-time monitoring and reconstruction of the temperature gradient can be realized.

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