Movable real-time online measuring device for atomic gas chamber filling platform

Abstract

The invention provides a movable real-time online measurement device for an atomic gas chamber filling platform, which belongs to the technical field of nuclear magnetic resonance gyroscopes and comprises a movable atomic gas chamber component measurement module, a data acquisition and processing module, a laser and a wavemeter, the movable atomic gas chamber component measurement module comprises an optical fiber collimator, a 1 / 2 wave plate, a first polarization splitting prism, a second polarization splitting prism, an atomic gas chamber, a heating device, a first photoelectric detector, a second photoelectric detector, an adjustable optical fiber collimator and a movable fixed supporting structure, the data acquisition and processing module is used for processing signals output by the wavemeter, the first photoelectric detector and the second photoelectric detector and calculating components of the atomic gas chamber; according to the invention, the components can be monitored and controlled in real time in the filling process of the atomic gas chamber, the components filled into the atomic gas chamber are adjusted in real time, the controllability of the filling precision is effectively improved, the process consistency is ensured, and the production quality is greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of nuclear magnetic resonance gyroscopes, and in particular to a movable real-time on-line measuring device for an atomic gas cell filling platform, which can be applied to the real-time on-line measurement and precise control of the components of the atomic gas cell of a nuclear magnetic resonance gyroscope. Background Art

[0002] As a sensitive element of a nuclear magnetic resonance gyroscope, the performance of the atomic gas cell essentially determines the performance of the nuclear magnetic resonance gyroscope.

[0003] The inside of the atomic gas cell is filled with a mixed vapor of alkali metal atoms, inert gas and buffer quenching gas. Among them, the alkali metal atoms are laser polarized and then undergo spin-exchange collisions with inert gas atoms to achieve hyperpolarization of nuclear spins, and inertial measurement is realized by measuring the angular velocity of the carrier; the inert gas plays a role in inertial sensitivity and is used for angular velocity detection; and filling an appropriate amount of buffer quenching gas in the atomic gas cell can slow down the relaxation of atoms and improve the detection sensitivity of the nuclear magnetic resonance gyroscope; therefore, only by precisely measuring the density of alkali metal atoms and the pressures of inert gas and buffer quenching gas in the atomic gas cell and ensuring that the actually filled components are consistent with the expected components can the performance of the atomic ensemble reach the best.

[0004] The prior art can only detect the components of the atomic gas cell by spectroscopic detection after the atomic gas cell is removed, lacking a real-time on-line measurement method during the filling process of the atomic gas cell, and unable to ensure that the components in the final atomic gas cell are consistent with the preset parameters. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a movable real-time on-line measuring device for an atomic gas cell filling platform, which can realize real-time monitoring and control of components during the filling process of the atomic gas cell, adjust the components filled into the atomic gas cell in real time, effectively improve the controllability of the filling accuracy, ensure process consistency, and greatly improve the production quality.

[0006] A movable real-time on-line measuring device for an atomic gas cell filling platform includes:

[0007] A movable atomic gas cell component measuring module, a data acquisition and processing module, a laser, and a wavelength meter;

[0008] The movable atomic gas cell component measuring module includes: an optical fiber collimator, a half-wave plate, a first polarization beam splitter prism, a second polarization beam splitter prism, an atomic gas cell, a heating device, a first photodetector, a second photodetector, an adjustable optical fiber collimator, and a movable fixed support structure, wherein:

[0009] The fiber collimator: It is used to collimate the divergent light emitted from the optical fiber into a beam with a very small divergence angle and approximately parallel, so as to improve the coupling efficiency;

[0010] After the laser is collimated and expanded by the fiber collimator, it is split by a half-wave plate and a first polarization beam splitter prism;

[0011] One of the beams of light is transmitted to the wavelength meter through an adjustable fiber collimator;

[0012] The other beam of light irradiates the second polarization beam splitter prism and is split again;

[0013] One of the split beams irradiates on the second photodetector as the reference incident light intensity;

[0014] The other split beam passes through the atomic gas cell and then irradiates on the first photodetector;

[0015] The data acquisition and processing module: It is used to process the signals output by the wavelength meter, the first photodetector, and the second photodetector, and calculate the components of the atomic gas cell;

[0016] The laser: It is used to generate laser light with the wavelength of the D2 line of alkali metal rubidium;

[0017] The wavelength meter: It is used to collect the change of wavelength during the frequency scanning process of the laser;

[0018] As an example, the movable and fixed support structure includes: an optical device fixed support frame, a slide rail, and a lifting table; it is used to fix and move the movable atomic gas cell component measurement module.

[0019] As an example, the movable and fixed support structure has the ability to move in four degrees of freedom, and the four degrees of freedom of movement include: linear movement in three directions and rotational movement around the vertical axis, which can better match the atomic gas cell filling platform to achieve the purpose of real-time on-line measurement.

[0020] As an example, for the convenience of replacing the atomic gas cell, the heating device is selected as a double-layer resistance wire, and the distance between the double-layer resistance wire and the atomic gas cell is set to 1 - 3 mm.

[0021] As an example, the pipeline of the atomic gas cell filling platform is connected to the atomic gas cell through a glass valve, and the glass valve is used to control the components filled into the atomic gas cell in real time. At the same time, the glass valve can not only prevent the reaction of alkali metal with other substances, but also avoid the problem of breaking the glass pipeline caused by installing a metal valve on the glass pipeline.

[0022] The present invention further includes: a manufacturing method of the movable atomic gas cell component measurement module, including:

[0023] Step 1: Determine the specific shapes and dimensions of structural components such as fiber collimators, half-wave plates, first polarization beam splitters, second polarization beam splitters, atomic gas cells and heating devices, first photodetectors, second photodetectors, and adjustable fiber collimators, draw a planar design diagram, and at the same time use 3D modeling software to design the model of the optical device fixing and supporting frame;

[0024] Step 2: Based on the planar design diagram, use 3D modeling software to establish its 3D model, and the shape and dimensions of the 3D model are consistent with the planar design diagram;

[0025] Step 3: Use the assembly function of 3D modeling software to assemble and experiment on the 3D model according to the actual assembly method of each structural component to check the rationality of the design of each structural component. If design defects are found, modify the planar design diagram, 3D model, and the model of the optical device fixing and supporting frame until it is reasonable and error-free;

[0026] Step 4: Conduct 3D printing of the optical device fixing and supporting frame, install each structural component on the printed optical device fixing and supporting frame, and perform matching assembly with the slide rail and lifting platform to complete the production of the movable atomic gas cell component measurement module.

[0027] Combine this structure with the atomic gas cell filling platform to achieve the purpose of real-time online measurement.

[0028] As an example, the 3D modeling software used is: SolidWorks.

[0029] Advantages of the present invention:

[0030] The present invention can realize real-time monitoring and control of components during the filling process of the atomic gas cell, perform real-time adjustment of the components filled into the atomic gas cell, effectively improve the controllability of the filling accuracy, ensure process consistency, and greatly improve the production quality.

[0031] The present invention adopts a movable fixing and supporting structure, which can better match with the atomic gas cell filling platform and is convenient to use. Description of the drawings

[0032] Figure 1 It is a schematic diagram of the overall structure of a movable real-time online measurement device for an atomic gas cell filling platform according to the present invention.

[0033] Figure 2 It is a three-dimensional model schematic diagram of the movable fixing and supporting structure of a movable real-time online measurement device for an atomic gas cell filling platform according to the present invention. Detailed implementation manners

[0034] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope of protection of the present application. Refer to Figures 1 to 2 as shown:

[0035] A movable real-time on-line measuring device for an atomic gas cell filling platform, comprising:

[0036] A movable atomic gas cell component measuring module, a data acquisition and processing module 100, a laser, and a wavelength meter;

[0037] The movable atomic gas cell component measuring module includes: an optical fiber collimator 101, a half-wave plate 102, a first polarization beam splitter prism 103, a second polarization beam splitter prism 104, an atomic gas cell 105, a heating device 106, a first photodetector 107, a second photodetector 109, an adjustable optical fiber collimator 108, and a movable fixed support structure 200, wherein:

[0038] The optical fiber collimator 101: is used to collimate the divergent light emitted from the optical fiber into a beam with a very small divergence angle and approximately parallel, so as to improve the coupling efficiency;

[0039] After the laser is collimated and expanded by the optical fiber collimator 101, it is split by the half-wave plate 102 and the first polarization beam splitter prism 103;

[0040] One beam of light is transmitted to the wavelength meter 110 through the adjustable optical fiber collimator 108;

[0041] The other beam of light irradiates the second polarization beam splitter prism 104 and is split again;

[0042] One of the split beams irradiates on the second photodetector 109 as the reference incident light intensity;

[0043] The other split beam passes through the atomic gas cell 105 and then irradiates on the first photodetector 107;

[0044] The data acquisition and processing module 100: is used to process the signals output by the wavelength meter 110, the first photodetector 107, and the second photodetector 109, and calculate the components of the atomic gas cell 105;

[0045] The laser 111: is used to generate laser light with the wavelength of the D2 line of alkali metal rubidium;

[0046] The wavelength meter 110: is used to collect the change of the wavelength during the frequency scanning process of the laser 111;

[0047] Reference Figure 2 As shown, the movable fixed support structure 200 includes: an optical device fixed support frame 201, a slide rail 202, and a lifting platform 203, which are used to fix and move the movable atomic gas cell component measurement module.

[0048] As an example, the movable fixed support structure 200 has the ability to move in four degrees of freedom, including linear motion in three directions and rotational motion around the vertical axis, which can better match the atomic gas cell filling platform to achieve the purpose of real-time online measurement.

[0049] As an example, for the convenience of replacing the atomic gas cell 105, the heating device 106 is selected as a double-layer resistance wire, and the distance between the double-layer resistance wire and the atomic gas cell is set to 1 - 3 mm.

[0050] Using a double-layer resistance wire can also reduce the influence of the interference magnetic field and improve the heating efficiency. The resistance wire material is made of copper material, which has high thermal conductivity, small thermal resistance, small temperature distribution gradient, and good thermal uniformity. The double-layer resistance wire is processed onto a high-temperature resistant material substrate.

[0051] As an example, the pipeline of the atomic gas cell filling platform is connected to the atomic gas cell 105 through a glass valve. The glass valve is used to control the components filled into the atomic gas cell in real time. At the same time, the glass valve can not only prevent the reaction of alkali metal with other substances, but also avoid the problem of breaking the glass pipeline caused by installing a metal valve on the glass pipeline.

[0052] Considering the corrosiveness of alkali metal in the selection of the valve sealing material, a tetrafluoro O-ring seal is selected, which has the advantages of good sealing performance, high temperature resistance, and alkali metal corrosion resistance, and its sealing performance can reach 10 -11 mbar.L / s.

[0053] A manufacturing method for a movable atomic gas cell component measurement module includes:

[0054] Step 1: Determine the specific shapes and dimensions of structural components such as the fiber collimator 101, 1 / 2 wave plate 102, first polarization beam splitter prism 103, second polarization beam splitter prism 104, atomic gas cell 105, heating device 106, first photodetector 107, second photodetector 109, and adjustable fiber collimator 108, draw a planar design diagram, and at the same time use 3D modeling software to design the model of the optical device fixed support frame;

[0055] Step 2: Based on the planar design diagram, use 3D modeling software to establish its 3D model, and the shape and size of the 3D model are consistent with the planar design diagram;

[0056] Step 3: Use the assembly function of 3D modeling software to assemble and experiment with the 3D model according to the actual assembly method of each structural component to check the rationality of the design of each structural component. If design defects are found, modify the planar design drawing, 3D model, and the optical device fixed support frame model until it is reasonable and error-free.

[0057] Step 4: Conduct 3D printing of the optical device fixed support frame, install each structural component on the printed optical device fixed support frame, and perform matching assembly with the slide rail 202 and the lifting platform 203 to complete the production of the movable atomic gas chamber component measurement module.

[0058] As an example, the 3D modeling software used is: SolidWorks.

[0059] After completing the production of the movable real-time online measurement device for the atomic gas chamber filling platform, combine it with the gas chamber filling platform, and control the components filled into the gas chamber through the glass valve to measure the gas chamber components online. The specific method includes:

[0060] Step 1: Change the frequency of the laser 111 to scan the atomic optical absorption spectrum line.

[0061] When the laser corresponding to the resonance frequency or including the resonance frequency passes through the atomic gas chamber 105, part of the laser is absorbed by the alkali metal atoms, resulting in attenuation of the light intensity. The attenuation amount is given by the following relational expression:

[0062] I o =I i exp(-nσ(ν)z)

[0063] Where σ(ν) is the photon absorption cross-section, and z is the relative position of the measurement point in the atomic gas chamber; for an atomic gas chamber with an optical path length of l, assuming that the temperature field in the atomic gas chamber is uniform, its total attenuation amount is expressed by the optical depth OD, and the expression is:

[0064] OD=nσ(ν)l

[0065] Measure the light intensity before and after the laser passes through the atomic gas chamber 105 through the first photodetector 107 and the second photodetector 109, and logarithmic processing can obtain the optical depth OD.

[0066]

[0067] Step 2: Fit to obtain the gas pressure and the alkali metal atom density

[0068] There are three types of line shapes of the absorption cross-section σ(ν): the Lorentz line shape caused by pressure broadening and natural line width, the Gaussian line shape caused by the Doppler effect, and the Voigt line shape which is the convolution form of the former two.

[0069] Considering that the atomic gas cell of the nuclear magnetic resonance gyro is a negative pressure atomic gas cell, the Doppler broadening has a greater impact on the absorption spectrum, and the relative pressure broadening cannot be ignored. The convolution Voigt line type of the Lorentz line type and the Gauss line type must be used for data fitting, where the Voigt line type fitting formula is:

[0070]

[0071] Where σ(ν) is the photon absorption cross-sectional area of ​​rubidium atoms, r e is the radius of the electron's classical orbit, c is the speed of light, is the oscillation intensity of the D2 line of the alkali metal atom, ν F,F' is the transition frequency of the hyperfine energy level of the rubidium atom D2 line from the ground state F to the excited state F', A F,F' is the corresponding relative intensity, ν is the frequency of the laser scanning infrared light, and Γ is the spectral line width of the rubidium atom;

[0072] Assuming that the pressures of xenon and nitrogen filled in the atomic gas chamber of the nuclear magnetic resonance gyroscope are P1 and P2 respectively, according to the known pressure broadening Γ1, Γ2 and frequency shift δ1, δ2 corresponding to the unit pressure of the two gases at a stable temperature, the specific coefficients are shown in Table 1, and the spectral line pressure broadening Γ and frequency shift δ are fitted. The pressures P1 and P2 of the two gases in the atomic gas chamber are calculated jointly. The formula used is

[0073]

[0074] Among them, Γ1, Γ2 are the pressure broadenings of the two gases per unit pressure at a stable temperature, and their magnitudes are known; δ1, δ2 are the frequency shifts of the two gases per unit pressure at a stable temperature, and their magnitudes are known; Γ and δ are the pressure broadening and frequency shift of the mixed gas actually measured.

[0075] Table 1 Broadening coefficients and frequency shift coefficients of several gases

[0076]

[0077] At the same time, the NMR gyroscope is usually filled with an excess of alkali metal rubidium, so the rubidium atoms are in a saturated state. The rubidium atom density can be calculated using the following formula:

[0078]

[0079] Among them, T a is the absolute temperature of the atomic vapor, A and B depend on the type and physical state of the alkali metal; see Table 2.

[0080] Table 2A, B parameter selection table

[0081]

[0082] Step 3: Determine whether the actual components in the air chamber are consistent with the expected components

[0083] The xenon and nitrogen contents actually filled into the atomic gas chamber obtained by fitting are compared with the contents to be filled into the atomic gas chamber. If they are consistent, the next step of atomic gas chamber removal is carried out. If they are not consistent, the components filled into the atomic gas chamber 105 are adjusted through the glass valve, and the components in the atomic gas chamber 105 are remeasured using the above-mentioned device.

[0084] It should be noted that, for the method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the order of the actions described, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all optional embodiments, and the actions involved are not necessarily required by the present application.

[0085] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0086] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for a terminal (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0087] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

[0088] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in the embodiments of the present application can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0089] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0090] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the couplings or direct couplings or communication connections shown or discussed with each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0091] If the above functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage media include: various media such as USB flash drives, mobile hard disks, ROM, RAM, magnetic disks, or optical discs that can store program codes.

[0092] The above are only the preferred embodiments of the present invention. It should be understood that the description of the above embodiments is only used to help understand the method and its core idea of the present invention, and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A movable real-time on-line measuring device for an atomic gas cell filling platform, characterized in that, Including: A movable atomic gas cell component measurement module, a data acquisition and processing module, a laser, and a wavelength meter; The movable atomic gas cell component measurement module includes: an optical fiber collimator, a half-wave plate, a first polarization beam splitter prism, a second polarization beam splitter prism, an atomic gas cell, a heating device, a first photodetector, a second photodetector, an adjustable optical fiber collimator, and a movable and fixed support structure, where: The optical fiber collimator: is used to collimate the divergent light emitted from the optical fiber into a beam with a very small divergence angle and approximately parallel, so as to improve the coupling efficiency; After the laser is collimated and expanded by the optical fiber collimator, it is split by passing through the half-wave plate and the first polarization beam splitter prism; one beam of light is transmitted to the wavelength meter through the adjustable optical fiber collimator; the other beam of light irradiates the second polarization beam splitter prism and is split again; one of the split beams irradiates on the second photodetector as the reference incident light intensity; the other split beam irradiates on the first photodetector after passing through the atomic gas cell; The data acquisition and processing module: is used to process the signals output by the wavelength meter, the first photodetector, and the second photodetector, and calculate the components of the atomic gas cell; The laser: is used to generate laser light with the wavelength of the D2 line of alkali metal rubidium; The wavelength meter: is used to collect the change of the wavelength during the laser frequency sweeping process.

2. The movable real-time on-line measuring device for an atomic gas cell filling platform according to claim 1, characterized in that, The movable and fixed support structure includes: an optical device fixed support frame, a slide rail, and a lifting table; it is used to fix and move the movable atomic gas cell component measurement module.

3. The movable real-time on-line measuring device for an atomic gas cell filling platform according to claim 1, characterized in that, The movable and fixed support structure has the ability to move in four degrees of freedom.

4. The movable real-time on-line measuring device for an atomic gas cell filling platform according to claim 3, characterized in that, The four degrees of freedom of movement include: linear movement in three directions and rotational movement around the vertical axis.

5. The movable real-time on-line measuring device for an atomic gas cell filling platform according to claim 1, characterized in that, The heating device selects a double-layer resistance wire, and the distance between the double-layer resistance wire and the atomic gas cell is set to 1-3 mm.

6. The movable real-time on-line measuring device for an atomic gas cell filling platform according to claim 1, characterized in that The pipeline of the atomic gas cell filling platform is connected to the atomic gas cell through a glass valve, and the glass valve is used to control the components filled into the atomic gas cell in real time.

7. The movable real-time on-line measuring device for an atomic gas cell filling platform according to claim 1, characterized in that, It also includes a manufacturing method for the movable atomic gas cell component measurement module, specifically: Step 1: Determine the specific shapes and sizes of the optical fiber collimator, half-wave plate, first polarization beam splitter prism, second polarization beam splitter prism, atomic gas cell, heating device, first photodetector, second photodetector, and adjustable optical fiber collimator, draw a planar design drawing, and at the same time use 3D modeling software to design the model of the optical device fixed support frame; Step 2: According to the planar design drawing, use 3D modeling software to establish its 3D model, and the shape and size of the 3D model are consistent with the planar design drawing; Step 3: Use the assembly function of 3D modeling software to assemble and experiment with the 3D model according to the actual assembly method of each structural part to check the rationality of the design of each structural part. If design defects are found, modify the planar design drawing, 3D model, and the model of the optical device fixed support frame until they are reasonable and error-free; Step 4: Perform 3D printing of the optical device fixed support frame, install each structural part on the printed optical device fixed support frame, and perform matching assembly with the slide rail and the lifting table to complete the production of the movable atomic gas cell component measurement module.

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