In-situ measurement method and device for temperature of atomic gas chamber

Abstract

The invention relates to the technical field of atom magnetometers, in particular to an atomic gas chamber temperature in-situ measurement method and device. In the invention, the atomic spin relaxation rate is obtained by measuring the line width of the resonance curve, and the atomic spin exchange collision rate is obtained by fitting the atomic spin relaxation rates under different pumping optical power densities, so that the temperature of the atomic gas chamber is obtained, and the accurate and in-situ measurement of the temperature in the gas chamber is realized. Compared with an existing method for carrying out contact type temperature measurement on the surface temperature of the air chamber by adopting a thermistor, the method does not need to add additional devices, carries out in-situ measurement on the temperature in the atomic air chamber by utilizing the atomic response signal, improves the measurement accuracy of the temperature of the air chamber, and provides necessary conditions for optimization of system parameters of the magnetometer.

Description

Technical Field

[0001] The invention relates to the technical field of atomic magnetometers, and in particular to an atomic gas chamber temperature in-situ measurement method and device. Background Art

[0002] Precision measurement of magnetic fields is of great significance to cutting-edge scientific research in life, physics, earth, and other fields, as well as the construction of major national projects. In recent years, with the development of quantum precision measurement technology, atomic magnetometers based on the interaction between magnetism, light, and atoms have become a research hotspot for high-sensitivity magnetic field measurements. The alkali metal atomic gas chamber is the sensitive core of the atomic magnetometer. The atomic number density inside it is proportional to the signal strength of the magnetometer. In order to improve the signal-to-noise ratio of magnetic field measurement, the atomic number density is usually increased by heating the atomic gas chamber. In order to suppress the fluctuation of the magnetometer output signal caused by the fluctuation of the atomic number density, the temperature of the atomic gas chamber needs to be closed-loop controlled. Accurate measurement of the gas chamber temperature is an important prerequisite for achieving its highly stable closed-loop control. Therefore, it is of great significance to carry out high-precision gas chamber temperature measurement.

[0003] At present, the contact temperature measurement method is mainly used for the gas chamber temperature. It uses a thermistor pasted on the gas chamber handle or the gas chamber surface to measure the temperature. However, due to the influence of the thickness of the glass gas chamber, the contact temperature measurement method cannot accurately measure the temperature inside the gas chamber. Therefore, it is urgent to propose an atomic gas chamber temperature in-situ measurement method to achieve accurate measurement of the temperature inside the gas chamber and create conditions for system parameter optimization. Summary of the invention

[0004] In view of this, the present invention provides an atomic gas chamber temperature in-situ measurement method and device to solve the problem in the prior art that the temperature measurement of the atomic gas chamber cannot accurately measure the temperature inside the gas chamber.

[0005] In a first aspect, the present invention provides an in-situ measurement method for the temperature of an atomic gas chamber, the method comprising: using a pumping laser to irradiate atoms in an atomic gas chamber in a heated state, and applying a magnetic field to the atomic gas chamber to polarize the atoms and put them into a resonant state; obtaining the resonance curve of the atoms, and determining the atomic spin transverse relaxation rate based on the line width of the resonance curve; changing the pumping laser power density to determine the atomic spin transverse relaxation rate corresponding to different pumping laser power densities; based on the relationship between the atomic spin transverse relaxation rate and the pumping rate, fitting the atomic spin transverse relaxation rate under different pumping light power densities to obtain fitting parameters, the fitting parameters including the atomic spin exchange collision rate; determining the atomic number density based on the atomic spin exchange collision rate; and determining the atomic gas chamber temperature based on the atomic number density and the saturated vapor pressure formula.

[0006] In the present invention, the atomic spin relaxation rate is obtained by measuring the line width of the resonance curve, and the atomic spin exchange collision rate is obtained by fitting the atomic spin relaxation rate under different pumping light power densities, thereby obtaining the atomic gas chamber temperature and realizing accurate, in-situ measurement of the temperature inside the gas chamber. Compared with the existing method of using a thermistor to perform contact temperature measurement on the surface temperature of the gas chamber, this method does not need to add additional devices, and uses the atomic response signal to perform in-situ measurement of the temperature inside the atomic gas chamber, thereby improving the measurement accuracy of the gas chamber temperature and providing necessary conditions for optimizing the parameters of the magnetometer system.

[0007] In an optional embodiment, using a pumping laser to irradiate atoms in an atomic gas chamber in a heated state, and applying a magnetic field to the atomic gas chamber to polarize the atoms and put them into a resonant state includes: using a pumping laser to irradiate atoms in an atomic gas chamber in a heated state to polarize the atoms; applying a longitudinal main magnetic field and a transverse radio frequency magnetic field to the atomic gas chamber; scanning the frequency of the transverse radio frequency magnetic field to put the atoms into a resonant state; obtaining the resonance curve of the atoms, and determining the transverse relaxation rate of the atomic spin based on the line width of the resonance curve, including: fitting the frequency change during the scanning process of the transverse radio frequency magnetic field and the output signal change of the atomic magnetometer to obtain the resonance curve of the atoms; determining the line width of the resonance curve according to the fitting parameters; and determining the transverse relaxation rate of the atomic spin according to the relationship between the line width of the resonance curve and the transverse relaxation rate of the atomic spin.

[0008] In an optional implementation, the frequency change during the transverse radio frequency magnetic field scanning process and the output signal change of the atomic magnetometer are fitted using the following formula:

[0009]

[0010] Where S represents the output signal of the atomic magnetometer, ω represents the frequency of the transverse radio frequency magnetic field, Γ represents the line width of the resonance curve, and A and ω0 are fitting parameters.

[0011] In the present invention, the frequency change in the transverse radio frequency magnetic field scanning process and the output signal change of the atomic magnetometer are fitted by using the formula, thereby providing a data basis for determining the line width of the resonance curve.

[0012] In an optional embodiment, using a pumping laser to irradiate atoms in an atomic gas chamber in a heated state, and applying a magnetic field to the atomic gas chamber to polarize the atoms and put them into a resonant state includes: using a pumping laser to irradiate atoms in an atomic gas chamber in a heated state to polarize the atoms; applying a longitudinal main magnetic field to the atomic gas chamber; modulating the parameters of the pumping laser to put the atoms into a resonant state; obtaining the resonance curve of the atoms, and determining the atomic spin transverse relaxation rate based on the line width of the resonance curve, including: fitting the parameter changes in the process of pumping laser parameter modulation and the output signal changes of the atomic magnetometer to obtain the atomic resonance curve; determining the resonance curve line width according to the fitting parameters; and determining the atomic spin transverse relaxation rate according to the relationship between the resonance curve line width and the atomic spin transverse relaxation rate.

[0013] In the present invention, the atoms may be put into a resonant state by radio frequency magnetic field modulation or by light modulation.

[0014] In an optional embodiment, the relationship between the pumping rate and the atomic spin transverse relaxation rate is expressed by the following formula:

[0015]

[0016] Where R2 represents the transverse relaxation rate of atomic spin, R p represents the pumping rate, R se represents the atomic spin exchange collision rate, R rel represents the residual relaxation rate.

[0017] In the present invention, based on this formula, it can be known that the influence of the spin exchange rate can be suppressed by increasing the pumping rate, thereby narrowing the line width, thereby providing a data basis for determining the atomic spin exchange collision rate.

[0018] In an optional implementation, the amplitude of the applied transverse radio frequency magnetic field satisfies the following formula:

[0019]

[0020] Where B1 represents the amplitude of the transverse RF magnetic field, R1 and R2 are the longitudinal relaxation rate and transverse relaxation rate of the atoms, respectively, and γ is the atomic gyromagnetic ratio.

[0021] In the present invention, the influence of the radio frequency magnetic field on the line width is reduced by limiting the amplitude of the applied transverse radio frequency magnetic field.

[0022] In an optional embodiment, the temperature of the atomic gas chamber is closed-loop controlled during the in-situ measurement of the temperature of the atomic gas chamber.

[0023] In the present invention, the temperature of the atomic gas chamber is controlled in a closed loop so that the temperature of the gas chamber can reach a stable state quickly.

[0024] In a second aspect, the present invention provides an in-situ measurement device for the temperature of an atomic gas chamber, the device comprising: a resonance control module, used to irradiate atoms in an atomic gas chamber in a heated state with a pumping laser, and apply a magnetic field to the atomic gas chamber to polarize the atoms and put them into a resonant state; a relaxation rate determination module, used to obtain the resonance curve of the atoms, and determine the atomic spin transverse relaxation rate based on the line width of the resonance curve; a temperature determination module, used to change the pumping laser power density, and determine the atomic spin transverse relaxation rate corresponding to different pumping laser power densities; based on the relationship between the atomic spin transverse relaxation rate and the pumping rate, the atomic spin transverse relaxation rate under different pumping light power densities is fitted to obtain fitting parameters, the fitting parameters including the atomic spin exchange collision rate; based on the atomic spin exchange collision rate, the atomic number density is determined; based on the atomic spin exchange collision rate, the atomic gas chamber temperature is determined based on the atomic number density and the saturated vapor pressure formula. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 is a schematic flow chart of an in-situ measurement method of an atomic gas chamber temperature according to an embodiment of the present invention;

[0027] Figure 2 4 is a structural block diagram of an atomic gas chamber temperature in-situ measurement device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0029] According to an embodiment of the present invention, an embodiment of an atomic gas chamber temperature in-situ measurement method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0030] In this embodiment, a method for in-situ measurement of atomic gas chamber temperature is provided. Figure 1 FIG. 4 is a flow chart of an in-situ measurement method of an atomic gas chamber temperature according to an embodiment of the present invention. Figure 1 As shown, the process includes the following steps:

[0031] Step S101, using a pumping laser to irradiate atoms in the atomic gas cell in a heated state, and applying a magnetic field to the atomic gas cell to polarize the atoms and put them into a resonant state.

[0032] Specifically, the in-situ measurement method of the atomic gas chamber temperature is for measuring the temperature of the atomic gas chamber in the atomic magnetometer. When the atomic magnetometer is working, the atomic gas chamber needs to be heated. The present embodiment mainly measures the temperature in the atomic gas chamber in the heated state. Therefore, before the measurement, the heat source for heating the atomic gas chamber can be turned on, wherein the heat source can adopt a common heating heat source, such as a thermocouple, a laser, an infrared heater, etc. In addition, before the measurement, the temperature of the atomic gas chamber can be closed-loop controlled by a temperature control circuit and a related algorithm, so that the gas chamber temperature can quickly reach a stable state, which is convenient for temperature measurement. The temperature control circuit and algorithm can adopt a 555 time base circuit and a PID control algorithm, etc.

[0033] Among them, the atoms in the atomic gas chamber can be atoms with a suitable energy level structure, for example, alkali metal atoms such as rubidium and cesium can be used. When the atomic magnetometer is working, a pumping laser (i.e., pumping light, for example, circularly polarized light) is first used to irradiate the laser in the atomic gas chamber, so that the electrons in the atoms transition from the ground state to the excited state, and return to the sub-energy level after spontaneous radiation in the excited state. The atoms on the sub-energy level are polarized and spin polarization is generated. Then, under the action of the external magnetic field, the polarized atoms will undergo Larmor precession and generate a precession frequency. By measuring this frequency, the size of the external magnetic field can be determined. In order to detect this precession, a beam of linearly polarized detection light perpendicular to the pump light is usually used. When the detection light passes through the polarized atom, its polarization plane will be deflected, and the deflection angle is proportional to the projection of the atomic spin along the propagation direction. Therefore, by measuring the size of the deflection angle, the Larmor precession frequency can be calculated, thereby determining the size of the external magnetic field and obtaining the output signal of the atomic magnetometer.

[0034] In this embodiment, when measuring temperature, it is necessary to put the atoms in the atomic gas chamber into a resonant state. Specifically, the atoms may be put into a resonant state by applying an external magnetic field or by modulating pumping light parameters.

[0035] In an optional implementation, the above step S101 includes:

[0036] Step a1, using pumping laser to irradiate atoms in the heated atomic gas chamber to polarize the atoms; wherein, using pumping laser to irradiate atoms is the same as the irradiation method and function of the pumping laser when the atomic magnetometer is working, and will not be repeated here.

[0037] Step a2, applying a longitudinal main magnetic field and a transverse radio frequency magnetic field to the atomic gas chamber; specifically, the longitudinal main magnetic field applied during temperature measurement is a constant magnetic field, and its direction is consistent with the propagation direction of the pumping laser, wherein the function of the longitudinal main magnetic field is the same as the function of the external magnetic field when the atomic magnetometer is working, that is, to make the atoms in the atomic gas chamber produce Larmor precession. The applied transverse radio frequency magnetic field is used to enable the atoms to enter a resonant state, and the transverse radio frequency magnetic field is an alternating magnetic field, and its direction is perpendicular to the longitudinal main magnetic field.

[0038] Step a3, scanning the frequency of the transverse RF magnetic field to make the atoms enter a resonant state; by scanning the frequency of the transverse RF magnetic field, that is, gradually changing the frequency of the transverse RF magnetic field, when the changed frequency matches the Larmor frequency of the atoms, the spins of the atoms will resonate.

[0039] In an optional implementation, the above step S101 includes:

[0040] Step b1, using a pumping laser to irradiate the atoms in the heated atomic gas chamber to polarize the atoms; please refer to the above step a1 for details, which will not be repeated here.

[0041] Step b2, applying a longitudinal main magnetic field to the atomic gas chamber; specifically, the applied longitudinal main magnetic field is the same as the longitudinal main magnetic field applied in step a2, which will not be repeated here.

[0042] Step b3, modulate the parameters of the pumping laser to make the atoms enter a resonant state; specifically, when using light modulation to make the atoms enter a resonant state, the parameters of the pumping laser can be modulated, such as modulating the frequency, intensity or phase, to make the atoms enter a resonant state.

[0043] Step S102, obtaining the resonance curve of the atom, and determining the atomic spin transverse relaxation rate based on the line width of the resonance curve. Specifically, according to the above step S101, it can be known that the atom can enter the resonance state by means of magnetic field modulation or light modulation, and thus, the resonance curve of the atom in the process of entering the resonance state can be determined by the change of the modulation parameter during the modulation process and the change of the output signal of the atomic magnetometer, and the half-height width of the resonance curve is the line width of the resonance curve, and thus, the atomic spin transverse relaxation rate can be further determined by the line width of the resonance curve.

[0044] In an optional implementation, when the atoms are made to enter a resonant state by means of magnetic field modulation, the above step S102 includes:

[0045] Step c1, fitting the frequency change during the transverse RF magnetic field scanning process and the output signal change of the atomic magnetometer to obtain the resonance curve of the atom; specifically, when the pump laser polarizes the atom along the z direction and the longitudinal main magnetic field B is applied along the z direction z , then the Larmor precession frequency of the atom along the z direction is ω0 = γB z , where γ is the atomic gyromagnetic ratio. In addition, the detection light can be used to detect the precession signal of the atom along the x direction to obtain the magnitude of the longitudinal main magnetic field, that is, the output signal of the atomic magnetometer. When the radio frequency magnetic field 2B1cos(ωt) is applied along the y direction, the atomic polarization rate in the x direction in the rotating coordinate system can be obtained by using the rotating wave approximation method:

[0046]

[0047] Among them, R1 and R2 are the longitudinal and transverse relaxation rates of the atoms, respectively, and R p is the pumping rate, which is proportional to the pumping light power density, and Γ is the line width of the resonance curve. In addition, the output signal of the atomic magnetometer is proportional to the atomic polarizability in the x direction. Therefore, according to the above formula, the frequency change during the transverse RF magnetic field scanning process and the output signal change of the atomic magnetometer can be fitted to obtain the resonance curve. The linear least squares fitting method can be used for fitting. Among them, the fitting result can be expressed by the following formula:

[0048]

[0049] Where S represents the output signal of the atomic magnetometer, ω represents the frequency of the transverse radio frequency magnetic field, Γ represents the line width of the resonance curve, and A and ω0 are fitting parameters.

[0050] Step c2, determining the line width of the resonance curve according to the fitting parameters; specifically, the corresponding line width of the resonance curve Γ can be obtained by calculation through the above formula.

[0051] Step c3, determining the atomic spin transverse relaxation rate according to the relationship between the resonance curve line width and the atomic spin transverse relaxation rate. Specifically, the relationship between the resonance curve line width and the atomic spin transverse relaxation rate can be expressed as R2=2πΓ, whereby, after obtaining the resonance curve line width, the atomic spin transverse relaxation rate is obtained by substituting it into the relationship.

[0052] In addition, when applying the transverse RF magnetic field, the amplitude B1 of the RF magnetic field can be set to satisfy This can reduce the impact of the radio frequency magnetic field on the line width.

[0053] In an optional implementation, when the atoms are made to enter a resonant state by light modulation, the above step S102 includes:

[0054] Step d1, fitting the parameter changes in the process of pump laser parameter modulation and the output signal changes of the atomic magnetometer to obtain the resonance curve of the atom.

[0055] Step d2, determining the line width of the resonance curve according to the fitting parameters.

[0056] Step d3, determining the atomic spin transverse relaxation rate according to the relationship between the line width of the resonance curve and the atomic spin transverse relaxation rate.

[0057] Specifically, when light modulation is used, the fitting formula corresponding to the above-mentioned radio frequency magnetic field cannot be used. Therefore, it is necessary to re-fit according to the changes in pump laser parameters during light modulation, such as laser frequency changes and the output signal of the atomic magnetometer, so as to further determine the resonance curve line width based on the fitting results. The method of determining the atomic spin transverse relaxation rate based on the resonance curve line width is the same as the method of the above-mentioned step c3, which will not be repeated here.

[0058] Step S103, changing the pumping laser power density, and determining the atomic spin transverse relaxation rate corresponding to different pumping laser power densities. Specifically, when changing the pumping laser power density, the above steps S101 and S102 can be performed at each pumping laser power density, thereby obtaining the atomic spin transverse relaxation rate corresponding to each pumping laser power density.

[0059] Step S104, based on the relationship between the atomic spin transverse relaxation rate and the pumping rate, the atomic spin transverse relaxation rate under different pumping light power densities is fitted to obtain fitting parameters, wherein the fitting parameters include the atomic spin exchange collision rate.

[0060] Specifically, there is a certain mapping relationship between the pumping laser power density and the pumping rate. Based on the mapping relationship and the atomic spin transverse relaxation rates corresponding to different pumping laser power densities, the atomic spin transverse relaxation rates corresponding to different pumping rates can be obtained. Specifically, the linear least squares fitting method can be used to fit the two, thereby obtaining the relationship between the pumping rate and the atomic spin transverse relaxation rate, which is expressed by the following formula:

[0061]

[0062] Where R2 represents the transverse relaxation rate of atomic spin, R p represents the pumping rate, R se represents the atomic spin exchange collision rate, R rel Represents the residual relaxation rate. According to this formula, by increasing the pumping rate, the influence of the spin exchange rate can be suppressed, thereby narrowing the line width, which is called the light narrowing effect.

[0063] Step S105, determining the atomic number density based on the atomic spin exchange collision rate; specifically, the atomic spin exchange collision rate and the atomic number density have the following relationship:

[0064] R se =nνσ

[0065] Where n is the atomic number density, ν and σ are the relative thermal motion speed and cross-sectional area of ​​alkali metal atoms.

[0066] Therefore, through this relationship, after the atomic spin exchange collision rate is calculated, it and the theoretical values ​​of ν and σ can be substituted into the relationship to obtain the atomic number density.

[0067] Step S106, determining the atomic gas chamber temperature based on the atomic number density and the saturated vapor pressure formula. Specifically, the saturated vapor pressure formula is expressed as follows:

[0068] n=(10 21.866+A-B / T ) / T

[0069] Where T represents temperature, A and B are alkali metal atom density parameters. After the atomic number density is calculated, substituting the theoretical values ​​of A and B into the calculated value can realize the in-situ measurement of the atomic gas chamber temperature.

[0070] The in-situ measurement method of the atomic gas chamber temperature provided by the embodiment of the present invention obtains the atomic spin relaxation rate by measuring the line width of the resonance curve, and obtains the atomic spin exchange collision rate by fitting the atomic spin relaxation rate under different pumping light power densities, thereby obtaining the atomic gas chamber temperature and realizing accurate, in-situ measurement of the temperature inside the gas chamber. Compared with the existing method of using thermistors to perform contact temperature measurement on the surface temperature of the gas chamber, this method does not need to add additional devices, and uses atomic response signals to perform in-situ measurement of the temperature inside the atomic gas chamber, thereby improving the measurement accuracy of the gas chamber temperature and providing necessary conditions for optimizing the parameters of the magnetometer system.

[0071] As a specific application example of the embodiment of the present invention, Figure 2 As shown, when a transverse radio frequency magnetic field is used to make the atomic ensemble (a collection of a large number of atoms of the same type) in the atomic gas chamber in a resonant state, the in-situ measurement method of the atomic gas chamber temperature can be implemented according to the following process:

[0072] (1) Turn on the atomic gas chamber for heating, use the pump laser to polarize the atoms longitudinally, apply the longitudinal main magnetic field and the transverse radio frequency magnetic field, and put the atoms in a resonant state.

[0073] (2) Scan the frequency of the RF magnetic field to obtain the resonance curve of the atomic ensemble with respect to the longitudinal main magnetic field, using the formula The test data are fitted, where A, ω0 and Γ are fitting parameters, Γ is the line width of the resonance curve, and the atomic spin transverse relaxation rate R2 = 2πΓ.

[0074] (3) The pumping light power density is changed, and step (2) is repeated to perform resonance line width test to obtain a curve of the atomic spin transverse relaxation rate changing with the pumping light power.

[0075] (4) According to the mapping relationship between pump light power density and pumping rate, the pumping rate under different pump light power densities is calculated using the formula The atomic spin transverse relaxation rate data under different pumping rates are fitted by using the light pressure narrowing effect, where R p is the pumping rate, R se and R rel is the fitting parameter, R se =nνσ is the atomic spin exchange collision rate, where n is the atomic number density, ν and σ are the relative thermal motion speed and cross-sectional area of ​​alkali metal atoms. se The atomic number density n can be calculated by the theoretical values ​​of ν and σ. Finally, the atomic number density value is substituted into the saturated vapor pressure formula n = (10 21.866+A-B / T ) / T can be used to obtain the atomic gas chamber temperature T, thereby realizing the in-situ measurement of the atomic gas chamber temperature.

[0076] In this embodiment, an atomic gas chamber temperature in-situ measurement device is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and the descriptions that have been made will not be repeated. As used below, the term "module" can implement a combination of software and / or hardware of a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0077] This embodiment provides an atomic gas chamber temperature in-situ measurement device, such as Figure 2 As shown, including:

[0078] The resonance control module 31 is used to irradiate the atoms in the atomic gas chamber in a heated state with a pumping laser, and apply a magnetic field to the atomic gas chamber to polarize the atoms and put them into a resonance state;

[0079] A relaxation rate determination module 32, used to obtain a resonance curve of an atom and determine a transverse relaxation rate of an atom's spin based on a line width of the resonance curve;

[0080] The temperature determination module 33 is used to change the pumping laser power density and determine the atomic spin transverse relaxation rate corresponding to different pumping laser power densities; based on the relationship between the atomic spin transverse relaxation rate and the pumping rate, the atomic spin transverse relaxation rate under different pumping light power densities is fitted to obtain fitting parameters, wherein the fitting parameters include the atomic spin exchange collision rate; based on the atomic spin exchange collision rate, the atomic number density is determined; based on the atomic spin exchange collision rate, the atomic gas chamber temperature is determined based on the atomic number density and the saturated vapor pressure formula.

[0081] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0082] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for in-situ measurement of atomic gas chamber temperature, characterized in that: The method comprises: A pump laser is used to irradiate atoms in the heated atomic gas cell, and a magnetic field is applied to the atomic gas cell to polarize the atoms and put them into a resonant state; Obtaining the atomic resonance curve, and determining the atomic spin transverse relaxation rate based on the line width of the resonance curve; Change the pump laser power density and determine the atomic spin transverse relaxation rate corresponding to different pump laser power densities; Based on the relationship between the atomic spin transverse relaxation rate and the pumping rate, the atomic spin transverse relaxation rate under different pumping light power densities is fitted to obtain fitting parameters, wherein the fitting parameters include the atomic spin exchange collision rate; determining an atomic number density based on the atomic spin exchange collision rate; The atomic gas chamber temperature is determined based on the atomic number density and the saturated vapor pressure formula.

2. The method according to claim 1, characterized in that Using a pump laser to irradiate atoms in an atomic gas cell in a heated state and applying a magnetic field to the atomic gas cell to polarize the atoms and put them into a resonant state includes: The atoms in the heated atomic gas chamber are irradiated with a pumping laser to polarize the atoms; applying a longitudinal main magnetic field and a transverse radio frequency magnetic field to the atomic gas chamber; The frequency of the transverse radio frequency magnetic field is scanned to bring the atoms into a resonant state; Obtain the atomic resonance curve and determine the atomic spin transverse relaxation rate based on the line width of the resonance curve, including: The frequency change during the scanning process of the transverse radio frequency magnetic field and the output signal change of the atomic magnetometer are fitted to obtain the resonance curve of the atom; Determine the line width of the resonance curve based on the fitting parameters; The atomic spin transverse relaxation rate is determined based on the relationship between the line width of the resonance curve and the atomic spin transverse relaxation rate.

3. The method according to claim 2, characterized in that The following formula is used to fit the frequency change during the transverse RF magnetic field scanning process and the output signal change of the atomic magnetometer: Where S is the output signal of the atomic magnetometer, ω is the frequency of the transverse radio frequency magnetic field, Γ represents the line width of the resonance curve, and A and ω0 are fitting parameters.

4. The method according to claim 1, characterized in that Using a pump laser to irradiate atoms in an atomic gas cell in a heated state and applying a magnetic field to the atomic gas cell to polarize the atoms and put them into a resonant state includes: The atoms in the heated atomic gas chamber are irradiated with a pumping laser to polarize the atoms; applying a longitudinal main magnetic field to the atomic gas chamber; Modulate the parameters of the pump laser to put the atoms into a resonant state; Obtain the atomic resonance curve and determine the atomic spin transverse relaxation rate based on the line width of the resonance curve, including: The parameter changes during the modulation of the pump laser parameters and the output signal changes of the atomic magnetometer are fitted to obtain the resonance curve of the atom; Determine the line width of the resonance curve based on the fitting parameters; The atomic spin transverse relaxation rate is determined based on the relationship between the line width of the resonance curve and the atomic spin transverse relaxation rate.

5. The method according to claim 1, characterized in that The relationship between the pumping rate and the atomic spin transverse relaxation rate is expressed by the following formula: Where R2 represents the transverse relaxation rate of atomic spin, R p represents the pumping rate, R se represents the atomic spin exchange collision rate, R rel represents the residual relaxation rate.

6. The method according to claim 2, characterized in that The amplitude of the applied transverse RF magnetic field satisfies the following formula: Where B1 represents the amplitude of the transverse RF magnetic field, R1 and R2 are the longitudinal relaxation rate and transverse relaxation rate of the atoms, respectively, and γ is the atomic gyromagnetic ratio.

7. The method according to claim 1, characterized in that The temperature of the atomic gas chamber is controlled in a closed loop during the in-situ measurement of the atomic gas chamber temperature.

8. An atomic gas chamber temperature in-situ measurement device, characterized in that: The device comprises: A resonance control module, used for irradiating atoms in the atomic gas chamber in a heated state with a pumping laser, and applying a magnetic field to the atomic gas chamber to polarize the atoms and put them into a resonance state; A relaxation rate determination module, used to obtain the resonance curve of the atom and determine the atomic spin transverse relaxation rate based on the line width of the resonance curve; The temperature determination module is used to change the pump laser power density and determine the atomic spin transverse relaxation rate corresponding to different pump laser power densities; based on the relationship between the atomic spin transverse relaxation rate and the pumping rate, the atomic spin transverse relaxation rate under different pump light power densities is fitted to obtain fitting parameters, wherein the fitting parameters include the atomic spin exchange collision rate; based on the atomic spin exchange collision rate, the atomic number density is determined; based on the atomic spin exchange collision rate, the atomic gas chamber temperature is determined based on the atomic number density and the saturated vapor pressure formula.

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