Inert gas atomic polarization parameter measurement method based on magneto-optical effect

Abstract

The invention discloses an inert gas atomic polarization parameter measurement method based on a magneto-optical effect, and belongs to the field of optical detection and quantum sensing. A direct-current magnetic field is applied along the Z axis, elliptical polarization pump light matched with the absorption peak of alkali metal atoms is emitted to an atomic gas chamber, and the gas chamber contains inert gas mixed components; applying excitation magnetic fields corresponding to the inert gases in sequence, and measuring attenuation time constants of the gases through a signal envelope curve of the detector; removing the excitation magnetic field in a reverse order, measuring signal amplitude change, fitting longitudinal relaxation time, and calculating transverse relaxation time in combination with a decay time constant; and calibrating the responsivity of the Z-axis parametric magnetometer, and calculating the atomic polarization magnetic field intensity of each inert gas according to the signal step and the calibration coefficient. According to the invention, continuous measurement of polarization magnetic field size and relaxation time parameters of multiple atom types is realized at the same time, the measurement time is reduced, and the measurement efficiency is greatly improved.

Description

Technical Field

[0001] The present invention relates to the fields of optical detection and quantum sensing, and in particular to a method for measuring polarization parameters of an inert gas based on magneto-optical effect. Background Art

[0002] Nuclear magnetic resonance gyroscopes (NMR gyroscopes) based on alkali metal-noble gas atomic systems have attracted research attention due to their small size, low power consumption, large dynamic range, and high sensitivity. NMR gyroscopes primarily utilize the magnetic resonance properties of noble gas nuclei in a magnetic field to detect angular velocity. Typically, light polarizes alkali metal atoms and transfers the polarization to the noble gas atoms through nuclear spin exchange. Common atomic spin systems used in gyroscopes include Rb-Xe, K-Rb-He, and Cs-Xe.

[0003] In order to improve the performance of nuclear magnetic resonance gyroscopes, it is necessary to conduct in-depth research on the mechanisms of atomic spin system self-selection exchange and relaxation. Furthermore, it is necessary to conduct rapid and accurate measurements of polarization-related parameters such as the polarizability and relaxation time of inert atoms. Among the current relaxation time measurement methods, the most common is the polarization reversal method, which has a long measurement time. A single measurement often takes several hours. If multiple isotopes need to be measured, the time is even longer. Other methods such as the exponential fitting method and the dark state sweep method all obtain the relaxation time from indirect parameters. The signal demodulation is complex, and it is more likely to introduce additional noise, resulting in large measurement noise. All of the above methods are difficult to achieve rapid and accurate measurement of polarization magnetic field and relaxation time at the same time. Summary of the Invention

[0004] To address the shortcomings of existing measurement methods, this paper proposes a method for measuring the polarization parameters of noble gases based on the magneto-optical effect. This method simplifies the measurement setup and, unlike conventional dual-beam detection, uses elliptically polarized light as both the polarization beam and the probe beam to directly measure the magnitude of the polarization magnetic field in the pump direction, avoiding the introduction of additional indirect measurement errors. This method also enables continuous measurement of the polarization magnetic field magnitude and relaxation time parameters of multiple atomic species, reducing measurement time and significantly improving measurement efficiency.

[0005] The technical solution adopted in the present invention is as follows:

[0006] In a first aspect, the present invention provides a method for measuring polarization parameters of noble gas atoms based on the magneto-optical effect, comprising the following steps:

[0007] S1, applying a DC magnetic field of magnitude B0 to the Z axis of the atomic gas chamber, and emitting pump light to the atomic gas chamber in the same direction, wherein the pump light is an elliptically polarized laser with a wavelength corresponding to the absorption peak of the alkali metal atoms in the atomic gas chamber; the atomic gas chamber contains one or more inert gas components;

[0008] S2, applying an excitation magnetic field corresponding to each noble gas atom to the atomic gas chamber in sequence, and measuring the decay time constant of each noble gas based on the detector signal envelope curve corresponding to the noble gas detected after applying the excitation magnetic field;

[0009] S3, removing the excitation magnetic fields corresponding to the various noble gas atoms in the reverse order of applying the excitation magnetic fields, measuring the detector signal amplitudes before and after the removal, recording the signal amplitude steps corresponding to each noble gas, fitting the longitudinal relaxation time constant of each noble gas, and then calculating the transverse relaxation time constant in combination with the decay time constant;

[0010] S4, calibrating the signal responsivity of the Z-axis intrinsic parameter magnetometer, and calculating the atomic polarization magnetic field of each noble gas according to the signal responsivity of the Z-axis intrinsic parameter magnetometer and the signal amplitude step of each noble gas.

[0011] Furthermore, step S1 includes:

[0012] A Helmholtz coil is used to apply a stable DC magnetic field of magnitude B0 to the atomic gas cell. A laser is arranged in the same direction. A polarizer and a quarter-wave plate are placed in sequence behind the laser. The angle between the polarization directions of the polarizer and the quarter-wave plate is adjusted so that the ratio of the left-handed circular polarization component to the linear polarization component in the output light is (10-20):1.

[0013] The current and temperature of the laser are controlled so that the power of the pump light entering the atomic gas cell is the optimal pump power of the atomic gas cell, and the frequency of the pump light has a certain detuning relative to the absorption peak of the alkali metal atoms.

[0014] Furthermore, the laser frequency control accuracy is 10 MHz, and the power control accuracy is 100 ppm.

[0015] Furthermore, the components of the atomic gas chamber include alkali metal atoms, buffer gas, and one or more inert gases.

[0016] Furthermore, the stability of the DC magnetic field in step S1 is better than 1 ppm.

[0017] Furthermore, step S2 includes:

[0018] After the initial pump state stabilizes, a first excitation magnetic field signal corresponding to the Larmor precession frequency of the first noble gas atoms is applied in the direction perpendicular to the pump light, and the decay time constant of the first noble gas is measured based on the detector signal envelope curve;

[0019] After the detector signal stabilizes, the next excitation magnetic field signal is applied in sequence while maintaining the previous excitation magnetic field signal and the decay time constant of the corresponding inert gas is measured, traversing all the inert gases.

[0020] Furthermore, the excitation magnetic field signal satisfies the following conditions:

[0021]

[0022] ω i =γ i B i

[0023] Where, γ i is the gyromagnetic ratio of the i-th noble gas atom, B i is the amplitude of the i-th excitation magnetic field, ω i is the frequency of the i-th excitation magnetic field, T 1i 、T 2i are the longitudinal relaxation time and transverse relaxation time of the i-th inert gas respectively; the amplitude condition of the excitation magnetic field is determined according to the magnitude relationship between the longitudinal relaxation time and the transverse relaxation time of the inert gas, the amplitude of the excitation magnetic field is selected when the amplitude condition is met, and then the frequency of the excitation magnetic field is determined according to the gyromagnetic ratio.

[0024] Furthermore, the fitting obtains the longitudinal relaxation time constant of each inert gas, and the fitting formula is as follows:

[0025]

[0026] Among them, V i V represents the detector signal amplitude before removing the i-th excitation magnetic field signal. i-1 The detector signal amplitude after the i-th excitation magnetic field signal is removed, t represents the time variable from the removal of the excitation signal to the stabilization of the detector signal, T 1i is the longitudinal relaxation time of the i-th noble gas;

[0027] The relationship between longitudinal relaxation time and transverse relaxation time is as follows:

[0028] T 2,i =-T 1,i / (2α i T 1,i +1)

[0029] Among them, T 2,i represents the transverse relaxation time of the i-th noble gas, α i represents the decay time constant of the i-th noble gas.

[0030] Furthermore, the magnitude of the atomic polarization magnetic field of the inert gas is the ratio of the signal amplitude step of the corresponding inert gas to the signal responsivity of the Z-axis intrinsic parameter magnetometer.

[0031] In a second aspect, the present invention proposes a device for measuring the polarization parameters of noble gas atoms based on the magneto-optical effect, which is used to implement the above-mentioned measurement method. The system includes:

[0032] Helmholtz coil, which is used to apply a DC magnetic field of magnitude B0 to the Z axis of the atomic gas chamber;

[0033] A laser device is used to emit pump light to the atomic gas chamber in the direction of a DC magnetic field, wherein the pump light is an elliptically polarized laser having a wavelength corresponding to an absorption peak of alkali metal atoms in the atomic gas chamber; the elliptically polarized laser can adjust the laser polarization state under the action of a polarizer and a quarter-wave plate;

[0034] an excitation magnetic field generator, which is used to generate an excitation magnetic field corresponding to the inert gas atoms;

[0035] A detection device, which is used to detect the magnetic field change signal in the Z direction and record the detector signal;

[0036] The signal processing unit is used to measure the decay time constant of each noble gas based on the detector signal envelope curve corresponding to the noble gas detected after applying the excitation magnetic field; measure the detector signal amplitude before and after the excitation magnetic field is removed, record the signal amplitude step corresponding to each noble gas, fit the longitudinal relaxation time constant of each noble gas, and then calculate the transverse relaxation time constant in combination with the decay time constant; and calculate the magnitude of the atomic polarization magnetic field of each noble gas.

[0037] The beneficial effects of the present invention are:

[0038] The innovative optical-magnetic fusion technology and optimized measurement process proposed in this paper achieve efficient and accurate measurement of the polarization parameters of noble gas atoms. Its core advantages are reflected in two aspects:

[0039] (1) Alkali metal atom polarization and noble gas detection are realized synchronously through elliptically polarized light, eliminating the traditional dual-light path design. Combined with the strategy of sequential application and reverse removal of the excitation magnetic field, it supports the continuous synchronous measurement of the polarization magnetic field and relaxation time of multi-component noble gases, significantly improving the detection efficiency.

[0040] (2) By establishing an analytical relationship model between longitudinal and transverse relaxation times, combined with a high-precision laser (frequency control accuracy of 10 MHz), an ultra-stable DC magnetic field (stability better than 1 ppm), and signal responsivity calibration technology, a joint calculation of the decay time constant and longitudinal / transverse relaxation times is achieved, effectively suppressing indirect measurement errors and ensuring system-level accuracy of the coordinated calibration of multiple physical quantities. This solution has shown important engineering application value in fields such as nuclear magnetic resonance gyroscopes and quantum sensing. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a flow chart of a method for measuring polarization parameters of noble gas atoms based on magneto-optical effect according to an embodiment of the present invention.

[0042] Figure 2 Schematic diagram of the experimental device of the embodiment of the present invention.

[0043] In the figure: 1-atomic gas chamber, 2-magnetic shielding device, 3-1 / 4λ wave plate, 4-1 / 2 wave plate, 5-polarizer, 6-fiber collimator, 7-laser, 8-temperature controller, 9-current controller, 10-mirror, 11-polarization beam splitter prism, 12-BPD detector, 13-Helmholtz coil.

[0044] Figure 3 This is a time domain evolution diagram of the Xe polarization field measurement signal in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The present invention will be further described and illustrated below in conjunction with specific embodiments. The embodiments are merely illustrative of the present disclosure and do not limit its scope. The technical features of the various embodiments of the present invention may be combined accordingly, provided that there is no conflict between them.

[0046] Figure 1 This is a flow chart of a method for measuring the polarization parameters of noble gas atoms based on the magneto-optical effect according to an embodiment of the present invention. The polarization parameters of noble gas atoms include polarization magnetic field, longitudinal relaxation time, and transverse relaxation time. The implementation method of the present invention mainly includes the following steps:

[0047] S1: Apply a DC magnetic field of magnitude B0 to the Z axis of the atomic gas chamber, and in the same direction, pump the gas chamber with an elliptically polarized laser at the absorption peak wavelength corresponding to the alkali metal atoms M. This process is achieved by a laser, which emits pump light to the atomic gas chamber. The pump light is an elliptically polarized laser at the absorption peak wavelength corresponding to the alkali metal atoms in the atomic gas chamber; the atomic gas chamber contains one or more noble gas components. S2: Apply an excitation magnetic field corresponding to each noble gas atom to the atomic gas chamber in sequence, record the detector signal envelope curve corresponding to the noble gas detected after applying the excitation magnetic field, and measure the decay time constant α when the signal envelope corresponding to the i-th noble gas reaches stability. i , i=1,2,…,n; here, n represents the number of types of inert gas components;

[0048] S3, remove the excitation magnetic fields corresponding to the various types of noble gas atoms in the reverse order of applying the excitation magnetic field, and record the signal amplitude step ΔV corresponding to each noble gas i , and the time constant T of the longitudinal relaxation of the detector signal corresponding to the i-th inert gas is obtained by fitting. 1,i , and according to the longitudinal relaxation time constant T 1,i, decay time constant α i Calculate the transverse relaxation time constant T 2,i ;

[0049] S4, calibrate the signal response R of the Z-axis intrinsic parameter magnetometer;

[0050] S5, through the signal amplitude step ΔV i , the signal response R of the Z-axis internal parameter magnetometer is used to calculate the polarization magnetic field size B of each noble gas atom i , which is calculated as follows:

[0051] B i =ΔV i / R.

[0052] Figure 2 This is a schematic diagram of the experimental device of an embodiment of the present invention, which includes an atomic gas chamber 1, a magnetic shielding device 2, a 1 / 4λ wave plate 3, a 1 / 2 wave plate 4, a polarizer 5, a fiber collimator 6, a laser 7, a temperature controller 8, a current controller 9, a reflector 10, a polarization beam splitter prism 11, a BPD detector 12, and a Helmholtz coil 13.

[0053] According to one aspect of the present application, step S1 further comprises:

[0054] A Helmholtz coil 13 is used to apply a stable DC magnetic field of size B0=10μT to the atomic gas chamber 1, and a laser 7 is used to pump alkali metal atoms in the same direction; a fiber collimator 6, a 1 / 2λ wave plate 4, a polarizer 5, and a 1 / 4λ wave plate 3 are placed in sequence behind the laser 7. The 1 / 2λ wave plate 4 is used to adjust the polarization direction of the light without changing the intensity of the incident 1 / 4λ wave plate 3. The angle between the polarization directions of the polarizer 4 and the 1 / 4λ wave plate is adjusted so that the outgoing light has a left-handed circular polarization component and a linear polarization component with a ratio of 10:1. By adjusting the reflector 10 and the polarization beam splitter prism After passing through the gas chamber at the mirror 11 position, the light is divided into two beams and enters the two probes of the BPD detector 12 respectively. At the same time, the temperature controller 8 and the current controller 9 control the temperature and current of the laser 7 to achieve stable output of the power and frequency of the laser 7. The power is the optimal pump power of the atomic gas chamber 1. At the same time, the laser frequency has a certain detuning relative to the alkali metal atomic absorption peak. In this embodiment, when the target current of the current controller 9 is set to 64.82 mA and the target resistance of the temperature sensor is set to 8.143 kΩ, the power and frequency of the laser 7 meet the experimental requirements.

[0055] According to one aspect of the present application, the components of the pumped atomic gas chamber 1 are alkali metal M, buffer gas and multiple inert gases N i , where i = 1, 2, ..., in this example, the components are alkali metal Rb, buffer gas N2 and inert gas129 Xe, 131 Xe.

[0056] According to one aspect of the present application, the stability of the DC magnetic field is better than 1 ppm.

[0057] According to one aspect of the present application, the pump laser achieves stable output of power and frequency by simultaneously controlling current and temperature, with a frequency control accuracy of 10M and a power control accuracy of 100ppm.

[0058] According to one aspect of the present application, step S2 is further:

[0059] S21, in the atomic gas chamber, the linearly polarized light is used as the detection light, and the detection light is decomposed into left-handed and right-handed circularly polarized light. The refractive index of the two beams in the gas chamber is different. Finally, after the light beam leaves the gas chamber, the polarization direction of the linear polarized light changes, and the change is proportional to the size of the magnetic field in the Z direction. The light beam emitted from the atomic gas chamber passes through the polarization beam splitter prism 11 and enters the BPD detector 12. The size of the detector signal change is proportional to the size of the magnetic field in the Z direction. After the initial state of the pump is stable, it enters step S22.

[0060] S22, add an excitation magnetic field signal B1cos(ω1t) in the direction perpendicular to the pump light. The frequency of the excitation magnetic field is equal to the Larmor precession frequency of the corresponding inert gas atoms. The atoms and the magnetic field generate nuclear magnetic resonance signals, which are detected by the linearly polarized detection light in the Z direction. The decay time constant α1 of the first inert gas is measured according to the detector signal envelope curve; after waiting for the system state to stabilize, the excitation magnetic field B2cos(ω2t), i=2, is added in sequence while maintaining the previous excitation magnetic field signal; and the decay time constant α2 of the corresponding inert gas is recorded and measured.

[0061] See for example Figure 3 The time-domain evolution diagram of the Xe polarization field measurement signal in the embodiment is shown. At time t1, the excitation magnetic field signal B1cos(ω1t) is added, and at time t2, the excitation magnetic field signal B2cos(ω2t) is added. The amplitude change of the signal envelope from time t1 to t2 follows an exponential decay function with a time constant of α1, and the amplitude change of the signal envelope from time t2 to t3 follows an exponential decay function with a time constant of α2. The decay time constants α1 and α2 are obtained by exponential function fitting.

[0062] The amplitude and frequency of the applied excitation magnetic field signal satisfy:

[0063]

[0064] Where, γ i is the gyromagnetic ratio of the i-th noble gas atom; B i is the amplitude of the i-th excitation magnetic field, ω iis the frequency of the i-th excitation magnetic field, T 1i 、T 2i are the longitudinal relaxation time and transverse relaxation time of the i-th inert gas respectively; the amplitude condition of the excitation magnetic field is determined according to the magnitude relationship between the longitudinal relaxation time and transverse relaxation time of the inert gas, the amplitude of the excitation magnetic field is selected when the amplitude condition is met, and the frequency of the excitation magnetic field is determined according to the gyromagnetic ratio. In this embodiment, the excitation field frequencies ω1 and ω2 are 118.6 Hz and 35.2 Hz respectively, and the excitation magnetic field amplitude B is 118.6 Hz and 35.2 Hz respectively. i The size is 1μT.

[0065] According to one aspect of the present application, step S3 is further:

[0066] Remove the excitation magnetic field in the reverse order of application and record the signal amplitude step corresponding to each inert gas. Figure 3 The Xe polarization field measurement signal time domain evolution diagram of the embodiment in the present invention is shown in FIG. 1 . In this embodiment, the Xe polarization field measurement signal is added at time t1 and time t2 respectively. 129 Xe and 131 The excitation magnetic field of Xe is removed at t3 and t4 respectively. 131 The excitation magnetic field of Xe and 129 For the excitation magnetic field of Xe, record the detector signal amplitude V2=0V before the second excitation magnetic field signal is removed at time t3. After the detector signal stabilizes, record the detector signal amplitude V1=1.09V after the second excitation magnetic field signal is removed, then the amplitude step ΔV2=V2-V1=-1.09V; record the detector signal amplitude V1=1.09V before the first excitation magnetic field signal is removed at time t4. After the detector signal stabilizes, record the detector signal amplitude V0=2.4V after the first excitation magnetic field signal is removed, then the amplitude step ΔV1=V1-V0=-1.31V.

[0067] See also Figure 3 The time domain evolution diagram of the Xe polarization field measurement signal of the embodiment, the signal curves from t3 to t4 and from t4 to the end of the signal satisfy the curve of the following equation, and the longitudinal relaxation time constant of each noble gas is obtained by fitting:

[0068]

[0069] Where V i is the signal amplitude before removing the i-th excitation magnetic field signal; V i-1 The signal amplitude after removing the i-th excitation magnetic field signal; t is time; T 1i is the longitudinal relaxation time of the i-th noble gas atom, and t represents the time variable from the removal of the excitation signal to the stabilization of the detector signal.

[0070] In step S22, an excitation magnetic field signal B is applied.i cos(ω i After t), the attenuation of the polarized magnetic field of the inert gas in the Z direction changes with time and is converted into a voltage signal by the detector. The amplitude of the signal changes as follows:

[0071]

[0072] Where, represents the decay time constant; is the signal attenuation frequency, is the phase of the sinusoidal part of the decay signal. Further, the longitudinal relaxation time T of the i-th noble gas atom obtained by the above fitting calculation is 1i , and the measured decay constant The transverse relaxation time T of the i-th noble gas atom 2,i It is obtained from the following formula:

[0073] T 2,i =-T 1,i / (2α i T 1,i +1).

[0074] like Figure 3 As shown, the time axis t3 and t4 on the figure are removed respectively. 129 Xe and 131 The excitation magnetic field of Xe is used to record the polarization recovery process, and the longitudinal relaxation time T is obtained by fitting the relaxation formula. 11 、T 12 are 20.2s and 10.7s respectively, the decay constants α1 and α2 are 12.9s and 6.72s respectively, and the transverse relaxation time T 21 、T 22 9.5s and 5s respectively.

[0075] In step S4, the Z-axis intrinsic magnetometer's signal responsivity R refers to the change in BPD signal amplitude per unit magnetic field strength. In this embodiment, the Z-axis intrinsic magnetometer's signal responsivity R is calibrated by actively varying the Z-axis magnetic field by 100 nT and observing a 3.43 V change in the BPD signal amplitude, resulting in a system magnetometer responsivity of 34.3 mV / nT.

[0076] After the magnetometer responsivity is calibrated in step S4, step S5 is performed to calculate the polarization magnetic field size B of the noble gas atoms using the signal amplitude steps ΔV1, ΔV2 and the Z-axis intrinsic parameter magnetometer signal responsivity R measured in step S2. i ,get 129 Xe, 131 The Z-axis polarization magnetic fields of Xe are 38.2nT and 31.78nT respectively.

[0077] The above is only the preferred implementation method of the present invention, not the only implementation method. Any possible changes and modifications made by any technician in this field after reading this application without departing from the spirit and scope of this application should be within the scope defined by the claims of this application.

Claims

1. A method for measuring the polarization parameters of noble gas atoms based on the magneto-optical effect, characterized in that: The following steps are involved: S1, applying a DC magnetic field to the Z axis of the atomic gas chamber and emitting pump light to the atomic gas chamber in the same direction, wherein the pump light is an elliptically polarized laser with a wavelength corresponding to the absorption peak of the alkali metal atoms in the atomic gas chamber; the atomic gas chamber contains one or more inert gas components; S2, applying an excitation magnetic field corresponding to each noble gas atom to the atomic gas chamber in sequence, and measuring the decay time constant of each noble gas based on the detector signal envelope curve corresponding to the noble gas detected after applying the excitation magnetic field; S3, removing the excitation magnetic fields corresponding to the various noble gas atoms in the reverse order of applying the excitation magnetic fields, measuring the detector signal amplitudes before and after the removal, recording the signal amplitude steps corresponding to each noble gas, fitting the longitudinal relaxation time constant of each noble gas, and then calculating the transverse relaxation time constant in combination with the decay time constant; S4, calibrating the signal responsivity of the Z-axis intrinsic parameter magnetometer, and calculating the atomic polarization magnetic field of each noble gas according to the signal responsivity of the Z-axis intrinsic parameter magnetometer and the signal amplitude step of each noble gas.

2. The method for measuring polarization parameters of noble gas atoms based on magneto-optical effect according to claim 1, wherein: Step S1 includes: A Helmholtz coil is used to apply a stable DC magnetic field of magnitude B0 to the atomic gas cell. A laser is arranged in the same direction. A polarizer and a quarter-wave plate are placed in sequence behind the laser. The angle between the polarization directions of the polarizer and the quarter-wave plate is adjusted so that the ratio of the left-handed circular polarization component to the linear polarization component in the output light is (10-20):

1. The current and temperature of the laser are controlled so that the power of the pump light entering the atomic gas cell is the optimal pump power of the atomic gas cell, and the frequency of the pump light has a certain detuning relative to the absorption peak of the alkali metal atoms.

3. The method for measuring polarization parameters of noble gas atoms based on magneto-optical effect according to claim 2, wherein: The laser frequency control accuracy is 10 MHz, and the power control accuracy is 100 ppm.

4. The method for measuring polarization parameters of noble gas atoms based on magneto-optical effect according to claim 1, wherein: The components of the atomic gas cell include alkali metal atoms, a buffer gas, and one or more inert gases.

5. The method for measuring polarization parameters of noble gas atoms based on magneto-optical effect according to claim 1, wherein: The stability of the DC magnetic field in step S1 is better than 1 ppm.

6. The method for measuring polarization parameters of noble gas atoms based on magneto-optical effect according to claim 1, wherein: Step S2 includes: After the initial pump state stabilizes, a first excitation magnetic field signal corresponding to the Larmor precession frequency of the first noble gas atoms is applied in the direction perpendicular to the pump light, and the decay time constant of the first noble gas is measured based on the detector signal envelope curve; After the detector signal stabilizes, the next excitation magnetic field signal is applied in sequence while maintaining the previous excitation magnetic field signal and the decay time constant of the corresponding inert gas is measured, traversing all the inert gases.

7. The method for measuring polarization parameters of noble gas atoms based on magneto-optical effect according to claim 6, characterized in that: The excitation magnetic field signal meets the following conditions: oh i =c i B i Where, γ i is the gyromagnetic ratio of the i-th noble gas atom, B i is the amplitude of the i-th excitation magnetic field, ω i is the frequency of the i-th excitation magnetic field, T 1i 、T 2i are the longitudinal relaxation time and transverse relaxation time of the i-th inert gas respectively; the amplitude condition of the excitation magnetic field is determined according to the magnitude relationship between the longitudinal relaxation time and the transverse relaxation time of the inert gas, the amplitude of the excitation magnetic field is selected when the amplitude condition is met, and then the frequency of the excitation magnetic field is determined according to the gyromagnetic ratio.

8. The method for measuring polarization parameters of noble gas atoms based on magneto-optical effect according to claim 1, wherein: The fitting method obtains the longitudinal relaxation time constant of each inert gas, and the fitting formula is as follows: Among them, V i V represents the detector signal amplitude before removing the i-th excitation magnetic field signal. i-1 The detector signal amplitude after the i-th excitation magnetic field signal is removed, t represents the time variable from the removal of the excitation signal to the stabilization of the detector signal, T 1i is the longitudinal relaxation time of the i-th noble gas; The relationship between longitudinal relaxation time and transverse relaxation time is as follows: T 2,i -T 1,i / (2α i T 1,i +1) Among them, T 2,i represents the transverse relaxation time of the i-th noble gas, α i represents the decay time constant of the i-th noble gas.

9. The method for measuring polarization parameters of noble gas atoms based on magneto-optical effect according to claim 1, characterized in that: The magnitude of the atomic polarization magnetic field of the inert gas is the ratio of the signal amplitude step of the corresponding inert gas to the signal responsivity of the Z-axis intrinsic parameter magnetometer.

10. A device for measuring the polarization parameters of noble gas atoms based on the magneto-optical effect, used to implement the measurement method according to claim 1, characterized in that: The system comprises: Helmholtz coil, which is used to apply a DC magnetic field to the Z axis of the atomic gas chamber; A laser device is used to emit pump light to the atomic gas chamber in the direction of a DC magnetic field, wherein the pump light is an elliptically polarized laser having a wavelength corresponding to an absorption peak of alkali metal atoms in the atomic gas chamber; the elliptically polarized laser can adjust the laser polarization state under the action of a polarizer and a quarter-wave plate; an excitation magnetic field generator, which is used to generate an excitation magnetic field corresponding to the inert gas atoms; A detection device, which is used to detect the magnetic field change signal in the Z direction and record the detector signal; The signal processing unit is used to measure the decay time constant of each noble gas based on the detector signal envelope curve corresponding to the noble gas detected after applying the excitation magnetic field; measure the detector signal amplitude before and after the excitation magnetic field is removed, record the signal amplitude step corresponding to each noble gas, fit the longitudinal relaxation time constant of each noble gas, and then calculate the transverse relaxation time constant in combination with the decay time constant; and calculate the magnitude of the atomic polarization magnetic field of each noble gas.

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