CN114234951B - Magnetic field fluctuation testing method of SERF inertial device based on nuclear spin polarization suppression - Google Patents

Magnetic field fluctuation testing method of SERF inertial device based on nuclear spin polarization suppression Download PDF

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CN114234951B
CN114234951B CN202111574884.8A CN202111574884A CN114234951B CN 114234951 B CN114234951 B CN 114234951B CN 202111574884 A CN202111574884 A CN 202111574884A CN 114234951 B CN114234951 B CN 114234951B
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inertial device
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全伟
庞昊颖
范文峰
黄炯
刘峰
刘祀浔
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Abstract

A magnetic field fluctuation testing method of a SERF inertial device based on nuclear spin polarization suppression includes the steps of firstly heating the inertial device to a working temperature required by alkali metal atoms, pumping the alkali metal atoms to enable the inertial device to work in an inertial measurement mode, testing angular velocity response and magnetic field response of a system, secondly applying a proper gradient magnetic field to the system by using a gradient coil to suppress polarization of nuclear spin, and enabling the inertial device to work in a magnetic field measurement mode. And finally, a high-sensitivity magnetometer is constructed and long-time data acquisition is carried out by adjusting the size of the gradient magnetic field, the magnetic field fluctuation analysis is carried out by adopting an Allan variance evaluation method, the method can be flexibly switched between an inertia measurement mode and a magnetic field measurement mode, the angular velocity can be measured, the in-situ high-sensitivity magnetic field measurement can be realized, a method is provided for accurately evaluating the magnetic field fluctuation in an inertia device, and the method has important significance for the error analysis of the SERF inertia device.

Description

Magnetic field fluctuation testing method of SERF inertial device based on nuclear spin polarization suppression
Technical Field
The invention belongs to the technical field of atomic sensors, and particularly relates to a magnetic field fluctuation testing method of an SERF inertial device based on nuclear spin polarization suppression.
Background
Atomic sensors composed of two spin species with different gyromagnetic ratios have been widely used in a variety of scientific exploration and medical applications, including basic physical research, magnetic resonance imaging, and inertial navigation. SERF inertial devices, in particular, for applications in the field of inertial measurement, are gaining wide attention due to their ultra-high sensitivity to abnormal fields and rotation (SERF, spin Exchange Relaxation Free).
Typically, the inertial device consists of a gas cell, a non-magnetic electric heating system, a magnetic compensation coil, a magnetic shielding system, and an orthogonal pumping detection optical path system. In practical applications, fluctuations in temperature, optical power and magnetic field can impair the stability of the system, especially low-frequency magnetic field fluctuations introduced by magnetic shields, magnetic compensation coils and electrical heating systems. The magnetic shielding system generally comprises permalloy with high magnetic conductivity and MnZn ferrite with low noise, and the magnetic conductivity can change along with the temperature change, so that residual magnetism in the shielding system fluctuates. The magnetic compensation coil is used for generating a compensation magnetic field required by the normal operation of the system, and the magnetic field fluctuation is directly caused by the current fluctuation in the coil. In addition, fluctuations in the current in the electrical heating wire used for heating likewise lead to fluctuations in the magnetic field.
At present, one type of test method for magnetic field fluctuation is to use magnetometers to perform testing, including fluxgate magnetometers, triaxial atomic magnetometers, and the like. The fluxgate magnetometer is often used for testing the magnitude of a magnetic field in a magnetic shielding and magnetic compensation system due to the characteristics of simple and convenient operation and easy movement, but the fluxgate magnetometer has low sensitivity and cannot detect a pt-magnitude magnetic field (pt, 10) -12 Tesla). Three-axis atomic magnetometers have also been proposed to measure magnetic field fluctuations with ultra-high sensitivity, allowing detection of magnetic fields in the order of ft (ft, 10) -15 Tesla). But it is not an in-situ measurement and requires replacement of the gas chamber when it is converted to an inertial measurement mode, which introduces other errors during the replacement process. Another type of test method is a method of simultaneous measurement of inertia and magnetic field. But the magnetic field can not be measured continuously, and the long-time continuous measurement of the magnetic field fluctuation can not be effectively carried out.
As the stability performance of SERF inertial devices increases, higher requirements are placed on the stability of the magnetic field. But at the present time there is still a lack of an effective high-sensitivity in-situ magnetic field test method to evaluate the long-term stability of the magnetic field in inertial devices. Therefore, how to realize in-situ high-sensitivity magnetic field test in the inertial device becomes a problem to be solved urgently.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the method overcomes the defect that the conventional inertial device cannot carry out in-situ, high-precision and long-time magnetic field fluctuation test, and provides a magnetic field fluctuation test method of the SERF inertial device based on nuclear spin polarization suppression, so that the fluctuation of a magnetic field in the inertial device is accurately tested and evaluated. Compared with the prior art, the invention has the following advantages: the method can be flexibly switched between an inertia measurement mode and a magnetic field measurement mode, can measure the angular velocity, can realize in-situ high-sensitivity magnetic field measurement, provides a method for accurately evaluating the magnetic field fluctuation in the inertia device, and has important significance for the error analysis of the SERF inertia device.
The technical scheme adopted by the invention for solving the technical problems is as follows:
a magnetic field fluctuation testing method of a SERF inertial device based on nuclear spin polarization suppression is characterized by comprising the following steps:
step 1, heating an alkali metal gas chamber in an inertia device to a working temperature;
step 2, starting a pumping laser and a detection laser in the inertial device, and performing magnetic field compensation to enable the inertial device to work in an inertial measurement mode;
step 3, testing angular velocity response and magnetic field response of the system in an inertial measurement mode to obtain a scale factor;
step 4, applying a proper magnetic field gradient by using a gradient coil to inhibit the polarization of nuclear spin, so that the inertial device works in a magnetic field measurement mode;
step 5, carrying out magnetic field compensation and sensitivity test of the magnetometer in a magnetic field measurement mode;
step 6, judging whether the sensitivity of the magnetometer meets the requirement and whether the nuclear spin polarization is inhibited, if yes, entering step 7, and if not, returning to step 4;
and 7, analyzing the magnetic field fluctuation by using the scale factor and the magnetic field data acquired by the magnetometer for a long time.
The long time in the step 7 is 1 hour to 3 hours.
The magnetic field fluctuation analysis in step 7 comprises an Allan variance estimation method.
And (2) filling alkali metal atoms of potassium and rubidium, an inert gas of neon and a buffer gas of nitrogen into the alkali metal gas chamber in the step (1).
The expression of the SERF inertial device for measuring the angular velocity and the magnetic field is as follows:
Figure GDA0003958625230000021
wherein, the first and the second end of the pipe are connected with each other,
Figure GDA0003958625230000022
is the transverse spin polarization component of the alkali metal electrons, B x And B y Magnetic fields in the x-and y-axis directions, omega, respectively x And Ω y Angular velocities, γ, in the x-and y-directions, respectively e And gamma n Are the gyromagnetic ratio of the electron spin and the nuclear spin,
Figure GDA0003958625230000023
and
Figure GDA0003958625230000024
are the compensation points for the alkali metal electrons and the inert gas atoms respectively,
Figure GDA0003958625230000025
and
Figure GDA0003958625230000026
is the transverse relaxation rate, K, of alkali electrons and inert gases bx 、K by 、K Ωx And K Ωx Are respectively B x 、B y 、Ω x And Ω y The expression of (a) is as follows:
Figure GDA0003958625230000031
wherein the content of the first and second substances,
Figure GDA0003958625230000032
and
Figure GDA0003958625230000033
the longitudinal spin polarization components of the alkali metal electrons and the inert gas atoms respectively,
Figure GDA0003958625230000034
is the spin exchange rate at which the alkali metal electrons and the inert gas atoms collide with each other.
The operation in step 2 is in an inertial measurement mode, and the mathematical relationship is as follows:
Figure GDA0003958625230000035
Figure GDA0003958625230000036
the expression of (c) is simplified as:
Figure GDA0003958625230000037
the radius of the gradient coil in the step 4 is r, and the expression of the generated first-order gradient magnetic field is as follows:
Figure GDA0003958625230000038
wherein, the first and the second end of the pipe are connected with each other,
Figure GDA0003958625230000039
is the first order gradient field vector, I is the current density of the gradient coil, and C is the coil constant.
Working in a magnetic field measurement mode in step 5, the magnetic field gradient increases the longitudinal relaxation rate and the transverse relaxation rate of the alkali metal atoms and the inert gas atoms, so that
Figure GDA00039586252300000310
Is far larger than other terms, and simultaneously the longitudinal relaxation rate is increased by 4 to 5 orders of magnitude compared with the inertia measurement state,
Figure GDA00039586252300000311
close to 0, i.e. the inert gas atoms are not polarized,
Figure GDA00039586252300000312
the expression of (c) is simplified as:
Figure GDA00039586252300000313
the invention has the following technical effects: the invention relates to a magnetic field fluctuation testing method of a SERF inertial device based on nuclear spin polarization inhibition. And finally, a high-sensitivity magnetometer is constructed and long-time data acquisition is carried out by adjusting the size of the gradient magnetic field, the magnetic field fluctuation analysis is carried out by adopting an Allan variance evaluation method, the method can be flexibly switched between an inertia measurement mode and a magnetic field measurement mode, the angular velocity can be measured, in-situ high-sensitivity magnetic field measurement can be realized, a method is provided for accurately evaluating the magnetic field fluctuation in an inertia device, and the method has important significance for the error analysis of the SERF inertia device.
Compared with the prior art, the invention has the advantages that: (1) The invention can be flexibly switched between an inertia measurement mode and a magnetic field measurement mode, and can measure the angular velocity and the magnetic field. And (2) the invention can realize in-situ high-precision magnetic field measurement. (3) The invention can carry out long-term magnetic field fluctuation test and provides a method for accurately evaluating the magnetic field fluctuation in the inertial device;
drawings
FIG. 1 is a schematic diagram of the working flow of a SERF inertial device magnetic field fluctuation testing method based on nuclear spin polarization suppression. FIG. 1 includes step 1, heating the inertial device to the desired operating temperature of the alkali metal gas cell (alkali metal atoms); step 2, starting pumping light and detecting light, performing operations such as magnetic field compensation and the like, and enabling the device to work in an inertia measurement mode; step 3, testing angular speed response and magnetic field response of the system in an inertial measurement mode; step 4, applying a proper magnetic field gradient by using a gradient coil to inhibit the polarization of nuclear spin, so that the device works in a magnetic field measurement mode; step 5, carrying out magnetic field compensation, magnetic field response and magnetometer sensitivity test in a magnetic field measurement mode; step 6, judging whether the sensitivity of the magnetometer meets the requirement and whether the nuclear spin polarization is inhibited, if so, entering step 7, and if not, returning to step 4; and 7, acquiring data for a long time (for example, about 2 hours, 1 hour to 3 hours) and carrying out magnetic field fluctuation analysis.
Fig. 2 is a schematic structural diagram of a SERF inertial device used for implementing the magnetic field fluctuation test method in fig. 1.
FIG. 3 is a schematic diagram of the gradient coil configuration of FIG. 1 or FIG. 2. R in the xyz coordinate axis of fig. 3 refers to the coil radius. The dotted and solid lines in fig. 3 represent the same magnitude but opposite direction of current applied.
The reference numbers are listed below: 1 is a pump laser; 2 is a first lens; 3 is a second lens; 4 is a first 1/2 wave plate; 5 is a pumping light power control module; 6 is a first control circuit; 7 is a reflector; 8 is a second 1/2 wave plate; 9 is a first polarization beam splitter prism; 10 is a 1/4 wave plate; 11 is a first photodetector; 12 is a detection laser; 13 is a third 1/2 wave plate; 14 is a detection optical power control module; 15 is a fourth 1/2 wave plate; 16 is a second polarization splitting prism; 17 is a second control circuit; 18 is a second photodetector; 19 is a fifth 1/2 wave plate; 20 is a third polarization beam splitter prism; 21 is a third photodetector; 22 is a fourth photodetector; 23 is a signal amplifying module; 24 is a magnetic shielding cylinder; 25 is a triaxial uniform magnetic field coil; 26 is a gradient coil; 27 is an alkali metal gas cell; 28 is an oven.
Detailed Description
The invention is explained below with reference to the figures (fig. 1-3) and examples.
Fig. 1 is a schematic diagram of a work flow of a magnetic field fluctuation testing method of an SERF inertial device based on nuclear spin polarization suppression according to the present invention. Fig. 2 is a schematic structural diagram of a SERF inertial device used for implementing the magnetic field fluctuation test method in fig. 1. FIG. 3 is a schematic diagram of the gradient coil configuration of FIG. 1 or FIG. 2. Referring to fig. 1 to 3, a method for testing magnetic field fluctuation of a SERF inertial device based on nuclear spin polarization suppression includes the following steps: step 1, heating an alkali metal gas chamber in an inertia device to a working temperature; step 2, starting a pumping laser and a detection laser in the inertial device, and performing magnetic field compensation to enable the inertial device to work in an inertial measurement mode; step 3, testing angular velocity response and magnetic field response of the system in an inertial measurement mode to obtain a scale factor; step 4, applying a proper magnetic field gradient by using a gradient coil to inhibit the polarization of nuclear spin, so that the inertial device works in a magnetic field measurement mode; step 5, carrying out magnetic field compensation and magnetometer sensitivity test in a magnetic field measurement mode; step 6, judging whether the sensitivity of the magnetometer meets the requirement and whether the nuclear spin polarization is inhibited, if yes, entering step 7, and if not, returning to step 4; and 7, carrying out magnetic field fluctuation analysis by using the scale factor and the magnetic field data acquired by the magnetometer for a long time.
The long time in the step 7 is 1 hour to 3 hours. The magnetic field fluctuation analysis in step 7 includes using an Allan variance estimation method. And (2) filling alkali metal atoms of potassium and rubidium, an inert gas of neon and a buffer gas of nitrogen into the alkali metal gas chamber in the step (1).
The expression of the SERF inertial device for measuring the angular velocity and the magnetic field is as follows:
Figure GDA0003958625230000051
wherein the content of the first and second substances,
Figure GDA0003958625230000052
is a baseTransverse spin polarization component of metal electrons, B x And B y Magnetic fields in the x-and y-axis directions, omega, respectively x And Ω y Angular velocities, γ, in the x-and y-directions, respectively e And gamma n Are the gyromagnetic ratio of the electron spin and the nuclear spin respectively,
Figure GDA0003958625230000053
and
Figure GDA0003958625230000054
are the compensation points for the alkali metal electrons and the inert gas atoms respectively,
Figure GDA0003958625230000055
and
Figure GDA0003958625230000056
is the transverse relaxation rate, K, of the electrons of the alkali metal and the inert gas bx 、K by 、K Ωx And K Ωx Are respectively B x 、B y 、Ω x And Ω y The expression of (b) is as follows:
Figure GDA0003958625230000057
wherein the content of the first and second substances,
Figure GDA0003958625230000058
and
Figure GDA0003958625230000059
the longitudinal spin polarization components of the alkali metal electrons and the inert gas atoms respectively,
Figure GDA00039586252300000510
is the spin exchange rate at which the alkali metal electrons and the inert gas atoms collide with each other.
The operation in step 2 is in an inertial measurement mode, and the mathematical relationship is as follows:
Figure GDA00039586252300000511
Figure GDA00039586252300000512
the expression of (c) is simplified as:
Figure GDA0003958625230000061
the radius of the gradient coil in the step 4 is r, and the expression of the generated first-order gradient magnetic field is as follows:
Figure GDA0003958625230000062
wherein the content of the first and second substances,
Figure GDA0003958625230000063
is the first order gradient magnetic field vector, I is the current density of the gradient coil, and C is the coil constant.
Working in a magnetic field measurement mode in step 5, the magnetic field gradient increases the longitudinal and transverse relaxivity of the alkali metal atoms and the inert gas atoms, so that
Figure GDA0003958625230000064
Is far larger than other terms, and simultaneously the longitudinal relaxation rate is increased by 4 to 5 orders of magnitude compared with the inertia measurement state,
Figure GDA0003958625230000065
close to 0, i.e., the inert gas atoms are not polarized,
Figure GDA0003958625230000066
the expression of (c) is simplified as:
Figure GDA0003958625230000067
fig. 1 shows an operation flow of the magnetic field fluctuation test method of the SERF inertial device based on the nuclear spin polarization suppression of the present invention: firstly, the inertial device is heated to the working temperature required by the alkali metal gas chamber 27, the pumping laser 1 and the detection laser 12 are started, and operations such as magnetic field compensation are carried out, so that the device works in an inertial measurement mode. In the inertial measurement mode, the angular velocity response and the magnetic field response of the system are tested. The apparatus is then operated in the magnetic field measurement mode by applying appropriate magnetic field gradients using the gradient coils 26 to suppress polarization of the nuclear spins. And in the magnetic field measurement mode, carrying out magnetic field compensation and magnetic field response and magnetometer sensitivity test. And finally, calculating whether the sensitivity of the magnetometer meets the requirement, checking whether the nuclear spin polarization is inhibited, if so, acquiring data for a long time and analyzing magnetic field fluctuation, and if not, adjusting the size of the magnetic field gradient and then carrying out testing and calculation again.
The expression of the SERF inertial device in the method for measuring the angular velocity and the magnetic field is as follows:
Figure GDA0003958625230000068
wherein the content of the first and second substances,
Figure GDA0003958625230000069
is the transverse spin polarization component of the alkali metal electrons, B x And B y Is a magnetic field in the x and y directions, omega x And Ω y Is the angular velocity, gamma, in the x and y directions e And gamma n Are the gyromagnetic ratio of the electron spin and the nuclear spin respectively,
Figure GDA00039586252300000610
and
Figure GDA00039586252300000611
is a compensation point for alkali metal electrons and inert gas atoms,
Figure GDA00039586252300000612
and
Figure GDA00039586252300000613
is alkali goldTransverse relaxation rate of electrons and inert gases, K bx 、K by 、K Ωx And K Ωx Are respectively B x 、B y 、Ω x And Ω y The expression of (a) is as follows:
Figure GDA0003958625230000071
wherein, the first and the second end of the pipe are connected with each other,
Figure GDA0003958625230000072
and
Figure GDA0003958625230000073
the longitudinal spin polarization components of the alkali metal electrons and the inert gas atoms respectively,
Figure GDA0003958625230000074
is the spin exchange rate at which the alkali metal electrons and the inert gas atoms collide with each other.
The method works in an inertia measurement mode, and has the following mathematical relation
Figure GDA0003958625230000075
Figure GDA0003958625230000076
The expression of (c) is simplified as:
Figure GDA0003958625230000077
the radius of the gradient coil 26 in the method is r, and the expression of the generated first-order gradient magnetic field is
Figure GDA0003958625230000078
Where I is the current density of the gradient coil and C is the coil constant.
In which method operation is in the magnetic fieldIn the measurement mode, the magnetic field gradient increases the longitudinal and transverse relaxivity of the alkali metal atoms and the rare gas atoms, so that
Figure GDA0003958625230000079
Is far larger than other terms, and simultaneously the longitudinal relaxation rate is increased by 4 to 5 orders of magnitude compared with the inertia measurement state,
Figure GDA00039586252300000710
close to 0, i.e. the inert gas atoms are not polarized,
Figure GDA00039586252300000711
the expression of (c) is simplified as:
Figure GDA00039586252300000712
fig. 2 shows an inertial device structure of the SERF inertial device magnetic field fluctuation test method based on nuclear spin polarization suppression of the present invention, and it can be seen from the figure that the device of the present invention includes a pumping laser 1, a first lens 2, a second lens 3, a first 1/2 wave plate 4, a pumping light power control module 5, a first control circuit 6, a reflecting mirror 7, a second 1/2 wave plate 8, a first polarization splitting prism 9, a 1/4 wave plate 10, a first photodetector 11, a detection laser 12, a third 1/2 wave plate 13, a detection light power control module 14, a fourth 1/2 wave plate 15, a second polarization splitting prism 16, a second control circuit 17, a second photodetector 18, a fifth 1/2 wave plate 19, a third polarization splitting prism 20, a third photodetector 21, a fourth photodetector 22, a signal amplification module 23, a magnetic shielding cylinder 24, a three-axis uniform magnetic field coil 25, a gradient coil 26, an alkali metal gas chamber 27, and an oven 28.
The alkali metal gas cell 21 is a spherical gas cell having a diameter of 8mm made of GE180 aluminosilicate glass, and filled with an alkali metal mixture of potassium and rubidium, an inert gas of neon, and a buffer gas of nitrogen. The air chamber is placed in an oven made of boron nitride ceramics, the surface of the oven is pasted with a non-magnetic heating film with double twisted-pair wires, and 99KHz alternating current is introduced to prevent low-frequency magnetic crosstalk.
The magnetic shielding cylinder 24 is composed of a permalloy cylinder with 2mm thick outer layers and high magnetic conductivity and a ferrite cylinder with 6mm thick inner layer, and is used for shielding external magnetic field interference and reducing low-frequency magnetic noise respectively.
The three-axis uniform magnetic field coil 25 is used to compensate for the residual magnetic field of the magnetic shielding system and to apply a specific calibration magnetic field to the system. Gradient coils 26 are used to apply gradient magnetic fields to suppress nuclear spins.
The pump laser 1 emits a pump beam whose center frequency is the D1 resonance line of potassium atoms. The pumping light beams are expanded through the first lens 2 and the second lens 3, the long-term stability of the light power is guaranteed through the first 1/2 wave plate 4 and the pumping light power control module 5, and the linearly polarized light is converted into circularly polarized light through the 1/4 wave plate 10 to polarize potassium atoms along the z axis. The rubidium atoms are polarized by the spin exchange collision of potassium atoms and rubidium atoms. The polarized potassium and rubidium atoms are then collided by spin exchange to hyperpolarize the neon gas. The detection laser 12 emits a detection beam whose center frequency is far detuned near the rubidium D1 resonance line. The detection light beam ensures the long-term stability of the optical power by detecting the optical power control module 14, and the second polarization splitting prism 16 re-polarizes the detection light into linearly polarized light for detecting the projection component of the polarized rubidium atom on the x axis. After the detection light is transmitted through the alkali metal air chamber 27, the differential signals of the third photodetector 21 and the fourth photodetector 22 are collected by a balanced polarization beam splitting method and are amplified by the signal amplification module 23 to obtain an output signal.
Figure 3 shows the configuration of the gradient coil 26 of the present invention to generate a first order gradient magnetic field. The dotted line and the solid line in the figure respectively represent the same magnitude of current but opposite direction.
Those skilled in the art will appreciate that the invention may be practiced without these specific details. It is pointed out here that the above description is helpful for the person skilled in the art to understand the invention, but does not limit the scope of protection of the invention. Any such equivalents, modifications and/or omissions as may be made without departing from the spirit and scope of the invention may be resorted to.

Claims (7)

1. A magnetic field fluctuation testing method of a SERF inertial device based on nuclear spin polarization suppression is characterized by comprising the following steps:
step 1, heating an alkali metal air chamber in an inertia device to a working temperature;
step 2, starting a pumping laser and a detection laser in the inertial device, and performing magnetic field compensation to enable the inertial device to work in an inertial measurement mode;
step 3, under an inertial measurement mode, testing angular velocity response and magnetic field response of the system to obtain a scale factor;
step 4, applying a proper magnetic field gradient by using a gradient coil to inhibit the polarization of nuclear spin, so that the inertial device works in a magnetic field measurement mode;
step 5, carrying out magnetic field compensation and sensitivity test of the magnetometer in a magnetic field measurement mode;
step 6, judging whether the sensitivity of the magnetometer meets the requirement and whether the nuclear spin polarization is inhibited, if so, entering step 7, and if not, returning to step 4;
step 7, carrying out magnetic field fluctuation analysis by using the scale factor and the magnetic field data acquired by the magnetometer for a long time;
the long time in the step 7 is 1 hour to 3 hours.
2. The SERF inertial device magnetic field fluctuation test method based on nuclear spin polarization suppression according to claim 1, wherein the magnetic field fluctuation analysis in step 7 comprises an Allan variance estimation method.
3. The method for testing the magnetic field fluctuation of the SERF inertial device based on the inhibition of nuclear spin polarization according to claim 1, wherein the alkali metal gas chamber in the step 1 is filled with alkali metal atoms of potassium and rubidium, an inert gas of neon and a buffer gas of nitrogen.
4. The SERF inertial device magnetic field fluctuation test method based on nuclear spin polarization suppression as claimed in claim 1, wherein the expressions of the SERF inertial device measurement angular velocity and magnetic field are:
Figure FDA0003958625220000011
wherein, the first and the second end of the pipe are connected with each other,
Figure FDA0003958625220000012
is the transverse spin polarization component of the alkali metal electrons, B x And B y Magnetic fields in the x-and y-axis directions, omega, respectively x And Ω y Angular velocities, γ, in the x-and y-directions, respectively e And gamma n Are the gyromagnetic ratio of the electron spin and the nuclear spin respectively,
Figure FDA0003958625220000013
and
Figure FDA0003958625220000014
are the compensation points for the alkali metal electrons and the inert gas atoms respectively,
Figure FDA0003958625220000015
and
Figure FDA0003958625220000016
is the transverse relaxation rate, K, of alkali electrons and inert gases bx 、K by 、K Ωx And K Ωx Are respectively B x 、B y 、Ω x And Ω y The expression of (b) is as follows:
Figure FDA0003958625220000021
wherein the content of the first and second substances,
Figure FDA0003958625220000022
and
Figure FDA0003958625220000023
the longitudinal spin polarization components of the alkali metal electrons and the inert gas atoms respectively,
Figure FDA0003958625220000024
is the spin exchange rate at which the alkali metal electrons and the inert gas atoms collide with each other.
5. A SERF inertial device magnetic field fluctuation test method based on nuclear spin polarization suppression according to claim 4, wherein the operation in step 2 in the inertial measurement mode has the following mathematical relationship:
Figure FDA0003958625220000025
Figure FDA0003958625220000026
the expression of (c) is simplified as:
Figure FDA0003958625220000027
6. the SERF inertial device magnetic field fluctuation test method based on nuclear spin polarization suppression according to claim 4, wherein the gradient coil radius in step 4 is r, and the expression of the generated first-order gradient magnetic field is as follows:
Figure FDA0003958625220000028
wherein the content of the first and second substances,
Figure FDA0003958625220000029
being first order gradient field vectors, I being gradient coilsThe current density, C is the coil constant, and Bz is the magnetic field in the z-axis direction.
7. The SERF inertial device magnetic field fluctuation test method based on nuclear spin polarization suppression according to claim 4, wherein in the step 5, operating in the magnetic field measurement mode, the magnetic field gradient increases the longitudinal relaxation rate and the transverse relaxation rate of the alkali metal atoms and the inert gas atoms, so that
Figure FDA00039586252200000210
Is far larger than other terms, and simultaneously the longitudinal relaxation rate is increased by 4 to 5 orders of magnitude compared with the inertia measurement state,
Figure FDA00039586252200000211
close to 0, i.e. the inert gas atoms are not polarized,
Figure FDA00039586252200000212
the expression of (c) is simplified as:
Figure FDA00039586252200000213
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