Atomic Spin Inertial Measurement Device Scale Factor and Electron Relaxation Rate Measurement Method

Abstract

A method for measuring the scale factor and electron relaxation rate of an atomic spin inertial measurement device, wherein the scale factor refers to the angular velocity scale factor, is calculated by measuring the first-order and second-order approximations of the output signal with respect to the Z-direction magnetic field. Based on the linear relationship between the first-order and second-order approximations and the Y-direction magnetic field and the X-direction magnetic field, the slopes of the first-order and second-order approximations are related to the scale factor and the electron relaxation rate. The method is rational, simple to perform, and applicable to atomic spin inertial measurement devices based on a coupled ensemble of alkali metal electron spins and inert gas nuclear spins. The method can accurately measure the scale factor and electron relaxation rate in real time, providing a foundation for the development of high-precision atomic spin inertial measurement devices.

Description

Technical Field

[0001] The present invention relates to the technical field of atomic spin inertia measurement, and in particular to a method for measuring the scale factor and electron relaxation rate of an atomic spin inertia measurement device. The experimental operation is simple, and the scale factor and electron relaxation rate can be accurately measured, providing a basis for the development of a high-precision atomic spin inertia measurement device. Background Art

[0002] In atomic inertial measurement devices, the scale factor and electron relaxation rate are important parameters that characterize the performance of the device, so they need to be measured precisely.

[0003] Currently, methods for measuring scale factors and electron relaxation rates include the S-curve method and the frequency response curve method. The S-curve method requires a large number of data points to fully fit the desired linear shape, and this can result in large fitting errors. The frequency response curve method requires fitting the frequency response curve near the electron resonance peak, which also suffers from large fitting errors. The accuracy of existing methods is often limited by experimental conditions. Summary of the Invention

[0004] In response to the defects or shortcomings in the prior art, the present invention provides a method for measuring the scale factor and electron relaxation rate of an atomic spin inertial measurement device. The scale factor refers to the angular velocity scale factor. The experimental operation is simple and the scale factor and electron relaxation rate can be accurately measured, providing a basis for the development of high-precision atomic spin inertial measurement devices.

[0005] The technical solutions of the present invention are as follows:

[0006] A method for measuring the scale factor and electron relaxation rate of an atomic spin inertial measurement device is characterized by comprising the following steps:

[0007] Step 1: Use an atomic spin inertial measurement device to measure the magnetic field Bn corresponding to the fastest response point in the Z direction;

[0008] Step 2, determine the Y-direction magnetic field array [By(1), By(2), ..., By(n)] that needs to be traversed, where n is the sequence number, n is a positive integer, and By(n) is the nth Y-direction magnetic field;

[0009] Step 3, start traversing [By(1), By(2), ..., By(n)], let By = By(i), i is the first counter, By is the Y-direction magnetic field;

[0010] Step 4: Apply square wave modulation of the Z-direction magnetic field at the compensation point to make the atomic spin inertial measurement device output a steady-state response signal S 1y and S 2y , S 1y is a high-level steady-state response signal, S 2yFor the low-level steady-state response signal, obtain the first-order approximation dS of the output signal with respect to the Z-direction magnetic field;

[0011] Step 5: Determine whether i≥n. If not, set i=i+1 and return to step 3. If yes, proceed to step 6.

[0012] Step 6, determine the X-direction magnetic field array [Bx(1), Bx(2), ..., Bx(m)] that needs to be traversed, where m is the sequence number, m is a positive integer, and Bx(m) is the mth X-direction magnetic field;

[0013] Step 7, start traversing [Bx(1), Bx(1), ..., Bx(m)], let Bx = Bx(j), j is the second counter, Bx is the X-direction magnetic field;

[0014] Step 8: Apply a Z-direction magnetic field square wave and DC modulation at the compensation point to make the atomic spin inertial measurement device output a steady-state response signal S 1x 、S 2x and S 0x , S 1x is a high-level steady-state response signal, S 2x is a low-level steady-state response signal, S 0x is the DC bias steady-state response signal, and the second-order approximation ddS of the output signal with respect to the Z-direction magnetic field is obtained;

[0015] Step 9, determine whether j ≥ m, if not, set j = j + 1 and return to step 7, if yes, go to step 10;

[0016] Step 10: Calculate the scale factor and the electron relaxation rate.

[0017] In step 2, n≥3, and each point in [By(1),By(2),…,By(n)] is a point within the range of ±5nT of the zero magnetic field point of the Y-direction magnetic field.

[0018] Step 4 includes the following formula:

[0019]

[0020] Where dBz is the peak-to-peak value of the Z-direction square wave modulated magnetic field, K By is the first-order approximation dS obtained by unit Z-direction square wave modulation and the slope that changes with the Y-direction magnetic field By.

[0021] In step 6, m≥3, and each point in [Bx(1), Bx(1),…, Bx(m)] is within the range of ±5nT of the zero magnetic field point of the X-direction magnetic field.

[0022] Step 8 includes the following formula:

[0023]

[0024] where K Bx It is the slope of the second-order approximation ddS of the output signal obtained by the unit Z-direction square wave and DC bias as the X-direction magnetic field Bx changes.

[0025] Step 10 includes the following formula:

[0026]

[0027] Where K is the scale factor, the scale factor refers to the angular velocity scale factor, γ n is the gyromagnetic ratio of the noble gas atoms, R e is the electron relaxation rate, is the gyromagnetic ratio of alkali metal electrons.

[0028] The advantages of the present invention compared with the prior art are:

[0029] (1) The present invention calculates the density of alkali metal atoms by measuring the linear fitting slopes of the first-order approximation and second-order approximation of the Y-direction magnetic field and the X-direction magnetic field and the output signal with respect to the Z-direction magnetic field. Compared with the existing methods, the fitting error is reduced and the method can be combined with the three-axis magnetic compensation process to ensure efficiency and accuracy.

[0030] (2) The method of the present invention is reasonable and the experimental operation is simple, which provides a basis for the development of high-precision atomic spin inertial measurement devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a flow chart of the method for measuring the scale coefficient and electron relaxation rate of the atomic spin inertia measurement device of the present invention. Figure 1 The method includes step 1, measuring the magnetic field Bn corresponding to the fastest response point in the Z direction; step 2, determining the Y-direction magnetic field array [By(1), By(2), ..., By(n)] that needs to be traversed, where n is the sequence number, n is a positive integer, and By(n) is the nth Y-direction magnetic field; step 3, starting to traverse [By(1), By(2), ..., By(n)], setting By = By(i), where i is the first counter; step 4, applying square wave modulation of the Z-direction magnetic field at the compensation point, and outputting a steady-state response signal S 1y and S 2y , S 1y is a high-level steady-state response signal, S 2yis a low-level steady-state response signal, and the first-order approximation dS of the output signal with respect to the Z-direction magnetic field is obtained; Step 5, determine whether i≥n, if not, set i=i+1 and return to Step 3, if yes, enter Step 6; Step 6, determine the X-direction magnetic field array [Bx(1), Bx(1),…, Bx(m)] that needs to be traversed, m is the serial number, m is a positive integer, and Bx(m) is the mth X-direction magnetic field; Step 7, start traversing [Bx(1), Bx(1),…, Bx(m)], set Bx=Bx(j), j is the second counter; Step 8, apply the Z-direction magnetic field square wave and DC modulation at the compensation point, and output the steady-state response signal S 1x 、S 2x and S 0x , S 1x is a high-level steady-state response signal, S 2x is a low-level steady-state response signal, S 0x For the DC bias steady-state response signal, obtain the second-order approximation ddS of the output signal with respect to the Z-direction magnetic field; Step 9, determine whether j≥m, if not, set j=j+1 and return to Step 7, if yes, enter Step 10; Step 10, calculate the scale factor and electron relaxation rate. DETAILED DESCRIPTION

[0032] Below is the attached figure ( Figure 1 ) and Examples illustrate the present invention.

[0033] Figure 1 This is a flow chart of the method for measuring the scale factor and electron relaxation rate of the atomic spin inertial measurement device of the present invention. Figure 1 As shown, a method for measuring the scale factor and electron relaxation rate of an atomic spin inertial measurement device comprises the following steps: step 1, measuring the magnetic field Bn corresponding to the fastest response point in the Z direction using the atomic spin inertial measurement device; step 2, determining the Y-direction magnetic field array [By(1), By(2), ..., By(n)] that needs to be traversed, where n is a sequence number, n is a positive integer, and By(n) is the nth Y-direction magnetic field; step 3, starting to traverse [By(1), By(2), ..., By(n)], setting By = By(i), where i is the first counter and By is the Y-direction magnetic field; step 4, applying Z-direction magnetic field square wave modulation at the compensation point to make the atomic spin inertial measurement device output a steady-state response signal S 1y and S 2y , S 1y is a high-level steady-state response signal, S 2yis a low-level steady-state response signal, and the first-order approximation dS of the output signal with respect to the Z-direction magnetic field is obtained; Step 5, determine whether i≥n, if not, set i=i+1 and return to Step 3, if yes, enter Step 6; Step 6, determine the X-direction magnetic field array [Bx(1), Bx(2),…, Bx(m)] that needs to be traversed, m is the sequence number, m is a positive integer, and Bx(m) is the mth X-direction magnetic field; Step 7, start traversing [Bx(1), Bx(1),…, Bx(m)], set Bx=Bx(j), j is the second counter, and Bx is the X-direction magnetic field; Step 8, apply a Z-direction magnetic field square wave and DC modulation at the compensation point, so that the atomic spin inertial measurement device outputs a steady-state response signal S 1x 、S 2x and S 0x , S 1x is a high-level steady-state response signal, S 2x is a low-level steady-state response signal, S 0x For the DC bias steady-state response signal, obtain the second-order approximation ddS of the output signal with respect to the Z-direction magnetic field; Step 9, determine whether j≥m, if not, set j=j+1 and return to Step 7, if yes, enter Step 10; Step 10, calculate the scale factor and electron relaxation rate.

[0034] In step 2, n≥3, and each point in [By(1),By(2),…,By(n)] is a point within the range of ±5nT of the zero magnetic field point of the Y-direction magnetic field.

[0035] Step 4 includes the following formula:

[0036]

[0037] Where dBz is the peak-to-peak value of the Z-direction square wave modulated magnetic field, K By is the first-order approximation dS obtained by unit Z-direction square wave modulation and the slope that changes with the Y-direction magnetic field By.

[0038] In step 6, m≥3, and each point in [Bx(1), Bx(1),…, Bx(m)] is within the range of ±5nT of the zero magnetic field point of the X-direction magnetic field.

[0039] Step 8 includes the following formula:

[0040]

[0041] where K Bx It is the slope of the second-order approximation ddS of the output signal obtained by the unit Z-direction square wave and DC bias as the X-direction magnetic field Bx changes.

[0042] Step 10 includes the following formula:

[0043]

[0044] Where K is the scale factor, the scale factor refers to the angular velocity scale factor, γ n is the gyromagnetic ratio of the noble gas atoms, R e is the electron relaxation rate, is the gyromagnetic ratio of alkali metal electrons.

[0045] The present invention relates to a method for measuring the scale factor and electron relaxation rate of an atomic spin inertial measurement device. The method can accurately measure the scale factor and the electron relaxation rate (the scale factor refers to the angular velocity scale factor). The method measures the first-order approximation and the second-order approximation of an output signal with respect to a Z-direction magnetic field. According to the linear relationship between the first-order approximation and the second-order approximation and the Y-direction magnetic field and the X-direction magnetic field, the slopes of the two are related to the scale factor and the electron relaxation rate, and the scale factor and the electron relaxation rate are calculated. The method is reasonable, simple to perform experimentally, and is applicable to an atomic spin inertial measurement device based on an ensemble coupled with an alkali metal electron spin and an inert gas nuclear spin. The scale factor and the electron relaxation rate can be accurately measured in real time, and a basis is provided for the development of a high-precision atomic spin inertial measurement device.

[0046] like Figure 1 As shown, the present invention provides a method for measuring the scale factor and electron relaxation rate of an atomic spin inertial measurement device, comprising the following steps:

[0047] Step (1): Measure the magnetic field B corresponding to the fastest response point in the Z direction n .

[0048] Step (2): Determine the Y-direction magnetic field array that needs to be traversed [B y (1),B y (1),…,B y (n)].

[0049] Step (3): Traverse [B y (1),B y (1),…,B y (n)], and apply Z-direction magnetic field square wave modulation at the compensation point, outputting the steady-state response signal S 1y and S 2y , S 1y is a high-level steady-state response signal, S 2y It is a low-level steady-state response signal, and the first-order approximation dS of the output signal with respect to the Z-direction magnetic field is obtained.

[0050] Step (4): Determine the X-direction magnetic field array that needs to be traversed [B x (1),B x (1),…,B x (m)].

[0051] Step (5): Traverse [Bx (1),B x (1),…,B x (m)], and apply Z-direction magnetic field square wave and DC modulation at the compensation point, outputting steady-state response signal S 1x 、S 2x and S 0x , S 1x is a high-level steady-state response signal, S 2x is a low-level steady-state response signal, S 0x is the DC bias steady-state response signal, and the second-order approximation ddS of the output signal with respect to the Z-direction magnetic field is obtained.

[0052] Step (6): Calculate the scale factor and electron relaxation rate.

[0053] The array [B y (1),B y (1),…,B y (n)] is a point within the range of ±5nT from the zero magnetic field point in the Y direction, where n is a positive integer and n≥3.

[0054] The output signal of step (3) is the first-order approximation dS and S of the Z-direction magnetic field. 1y and S 2y and B y The relationship is as follows:

[0055]

[0056] Where dS is the first-order approximation of the output signal with respect to the Z-direction magnetic field, S 1y is a high-level steady-state response signal, S 2y is a low level steady state response signal, dB z is the peak-to-peak value of the Z-direction square wave modulated magnetic field, The first-order approximation dS obtained by unit Z-direction square wave modulation and the Y-direction magnetic field B y The slope of change.

[0057] The X-direction magnetic field array [B x (1),B x (1),…,B x (m)] is a point within the range of ±5nT from the zero magnetic field point in the X direction, m is a positive integer, and m≥3.

[0058] The output signal of step (5) is the second order approximation ddS and S of the Z-direction magnetic field. 1z 、S 2x and S 0x and B x The relationship is as follows:

[0059]

[0060] Where ddS is the second-order approximation of the output signal with respect to the Z-direction magnetic field, S 1x is a high-level steady-state response signal, S 2x is a low-level steady-state response signal, S 0x is the DC bias steady-state response signal, dB z is the peak-to-peak value of the Z-direction square wave modulated magnetic field, The second-order approximation ddS of the output signal obtained by the unit Z-direction square wave and DC bias changes with the X-direction magnetic field B x The slope of change.

[0061] The scale factor K and the electron relaxation rate R in step (6) e The calculation method is as follows:

[0062]

[0063] where γ n is the gyromagnetic ratio of the noble gas atoms, γ e is the gyromagnetic ratio of alkali metal electrons.

[0064] Any content not described in detail in this specification is prior art known to those skilled in the art. It should be noted that the above description is intended to help those skilled in the art understand the present invention, but does not limit the scope of protection of the present invention. Any equivalent substitution, modification, improvement, and / or simplification of the above description that does not depart from the essence of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A method for measuring the scale factor and electron relaxation rate of an atomic spin inertial measurement device, characterized in that: The following steps are involved: Step 1: Use an atomic spin inertial measurement device to measure the magnetic field Bn corresponding to the fastest response point in the Z direction; Step 2, determine the Y-direction magnetic field array [By(1), By(2), ..., By(n)] that needs to be traversed, where n is the sequence number, n is a positive integer, and By(n) is the nth Y-direction magnetic field; Step 3, start traversing [By(1), By(2), ..., By(n)], let By = By(i), i is the first counter, By is the Y-direction magnetic field; Step 4: Apply square wave modulation of the Z-direction magnetic field at the compensation point to make the atomic spin inertial measurement device output a steady-state response signal S 1y and S 2y , S 1y is a high-level steady-state response signal, S 2y For the low-level steady-state response signal, obtain the first-order approximation dS of the output signal with respect to the Z-direction magnetic field; Step 5: Determine whether i≥n. If not, set i=i+1 and return to step 3. If yes, proceed to step 6. Step 6, determine the X-direction magnetic field array [Bx(1), Bx(2), ..., Bx(m)] that needs to be traversed, where m is the sequence number, m is a positive integer, and Bx(m) is the mth X-direction magnetic field; Step 7, start traversing [Bx(1), Bx(1), ..., Bx(m)], let Bx = Bx(j), j is the second counter, Bx is the X-direction magnetic field; Step 8: Apply a Z-direction magnetic field square wave and DC modulation at the compensation point to make the atomic spin inertial measurement device output a steady-state response signal S 1x 、S 2x and S 0x , S 1x is a high-level steady-state response signal, S 2x is a low-level steady-state response signal, S 0x is the DC bias steady-state response signal, and the second-order approximation ddS of the output signal with respect to the Z-direction magnetic field is obtained; Step 9, determine whether j ≥ m, if not, set j = j + 1 and return to step 7, if yes, go to step 10; Step 10, calculating the scale factor and the electron relaxation rate; Step 10 includes the following formula: Where K is the scale factor, the scale factor refers to the angular velocity scale factor, γ n is the gyromagnetic ratio of the noble gas atoms, R e is the electron relaxation rate, γ e is the gyromagnetic ratio of alkali metal electrons, is the first-order approximation dS obtained by unit Z-direction square wave modulation and the slope changing with the Y-direction magnetic field By, It is the slope of the second-order approximation ddS of the output signal obtained by the unit Z-direction square wave and DC bias as the X-direction magnetic field Bx changes.

2. The method for measuring the scale factor and electron relaxation rate of an atomic spin inertial measurement device according to claim 1, wherein: In step 2, n≥3, and each point in [By(1),By(2),…,By(n)] is a point within the range of ±5nT of the zero magnetic field point of the Y-direction magnetic field.

3. The method for measuring the scale factor and electron relaxation rate of an atomic spin inertial measurement device according to claim 1, wherein: Step 4 includes the following formula: Where dBz is the peak-to-peak value of the square wave modulated magnetic field in the Z direction.

4. The method for measuring the scale factor and electron relaxation rate of an atomic spin inertial measurement device according to claim 1, wherein: In step 6, m≥3, and each point in [Bx(1), Bx(1),…, Bx(m)] is within the range of ±5nT of the zero magnetic field point of the X-direction magnetic field.

5. The method for measuring the scale factor and electron relaxation rate of an atomic spin inertial measurement device according to claim 1, wherein: Step 8 includes the following formula:

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