Method for measuring scale coefficient and electronic relaxation rate of atomic spin inertial measurement device

Abstract

According to the method for measuring the scale coefficient and the electronic relaxation rate of the atomic spin inertial measurement device, the scale coefficient refers to an angular velocity scale coefficient, first-order approximation and second-order approximation of an output signal relative to a Z-direction magnetic field are measured, and the electronic relaxation rate of the atomic spin inertial measurement device is measured according to linear relations between the first-order approximation and the second-order approximation and between a Y-direction magnetic field and an X-direction magnetic field. The slopes of the two have a relationship with the scale coefficient and the electronic relaxation rate, and the scale coefficient and the electronic relaxation rate are calculated. The method is reasonable, the experimental operation is simple, the method is suitable for an atomic spin inertial measurement device based on an alkali metal electron spin and inert gas nuclear spin coupling ensemble, the scale coefficient and the electron relaxation rate can be accurately measured in real time, and a basis is provided for development of a high-precision atomic spin inertial measurement device.

Description

Technical Field

[0001] The invention relates to the technical field of atomic spin inertia measurement, and in particular to a method for measuring the calibration coefficient and electron relaxation rate of an atomic spin inertia measurement device. The experimental operation is simple, the calibration coefficient and the electron relaxation rate can be accurately measured, and a basis is provided 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] At present, there are two methods for measuring the scale factor and the electron relaxation rate: the S-curve method and the frequency response curve method. The S-curve method requires more data points to completely fit the required linear shape, and the fitting error is large; the frequency response curve method requires fitting the frequency response curve near the electron resonance peak, and there is also the problem of large fitting error. The accuracy and accuracy of the existing methods are limited by experimental conditions. Summary of the invention

[0004] In view of 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, which provides a basis for the development of a high-precision atomic spin inertial measurement device.

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

[0006] A method for measuring the calibration coefficient and electron relaxation rate of an atomic spin inertial measurement device, characterized in that it comprises the following steps:

[0007] Step 1, using 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-voltage steady-state response signal, S 2yIt is a low-level steady-state response signal, and obtains 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 a 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 square wave magnetic field and DC modulation in the Z direction 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-voltage steady-state response signal, S 2x is the 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 square wave modulated magnetic field in the Z direction, 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, which 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 method, 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 schematic 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 The method comprises the steps of: measuring the magnetic field Bn corresponding to the fastest response point in the Z direction; determining the Y-direction magnetic field array [By(1), By(2), ..., By(n)] to be traversed, where n is the sequence number, n is a positive integer, and By(n) is the nth Y-direction magnetic field; starting to traverse [By(1), By(2), ..., By(n)], setting By = By(i), where i is the first counter; and applying square wave modulation of the Z-direction magnetic field at the compensation point to output a steady-state response signal S. 1y and S 2y , S 1y is a high-voltage steady-state response signal, S 2yis a low-voltage steady-state response signal, and obtains the first-order approximation dS of the output signal with respect to the Z-direction magnetic field; step 5, determines whether i≥n, if not, sets i=i+1 and returns to step 3, if yes, proceeds to step 6; step 6, determines the X-direction magnetic field array [Bx(1), Bx(1),…, 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, starts traversing [Bx(1), Bx(1),…, Bx(m)], sets Bx=Bx(j), j is the second counter; step 8, applies a Z-direction magnetic field square wave and DC modulation at the compensation point, and outputs a steady-state response signal S 1x , S 2x and S 0x , S 1x is a high-voltage steady-state response signal, S 2x is the 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 the electron relaxation rate. DETAILED DESCRIPTION

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

[0033] Figure 1 The figure is a schematic 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, using the atomic spin inertial measurement device to measure 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)] 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)], let By = By(i), where i is a first counter, and By is the Y-direction magnetic field; step 4, applying square wave modulation of the Z-direction magnetic field at the compensation point, so that the atomic spin inertial measurement device outputs a steady-state response signal S 1y and S 2y , S 1y is a high-voltage steady-state response signal, S 2yis a low-voltage steady-state response signal, and obtains the first-order approximation dS of the output signal with respect to the Z-direction magnetic field; step 5, determines whether i≥n, if not, sets i=i+1 and returns to step 3, if yes, enters step 6; step 6, determines 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, starts traversing [Bx(1), Bx(1),…, Bx(m)], sets Bx=Bx(j), j is the second counter, and Bx is the X-direction magnetic field; step 8, applies 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-voltage steady-state response signal, S 2x is the 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 the 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 square wave modulated magnetic field in the Z direction, 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, which 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, and 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 the output signal about the Z-direction magnetic field, and 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 slope of the two is related to the scale factor and the electron relaxation rate, and the scale factor and the electron relaxation rate are calculated. The method of the present invention is reasonable, the experimental operation is simple, and it is suitable for an atomic spin inertial measurement device based on an alkali metal electron spin and an inert gas nuclear spin coupling ensemble, and the scale factor and the electron relaxation rate can be accurately measured in real time, providing a basis 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 square wave modulation of the Z-direction magnetic field at the compensation point, and output a steady-state response signal S 1y and S 2y , S 1y is a high-voltage 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 a square wave magnetic field and DC modulation in the Z direction at the compensation point, and output a steady-state response signal S 1x , S 2x and S 0x , S 1x is a high-voltage steady-state response signal, S 2x is the 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-voltage steady-state response signal, S 2y is the low level steady state response signal, dB z is the peak-to-peak value of the square wave modulated magnetic field in the Z direction, The first-order approximate 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-voltage steady-state response signal, S 2x is the 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 square wave modulated magnetic field in the Z direction, The second-order approximation ddS of the output signal obtained by the unit Z-direction square wave and DC bias varies 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] The contents not described in detail in the specification of the present invention belong to the prior art known to the professional and technical personnel in the field. It is pointed out here that the above description helps those skilled in the art to understand the invention, but does not limit the protection scope of the invention. Any equivalent replacement, modification and / or simplification of the above description without departing from the essence of the invention falls within the protection scope of the invention.

Claims

1. A method for measuring the calibration coefficient and electron relaxation rate of an atomic spin inertial measurement device, characterized in that: The following steps are involved: Step 1, using 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-voltage steady-state response signal, S 2y It is a low-level steady-state response signal, and obtains 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 a 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 square wave magnetic field and DC modulation in the Z direction 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-voltage steady-state response signal, S 2x is a low-voltage 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, calculate the scale factor and the electron relaxation rate.

2. The method for measuring the calibration coefficient and electron relaxation rate of an atomic spin inertial measurement device according to claim 1, characterized in that: 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 calibration coefficient and electron relaxation rate of an atomic spin inertial measurement device according to claim 1, characterized in that: 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, 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.

4. The method for measuring the calibration coefficient and electron relaxation rate of an atomic spin inertial measurement device according to claim 1, characterized in that: 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 calibration coefficient and electron relaxation rate of an atomic spin inertial measurement device according to claim 1, characterized in that: Step 8 includes the following formula: 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.

6. The method for measuring the calibration coefficient and electron relaxation rate of an atomic spin inertial measurement device according to claim 1, characterized in that: Step 10 includes the following formula: Where K is the scale factor, which 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.

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