Non-magnetic electric heating film configuration design method based on region division

Abstract

The invention discloses a non-magnetic electric heating film configuration design method based on region division, and belongs to the technical field of electric heating magnetic field suppression, and the method comprises the steps: carrying out the region division of a heating film plane according to the contribution value; establishing a primary function in the area to represent a flow function of current distribution, and calculating magnetic field distribution and temperature distribution of the alkali metal air chamber based on the flow function; establishing constraint conditions about each coefficient in the primary function according to the magnetic noise uniformity and the temperature uniformity; establishing a cost function according to the principle of the minimum magnetic noise mode of the air chamber, and calculating the optimal solution of each coefficient in a primary function to obtain a flow function expression of current distribution; and heating film configuration is designed according to current isoline distribution. By adopting the method, the magnetic noise of the heating film can be effectively reduced, the heating uniformity is considered, and the magnetic resonance signal quality in the quantum sensor can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of electric heating magnetic field suppression, and in particular to a method for designing a non-magnetic electric heating film configuration based on regional division. Background Art

[0002] With the in-depth development of theories such as quantum manipulation, physical optics, and electromagnetic compatibility, quantum sensors have been favored by many researchers for their high sensitivity, chip-based, and low-cost characteristics. This type of sensor uses an alkali metal gas chamber as the core sensitive element. The spatial distribution characteristics of the magnetic field and temperature field greatly affect the regulation of the quantum state, and thus affect the sensitivity and measurement accuracy of the magnetometer. However, while the electric heating film provides heat to the gas chamber, it will inevitably introduce magnetic field interference. This magnetic noise has an adverse effect on the preset magnetic field required by the gas chamber.

[0003] In order to solve the problem of magnetic noise generated by the heating film, the existing technology usually adopts a specific heating wire routing configuration to suppress it. However, this layout method fails to fully consider the problem of temperature field uniformity, especially in quantum state control that requires a highly uniform temperature field. Therefore, the existing electric heating technology is difficult to achieve the dual tasks of magnetic field suppression and uniform heating, and the electric heating film has serious defects in the layout of the heating wire. Summary of the invention

[0004] The purpose of the present invention is to provide a non-magnetic electric heating film configuration design method based on regional division, so as to realize effective regulation of temperature field and magnetic field, which is beneficial to improving the magnetic resonance signal quality of the atomic magnetometer.

[0005] To achieve the above object, the present invention provides a method for designing a non-magnetic electric heating film configuration based on regional division, the steps comprising:

[0006] S1. Analyze the contribution value of the current element position on the heating film to the magnetic noise at the center of the air chamber, and divide the heating film into regions according to the contribution value;

[0007] S2. Establishing a stream function of current distribution in the region, and calculating the magnetic field distribution and temperature distribution of the alkali metal gas chamber according to the stream function;

[0008] S3. Establishing constraints on the coefficients in the stream function according to magnetic noise uniformity and temperature uniformity;

[0009] S4. According to the principle of minimizing the air chamber magnetic noise modulus, a cost function is established and the optimal solution of each coefficient in the stream function is calculated to obtain the stream function expression of the current distribution;

[0010] S5. Design the heating film configuration according to the current contour distribution.

[0011] Preferably, in step S1, the contribution value of the position of the current element on the heating film to the magnetic noise at the center of the air chamber is analyzed, and the heating film is divided into regions according to the contribution value, including:

[0012]

[0013] In the formula, B(r) represents the contribution of a current element at a certain location to the magnetic field at the center of the air chamber, μ 0 represents the vacuum magnetic permeability, I represents the heating wire current, represents the current element vector, l represents the current element length, represents the position vector from the current element to the center of the air chamber, r represents the distance from the current element to the center of the air chamber, and d represents the distance from the center of the air chamber to the heating film;

[0014] The heating film is divided into regions according to the change of |B(r)|. The straight line through the center of the air chamber is assumed to be perpendicular to the heating film, and the foot point is P. According to the magnetic noise equation at the center of the air chamber, the contribution value of point P is the largest, which is recorded as |B(r)| max , with |B(r)| max As a benchmark, the heating film is divided into regions according to the change in the magnetic noise contribution value. The formula is:

[0015]

[0016] In the formula, Ω n ={r∈Ω||B(r)|∈[a n |B(r)| max ,a n-1 |B(r)| max )} means that on the heating film (r∈Ω) |B(r)|∈[a n |B(r)| max ,a n-1 |B(r)| max ), a 1 ,a 2 ,…,a n Represents the weight coefficient.

[0017] Preferably, in step S2:

[0018] The stream function of the current distribution in the region is established using the Fourier series, and the formula is:

[0019]

[0020] In the formula, y i (x,y) represents the i-th region Ω i The stream function of and They represent the expansion coefficients of the Fourier series, m and n represent the mode numbers of the Fourier series, corresponding to the wave numbers in the x and y directions, respectively. x , L y Represents the region Ω i The length in the x and y directions, (x, y) represents the coordinates, where the origin of the coordinate system is the center of the heating film;

[0021] Based on the stream function y i (x,y) to obtain the magnetic field B(x,y,z) and temperature field T(x,y,z) of the alkali metal gas cell.

[0022] Preferably, in step S3, establishing constraints on coefficients in the stream function according to magnetic noise uniformity and temperature uniformity includes:

[0023]

[0024] subject to:

[0025]

[0026] In the formula, ∈ 1 represents the maximum allowable magnetic field inhomogeneity, ∈ 2 represents the maximum allowable non-uniformity of the temperature field, (b i,1 ,b i,2 )express The value range of (α i,1 ,α i,2 )express The value range of and Respectively represent the mean values ​​of the magnetic field and temperature field in the air chamber space.

[0027] Preferably, in step S4, establishing a cost function and calculating the optimal solution of each coefficient in the stream function according to the principle of minimizing the air chamber magnetic noise modulus includes:

[0028]

[0029] subject to:

[0030]

[0031] Where f represents the stream function expression.

[0032] Therefore, the present invention adopts the above-mentioned non-magnetic electric heating film configuration design method based on regional division, which can effectively reduce the magnetic noise generated by the heating film during operation and take into account the heating uniformity, which is beneficial to improving the signal quality of the quantum sensor and has a broader application prospect.

[0033] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A method flow chart of an embodiment of a method for designing a configuration of a non-magnetic electric heating film based on regional division according to the present invention;

[0035] Figure 2 It is a schematic diagram of the heating film area division according to an embodiment of a method for designing a non-magnetic electric heating film configuration based on area division of the present invention. DETAILED DESCRIPTION

[0036] Example

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0038] Reference Figure 1 The present invention provides a method for designing a non-magnetic electric heating film configuration based on regional division, which can be used for the non-magnetic heating system of quantum sensors such as atomic magnetometers and atomic gyroscopes.

[0039] The steps include:

[0040] S1. Analyze the contribution of the current element position on the heating film to the magnetic noise at the center of the air chamber, and divide the heating film into regions according to the contribution value. Figure 2 As shown, the left half is a schematic diagram of the relative spatial position of the alkali metal gas chamber and the non-magnetic electric heating film in the quantum sensor, and the right half is the division result, where each physical area corresponds to a range of magnetic noise contribution values.

[0041] Specifically include:

[0042]

[0043] In the formula, B(r) represents the contribution of a current element at a certain location to the magnetic field at the center of the air chamber, μ 0 represents the vacuum magnetic permeability, I represents the heating wire current, represents the current element vector, l represents the current element length, Represents the position vector from the current element to the center of the air chamber, r represents the distance from the current element to the center of the air chamber, and d represents the distance from the center of the air chamber to the heating film. As the position of the current element changes, its contribution to the magnetic noise at the center of the air chamber will also change, that is, as r increases, |B(r)| will decrease. Therefore, based on the reverse design thinking, the heating film is divided into regions according to the change in |B(r). Assume that the straight line through the center of the air chamber is perpendicular to the heating film, and the foot point is P. According to the magnetic noise equation at the center of the air chamber, it is known that the contribution value of point P is the largest, recorded as |B(r)| max , with |B(r)| max As a benchmark, the heating film is divided into regions according to the change in the magnetic noise contribution value. The formula is:

[0044]

[0045] In the formula, Ω n ={r∈Ω||B(r)|∈[a n |B(r)| max ,a n-1 |B(r)| max )} means that on the heating film (r∈Ω) |B(r)|∈[a n |B(r)| max ,a n-1 |B(r)| max ), a 1 ,a 2 ,…,a n Represents the weight coefficient.

[0046] S2. Establish a basis function in the region to characterize the stream function of the current distribution, and calculate the magnetic field distribution and temperature distribution of the alkali metal gas chamber based on the stream function. Specifically including:

[0047] First, the Fourier series is used to establish the stream function of the current distribution in the region, the formula is:

[0048]

[0049] In the formula, y i (x,y) represents the i-th region Ω i The stream function describes the current distribution in the region. and They represent the expansion coefficients of the Fourier series, which determine the specific form of the stream function. m and n represent the mode numbers of the Fourier series, which are integers and correspond to the wave numbers in the x and y directions, respectively. x , L y Represents the region Ω i The lengths in the x and y directions, (x, y) represent coordinates, wherein the origin of the coordinate system is the center of the heating film.

[0050] Then based on the stream function y i (x,y) to obtain the magnetic field B(x,y,z) and temperature field T(x,y,z) of the alkali metal gas cell.

[0051] When establishing the stream function, spherical harmonics can also be used for representation.

[0052] S3. Establish constraints on the coefficients in the stream function based on the uniformity of magnetic noise and temperature. Specifically include:

[0053]

[0054] subject to:

[0055]

[0056] In the formula, ∈ 1 represents the maximum allowable magnetic field inhomogeneity, ∈ 2 represents the maximum allowable non-uniformity of the temperature field, (b i,1 ,b i,2 )express The value range of (α i,1 ,α i,2 )express The value range of and Respectively represent the mean values ​​of the magnetic field and temperature field in the air chamber space.

[0057] S4. According to the principle of minimizing the air chamber magnetic noise modulus, a cost function is established and the optimal solution of each coefficient in the stream function is calculated to obtain the stream function expression of the current distribution.

[0058] According to the principle of minimum air chamber magnetic noise modulus, the cost function is established and the optimal solution of each coefficient in the stream function is calculated, including:

[0059]

[0060] subject to:

[0061]

[0062] Where f represents the stream function expression.

[0063] S5. Design the heating film configuration according to the current contour distribution.

[0064] Therefore, the present invention adopts the above-mentioned non-magnetic electric heating film configuration design method based on regional division, which can effectively reduce the magnetic noise generated by the heating film during operation and take into account the heating uniformity, which is beneficial to improving the signal quality of the quantum sensor and has a broader application prospect.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for designing a non-magnetic electric heating film configuration based on regional division, characterized in that the steps include: S1. Analyze the contribution value of the current element position on the heating film to the magnetic noise at the center of the air chamber, and divide the heating film into regions according to the contribution value; S2. Establishing a stream function of current distribution in the region, and calculating the magnetic field distribution and temperature distribution of the alkali metal gas chamber according to the stream function; S3. Establishing constraints on the coefficients in the stream function according to magnetic noise uniformity and temperature uniformity; S4. According to the principle of minimizing the air chamber magnetic noise modulus, a cost function is established and the optimal solution of each coefficient in the stream function is calculated to obtain the stream function expression of the current distribution; S5. Design the heating film configuration according to the current contour distribution.

2. A method for designing a non-magnetic electric heating film configuration based on regional division according to claim 1, characterized in that: In step S1, the contribution value of the current element position on the heating film to the magnetic noise at the center of the air chamber is analyzed, and the heating film is divided into regions according to the contribution value, including: In the formula, B(r) represents the contribution of a current element at a certain location to the magnetic field at the center of the air chamber, μ0 represents the vacuum magnetic permeability, I represents the heating wire current, represents the current element vector, l represents the current element length, represents the position vector from the current element to the center of the air chamber, r represents the distance from the current element to the center of the air chamber, and d represents the distance from the center of the air chamber to the heating film; The heating film is divided into regions according to the change of |B(r)|. The straight line through the center of the air chamber is assumed to be perpendicular to the heating film, and the foot point is P. According to the magnetic noise equation at the center of the air chamber, the contribution value of point P is the largest, which is recorded as |B(r). max , with |B(r) max As a benchmark, the heating film is divided into regions according to the change in the magnetic noise contribution value. The formula is: In the formula, Ω n ={r∈Ω||B(r)|∈[a n |B(r)| max ,a n-1 |B(r)| max )} means that on the heating film (r∈Ω) |B(r)|∈[a n |B(r)| max ,a n-1 |B(r)| max ) consists of all subsets of r, a1, a2, …, a n Represents the weight coefficient.

3. The method for designing a non-magnetic electric heating film configuration based on regional division according to claim 1, characterized in that: In step S2: The stream function of the current distribution in the region is established using the Fourier series, and the formula is: In the formula, y i (x,y) represents the i-th region Ω i The stream function of and They represent the expansion coefficients of the Fourier series, m and n represent the mode numbers of the Fourier series, corresponding to the wave numbers in the x and y directions, respectively. x , L y Represents the region Ω i The length in the x and y directions, (x, y) represents the coordinates, where the origin of the coordinate system is the center of the heating film; Based on the stream function y i (x,y) to obtain the magnetic field B(x,y,z) and temperature field T(x,y,z) of the alkali metal gas cell.

4. The method for designing a non-magnetic electric heating film configuration based on regional division according to claim 3, characterized in that: In step S3, the constraint conditions for each coefficient in the stream function are established according to the uniformity of magnetic noise and temperature, including: Where, ∈1 represents the maximum allowable inhomogeneity of the magnetic field, ∈2 represents the maximum allowable inhomogeneity of the temperature field, (b i,1 ,b i,2 )express The value range of (α i,1 ,α i,2 )express The value range of and Respectively represent the mean values ​​of the magnetic field and temperature field in the air chamber space.

5. The method for designing a non-magnetic electric heating film configuration based on regional division according to claim 1, characterized in that: In step S4, the cost function is established according to the principle of minimizing the air chamber magnetic noise modulus and the optimal solution of each coefficient in the stream function is calculated, which includes: Where f represents the stream function expression.

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