Method and system for scanning electron beam to reconstruct heat flux density field and storage medium

Abstract

The invention discloses a method and system for reconstructing a heat flux density field by scanning electron beams and a storage medium. The method for reconstructing the heat flux density field by scanning electron beams comprises the following steps: S1, dispersing scanning points of a target heat flux density field; s2, planning a scanning track, a scanning field frequency and an electron beam spot radius, wherein the scanning track is connected with all scanning points in series; s3, carrying out performance calibration on the scanning driving system, and constructing a transfer function of an ideal current output signal It-s (s) of the scanning driving system after pull-type transformation and a real output current signal Ir-s (s) of the scanning driving system; and S4, establishing a scanning point energy balance equation set, and carrying out iterative solution. The method effectively solves the problem that an ideal jump model is difficult to reconstruct a target heat flux field with high precision under a high-frequency scanning working condition, and a feasible method is provided for developing a heat flux field reconstruction working condition which needs a large number of scanning points, such as a large workpiece, a high length-width ratio scanning area and a large heat flux gradient; and the engineering application scene of the scanning electron beam thermal assessment method is widened.

Description

Technical Field

[0001] The present invention relates to the field of aerospace technology, and in particular to a method, system and storage medium for reconstructing a heat flux density field by scanning electron beams. Background Art

[0002] Since the first hypersonic flight, ground thermal assessment tests have been extremely important and are an essential test link to ensure the effectiveness of aerodynamic thermal protection design. As an emerging ground thermal test technology, the scanning electron beam thermal assessment method has outstanding advantages over the traditional quartz lamp array thermal assessment method in creating a high temperature, high heat flux density, non-uniform and large gradient thermal environment, and is expected to meet the increasingly stringent thermal assessment requirements of hypersonic aircraft.

[0003] The patent with publication number CN112719557A discloses a method and device for realizing non-uniform heat flux density distribution by electron beam scanning. This scheme ignores the jumping process of the electron beam and constructs a method for reconstructing the target heat flux density field, thereby simplifying the solution process of the electron beam scanning strategy. However, this assumption is valid when the response time of the scanning drive system is much smaller than the residence time of the electron beam. In a large-scale thermal assessment experiment with multiple residence points, the residence time is on the same time scale as the response time of the scanning drive system. At this time, the assumption of ignoring the electron beam jumping process is no longer valid, and the deviation of the reconstructed target heat flux density field will increase sharply. To solve this problem, a method, system and storage medium for reconstructing the heat flux density field by scanning electron beam must be constructed. Summary of the invention

[0004] Based on the technical problems existing in the background technology, the present invention proposes a method, system and storage medium for reconstructing the heat flux density field by scanning electron beam, which effectively solves the problem that the ideal jump model is difficult to reconstruct the target heat flux density field with high precision under high-frequency scanning conditions, and provides a feasible method for carrying out heat flux density field reconstruction conditions that require a large number of scanning points such as large workpieces, high aspect ratio scanning areas and large heat flux density gradients, thereby broadening the engineering application scenarios of the scanning electron beam thermal assessment method.

[0005] The method for reconstructing heat flux density field by scanning electron beam proposed by the present invention comprises the following steps:

[0006] S1: Discrete scanning points of target heat flux density field;

[0007] S2: planning of scanning trajectory, scanning field frequency and electron beam spot radius, where the scanning trajectory connects all scanning points in series;

[0008] S3: Performance calibration of the scan drive system and construction of the ideal current output signal I of the scan drive system after pull-type conversion t-s (s) and the actual output current signal I of the scanning drive system r-s(s) transfer function;

[0009] S4: Establish the energy balance equations of the scanning points and solve them iteratively; the specific method is:

[0010] According to the ratio k of the electron beam’s target deflection distance and the output current signal of the scanning drive system, the transfer function of S3 is used to obtain the real scanning trajectory time series of the electron beam. The real scanning trajectory time series of the electron beam is divided into n segments at intervals of Δt0. The average scanning position of the electron beam in the jth time period is recorded as (x j ,y j ), the spatial position is (x i ,y i )’s target heat flux density for the i-th unit is as follows:

[0011]

[0012] In the formula, q″ i is the target heat flux density of the i-th unit; ΔQ ij is the total energy absorbed by the i-th unit; P is the total power of the electron beam absorbed by the sample; R is the electron beam spot radius; ΔL is the scanning point spacing.

[0013] Preferably, the electron beam spot radius is equal to the spacing between discrete scanning points.

[0014] Preferably, the scanning system in S3 is an open-loop scanning drive system, a second-order negative feedback scanning drive system, or a higher-order negative feedback scanning drive system.

[0015] Preferably, the iterative solution method in S4 is: set a uniform residence time distribution, compare the average heat flux density at each scanning point with the target heat flux density, if the average heat flux density at the scanning point is lower than the target heat flux density, extend the residence time of the scanning point; if the average heat flux density at the scanning point is higher than the target heat flux density, shorten the residence time of the scanning point; when the absolute value of the reconstruction deviation of the average heat flux density at all scanning points is less than the set reconstruction accuracy, the solution of the scanning point energy balance equation group is completed.

[0016] The present invention proposes a system for reconstructing a heat flux density field by scanning an electron beam, comprising:

[0017] Data processing module, used for discretization of target heat flux density field scanning points;

[0018] Scanning strategy planning module, used for planning scanning trajectory, scanning field frequency and electron beam spot radius, where the scanning trajectory connects all scanning points in series;

[0019] Scan drive module, used for performance calibration of scan drive system and constructing ideal current output signal I of scan drive system after pull-type conversiont-s (s) and the actual output current signal I of the scanning drive system r-s (s) transfer function;

[0020] The dwell time analysis module is used to establish the energy balance equations of the scanning points and solve them iteratively; the specific method is:

[0021] According to the ratio k of the electron beam’s target deflection distance and the output current signal of the scanning drive system, the transfer function of S3 is used to obtain the real scanning trajectory time series of the electron beam. The real scanning trajectory time series of the electron beam is divided into n segments at intervals of Δt0. The average scanning position of the electron beam in the jth time period is recorded as (x j ,y j ), the spatial position is (x i ,y i )’s target heat flux density for the i-th unit is as follows:

[0022]

[0023] In the formula, q″ i is the target heat flux density of the i-th unit; ΔQ ij is the total energy absorbed by the i-th unit; P is the total power of the electron beam absorbed by the sample; R is the electron beam spot radius; ΔL is the scanning point spacing.

[0024] The present invention provides a computer storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for reconstructing a heat flux density field by a scanning electron beam are implemented.

[0025] Beneficial technical effects of the present invention:

[0026] The method for reconstructing the heat flux density field of the present invention takes into account the actual jumping process of the electron beam between scanning points, and effectively solves the problem that the ideal jumping model is difficult to reconstruct the target heat flux density field with high precision under high-frequency scanning conditions, and provides a feasible method for carrying out heat flux density field reconstruction conditions that require a large number of scanning points such as large workpieces, high aspect ratio scanning areas and large heat flux density gradients, thereby broadening the engineering application scenarios of the scanning electron beam thermal assessment method; in addition, the basic principle of scanning electron beams is to simulate a stable heat flux density field input through high-frequency scanning. The present method can improve the reconstruction accuracy of the target heat flux density field under high-frequency scanning conditions, thereby improving the engineering application reliability of the scanning electron beam thermal assessment method. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The target heat flux density field proposed by the present invention;

[0028] Figure 2 The discrete results of the target heat flux density field scanning points proposed by the present invention;

[0029] Figure 3 The raster scanning track proposed by the present invention;

[0030] Figure 4 The calibration process of the scanning drive system proposed by the present invention;

[0031] Figure 5 The calibration result of the scanning drive system proposed by the present invention;

[0032] Figure 6 The iterative history of the target heat flux field is reconstructed for the model considering the jump process in the first embodiment of the present invention;

[0033] Figure 7 It is an ideal output current signal of the scanning driving system considering the jumping process in the first embodiment of the present invention;

[0034] Figure 8 It is the real output current signal of the scanning driving system considering the jumping process in the embodiment 1 of the present invention;

[0035] Fig. 9 The solution result of the residence time distribution considering the jump process in Example 1 proposed by the present invention;

[0036] Fig.10 The scanning heat flux density field solution result considering the jump process in Example 1 proposed by the present invention;

[0037] Fig.11 The target heat flux density field reconstruction deviation distribution considering the jump process in embodiment 1 proposed by the present invention;

[0038] Fig.12 It is an ideal output current signal of the scanning driving system in which the jump process is ignored in the embodiment 1 of the present invention;

[0039] Fig.13 It is the real output current signal of the scanning driving system in which the jump process is ignored in the embodiment 1 of the present invention;

[0040] Fig.14 The dwell time distribution solution result of Example 1 proposed by the present invention ignoring the jump process;

[0041] Fig.15 The scanning heat flux density field solution result of Example 1 proposed by the present invention ignoring the jumping process;

[0042] Fig.16 The target heat flux density field reconstruction deviation distribution is neglected in Example 1 of the present invention when the jump process is not considered;

[0043] Fig.17 The two-stage reciprocating raster scanning trajectory proposed by the present invention;

[0044] Fig.18 The dwell time distribution solution result considering the jump process in Example 2 proposed by the present invention;

[0045] Fig.19 The scanning heat flux density field solution result considering the jump process in Example 2 proposed by the present invention;

[0046] Fig. 20 The target heat flux density field reconstruction deviation distribution considering the jump process in embodiment 2 proposed by the present invention;

[0047] Fig.21 The dwell time distribution solution result of Example 2 proposed by the present invention ignoring the jump process;

[0048] Fig. 22 The scanning heat flux density field solution result of Example 2 proposed by the present invention ignoring the jumping process;

[0049] Fig.23 This is the target heat flux field reconstruction deviation distribution that ignores the jumping process in Example 2 proposed by the present invention. DETAILED DESCRIPTION

[0050] The present invention will be further explained below in conjunction with specific embodiments.

[0051] Example 1

[0052] Gaussian distribution is usually used to describe the heat flux density field distribution characteristics of the leading edge of a hypersonic aircraft. Figure 1 The target heat flux field shown in the figure shows a Gaussian distribution. The peak heat flux density of the target heat flux field is about 10MW / m 2 , size is 40mm×40mm.

[0053] The method steps of scanning electron beam to reconstruct the heat flux density field proposed in this embodiment are as follows:

[0054] S1: Discrete scanning points of target heat flux density field.

[0055] 20×20 scanning points are evenly arranged in the scanning area, and the scanning point spacing is 2 mm. The discrete results of the target heat flux density field are as follows: Figure 2 shown.

[0056] For the discretization of the target heat flux density field scanning points of this embodiment, the existing technology can be used, such as the discretization method described in the patent with publication number CN112719557A. Both uniform grid discretization method and non-uniform grid can be used; the shape of the grid is not limited to rectangle and triangle; in addition to being located at the center of gravity of the grid, the scanning point can also be located at other positions of the grid according to certain mathematical methods, not limited to the circumcenter, incenter and orthocenter, etc.

[0057] S2: Planning of scanning trajectory, scanning field frequency and electron beam spot radius.

[0058] For the scanning trajectory, in addition to the raster scanning trajectory of the present embodiment, any trajectory that connects all scanning points in series can also be used, which is not limited to a regular sequential connection, but can also be a disordered connection; in addition, it can also be a large scanning cycle composed of multiple groups of scanning trajectories. For the scanning field frequency, it is generally hoped that the scanning electron beam has a higher scanning field frequency, that is, the electron beam completes as many scanning cycles as possible within a certain period of time, in order to utilize the dynamic heating effect of the high-speed scanning electron beam to simulate the stable heating effect of the target heat flux density field. For the beam spot radius, this parameter is usually set equal to the scanning point spacing. Under this condition, the best reconstruction accuracy can be obtained for most working conditions.

[0059] The scanning path of this embodiment is as follows Figure 3 The raster scanning shown has a scanning field frequency of 60 Hz, that is, the electron beam passes through all scanning points 60 times per second along the scanning path, and the electron beam spot radius is set to be the same as the scanning point spacing, both of which are 2 mm.

[0060] S3: Performance calibration of the scan drive system and construction of the ideal current output signal I of the scan drive system after pull-type conversion t-s (s) and the actual output current signal I of the scanning drive system r-s (s) transfer function.

[0061] The driving process of the scanning electron beam can be described as follows: first, the digital signal containing the dwell time distribution and scanning trajectory information is converted into a voltage excitation signal through a waveform generator, and then input into the scanning drive system to be converted into a current signal that can drive the coil to generate a time-varying magnetic field. The electron beam performs regular high-speed scanning under the action of the time-varying magnetic field. The response time of the scanning drive system to convert the voltage excitation signal into a current drive signal is the most important factor affecting the response performance of the entire system. Therefore, the performance of the scanning drive system needs to be calibrated and the transfer function needs to be established.

[0062] The scanning drive system used in this embodiment is a typical second-order negative feedback scanning drive system. The ideal current output signal of the scanning drive system is I t(t), which is the ratio of the voltage excitation signal of the scanning drive system multiplied by the power amplifier coefficient and the output loop resistance of the scanning drive system. The actual output current signal of the scanning drive system is I r (t), then after the Lapse transformation I t (t) and I r (t) are converted into I t-s (s) and I r-s (s), the transfer function is:

[0063]

[0064] In the formula, ω n is the natural oscillation frequency; ξ is the damping coefficient. By measuring the voltage excitation signal, output loop resistance and output current signal of the scanning drive system, ω can be obtained by fitting. n and ξ. The specific fitting process is as follows:

[0065] In order to calibrate the key parameters of the scanning drive system, namely the natural oscillation frequency and the damping coefficient, the electron beam is designed to jump once every 2mm with the same dwell time, and the dwell positions are 0mm, 2mm, 4mm and 6mm respectively. Three independent experiments were carried out, with dwell times of 100μs, 50μs and 20μs respectively. The proportionality coefficient between the deflection distance of the electron beam and the output current of the scanning drive system is 11A / m. From this, the ideal output current signal of the scanning drive system can be converted. The power amplifier coefficient of the scanning drive system is 1.4, and the output loop resistance is 3.7Ω. Therefore, the excitation voltage signal of the scanning drive system can be calculated based on the ideal output current signal. Figure 4 As shown, the excitation voltage signal is input into the scanning drive system to obtain Figure 5 The measured value of the output current signal is shown in the black line. Assuming that the initial values ​​of the natural oscillation frequency and the damping coefficient are both 0.5, the excitation voltage signal is input into the scanning drive system transfer function to obtain the calculated value of the output current signal. The measured and calculated results are compared, and the natural oscillation frequency and damping coefficient are iterated. The calculated value of the output current signal obtained by the final iteration is as follows: Figure 5 As shown by the medium gray line, the natural oscillation frequency and damping coefficient are 0.13918 and 0.31155 respectively.

[0066] In addition, in addition to using the second-order negative feedback scanning drive system of this embodiment, a higher-order negative feedback scanning drive system can also be used, or an open-loop scanning drive system can be used. The transfer functions of these scanning drive systems can be calibrated based on the method of the present invention, and then the jumping process of the electron beam can be incorporated into the target heat flux density field reconstruction model.

[0067] Regarding the construction of the transfer function of the scanning drive system, in addition to obtaining the specific transfer function by finding the form of the known transfer function and then fitting the key parameters in the present embodiment, one can also directly focus on the input and output signals of the scanning drive system and perform function fitting on the response curves between the two to obtain the transfer function of the scanning drive system.

[0068] S4: Establish the energy balance equations of the scanning points and solve them iteratively.

[0069] Based on the discrete unit design of the target heat flux field in S1 and the scanning trajectory planned in S2, the electron beam scanning trajectory time series is obtained, which is recorded as S t (t). Based on the proportionality coefficient between the target deflection distance of the electron beam and the output current signal of the scanning drive system, that is, k = 11A / m, the formula I t (t) = k·S t (t), and convert it to obtain the ideal current output signal. Based on the transfer function established by S3, I t (t) is converted to I r (t), and further combined with the proportional coefficient between the target deflection distance of the electron beam and the output current signal of the scanning drive system, the actual scanning trajectory of the electron beam can be obtained, which is denoted as S r (t). The sequence is divided into 16667 segments at intervals of 1 μs. The average scanning position of the electron beam in the jth time period is recorded as (x j ,y j ). In this j period, the total energy absorbed by the i-th unit is:

[0070]

[0071] The average heat flux absorbed by the i-th unit in a scanning cycle should be equal to the target heat flux, that is:

[0072]

[0073] For the 400 discrete units in S1, 400 of the above equations can be established and combined to obtain the energy balance equation group of the scanning points.

[0074] The method for iteratively solving the energy balance equations at the scanning point is as follows: the initial dwell time is set to be uniformly distributed, the target reconstruction accuracy is 2%, and the iterative convergence curve is shown in Figure 6. The final ideal current output signal, real output current signal, dwell time distribution, scanning heat flux density field and reconstruction deviation distribution are shown in Figure 6. Figure 7-Figure 11 shown. Figure 12-16The reconstruction results of the target heat flux field by the reconstruction model ignoring the electron beam jumping process under the same reconstruction parameters are given respectively, including the ideal current output signal, the real output current signal, the dwell time distribution, the scanned heat flux field and the reconstruction deviation distribution. Fig.11 and Fig.16 By comparison, compared with the reconstruction model that ignores the electron beam jumping process, considering the electron beam jumping process to analyze the target heat flux density field can reduce the maximum absolute value of the reconstruction deviation from 89.95% to 1.98%, and the optimization range is 97.80%.

[0075] Example 2

[0076] In Example 1, the electron beam always scans from left to right, and when the electron beam moves to the rightmost end, it will jump to the leftmost end. At this time, the response time of the scanning drive system is relatively long. This scanning trajectory is not conducive to the solution model that ignores the jump process to reconstruct the target heat flux density field with high precision. Therefore, the comparison of the two models in Example 1 is not of general significance. This example also compares the two models under the condition of continuous small jumps for the target heat flux density field in Example 1.

[0077] The method steps of scanning electron beam to reconstruct the heat flux density field proposed in this embodiment are as follows:

[0078] S1: Discrete scanning points of target heat flux density field.

[0079] The discrete settings and discrete results of Example 1 are adopted.

[0080] S2: Planning of scanning trajectory, scanning field frequency and electron beam spot radius.

[0081] The scanning path of this embodiment is as follows Fig.17 The two-stage reciprocating raster scanning shown, that is, two small scanning cycles constitute a large scanning cycle, in each scanning cycle, the electron beam jumps continuously at adjacent scanning points, and the movement of the electron beam is also continuous in the connection of two small cycles. The scanning field frequency is 100Hz, that is, the electron beam completes 50 large scanning cycles per second, and the electron beam spot radius is set to 2mm.

[0082] S3: Performance calibration of the scanning drive system and construction of the ideal current output signal I of the scanning drive system t (t) and the actual output current signal I of the scanning drive system r (t) is the transfer function of

[0083] The scanning drive system, calibration method and results of this embodiment are the same as those of Embodiment 1.

[0084] S4: Establish the energy balance equations of the scanning points and solve them iteratively.

[0085] Based on the discrete unit design of the target heat flux field in S1 and the scanning trajectory planned in S2, the electron beam scanning trajectory time series is obtained, which is recorded as S t (t). Based on the proportionality coefficient between the target deflection distance of the electron beam and the output current signal of the scanning drive system, that is, k = 11A / m, the formula I t (t) = k·S t (t), and convert it to obtain the ideal current output signal. Based on the transfer function established by S3, I t (t) is converted to I r (t), and further combined with the proportional coefficient between the target deflection distance of the electron beam and the output current signal of the scanning drive system, the actual scanning trajectory of the electron beam can be obtained, which is denoted as S r (t). The sequence is divided into 10,000 segments at intervals of 1 μs. The average scanning position of the electron beam in the jth time segment is recorded as (x j ,y j ). In this j period, the total energy absorbed by the i-th unit is:

[0086]

[0087] The average heat flux absorbed by the i-th unit in a scanning cycle should be equal to the target heat flux, that is:

[0088]

[0089] For the 400 discrete units in step 1, 400 of the above equations can be established and combined to obtain the energy balance equation group of the scanning points.

[0090] The iterative solution method of the scanning point energy balance equation group is as follows: the initial residence time is set to be uniformly distributed, the target reconstruction accuracy is 2%, and the residence time distribution, scanning heat flux density field and reconstruction deviation distribution obtained by iterative solution are respectively as follows: Figure 18-Figure 20 shown. Figure 21-23 The reconstruction results of the target heat flux field using the reconstruction model that ignores the electron beam jumping process under the same reconstruction parameters are given respectively, including the residence time distribution, the scanning heat flux field and the reconstruction deviation distribution. Fig. 20 and Fig.23 By comparison, compared with the reconstruction model that ignores the electron beam jumping process, considering the electron beam jumping process to analyze the target heat flux density field can reduce the maximum absolute value of the reconstruction deviation from 29.80% to 1.98%, and the optimization range is 93.36%.

[0091] Example 3

[0092] This embodiment proposes a system for reconstructing a heat flux density field by scanning an electron beam, comprising:

[0093] Data processing module, used for discretization of target heat flux density field scanning points;

[0094] Scanning strategy planning module, used for planning scanning trajectory, scanning field frequency and electron beam spot radius, where the scanning trajectory connects all scanning points in series;

[0095] Scan drive module, used for performance calibration of scan drive system and constructing ideal current output signal I of scan drive system after pull-type conversion t-s (s) and the actual output current signal I of the scanning drive system r-s (s) transfer function;

[0096] The dwell time analysis module is used to establish the energy balance equations of the scanning points and perform iterative solutions.

[0097] Example 4

[0098] This embodiment proposes a computer storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for reconstructing a heat flux density field by scanning electron beams in Embodiment 1 or Embodiment 2 are implemented.

Claims

1. A method for reconstructing a heat flux density field by scanning an electron beam, characterized in that: The steps are as follows: S1: Discrete scanning points of target heat flux density field; S2: planning of scanning trajectory, scanning field frequency and electron beam spot radius, where the scanning trajectory connects all scanning points in series; S3: Performance calibration of the scan drive system and construction of the ideal current output signal I of the scan drive system after pull-type conversion t-s (s) and the actual output current signal I of the scanning drive system r-s (s) transfer function; S4: Establish the energy balance equations of the scanning points and solve them iteratively; the specific method is: According to the ratio k of the electron beam’s target deflection distance to the output current signal of the scanning drive system and the transfer function of S3, the real scanning trajectory time series of the electron beam is obtained. The real scanning trajectory time series of the electron beam is divided into n segments at intervals of Δt0. The average scanning position of the electron beam in the jth time period is recorded as (x j ,y j ), the spatial position is (x i ,y i )’s target heat flux for the ith unit is as follows: In the formula, q″ i is the target heat flux density of the i-th unit; ΔQ ij is the total energy absorbed by the i-th unit; P is the total power of the electron beam absorbed by the sample; R is the electron beam spot radius; ΔL is the scanning point spacing.

2. The method for reconstructing heat flux density field by scanning electron beam according to claim 1, characterized in that: The electron beam spot radius is equal to the spacing between discrete scanning points.

3. The method for reconstructing heat flux density field by scanning electron beam according to claim 1, characterized in that: The scanning system in S3 is an open-loop scanning drive system or a second-order or higher-order negative feedback scanning drive system.

4. The method for reconstructing heat flux density field by scanning electron beam according to claim 1, characterized in that: The iterative solution method in S4 is: set the initial residence time to be uniformly distributed, compare the average heat flux density at each scanning point with the target heat flux density, if the average heat flux density at the scanning point is lower than the target heat flux density, extend the residence time of the scanning point; if the average heat flux density at the scanning point is higher than the target heat flux density, shorten the residence time of the scanning point; when the absolute value of the reconstruction deviation of the average heat flux density at all scanning points is less than the set reconstruction accuracy, the solution of the scanning point energy balance equation group is completed.

5. A system for reconstructing heat flux density field by scanning electron beam, characterized in that: include: Data processing module, used for discretization of target heat flux density field scanning points; Scanning strategy planning module, used for planning scanning trajectory, scanning field frequency and electron beam spot radius, where the scanning trajectory connects all scanning points in series; Scan drive module, used for performance calibration of scan drive system and constructing ideal current output signal I of scan drive system after pull-type conversion t-s (s) and the actual output current signal I of the scanning drive system r-s (s) transfer function; The dwell time analysis module is used to establish the energy balance equations of the scanning points and solve them iteratively; the specific method is: According to the ratio k of the electron beam’s target deflection distance to the output current signal of the scanning drive system and the transfer function of S3, the real scanning trajectory time series of the electron beam is obtained. The real scanning trajectory time series of the electron beam is divided into n segments at intervals of Δt0. The average scanning position of the electron beam in the jth time period is recorded as (x j ,y j ), the spatial position is (x i ,y i )’s target heat flux for the ith unit is as follows: In the formula, q″ i is the target heat flux density of the i-th unit; ΔQ ij is the total energy absorbed by the i-th unit; P is the total power of the electron beam absorbed by the sample; R is the electron beam spot radius; ΔL is the scanning point spacing.

6. A computer storage medium, characterized in that: The computer storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for reconstructing a heat flux density field by a scanning electron beam as described in any one of claims 1 to 4 are implemented.

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