Electron back scattering noise modeling calibration method based on power function

Abstract

The invention relates to an electron back scattering noise modeling calibration method based on a power function, which comprises the following steps of: firstly, carrying out simplified modeling on a ground simulation space environment device and a material to be tested, and then selecting a pre-calibration point location in a manner of uniformly distributing random numbers and equidistantly through the power function; a Monte Carlo method is used for performing absorbed dose simulation of selected energy on a pre-calibration point location, and finally, an optimal calibration point is determined through comparison and screening, so that the method can reduce noise interference caused by factors such as environment, has certain help for evaluation of indexes such as circuit total dose effect and material shielding performance which are sensitive to back scattering, and can be widely applied to the field of back scattering detection. According to the method, the rough calibration position of the test device can be determined before the field test, and an ideal test result can be obtained on the premise that the test cost is low.

Description

Technical Field

[0001] The invention relates to a simulation modeling method for reducing backscatter noise, in particular to an electron backscatter noise modeling calibration method based on a power function, and belongs to the field of dose measurement and radiation effect. Background Art

[0002] There are a large number of charged particles, such as electrons and protons, in the near-Earth environment / deep space Jupiter orbit, etc., which can easily cause dose accumulation and damage effects after entering the device, affecting the device performance and even causing irreparable losses. How to correctly simulate particle damage in the space environment has become an important topic. At present, the main way to simulate the total dose loss on the ground is cobalt 60 equivalent, but whether cobalt source should be used as the equivalent of electron-rich environment has always been controversial. Under the same dose irradiation, the static damage to the device caused by electrons is smaller than that of cobalt source; while in dynamic testing, electrons above a few MeV may cause permanent damage, thus affecting the estimated results of device performance. Therefore, directly using electron source as radiation source is the most ideal way. However, there are many uncertain factors in the total dose test of electron accelerators. When the electron beam is shot into the solid material along a certain direction, the electrons and the nuclei or extranuclear electrons are elastically or inelastically scattered, the incident direction changes greatly, and the atoms are excited to produce secondary electrons, photons and other signals. This type of secondary signal will have a certain impact on the total dose measurement results, resulting in inaccurate test results such as the total dose effect of the circuit and the shielding rate of the material. Summary of the invention

[0003] The technical problem solved by the present invention is: a proposed electron backscatter noise modeling and calibration method based on a power function can reduce noise interference caused by environmental factors and the like, can clarify the approximate calibration position of a test device before a field test, can obtain ideal test results at a relatively low test cost, and is helpful for evaluating indicators sensitive to backscattering, such as total circuit dose effect and material shielding performance, thereby improving credibility.

[0004] The technical solution of the present invention is as follows:

[0005] A quantitative modeling method for electron backscatter noise based on power function, comprising:

[0006] Construct a simplified model of the test environment for simulation, including decomposing the main structure of the accelerator into the base plate, the launch gun and the shell, and obtaining the atomic number and density information of the base plate, the launch gun and the shell;

[0007] In the simplified test environment model, a plurality of positions for placing absorbed dose counters are selected in the area between the bottom plate and the launch gun, including: taking the bottom plate as the zero point, setting the distance from the bottom plate to the launch gun as L, selecting n positions for placing absorbed dose counters between the positions L and 2 / 3L from the launch gun by using an averagely distributed random number method, and selecting m positions for placing absorbed dose counters between the positions 2 / 3L and 0 from the launch gun at equal intervals, where m and n are both positive integers;

[0008] Place absorbed dose counters one by one at each selected placement position of absorbed dose counters, perform a Monte Carlo simulation each time the absorbed dose counters are placed, and obtain m+n absorbed dose values;

[0009] The absorbed dose value T1 of the absorbed dose counter placed closest to the base plate is compared with other absorbed dose values, and all absorbed dose values ​​less than T1 are compared twice to select the minimum value. The placement position of the absorbed dose counter corresponding to the minimum value is taken as the final test calibration position; if there is no absorbed dose value smaller than T1, 1 / 2L is taken as the final test calibration position.

[0010] In the above-mentioned quantitative modeling method of electron backscatter noise based on power function, the method of selecting the placement positions of several absorbed dose counters includes:

[0011] The serial number of the n absorbed dose counter placement points selected by the average distribution random number method is defined as x, that is, x represents the x-th placement point, and the distance y between the absorbed dose counter of the x-th placement point and the launch gun is calculated according to the following formula. The calculation result is rounded off to obtain the first set of distance values ​​{y 1,1 ,y 1,2 …y 1,n}:

[0012] y≤L

[0013] Define the arrangement sequence of the placement points of m absorbed dose counters selected at equal intervals as x, that is, x represents the xth placement point, and calculate the distance y between the absorbed dose counter at the xth placement point and the launch gun according to the following formula. Round the calculation result to get the second set of distance values ​​{y 2,1 ,y 2,2 …y 2,m}:

[0014] y≤L.

[0015] In the above-mentioned quantitative modeling method of electron backscatter noise based on power function, the absorbed dose counter includes a cover plate and a dose sheet, wherein the cover plate is made of aluminum plate, silicon plate and circuit and shielding structure materials, and the dose sheet is an alanine dose sheet or a sensitized dose sheet.

[0016] In the above-mentioned quantitative modeling method of electron backscatter noise based on power function, the thickness of the cover plate is 2 to 3 mm.

[0017] In the above-mentioned quantitative modeling method of electron backscatter noise based on power function, the thickness of the dose sheet is 2 to 3 mm.

[0018] In the above-mentioned quantitative modeling method of electron backscatter noise based on power function, in {y 1,1 ,y 1,2 …y 1,n} and {y 2,1 ,y 2,2 …y 2,m}, and place an absorbed dose counter at the corresponding position of each y value, and select energy for Monte Carlo simulation to count the absorbed dose values ​​to form a dose statistics array {T1, T2…T n+m}, where T represents the absorbed dose.

[0019] In the above-mentioned quantitative modeling method of electron backscatter noise based on power function, the absorbed dose value T1 of the absorbed dose counter placed closest to the base plate is compared with other absorbed dose values ​​one by one, and all absorbed dose values ​​less than T1 are selected. All absorbed dose values ​​less than T1 are compared and the minimum value is selected.

[0020] In the above-mentioned quantitative modeling method of electron backscatter noise based on power function, the value of m is at least 3, the value of n is at least 3, and the values ​​of m and n are the same or different.

[0021] An electronic device, comprising a memory and a processor:

[0022] The memory is used to store one or more computer instructions;

[0023] The processor is configured to execute the one or more computer instructions to:

[0024] Construct a simplified model of the test environment for simulation, including decomposing the main structure of the accelerator into the base plate, the launch gun and the shell, and obtaining the atomic number and density information of the base plate, the launch gun and the shell;

[0025] In the simplified test environment model, a plurality of positions for placing absorbed dose counters are selected in the area between the bottom plate and the launch gun, including: taking the bottom plate as the zero point, setting the distance from the bottom plate to the launch gun as L, selecting n positions for placing absorbed dose counters between the positions L and 2 / 3L from the launch gun by using an averagely distributed random number method, and selecting m positions for placing absorbed dose counters between the positions 2 / 3L and 0 from the launch gun at equal intervals, where m and n are both positive integers;

[0026] Place absorbed dose counters one by one at each selected placement position of absorbed dose counters, perform a Monte Carlo simulation each time the absorbed dose counters are placed, and obtain m+n absorbed dose values;

[0027] The absorbed dose value T1 of the absorbed dose counter placed closest to the base plate is compared with other absorbed dose values, and all absorbed dose values ​​less than T1 are compared twice to select the minimum value. The placement position of the absorbed dose counter corresponding to the minimum value is taken as the final test calibration position; if there is no absorbed dose value smaller than T1, 1 / 2L is taken as the final test calibration position.

[0028] Compared with the prior art, the embodiments of the present invention have at least the following beneficial effects:

[0029] (1) An embodiment of the present invention proposes a power function-based electron backscatter noise modeling and calibration method, which includes constructing a simplified model of the test environment for simulation, constructing an absorbed dose statistic at an appropriate location, conducting dose simulation on the test model according to certain rules, and obtaining calibration information based on dose calculation. The method of the present invention can reduce noise interference caused by environmental factors, and is helpful for evaluating indicators sensitive to backscattering, such as total circuit dose effect and material shielding performance, thereby improving credibility.

[0030] (2) A quantitative modeling method for electron backscatter noise based on a power function is proposed in an embodiment of the present invention. First, a simplified modeling is performed on a ground-based simulated space environment device and a material to be tested. Then, pre-calibration points are selected by using a power function with evenly distributed random numbers and equal intervals. The Monte Carlo method is used to simulate the absorbed dose of the selected energy at the pre-calibration points. Finally, the optimal calibration point is determined by comparison and screening. The present invention can clarify the approximate calibration position of the test device before the field test, and can obtain ideal test results at a lower test cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A method flow chart of a method for modeling and calibrating electron backscatter noise based on a power function in an embodiment of the present invention;

[0032] Figure 2 Schematic diagram of the simulation structure in the embodiment of the present invention. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0034] like Figure 1 As shown, the method of the electron backscatter noise modeling and calibration method based on the power function in the embodiment of the present invention specifically includes the following steps:

[0035] 1. Construct a simplified model of the test environment for simulation

[0036] According to the on-site conditions of the electronic test, a simplified model of the test environment for simulation was constructed, and the main structure of the accelerator was decomposed into the base plate, launch gun and vacuum shell, and basic information such as the atomic number and density of the corresponding main structure material was obtained.

[0037] 2. Select appropriate location to construct absorbed dose counter

[0038] like Figure 2 As shown, an absorbed dose counter is constructed at an appropriate position of the simplified model of the test environment. The absorbed dose counter is mainly composed of a cover plate and a dose sheet. The cover plate can be made of an aluminum plate, a silicon plate and related circuit and shielding structure materials, and the thickness is preferably 2-3 mm. The dose sheet can be alanine dose sheet, sensitized dose sheet or other dose-measurable materials, and the thickness is preferably 2-3 mm.

[0039] The bottom plate is taken as the zero point, and the total distance from the bottom plate to the transmitting gun is L. n positions for placement of absorbed dose counters are selected from the position L to 2 / 3L from the transmitting gun by using the method of evenly distributed random numbers. m positions for placement of absorbed dose counters are selected from the position 2 / 3L to 0 from the transmitting gun at equal intervals. Both m and n are positive integers, and the values ​​of m and n may be the same or different.

[0040] The distance y between the absorbed dose counter and the launch gun is defined by the following formula:

[0041] y≤L

[0042] Where x represents the xth placement point. At least three x coordinate points are selected from the distance between L and 2 / 3L of the launch gun by using the method of evenly distributed random numbers. For example, there are 200 selected points from 40 to 240 between L and 2 / 3L. The 62nd, 98th, and 175th points are selected respectively. Then, x=62, 98th, and 175th are substituted into the above formula respectively and rounded to obtain the first set of distance values ​​{y 1,1 ,y 1,2 …y 1,n}, between 2 / 3L and 0 from the launch gun, select at least 3 x coordinate points at equal intervals. For example, there are 40 selected points from 1 to 40 between 2 / 3L and 0. The 10th, 20th, and 30th points are selected respectively. Then, substitute x=10, 20, and 30 into the above formula respectively and round them to get the second set of distance values ​​{y 2,1 ,y 2,2 …y 2,m}, the first and second groups of distance values ​​are used as the above appropriate positions to construct the corresponding absorbed dose statistics, such as Figure 2 shown.

[0043] 3. Dose simulation for simplified model of test environment

[0044] In {y 1,1 ,y 1,2 …y 1,n} and {y 2,1 ,y 2,2 …y 2,m}, and place an absorbed dose counter at the corresponding position of each y value, and select the energy to perform Monte Carlo simulation in turn to count the absorbed dose values ​​to form a dose statistics array {T1, T2…T n+m}, where T represents the absorbed dose. Each time an absorbed dose counter is placed, a Monte Carlo simulation is performed to obtain m+n absorbed dose values.

[0045] 4. Obtain calibration information based on dose calculation

[0046] Based on the calibration information obtained by dose calculation, the dose statistics array obtained in step 3 is screened according to the following rules: the absorbed dose value closest to the base plate is taken as T ori (i.e. T1), T ori Compare with other T values ​​in the array and find all values ​​less than T. ori The values ​​of are compared twice, and the minimum value is selected (that is, all absorbed dose values ​​less than T1 are selected, and all absorbed dose values ​​less than T1 are compared, and the minimum value is selected). The y value corresponding to the minimum value is the final test calibration position. If there is no value greater than T ori If the value is small, 1 / 2L is used as the test calibration position.

[0047] The present invention provides an electronic device, including a memory and a processor:

[0048] The memory is used to store one or more computer instructions;

[0049] The processor is configured to execute the one or more computer instructions to:

[0050] Construct a simplified model of the test environment for simulation, including decomposing the main structure of the accelerator into the base plate, the launch gun and the shell, and obtaining the atomic number and density information of the base plate, the launch gun and the shell;

[0051] In the simplified test environment model, a plurality of positions for placing absorbed dose counters are selected in the area between the bottom plate and the launch gun, including: taking the bottom plate as the zero point, setting the distance from the bottom plate to the launch gun as L, selecting n positions for placing absorbed dose counters between the positions L and 2 / 3L from the launch gun by using an averagely distributed random number method, and selecting m positions for placing absorbed dose counters between the positions 2 / 3L and 0 from the launch gun at equal intervals, where m and n are both positive integers;

[0052] Place absorbed dose counters one by one at each selected placement position of absorbed dose counters, perform a Monte Carlo simulation each time the absorbed dose counters are placed, and obtain m+n absorbed dose values;

[0053] The absorbed dose value T1 of the absorbed dose counter placed closest to the base plate is compared with other absorbed dose values, and all absorbed dose values ​​less than T1 are compared twice to select the minimum value. The placement position of the absorbed dose counter corresponding to the minimum value is taken as the final test calibration position; if there is no absorbed dose value smaller than T1, 1 / 2L is taken as the final test calibration position.

[0054] The present invention proposes a quantitative modeling method for electron backscatter noise based on a power function. First, a simplified modeling is performed on the ground simulation space environment device and the material to be tested. Then, the pre-calibration points are selected by the power function in a manner of evenly distributed random numbers and equal intervals. The Monte Carlo method is used to simulate the absorbed dose of the selected energy for the pre-calibration points. Finally, the optimal calibration point is determined by comparison and screening. The present invention can clarify the approximate calibration position of the test device before the field test, and can obtain ideal test results at a lower test cost.

[0055] Example 1

[0056] like Figure 1 As shown, the steps of the quantitative modeling method of electron backscatter noise based on power function proposed in this embodiment are as follows:

[0057] Step 1: According to the on-site conditions of the electronic test, a simplified model of the test environment for simulation is constructed, and the main structure of the accelerator is decomposed into the base plate, launch gun, vacuum shell, etc., and basic information such as the atomic number and density of the corresponding main structure materials is obtained. The base plate and launch gun are made of brass, and the vacuum shell is made of aluminum.

[0058] Step 2: Construct an absorbed dose counter at an appropriate location and construct a basic absorbed dose statistics structure, which is mainly composed of a cover plate and a dose sheet. The cover plate is made of a silicon plate with a thickness of 3 mm. The dose sheet model is set to a standard alanine dose sheet with a thickness of 2.3 mm. Then, the bottom plate is taken as the zero point. The total distance from the bottom plate to the launch gun is 18 cm. The distance y from the absorbed dose counter to the launcher is defined by the following formula:

[0059] y≤L

[0060] Where x represents the xth selected point (a positive integer is used for the convenience of calculating the x coordinate). Three x coordinate points are selected between 18 and 12 cm from the launch gun by using the method of average distribution random numbers. They are 132, 50, and 31 respectively. Substituting them into the above formula, the first set of distance values ​​{16, 13, 12} (in cm) is obtained. Three x coordinate points are selected between 12 cm and 0 from the launch gun at equal intervals. They are 11, 6, and 1 respectively. Substituting them into the above formula, the second set of distance values ​​{10, 9, 6} (in cm) is obtained. The first and second sets of distance values ​​are used as the above appropriate positions to construct the corresponding absorbed dose statistics, such as Figure 2 shown.

[0061] Step 3: Carry out dose simulation on the test model according to certain rules, place the basic absorbed dose statistical structure at each y value corresponding to {16,13,12} and {10,9,6}, and perform Monte Carlo simulation with the electron energy of 3MeV to count the absorbed dose values ​​and form a statistical array {1.51E+5,1.24E+05,1.22E+05,1.19E+05…,1.23E+05} (in rad).

[0062] Step 4: Based on the calibration information obtained by dose calculation, the dose statistics array obtained in step 3 is screened according to the following rules: the absorbed dose value closest to the base plate is taken as T ori =1.51E+5, T ori Compare with other values ​​in the array and find all values ​​less than T. ori A second comparison is made with the values ​​of and the minimum value is selected. The y value corresponding to the minimum value is the final test calibration position. Therefore, the best position is 10 cm away from the launch gun.

[0063] The above description is only the best specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

[0064] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A quantitative modeling method for electron backscatter noise based on power function, characterized in that: include: Construct a simplified model of the test environment for simulation, including decomposing the main structure of the accelerator into the base plate, the launch gun and the shell, and obtaining the atomic number and density information of the base plate, the launch gun and the shell; In the simplified test environment model, a plurality of positions for placing absorbed dose counters are selected in the area between the bottom plate and the launch gun, including: taking the bottom plate as the zero point, setting the distance from the bottom plate to the launch gun as L, selecting n positions for placing absorbed dose counters between the positions L and 2 / 3L from the launch gun by using an averagely distributed random number method, and selecting m positions for placing absorbed dose counters between the positions 2 / 3L and 0 from the launch gun at equal intervals, where m and n are both positive integers; Place absorbed dose counters one by one at each selected placement position of absorbed dose counters, perform a Monte Carlo simulation each time the absorbed dose counters are placed, and obtain m+n absorbed dose values; The absorbed dose value T1 of the absorbed dose counter placed closest to the base plate is compared with other absorbed dose values, and all absorbed dose values ​​less than T1 are compared twice to select the minimum value. The placement position of the absorbed dose counter corresponding to the minimum value is taken as the final test calibration position; if there is no absorbed dose value smaller than T1, 1 / 2L is taken as the final test calibration position.

2. The method for quantitative modeling of electron backscatter noise based on power function according to claim 1, characterized in that: Methods for selecting the placement locations of several absorbed dose counters include: The serial number of the n absorbed dose counter placement points selected by the average distribution random number method is defined as x, that is, x represents the x-th placement point, and the distance y between the absorbed dose counter of the x-th placement point and the launch gun is calculated according to the following formula. The calculation result is rounded off to obtain the first set of distance values ​​{y 1,1 ,y 1,2 …y 1,n }: Define the arrangement sequence of the placement points of m absorbed dose counters selected at equal intervals as x, that is, x represents the xth placement point, and calculate the distance y between the absorbed dose counter at the xth placement point and the launch gun according to the following formula. Round the calculation result to get the second set of distance values ​​{y 2,1 ,y 2,2 …y 2,m }:

3. The method for quantitative modeling of electron backscatter noise based on power function according to claim 1, characterized in that: The absorbed dose counter comprises a cover plate and a dose sheet, wherein the cover plate is made of an aluminum plate, a silicon plate, and circuit and shielding structure materials, and the dose sheet is an alanine dose sheet or a sensitized dose sheet.

4. The method for quantitative modeling of electron backscatter noise based on power function according to claim 3, characterized in that: The thickness of the cover plate is 2-3 mm.

5. The method for quantitative modeling of electron backscatter noise based on power function according to claim 3, characterized in that: The thickness of the dosage sheet is 2 to 3 mm.

6. The method for quantitative modeling of electron backscatter noise based on power function according to claim 2, characterized in that: In {y 1,1 ,y 1,2 …y 1,n } and {y 2,1 ,y 2,2 …y 2,m }, and place an absorbed dose counter at the corresponding position of each y value, and select energy for Monte Carlo simulation to count the absorbed dose values ​​to form a dose statistics array {T1, T2…T n+m }, where T represents the absorbed dose.

7. The method for quantitative modeling of electron backscatter noise based on power function according to claim 1, characterized in that: Compare the absorbed dose value T1 of the absorbed dose counter placed closest to the base plate with other absorbed dose values ​​one by one, select all absorbed dose values ​​less than T1, and compare all absorbed dose values ​​less than T1 to select the minimum value.

8. The method for quantitative modeling of electron backscatter noise based on power function according to claim 1, characterized in that: The value of m is at least 3, the value of n is at least 3, and the values ​​of m and n may be the same or different.

9. An electronic device, characterized in that: Including memory and processor: The memory is used to store one or more computer instructions; The processor is configured to execute the one or more computer instructions to: Construct a simplified model of the test environment for simulation, including decomposing the main structure of the accelerator into the base plate, the launch gun and the shell, and obtaining the atomic number and density information of the base plate, the launch gun and the shell; In the simplified test environment model, a plurality of positions for placing absorbed dose counters are selected in the area between the bottom plate and the launch gun, including: taking the bottom plate as the zero point, setting the distance from the bottom plate to the launch gun as L, selecting n positions for placing absorbed dose counters between the positions L and 2 / 3L from the launch gun by using an averagely distributed random number method, and selecting m positions for placing absorbed dose counters between the positions 2 / 3L and 0 from the launch gun at equal intervals, where m and n are both positive integers; Place absorbed dose counters one by one at each selected placement position of absorbed dose counters, perform a Monte Carlo simulation each time the absorbed dose counters are placed, and obtain m+n absorbed dose values; The absorbed dose value T1 of the absorbed dose counter placed closest to the base plate is compared with other absorbed dose values, and all absorbed dose values ​​less than T1 are compared twice to select the minimum value. The placement position of the absorbed dose counter corresponding to the minimum value is taken as the final test calibration position; if there is no absorbed dose value smaller than T1, 1 / 2L is taken as the final test calibration position.

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