Elemental analysis system, method and apparatus, and program product

Abstract

The present invention relates to the field of radioactivity-based elemental analysis, and more particularly, to an elemental analysis system, method and apparatus, and a program product, the elemental analysis system comprising: an X-ray scanning device comprising an X-ray source and a detector array for performing dual-energy X-ray scanning on a material; the instant gamma neutron activation analysis equipment is arranged on the downstream of the X-ray scanning equipment in the material transmission direction; and the control device is used for calculating a self-absorption correction coefficient based on the size, the mass attenuation coefficient and the density of the material at each position obtained by the X-ray scanning, and correcting the gamma-ray energy spectrum. By means of the elemental analysis system, method and device and the program product, the calculation accuracy of the correction coefficient can be improved, and therefore the elemental analysis detection precision is improved.

Description

[0001] This divisional application is a divisional application of the patent application No. 202410911913.2, filed on July 9, 2024, for the applicant of Jiangsu Tongfang Weishi Technology Co., Ltd., Tsinghua University and Tongfang Weishi Technology Co., Ltd., the patent application is entitled as “Element analysis system, method and device, and program product”. TECHNICAL FIELD

[0002] The present application relates to the field of radio-based element analysis, in particular, to an element analysis system, method and device based on prompt gamma neutron activation analysis (PGNAA), and a program product. BACKGROUND

[0003] Prompt gamma neutron activation analysis (PGNAA) is a fast, non-contact multi-element analysis technology, which is widely used in cement, coal, steel, mining and other industries.

[0004] This technology uses thermal neutrons to activate the nuclei in the measured material, which will de-excite and emit characteristic gamma rays in a very short time. After the gamma rays pass through the material, they are detected by a gamma spectrometer system, and processed into a gamma ray spectrum by a multichannel analyzer, which is ultimately used to analyze the elemental composition information of the material.

[0005] However, the characteristic gamma rays are partially blocked by the material itself when penetrating the measured material, resulting in a deviation between the final gamma ray spectrum and the true situation. In actual application, the distribution of the material on the conveyor belt is often uneven, and the thickness and width vary. These factors will affect the degree of self-absorption of gamma rays, making the gamma spectrum cannot be effectively corrected, and thus affecting the accuracy of the elemental composition information. SUMMARY

[0006] In order to improve the accuracy of element analysis, the skilled person in the art thinks of correcting the self-absorption of gamma rays in real time according to the material condition. For this purpose, one existing method is to add a nuclear scale to measure the mass of the material, and to correct according to the pre-calibrated mass-correction coefficient curve. However, this method is relatively simple and does not take into account the influence of material component changes or the same mass but different distribution. Another method is also to use a nuclear scale, which calculates the amount of characteristic gamma rays in the PGNAA device by measuring the degree of attenuation of the gamma rays of the nuclear scale, but it also has the same shortcomings as the first method.

[0007] The present application provides an element analysis system, method and device, and a program product for accurately calculating the self-absorption correction coefficient, thereby improving the detection accuracy of element analysis.

[0008] The first aspect of the present application provides an elemental analysis system, including: an X-ray scanning device including an X-ray source and a detector array, performing dual-energy X-ray scanning on a material; a prompt gamma neutron activation analysis device installed downstream of the X-ray scanning device in a material transport direction; and a control device, calculating a self-absorption correction coefficient based on a change in a transmission rate of the material relative to a transmission rate at a time of calibration, based on a size, a mass attenuation coefficient, and a density of the material at each position obtained by the X-ray scanning, and correcting a gamma energy spectrum.

[0009] The second aspect of the present application provides an elemental analysis method, including: obtaining a size, a mass attenuation coefficient, and a density of a material at each position based on dual-energy X-ray scanning; and calculating a self-absorption correction coefficient based on a change in a transmission rate of the material relative to a transmission rate at a time of calibration, based on the size, the mass attenuation coefficient, and the density of the material at each position.

[0010] The third aspect of the present application provides an elemental analysis device, including: an X-ray scanning information acquisition unit, obtaining a size, a mass attenuation coefficient, and a density of a material at each position based on dual-energy X-ray scanning; and a correction coefficient calculation unit, calculating a self-absorption correction coefficient based on a change in a transmission rate of the material relative to a transmission rate at a time of calibration, based on the size, the mass attenuation coefficient, and the density of the material at each position.

[0011] The fourth aspect of the present application provides an elemental analysis program product, including a computer program, which, when executed by a processor, performs the steps of the elemental analysis method of the second aspect described above.

[0012] According to the elemental analysis system and method, the elemental analysis device, and the elemental analysis program product provided by the present application, the size, the mass attenuation coefficient, and the density of the material at different positions can be obtained by dual-energy X-ray scanning, and thus the self-absorption correction coefficient considering the element component distribution of the material at different positions can be calculated based on the size, the mass attenuation coefficient, and the density at such different positions, so that the accuracy of the self-absorption correction coefficient can be improved, and thus the detection precision of the elemental analysis can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a structural schematic diagram of an elemental analysis system according to a first embodiment of the present application.

[0014] Figure 2 is a schematic diagram of an X-ray scanning device along a material transport direction.

[0015] Figure 3 is a model diagram for calculating a self-absorption coefficient of a material.

[0016] Figure 4 This is a flowchart illustrating the elemental analysis method according to the second embodiment of this application.

[0017] Figure 5 This is a flowchart illustrating an example of the X-ray scanning stage in the elemental analysis method according to the second embodiment of this application.

[0018] Figure 6 This is a flowchart illustrating an example of the transient gamma neutron activation analysis stage in the elemental analysis method according to the second embodiment of this application.

[0019] Figure 7 This is a flowchart illustrating another embodiment of the elemental analysis method according to the second embodiment of this application.

[0020] Figure 8 This is a flowchart illustrating the functional module configuration of the control device in the elemental analysis system according to the first embodiment of this application.

[0021] Figure 9 This is a schematic diagram illustrating the structure of an electronic device provided in the third embodiment of this application. Detailed Implementation

[0022] Exemplary embodiments or examples of this application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments or examples set forth herein. Rather, these embodiments or examples are provided to enable a clearer understanding of this application.

[0023] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects, not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments or examples of this application described herein can be implemented in a sequence other than that illustrated or described. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such as a process, method, system, product, or apparatus that includes a series of steps or units, not limited to those explicitly listed, but may include other steps or units not explicitly listed. Identical or similar reference numerals throughout the document denote constituent elements having the same or similar functions.

[0024] The first embodiment of this application provides an elemental analysis system. Figure 1 This is a schematic diagram showing the structure of the elemental analysis system according to the first embodiment.

[0025] like Figure 1 As shown, the elemental analysis system 10 includes: an X-ray scanning device comprising an X-ray source 1 and a detector array 2; a Prompt Gamma Neutron Activation Analysis (PGNAA) device 5; and a control device 6. Additionally, in Figure 1 In the diagram, 3 represents the material being measured, and 4 represents the conveyor belt that transports the material.

[0026] In the material transport direction X, the PGNAA device 5 is installed downstream of the X-ray scanning device. Both the PGNAA device 5 and the X-ray scanning device are communicatively connected to the control unit 6.

[0027] In this application, the X-ray source 1 can be a multi-energy X-ray source or a single-energy X-ray source. Depending on the X-ray source, the detector array can be selected as a single-energy detector array or a dual-energy detector array. For example, the X-ray source and detector can be a multi-energy X-ray source paired with a single-energy detector array, or a single-energy X-ray source paired with a multi-energy detector array.

[0028] The X-ray source 1 can be any of an accelerator, an X-ray machine, or an isotope source. The detector of the X-ray scanning equipment can be a single-row detector or a multi-row detector.

[0029] Figure 2 This is a schematic diagram showing an X-ray scanning device along the material transport direction. In the diagram, 1 represents the X-ray source, 2 represents the detector array, 3 represents the material being measured, and 4 represents the conveyor belt transporting the material. The dashed line represents the maximum X-ray angle range.

[0030] like Figure 2 As shown in this application, the detector array covers the maximum X-ray angular range.

[0031] The detector array can be a single row of detectors or multiple rows of detectors. Taking a single row of detectors as an example, X-rays pass through the cross-section of the object being inspected and are received by the detector array, obtaining a series of data in each scan cycle. By stitching together multiple series of data obtained over a period of time, an X-ray image can be obtained.

[0032] In this application, a detector array is used instead of a single detector. By using a detector array, X-ray images of the material at different locations can be acquired, thereby obtaining the material's size information from the X-ray images. Furthermore, the mass attenuation coefficient μ of the material at different locations can be detected. m And density ρ, thus enabling the detection of changes in the composition of materials at different locations.

[0033] In some embodiments, the X-ray scanning frequency is:

[0034]

[0035] Where v is the speed of the conveyor belt, and widtμ is the length of the detector unit along the transmission direction X of the conveyor belt. This ensures that the spatial resolution of the X-ray scan image is the same in both the horizontal and vertical directions.

[0036] PGNAA device 5 is a device that analyzes the elemental composition of a material based on transient gamma neutron activation analysis (TGA) technology and gamma energy spectrum. PGNAA device 5 includes a detector for detecting gamma rays.

[0037] In PGNAA device 5, the material being detected interacts with neutrons to generate transient characteristic gamma rays, which can originate from any location within the material. As the material is transported along the conveyor belt, some of the gamma rays are absorbed by the material itself, causing a decrease in the intensity of the rays reaching the detector in PGNAA device 5.

[0038] Figure 3 This is a model diagram illustrating the calculation of the self-absorption coefficient of a material. Figure 3 In the diagram, 3 represents the material, 31 represents any volume element within the material, 4 represents the conveyor belt transporting the material, and 51 represents the detector of PGNAA device 5.

[0039] like Figure 3 As shown, taking a volume element at any position within the material as an example, the transmittance of the gamma rays generated by this volume element to the detector 51 of the PGNAA device 5 is:

[0040]

[0041] Where I0 and I are the intensities of the characteristic gamma rays before and after they pass through the material, respectively, and μ m ρ is the mass decay coefficient, ρ is the density, and r is the distance the characteristic gamma rays emitted by the volume element travel through the material.

[0042] The self-absorption correction factor in the transient gamma neutron activation analysis technique can be calculated based on such transmittance T.

[0043] As an example, the self-absorption correction factor in the transient gamma neutron activation analysis technique is:

[0044]

[0045] Among them, T ref T is the X-ray transmittance at calibration time. exp The transmittance of the radiation during measurement is denoted as .

[0046] The control device 6 is a device that can communicate with the X-ray scanning equipment and the PGNAA device 5 to control the X-ray scanning equipment and the PGNAA device 5.

[0047] In this application, in order to improve the accuracy of elemental analysis, the control device 6 uses the size of the material detected by the X-ray scanning equipment and the mass attenuation coefficient μ at different locations. m The density ρ is used to calculate correction factors, thereby correcting the gamma spectrum of PGNAA device 5 and improving the accuracy of elemental analysis results.

[0048] The control device 6 can be located inside or outside the PGNAA device 5, as long as it can communicate with the X-ray scanning equipment and other components in the PGNAA device 5.

[0049] The second embodiment of this application also provides an elemental analysis method. Figure 4 This is a flowchart illustrating the elemental analysis method according to the second embodiment of this application. The elemental analysis method can be executed by an elemental analysis system, specifically by the control device 6 of the elemental analysis system.

[0050] The elemental analysis method involved in the second embodiment may include steps S10 and S20. Step S10 involves an X-ray scanning stage, and step S20 involves a transient gamma neutron activation analysis stage.

[0051] X-ray scanning stage

[0052] In step S10, the mass attenuation coefficient μ of the material at each location is obtained based on dual-energy X-ray scanning. m Density ρ, and size.

[0053] First, let me briefly explain the principle of the X-ray scanning stage.

[0054] During the X-ray scanning phase, the attenuation of X-rays follows Beer-Lambert's law.

[0055] I = I0 exp(-μ m t m )=I0 exp(-μ m ρl) (3)

[0056] Where I0 and I are the X-ray intensities before and after the X-rays pass through the material, respectively, and μ m ρ is the mass decay coefficient, ρ is the density, and l represents the thickness of the material.

[0057] In equation (3) above, I0 and I can be obtained from the detector array of the X-ray scanning equipment, while the mass attenuation coefficient μ m Density ρ can be obtained by determining the material.

[0058] In this application, the X-ray scanning equipment obtains dual-energy images through dual-energy X-ray scanning, and determines the material of the material based on the dual-energy images. Dual-energy X-ray scanning refers to generating high-energy images and low-energy images separately using high-energy rays and low-energy rays.

[0059] In some optional embodiments, dual-energy X-ray scanning can be achieved by having an X-ray source emit high-energy and low-energy rays separately, and then using a detector array to receive the high-energy and low-energy rays separately (true dual-energy mode). For example, two X-ray sources can emit high-energy and low-energy rays separately, or a single X-ray source can emit high-energy and low-energy rays in time intervals. That is, it can be achieved by using multiple single-energy X-ray sources in combination with a multi-energy detector array. In other optional embodiments, dual-energy X-ray scanning can also be achieved by having an X-ray source emit multi-energy rays, and then using a high-energy detector array and a low-energy detector array to receive the high-energy and low-energy rays separately (pseudo-dual-energy mode). That is, it can be achieved by using a multi-energy X-ray source in combination with multiple single-energy detector arrays.

[0060] First, the mass attenuation coefficient μ of the material at each location is obtained by performing a dual-energy X-ray scan in step S10. m The process of handling density ρ will be explained.

[0061] In this process, the mass decay coefficient μ of the matter can be determined based on the transparency of high-energy rays and low-energy rays in the dual-energy image. m and density ρ.

[0062] Example 1

[0063] In Example 1, the mass decay coefficient μ of the substance can be determined based on the ratio of the logarithmic transparency of high-energy rays to low-energy rays in a dual-energy image. m and density ρ.

[0064] In step S11, the intensity I of high-energy X-rays detected by the detector of the X-ray scanning device before and after passing through the material is received. 0H and I H and the intensity I of low-energy X-rays before and after passing through the material. 0L and I L .

[0065] In step S12, for both high-energy and low-energy settings, the transparency T of the high-energy setting is calculated based on the X-ray intensity before and after the X-rays pass through the material. H and low-power transparency T L .

[0066] When dual-energy X-rays pass through a material with atomic number Z, density ρ, and thickness l, the high-energy transparency T H and low-power transparency T L They are respectively:

[0067]

[0068] In equations (4) and (5), H and L correspond to high-energy X-rays and low-energy X-rays, respectively, and I 0H and I H I represents the intensity of the high-energy X-rays before and after they pass through the material. 0L and I L The values ​​in μ represent the intensity of low-energy X-rays before and after they pass through the material. m (E eH ,Z) and μ m (E eL Z and Z represent the mass attenuation coefficients of high-energy X-rays and low-energy X-rays respectively when they pass through the material.

[0069] In step S13, the transparency T is based on the high energy level. H and low-power transparency T L Calculate the transparency T of the high-energy level. H and low-power transparency T L The ratio R of the logarithmic transparency is used as a transparency comparison parameter. That is, in step S13, the transparency T is based on the high energy level. H and low-power transparency T L Calculate the transparency comparison parameters.

[0070] As an example, the high-energy transparency T H and low-power transparency T L The logarithmic transparency ratio R can be calculated using the following formula (6):

[0071]

[0072] In step S14, the mass decay coefficient μ of the material is determined based on the logarithmic transparency ratio R. m And density ρ. That is, in step S14, the mass decay coefficient μ of the material is determined based on the transparency comparison parameter. m and density ρ.

[0073] As an example, material information at different locations can be determined by comparing the calculated logarithmic transparency ratio R with a calibration data table.

[0074] Materials with different properties exhibit varying degrees of blocking ability against rays of different energies, thus their R values ​​also differ. Based on this property, a calibration data table has been established in the field to represent the relationship between the logarithmic transparency ratio R and the elements of the material. After calculating R, the material information of the corresponding material can be retrieved from this calibration data table. Based on this material information, the mass attenuation coefficient μ of the material can be determined. m And density ρ. For different locations of the material, the ratio of logarithmic transparency R is calculated to obtain the mass decay coefficient μ at different locations of the material. m (x,y,z) and density ρ(x,y,z).

[0075] In this application, by utilizing dual-energy images, based on the transparency T of the high-energy level... H and low-power transparency T L The ratio of logarithmic transparency R is used to determine the material's mass decay coefficient μ. m Compared with the existing technology that uses nuclear balances to measure material mass and correct it based on a pre-calibrated mass-correction coefficient curve, the method of obtaining material information at different locations of the material (x,y,z) and density ρ(x,y,z) can obtain material information at different locations of the material, i.e., obtain the component distribution of the material. This allows for more accurate detection of materials with changing components, improves detection accuracy, and expands application scenarios.

[0076] Furthermore, by determining the mass attenuation coefficient and density of a material based on the ratio of the logarithmic transparency of high-energy rays to low-energy rays, the mass attenuation coefficient μ at different locations can be easily determined using existing calibration data tables. m (x,y,z) and density ρ(x,y,z).

[0077] In the above-described embodiment 1, the logarithmic transparency ratio was used as a transparency comparison parameter, along with a pre-existing calibration data table, to determine the mass attenuation coefficient μ at different locations. m (x,y,z) and density ρ(x,y,z), however, the transparency comparison parameter only needs to be able to reflect the high-energy transparency T. H and low-power transparency T L The comparison between the two parameters is sufficient to determine the material's parameters. That is, it can also be based on the transparency T of the high-energy level in the dual-energy image. H and low-power transparency T L The relationship between other transparency comparison parameters and their corresponding materials is used to calculate the mass attenuation coefficient μ at different locations. m (x,y,z) and density ρ(x,y,z).

[0078] Example 2

[0079] In Example 2, the mass decay coefficient μ at different locations was calculated using an alpha curve. m (x,y,z) and density ρ(x,y,z).

[0080] In this embodiment, in step S13, the Alpha transformation value of the high-energy level transparency, the Alpha transformation value of the low-energy level transparency, and the difference between the two are calculated as transparency comparison parameters.

[0081] You can first adjust the transparency T of the high-energy setting. H and low-power transparency T L Perform the following Alpha transformation to obtain the Alpha transformation value alphaH for high-energy transparency and the Alpha transformation value alphaL for low-energy transparency.

[0082] alphaL= (1-log(T L ))Scale (7)

[0083] alphaH = (1-log(T) H ))Scale (8)

[0084] Then calculate the difference between the alpha transformation value alphaH of the high-energy transparency and the alpha transformation value alphaL of the low-energy transparency.

[0085] alphaL-alphaH=(log(T H )-log(T L ))Scale(9) in the above formula

[0086] In (7) to (9), Scale is the scaling factor.

[0087] Then, an Alpha curve can be plotted with alphaH as the horizontal axis and alphaL-alphaH as the vertical axis.

[0088] Since the alpha curve is different for each material, the mass decay coefficient μ at different locations can be obtained from this alpha curve. m (x,y,z) and density ρ(x,y,z).

[0089] Therefore, in step S14, the mass decay coefficient μ of the material is determined based on the alpha curve (transparency comparison parameter). m and density ρ.

[0090] The specific processing in the other steps of this embodiment 2 is the same as that in embodiment 1 above, and repeated descriptions are omitted.

[0091] Compared to using the R-value, using the Alpha curve can make the material resolution model for high-energy X-ray dual-energy imaging more linear, which is more conducive to resolving materials and improving the determination of the mass attenuation coefficient μ. m The accuracy of (x,y,z) and density ρ(x,y,z).

[0092] In step S10, it is also necessary to obtain the dimensions of the material at each location. That is, such as... Figure 5 As shown, step S10 may also include step S15.

[0093] In step S15, based on the material's mass decay coefficient μ m The thickness l of the material is calculated using the density ρ and the intensity of X-rays before and after they pass through the material.

[0094] When the X-ray intensity I0 and I, and the mass attenuation coefficient μ m When both the density ρ and the density ρ are known, the above equation (1) can be modified as follows:

[0095]

[0096] Therefore, if the X-ray intensity I0 and I, and the mass attenuation coefficient μ m If both the density ρ and the material thickness ρ are known, the material thickness l can be obtained. This material thickness l can be sent as the material's dimension to the control device 6 for the calculation of correction factors.

[0097] The mass decay coefficient μ is obtained in step S14. m After obtaining the density ρ, the thickness l of the material can be obtained by substituting it into equation (10) above. In some embodiments, the obtained mass decay coefficient μ can also be used. m Substituting the density ρ into equation (4) or equation (5) above, we obtain the thickness l of the material.

[0098] Based on the above process, the mass attenuation coefficient μ at different locations of the material can be used as a basis. m Given (x,y,z) and density ρ(x,y,z), calculate the thickness l(x,y,z) at different locations of the material.

[0099] In some embodiments, the size of the material may also include its width, which can be obtained by counting the pixels in the width direction of the X-ray image detected by the detector array. As an example, the pixels in the width direction of the material in the X-ray image can be counted, and the real-time changes in the material width can be obtained based on a pre-defined correspondence between pixel widths in the image and the actual width dimensions. Because a detector array is used, the width of the material at different locations can also be obtained.

[0100] In some embodiments, the dimensions of the material may also include the length of the material, which can be obtained by the travel distance of the conveyor belt, or the travel speed of the conveyor belt and the travel time of the material on the conveyor belt.

[0101] Therefore, in this application, the mass attenuation coefficient μ at different locations obtained during the X-ray scanning phase is used. m The material's dimensions, such as density ρ, thickness, width, and length, are transferred to the transient gamma neutron activation analysis stage to calculate correction coefficients. This improves the accuracy of correction coefficient calculations, thereby enhancing the detection precision of elemental analysis.

[0102] In an optional embodiment, during the X-ray scanning phase, in addition to the aforementioned material mass attenuation coefficient μ... m In addition to density ρ and size, other information can be obtained.

[0103] As an example, real-time material quality information can also be obtained. However, the actual quality can vary because the ray reception angles of volume elements at different locations within the material are inconsistent, and factors such as conveyor belts and dust can also affect the measurement.

[0104] In this example, a mass correction factor can be determined based on the calibration of a standard sample, and the actual mass of the test material can be determined based on this correction factor and the density at various locations of the test material.

[0105] First, the mass of the standard sample is calibrated to obtain the calculated mass value of the standard sample.

[0106] When performing calibration,

[0107]

[0108] Where, m ref ρ is the calculated mass of the standard sample. ref It is the density of the standard sample, V ref It is the volume of the standard sample. For the standard sample, ρ ref V ref All are preset fixed values. x, y, and z represent the coordinates of the material's length, width, and thickness, respectively.

[0109] Secondly, based on the calculated mass of the standard sample and the mass of the standard sample measured by the electronic scale, a mass correction factor is calculated.

[0110] Quality correction factor k corr for:

[0111]

[0112] Among them, Mref The mass of the standard sample is measured by an electronic scale.

[0113] Then, based on the calculated mass correction factor and the density ρ(x,y,z) and volume V obtained for the material to be tested... exp Calculate the mass of the material in the actual measurement.

[0114] The mass M of the material in actual measurement exp for:

[0115]

[0116] Where ρ(x,y,z) is the density at the position with coordinates x,y,z determined in step S14 above, and V exp The volume of the material to be measured is calculated based on the thickness, width, and length of the material calculated in step S15 above. x, y, and z represent the coordinates of the length, width, and thickness of the material, respectively.

[0117] In this example, based on the density ρ of the material obtained during the X-ray scanning stage, the mass correction factor k is further calculated. corr The actual material mass M is obtained by performing quality correction. exp This enables non-contact measurement of material quality.

[0118] Prompt gamma neutron activation analysis stage

[0119] Next, the processing of the transient gamma neutron activation analysis stage will be explained.

[0120] In step S20, the mass decay coefficient μ at different locations of the material obtained in step S10 is used... m Given density ρ and size, the self-absorption correction factor is calculated.

[0121] In the activated neutron analysis stage of the transient gamma ionosphere, the self-absorption correction coefficient can be expressed as:

[0122]

[0123] I exp and I corr T represents the gamma ray intensity before and after correction, respectively. ref T is the gamma ray transmittance at calibration. exp The gamma ray transmittance at the time of measurement is denoted as .

[0124] As an optional embodiment, such as Figure 6 As shown, step S20 may include steps S21 to S23.

[0125] In step S21, for a well-mixed standard sample, a mass decay coefficient μ that does not change with position is used. m Given density ρ, calculate the transmittance T of the standard sample. ref .

[0126] During calibration, standard samples with standard mass, standard content, and uniform distribution are used. With the standard samples thoroughly mixed, μ m And ρ does not change with position. The transmittance under the influence of self-absorption is:

[0127]

[0128] Among them, T ref and V ref These represent the X-ray transmittance and standard sample volume during calibration, respectively.

[0129] μ m,ref and ρ ref These are the mass decay coefficient and density of the standard sample, respectively. For the standard sample, μ m,ref ρ ref V ref All are fixed values. x, y, and z represent the coordinates of the material's length, width, and thickness, respectively.

[0130] In step S22, for insufficiently mixed test material, a mass decay coefficient μ that does not change with position is used. m Given (x,y,z) and density ρ(x,y,z), calculate the transmittance T of the material to be tested. exp .

[0131] X-ray scanning can reveal that when the composition of the material is unevenly distributed, μ m ρ and μ are not fixed values, but vary with position. m ρ should be the mass attenuation coefficient μ. m (x,y,z) and density ρ(x,y,z). Therefore, in the transient gamma neutron activation analysis stage, the transmittance of the non-uniform analyte is:

[0132]

[0133] Among them, T exp and V exp The gamma transmittance and material volume were measured using PGNAA device 5, respectively. x, y, and z represent the coordinates of the material's length, width, and thickness, respectively. μ m (x,y,z) is the mass decay coefficient of the volume element at coordinates x,y,z in the material, and ρ(x,y,z) is the density of the mass decay coefficient of the volume element.

[0134] In equation (16) above, μ at different positions m (x,y,z) and ρ(x,y,z) were obtained through the X-ray scanning phase, and the volume V exp It is calculated based on the thickness, width, and length of the material obtained during the X-ray scanning stage described above. The dimensions of the material and its mass attenuation coefficient μ at different locations are obtained during the X-ray scanning stage. m The parameters (x,y,z) and density ρ(x,y,z) can be used to calculate the transmittance, taking into account the non-uniform material composition distribution at different locations, during the transient gamma neutron activation analysis stage.

[0135] In step S23, the transmittance T of the standard sample is used as a basis. ref and the transmittance T of the material to be tested exp Calculate the self-absorption correction factor k exp .

[0136] By using the transmittance T of the standard sample calculated in step S21 ref and the transmittance T of the test material calculated in step S22. exp Substituting into equation (11) above, the self-absorption correction coefficient k can be calculated. exp .

[0137] As described above, in step S20, the mass attenuation coefficient μ obtained during the X-ray scanning phase is used. m Using (x,y,z) and density ρ(x,y,z) as well as the size of the material, the transmittance is calculated to account for the non-uniform distribution of material components at different locations, thus enabling the calculation of a more accurate correction factor that reflects the different component distributions.

[0138] Elemental analysis stage

[0139] In some embodiments, such as Figure 7 As shown, the elemental analysis method involved in the second embodiment may further include step S30.

[0140] In step S30, the self-absorption correction coefficient k calculated in step S23 is used. exp The gamma spectrum measured by PGNAA device 5 is corrected, and the elemental composition of the material at each location is analyzed based on the corrected gamma spectrum. That is, step S30 is the elemental analysis stage.

[0141] Because the gamma spectrum is corrected using a more accurate correction coefficient that reflects the distribution of different components, elemental analysis that takes into account the distribution of components can also be achieved, thereby improving the detection accuracy of elemental analysis.

[0142] Composition of control device

[0143] The following describes the functional module composition of control device 6. Figure 8 This is a flowchart illustrating the functional module structure of the control device 6 in the elemental analysis system according to the first embodiment of this application. Such modules are divided only by function; physically, the function of one module can be implemented by multiple components, or the function of multiple modules can be implemented by one component. The control device 6 can be implemented solely by software, or it can be implemented using a combination of software and hardware.

[0144] like Figure 8 As shown, the control device 6 may include an X-ray scanning information acquisition unit 61 and a correction coefficient calculation unit 62.

[0145] The X-ray scanning information acquisition unit 61 obtains the mass attenuation coefficient μ of the material at each location based on X-ray scanning. m Density ρ, and size.

[0146] The X-ray scanning information acquisition unit 61 may include: a receiving module 611, a dual-energy transparency calculation module 612, a transparency comparison parameter calculation module 613, a determination module 614, and a size calculation module 615.

[0147] The receiving module 611 receives the intensity of high-energy X-rays before and after they pass through the material, as well as the intensity of low-energy X-rays before and after they pass through the material, detected by the detector of the X-ray scanning equipment.

[0148] The dual-energy transparency calculation module 612 calculates the transparency of the high-energy setting and the transparency of the low-energy setting based on the X-ray intensity before and after the X-rays pass through the material.

[0149] The transparency comparison parameter calculation module 613 calculates the ratio of the logarithmic transparency of the high-energy level and the low-energy level transparency as a transparency comparison parameter, based on the high-energy level transparency and the low-energy level transparency. Alternatively, it calculates the alpha transformation value of the high-energy level transparency, the alpha transformation value of the low-energy level transparency, and the difference between the two as a transparency comparison parameter.

[0150] The determination module 614 determines the mass decay coefficient and density of the material based on the transparency comparison parameter.

[0151] The size calculation module 615 calculates the thickness of the material based on the material's mass attenuation coefficient and density, as well as the intensity of X-rays before and after passing through the material. The size calculation module 615 can also calculate the width of the material by statistically analyzing the pixels in the width direction of the X-ray image detected by the detector array of the X-ray scanning device.

[0152] The specific processing and technical effects of the receiving module 611, dual-energy transparency calculation module 612, transparency comparison parameter calculation module 613, determination module 614, and size calculation module 615 are the same as those of steps S11 to S15 above. Therefore, you can refer to the detailed description of steps S11 to S15 above.

[0153] The X-ray scanning information acquisition unit 61 may also include a mass calculation module. The mass calculation module calculates a mass correction factor based on the calibration of the standard sample, and calculates the actual mass of the test material based on the correction factor and the density at various locations of the test material.

[0154] The correction factor calculation unit 62 calculates the self-absorption correction factor based on the obtained size, mass attenuation coefficient and density of the material at each location.

[0155] The correction factor calculation unit 62 may include: a calibration module 621, a test material transmittance calculation module 622, and a correction factor module 623.

[0156] The calibration module 621 calculates the transmittance of a well-mixed standard sample using a mass attenuation coefficient and density that do not change with position.

[0157] The transmittance calculation module 622 calculates the transmittance of the test material for insufficiently mixed test materials using a mass decay coefficient and density that do not change with position.

[0158] The correction factor module 623 calculates the self-absorption correction factor based on the transmittance of the standard sample and the transmittance of the test material.

[0159] The specific processing and technical effects of calibration module 621, test material transmittance calculation module 622, and correction coefficient module 623 are the same as those of steps S21 to S23 above. Therefore, you can refer to the detailed description of steps S21 to S23 above.

[0160] Alternatively, this application can also be implemented as an elemental analysis apparatus that includes the control device 6 described above. That is, the elemental analysis apparatus may include an X-ray scan information acquisition unit 61 and a correction coefficient calculation unit 62. The X-ray scan information acquisition unit 61 and the correction coefficient calculation unit 62 can be referred to the above description, and therefore will not be described again.

[0161] As an example, in addition to the X-ray scanning information acquisition unit 61 and the correction coefficient calculation unit 62, the elemental analysis apparatus may also include an elemental analysis unit.

[0162] The elemental analysis department can correct the gamma spectrum based on the calculated self-absorption correction coefficient, and analyze the elemental composition of the material at each position based on the corrected gamma spectrum.

[0163] The control device 6 and elemental analysis device provided in this application can achieve the same technical effects as the elemental analysis system of the first embodiment and the elemental analysis method of the second embodiment, and will not be described again here.

[0164] The third embodiment of this application may also provide an electronic device. Figure 9 This diagram illustrates the structure of an electronic device according to a third embodiment of this application. Figure 9 As shown, the electronic device may include a processor 801 and a memory 802 storing computer programs or instructions.

[0165] Specifically, the processor 801 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0166] Memory 802 may include mass storage for data or instructions. For example, and not limitingly, memory 802 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 802 may include removable or non-removable (or fixed) media. Where appropriate, memory 802 may be internal or external to the integrated gateway disaster recovery device. In a particular embodiment, memory 802 is non-volatile solid-state memory. In a particular embodiment, memory 802 includes read-only memory (ROM). Where appropriate, the ROM may be a mask-programmed ROM, a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), an electrically rewritable ROM (EAROM), or flash memory, or a combination of two or more of these.

[0167] The processor 801 implements any of the element analysis methods described in the above embodiments by reading and executing computer program instructions stored in the memory 802.

[0168] In one example, the electronic device may also include a communication interface 803 and a bus 810. For example, Figure 9 As shown, the processor 801, memory 802, and communication interface 803 are connected through bus 810 and complete communication with each other.

[0169] The communication interface 803 is mainly used to realize communication between various modules, devices, units and / or devices in the embodiments of this application.

[0170] Bus 810 includes hardware, software, or both, that couples components of an electronic device together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 810 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, this application contemplates any suitable bus or interconnect.

[0171] The electronic device can execute the elemental analysis method in the second embodiment of this application, thereby realizing the control device 6 or elemental analysis device described in the first embodiment.

[0172] In addition, in conjunction with the element analysis methods in the above embodiments, this application can also provide a readable storage medium for implementation. The readable storage medium stores program instructions; when executed by a processor, these program instructions implement any one of the element analysis methods in the above embodiments. This application can also provide a computer program product. This computer program product includes program instructions; when executed by a processor, these program instructions implement any one of the element analysis methods in the above embodiments.

[0173] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0174] The functional blocks shown in the above-described structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0175] It should also be noted that the exemplary embodiments mentioned in this application describe methods or apparatuses based on a series of steps or devices. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0176] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the devices, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0177] It should be understood that the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in this application, and such modifications or substitutions should be covered within the scope of protection of this application.

Claims

1. An elemental analysis system, comprising: X-ray scanning equipment, including an X-ray source and a detector array, performs dual-energy X-ray scanning on materials; The transient gamma neutron activation analysis device is installed downstream of the X-ray scanning device in the material transport direction; as well as The control device calculates the transmittance of the material based on the size, mass attenuation coefficient, and density of the material at each location obtained by the X-ray scan. It then calculates a self-absorption correction coefficient by measuring the change in the transmittance of the material relative to the transmittance at calibration, and corrects the gamma spectrum.

2. The elemental analysis system according to claim 1, wherein, The mass decay coefficient and density of a material are determined based on the transparency of high-energy rays and low-energy rays.

3. The elemental analysis system according to claim 2, wherein, The mass decay coefficient and density of the material are determined based on the ratio of the logarithmic transparency of high-energy rays to low-energy rays, or based on the alpha curves of the transparency of high-energy rays to low-energy rays.

4. The elemental analysis system according to claim 2, wherein, The control device includes an X-ray scanning information acquisition unit, which includes: The receiving module receives, for each location of the material, the intensity of high-energy X-rays before and after they pass through the material, and the intensity of low-energy X-rays before and after they pass through the material, as detected by the detector of the X-ray scanning equipment. The dual-energy transparency calculation module calculates the transparency of the high-energy and low-energy levels based on the X-ray intensity before and after the X-rays pass through the material. The transparency comparison parameter calculation module calculates the ratio of the logarithmic transparency of the high-energy level and the low-energy level transparency as a transparency comparison parameter, or calculates the alpha transformation value of the high-energy level transparency, the alpha transformation value of the low-energy level transparency, and the difference between the two as a transparency comparison parameter. The determining module, based on the transparency comparison parameters, determines the mass decay coefficient and density of the material; and The size calculation module calculates the thickness of the material at the specified location based on the material's mass attenuation coefficient and density, as well as the intensity of X-rays before and after passing through the material.

5. The elemental analysis system according to claim 4, wherein, The dimensions of the material also include the width of the material, which is obtained by counting the pixels in the width direction of the X-ray image detected by the detector array of the X-ray scanning device.

6. The elemental analysis system according to claim 1, wherein, The control device further includes a transient gamma neutron activation analysis unit, which comprises: The calibration module calculates the transmittance of a well-mixed standard sample using a mass attenuation coefficient and density that do not change with position. The transmittance calculation module for the test material calculates the transmittance of the insufficiently mixed test material using the mass decay coefficient and density that vary with location; and The correction factor module calculates the self-absorption correction factor by dividing the transmittance of the standard sample by the transmittance of the test material.

7. The elemental analysis system according to claim 4, wherein, The X-ray scanning information acquisition unit also includes a mass calculation module, which calculates a mass correction factor based on the calibration of a standard sample, and calculates the actual mass of the material based on the mass correction factor and the density at each location of the material.

8. An elemental analysis method, comprising: Based on dual-energy X-ray scanning, the size, mass attenuation coefficient, and density of the material at various locations are obtained; The transmittance of the material is determined based on the size, mass decay coefficient, and density of the material at each location. The self-absorption correction coefficient is calculated by the change in the transmittance of the material relative to the transmittance at calibration.

9. The elemental analysis method according to claim 8, wherein, The mass decay coefficient and density of a material are determined based on the transparency of high-energy rays and low-energy rays.

10. The elemental analysis method according to claim 9, wherein, The mass decay coefficient and density of the material are determined based on the ratio of the logarithmic transparency of high-energy rays to low-energy rays, or based on the alpha curves of the transparency of high-energy rays to low-energy rays.

11. The elemental analysis method according to claim 9, wherein, Based on X-ray scanning, the size, mass attenuation coefficient, and density of the material at various locations were obtained, including: For each location of the material, the detector of the X-ray scanning equipment detects the intensity of high-energy X-rays before and after they pass through the material, as well as the intensity of low-energy X-rays before and after they pass through the material. For high-energy and low-energy levels, the transparency of high-energy and low-energy levels is calculated based on the X-ray intensity before and after the X-rays pass through the material. Based on the high-energy level transparency and the low-energy level transparency, the ratio of the logarithmic transparency of the high-energy level transparency to the low-energy level transparency is calculated as a transparency comparison parameter, or the alpha transformation value of the high-energy level transparency, the alpha transformation value of the low-energy level transparency, and the difference between the two are calculated as transparency comparison parameters. Based on the transparency comparison parameters, the mass decay coefficient and density of the material are determined; and The thickness of the material at that location is calculated based on the material's mass attenuation coefficient and density, as well as the intensity of X-rays before and after they pass through the material.

12. The elemental analysis method according to claim 11, wherein, The dimensions of the material also include the width of the material, which is obtained by counting the pixels in the width direction of the X-ray image detected by the detector array of the X-ray scanning device.

13. The elemental analysis method according to claim 8, wherein, Based on the obtained material size, mass decay coefficient, and density at each location, the self-absorption correction coefficient is calculated as follows: For a well-mixed standard sample, the transmittance of the standard sample is calculated using the mass attenuation coefficient and density that do not change with position. For insufficiently mixed test materials, the transmittance of the test material is calculated using the mass decay coefficient and density as a function of position; and The self-absorption correction factor is calculated by dividing the transmittance of the standard sample by the transmittance of the test material.

14. The elemental analysis method according to claim 8, further comprising: The mass correction factor is determined based on the calibration of the standard sample. Based on the mass correction factor and the density at each location of the material, the actual mass of the material is determined.

15. An elemental analysis apparatus, comprising: The X-ray scanning information acquisition unit, based on dual-energy X-ray scanning, obtains the size, mass attenuation coefficient, and density of the material at various locations; as well as The correction factor calculation unit calculates the transmittance of the material based on the size, mass decay coefficient, and density of the material at each location, and calculates the self-absorption correction factor by measuring the change in the transmittance of the material relative to the transmittance at calibration.

16. An elemental analysis program product comprising a computer program that, when executed by a processor, implements the steps of the elemental analysis method according to any one of claims 8 to 14.

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