Method and system for determining continuous X-ray background intensity by using fine spectrum scanning

Abstract

The invention belongs to but not limited to the technical field of electronic probe testing, and discloses a method and a system for determining continuous X-ray background intensity by utilizing fine spectrum scanning. Utilizing an electronic probe to obtain a wave spectrum scanning graph of the to-be-detected element through wave spectrum scanning; selecting one or more sections of spectrum positions on the left side and one or more sections of spectrum positions on the right side of the peak of the spectrum scanning graph of the to-be-detected element; carrying out fine spectrum scanning on the continuous X-rays at the position of each section of the selected spectrum by utilizing an electronic probe to obtain the intensity of the continuous X-rays at the position of each section of the spectrum; performing curve fitting by taking the selected wave spectrum position as an x axis and taking the intensity of the continuous X rays at each section of the tested wave spectrum position as a y axis to obtain a background fitting equation of the to-be-tested element; and substituting the spectrum position of the peak of the to-be-detected element into the background fitting equation to obtain the background intensity value of the to-be-detected element. The method can effectively eliminate the influence of background intensity on the test result of the content of trace elements.

Description

Technical Field

[0001] This invention belongs to, but is not limited to, the field of electron probe testing technology, and particularly relates to a method and system for determining the intensity of continuous X-ray background using fine spectral scanning. Background Technology

[0002] Electron probe microanalysis (EPMA) is a micro-area in-situ analytical technique that can rapidly and accurately analyze the elemental content of solid samples. It is widely used in geology, materials science, and other fields, primarily for the analysis and testing of major elements. Compared to other micro-area in-situ analytical techniques, EMA offers advantages such as low spatial resolution, non-destructive testing, and high accuracy. Therefore, the use of EMA for micro-area in-situ trace element analysis is receiving increasing attention.

[0003] The basic principle of electron probe microanalysis is based on the generation of X-rays by bombarding a sample with an electron beam. By comparing the intensity of the characteristic X-rays of elements in the sample with that of elements in a standard sample, the percentage content of elements in the sample is determined through matrix correction. The formula is as follows:

[0004]

[0005] Therefore, accurately obtaining the intensity of the characteristic X-rays of the elements is a very important factor in accurately obtaining the element content in a sample.

[0006] The interaction between the electron beam and the sample generates continuous X-rays. Continuous X-rays are a significant and unavoidable background source in X-ray measurements. Therefore, the characteristic X-ray intensity measured in the experiment must be subtracted from the background intensity caused by continuous X-rays; this is called background correction. The formula for background correction is:

[0007] I NET =I PEAK -I BG

[0008] In the formula, I NET I represents the intensity value of the characteristic X-rays of the element to be measured. PEAK I represents the total X-ray intensity value at the peak position of the element to be measured. BG This is the background value for the peak position of the element to be measured.

[0009] In traditional electron probe microanalysis, background intensity is measured using a two-point background testing method, which involves selecting a location on each side of the peak (at a distance L from the peak). BG- and L BG+ ) Test the intensity of continuous X-rays (I, respectively) BG- and I BG+ Then the background intensity I BG It can be calculated using the following formula:

[0010]

[0011] Then the characteristic X-ray intensity of the element to be measured, i.e., I, is calculated. NET =I PEAK -I BG Substitute the values ​​into the formula for calculating element content to determine the content of the element to be measured.

[0012] However, the background shape is not a perfectly straight line; it is often curved. In this case, the two-point interpolation method will introduce some error. This is acceptable for major elements with high signal peaks, but it will seriously affect the accuracy of the test for trace elements with low peaks. Therefore, accurate measurement of background intensity is crucial in trace element testing, and the traditional two-point background testing method is not suitable for the determination of trace elements.

[0013] Spectral scanning refers to setting the total number of pixels, step size, residence time, voltage, and current within a specific X-ray wavelength or energy range, and then using a spectrometer to measure the X-ray intensity of each pixel to form a continuous X-ray spectral curve. Fine spectral scanning utilizes high current and long residence time for spectral scanning, which can accurately reflect the shape of X-ray spectral lines and detect and eliminate the influence of minor interfering factors.

[0014] Existing technology 1: Element mapping unit, scanning transmission electron… background correction and fitting methods; Published literature or patents contain methods for background correction and fitting of loss spectra or electron energy distributions in electron microscopy or scanning transmission electron technology. For example, in “Element mapping unit, scanning transmission electron…”, the background correction process specifies procedures such as “specifying the background region” and “specifying the background fitting function (e.g., power law model I = A·E^(–r))” to distinguish continuous background from signal peaks in the spectrum for subtraction correction. While this method can achieve basic background subtraction in practical applications, it has the following problems: its background fitting mainly relies on a single model (e.g., a power law model), and it cannot adapt to non-power law deformations of complex continuous spectra; furthermore, it lacks a strategy for eliminating points containing interfering peaks or negative peaks, easily introducing outliers into the fitting, thus introducing errors.

[0015] Existing technology 2: Simultaneous multi-region background subtraction for core-level EEL spectra; In academic literature, there is a method of "simultaneous background subtraction in multiple regions" that simultaneously fits the background to several boundary regions (pre-edge and post-edge regions) in the electron energy loss spectrum (EELS) to enhance the stability and consistency of the fitting.

[0016] Although this method can improve the consistency of background fitting in EELS spectral processing, it is mainly used in the field of electronic energy spectroscopy and is not designed for X-ray continuous spectrum background. In addition, this method still generally assumes that the background function is in the form of power law or linear transformation, and lacks the flexibility to choose fitting models such as exponential, logarithmic or polynomial. More importantly, this method does not have a strategy for "refitting after removing interference points", and it is difficult to handle the stray peaks or negative peaks that appear in the measurement.

[0017] Based on the above analysis, the urgent technical problems that need to be solved in the existing technology are:

[0018] First, existing technologies often rely on a single model (such as power law, linear or fixed power exponent models) for background subtraction, lacking the ability to adaptively model complex deformations in continuous X-ray spectral regions.

[0019] Secondly, there is a lack of mechanisms to remove or filter data points containing interfering peaks, negative peaks, or outliers, which may cause these outliers to severely distort the background fitting curve.

[0020] Finally, most existing methods are proposed in specific spectral systems (such as EELS and electron energy spectroscopy), while there are few high-precision background fitting methods for X-ray spectra, especially continuous spectral bands, which makes it difficult to meet the high requirements of background subtraction accuracy for quantitative analysis of trace elements. Summary of the Invention

[0021] To address the problems existing in the prior art, this invention provides a method and system for determining the intensity of continuous X-ray background using fine spectral scanning.

[0022] This invention is implemented as follows: a method for determining the intensity of continuous X-ray background using fine spectral scanning, comprising the following steps:

[0023] (1) Obtain the spectral scan of the element to be measured by an electron probe;

[0024] (2) In the spectral scan, at least one continuous X-ray position is selected on the left and right sides of the characteristic peak of the element to be measured, and the position does not contain interfering peaks or negative peaks.

[0025] (3) Perform fine spectral scanning on the location using an electron probe to measure the continuous X-ray intensity at each location and remove spectral points containing interference signals;

[0026] (4) Establish a fitting curve with spectral position as independent variable and corresponding intensity as dependent variable to obtain the background fitting equation;

[0027] (5) Substitute the spectral position corresponding to the characteristic peak into the background fitting equation to obtain the background intensity value at that position;

[0028] (6) Calculate the characteristic X-ray intensity based on the difference between the total intensity of the characteristic peak and the background intensity, and determine the content of the element to be measured.

[0029] The method for determining the intensity of continuous X-ray background using fine spectral scanning specifically includes the following steps:

[0030] S1, the spectral scan of the element to be measured is obtained by using an electron probe through spectral scanning;

[0031] S2, select a point on the continuous X-ray spectrum to the left of the peak in the spectral scan of the element to be measured that is free from interfering factors (such as interfering peaks, negative peaks, etc.). For the spectral position, the continuous X-ray section on the right should be selected where there are no interfering factors (such as interfering peaks, negative peaks, etc.). Spectral position of segment (n≥1);

[0032] S3. Using an electron probe to test the intensity of continuous X-rays at each selected spectral position through fine spectral scanning, if the scanned spectral lines contain interfering factors (such as interfering peaks, negative peaks, etc.), the data containing interfering factors can be removed.

[0033] S4. Using the spectral position selected in step S2 as the x-axis and the intensity of continuous X-rays at each spectral position tested in step S3 as the y-axis, perform curve fitting to obtain the background fitting equation for the element to be measured.

[0034] S5, Substitute the spectral position of the peak of the element to be measured into the background fitting equation to obtain the background intensity value of the element to be measured.

[0035] S6. By using the background intensity value and the total peak intensity value of the element to be measured, the characteristic X-ray intensity value of the element to be measured can be obtained, thereby accurately calculating the content of the element to be measured and eliminating the influence of background intensity on the test results of trace element content.

[0036] Furthermore, in step (2), the number of continuous spectral points selected on the left is an integer not less than 1, and the number of continuous spectral points selected on the right is an integer not less than 1. That is, in S2 The value of is an integer not less than 1. The value of is an integer not less than 1.

[0037] Furthermore, the judgment condition for eliminating spectral points containing interference signals in step (3) is: when the intensity of a single spectral point deviates from the fitted curve by more than three times the square root of the intensity of the fitted curve at the spectral point position, it is determined to be an interference point.

[0038] Furthermore, in step (4), the model of the fitted curve is one of a quadratic polynomial function, an exponential function, a power function, or a logarithmic function, and the fitted model is automatically selected based on the principle of minimum residual.

[0039] The fitting equation for the quadratic polynomial is In the formula, The constant is ; the fitting equation for the exponential function is In the formula, The constant is ; the fitting equation for the power function is In the formula, The constant is ; the fitting equation for the logarithmic function is In the formula, It is a constant.

[0040] Furthermore, in step (6), the characteristic X-ray intensity is obtained by subtracting the background intensity from the total peak intensity, and the content of the element to be measured is calculated by combining the ratio of the characteristic X-ray intensity of the unknown sample to the characteristic X-ray intensity of the standard sample with the matrix correction factor.

[0041] The specific method for calculating the content of the element to be measured using the obtained background intensity value and total peak intensity value is as follows:

[0042] S6.1, The total peak intensity value at the peak position of the element to be measured is obtained by quantitative analysis using an electron probe.

[0043] S6.2 Calculate the characteristic X-ray intensity value of the element to be measured by subtracting the background intensity value from the total peak intensity value at the peak position;

[0044] S6.3 Calculate the content of the element to be tested based on the characteristic X-ray intensity value of the element to be tested.

[0045] Furthermore, in S6.2, the formula for calculating the characteristic X-ray intensity value of the element to be measured is as follows:

[0046] ,

[0047] In the formula, The characteristic X-ray intensity value of the element to be measured. This represents the total peak intensity at the peak position of the element to be measured. This represents the background intensity value of the element to be measured.

[0048] Furthermore, in step S63, the formula for calculating the content of the element to be measured is as follows:

[0049] ,

[0050] In the formula, This represents the percentage content of the element to be measured in the unknown sample. This represents the percentage content of the element to be tested in the standard sample. The characteristic X-ray intensity value of the element to be measured in the unknown sample; The characteristic X-ray intensity value of the element to be measured in the standard sample; This is the matrix correction factor for the element to be measured in the unknown sample. This is the matrix correction factor for the analyte in the standard sample.

[0051] Another object of the present invention is to provide a system for determining the intensity of continuous X-ray background using fine spectral scanning, comprising:

[0052] The spectral acquisition module is used to acquire the spectral signal of the sample to be tested;

[0053] The spectral point filtering module is used to automatically identify non-interference continuous spectral points and exclude abnormal data;

[0054] The background fitting module is used to establish a background fitting equation based on the intensity of the spectral points.

[0055] The data processing module is used to calculate the intensity and elemental content of characteristic X-rays.

[0056] Furthermore, the background fitting module includes a model selection unit and a residual verification unit. The model selection unit is used to optimize the fitting among multiple function models, and the residual verification unit is used to verify the fitting accuracy and correct the background curve.

[0057] Another object of the present invention is to provide a computer device including a memory and a processor, the memory storing a computer program, which, when executed by the processor, causes the processor to perform the steps of the method for determining the intensity of continuous X-ray background using fine spectral scanning.

[0058] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method for determining the intensity of continuous X-ray background using fine spectral scanning.

[0059] Another object of the present invention is to provide an information data processing terminal, which includes the system described above for determining the intensity of continuous X-ray background using fine spectral scanning.

[0060] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows:

[0061] Traditional two-point background testing methods often result in overestimation of background intensity values, which can lead to a discrepancy of tens of ppm in the test results. While this has minimal impact on major element testing, it can significantly affect trace element testing (ranging from a few to hundreds of ppm). The method provided in this invention, through a refined spectral scanning method, greatly eliminates the influence of background intensity values ​​on the trace element content test results in the sample. Furthermore, the method provided in this invention is simple to use, has a straightforward calculation process, and yields accurate background intensity values.

[0062] The technical solution of this invention solves a long-standing but unresolved technical problem: in in-situ micro-area trace element analysis, a combination of laser ablation systems and inductively coupled plasma mass spectrometry (ICP-MS) is commonly used. However, laser ablation systems have low spatial resolution (30-50 μm), and the analytical point locations cannot be repeatedly tested. Achieving high spatial resolution in-situ micro-area trace element analysis has been a long-desired technical challenge. Electron probe microanalysis (EPMA) offers the advantage of high spatial resolution, enabling analysis of sample chemical composition at a scale of ~1 μm without sample damage. Furthermore, the analytical point locations can be repeatedly tested. Developing EPM-based trace element methods can achieve high spatial resolution in-situ micro-area trace element analysis.

[0063] The technical solution of this invention overcomes technical bias: Electron probe microanalysis has long been used as a method for in-situ analysis of major element content in micro-regions. However, due to its high detection limit, it is generally believed that electron probe microanalysis cannot analyze the composition of trace elements. The technical solution of this invention achieves high spatial resolution trace element analysis using electron probe microanalysis, broadens the application scope of electron probe analysis, and overcomes technical bias. Attached Figure Description

[0064] Figure 1 This is a flowchart of a method for determining the intensity of continuous X-ray background using fine spectral scanning, provided in an embodiment of the present invention.

[0065] Figure 2 This is a schematic diagram comparing the fine spectral scanning method provided in this embodiment of the invention with the traditional two-point background testing method.

[0066] Figure 3 This is a spectral scan of quartz provided in an embodiment of the present invention.

[0067] Figure 4 This is a fine spectral scan image provided in an embodiment of the present invention.

[0068] Figure 5This is a background fitting image provided in an embodiment of the present invention. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0070] In electron probe microscopy (EPMA), characteristic X-ray peaks are superimposed on a continuous X-ray background, and the background intensity varies slowly with wavelength or energy. Inaccurate background subtraction directly affects the calculation of the net intensity of characteristic peaks, thus impacting the accuracy of elemental content determination. This invention obtains the background variation pattern through fine spectral scanning and constructs a background fitting equation to achieve high-precision prediction of the background intensity at the corresponding positions of characteristic peaks. Its working principle is as follows:

[0071] First, when an electron probe excites a sample, the incident electrons interact with the sample matrix, generating various radiation signals, including characteristic X-rays and continuous X-rays. The continuous X-ray signal originates from Bremstrahlung radiation generated by electrons in the sample, and its intensity is continuously distributed across the spectral channels. In traditional analysis, the selection of background locations relies on manual experience, and the limited number of scan points makes it susceptible to the influence of neighboring peaks, negative peaks, or noise points, leading to unstable background estimation.

[0072] This method first acquires a complete spectral scan using an electron probe microanalysis to understand the overall morphology of the characteristic peak and its surrounding regions. Then, at least one continuous X-ray position is selected on either side of the characteristic peak, explicitly avoiding interfering peaks, spurious peaks, and negative peaks to ensure the authenticity of the background signal. Next, high-density fine spectral scans are performed at these background positions, ensuring that each scan point corresponds to a high-resolution continuous X-ray intensity value. Fine scanning effectively captures subtle changes in the continuous spectrum within this region, providing stronger data support for the establishment of the background curve.

[0073] Subsequently, by eliminating abnormal spectral points containing interfering signals (such as suddenly rising false peaks and noise points) during the scan, the true distribution of the background signal is obtained. Using spectral position as the independent variable and the corresponding continuous spectral intensity as the dependent variable, the data is fitted to form a background fitting curve. Since continuous X-rays generally exhibit a linear or weakly nonlinear trend near characteristic peaks, linear, polynomial, or exponential fitting methods can be used for background fitting. The fitted background equation can reflect the true variation law of continuous X-rays within this micro-region.

[0074] Substituting the spectral position of the characteristic peak center into the background fitting equation yields an estimate of the background intensity at the characteristic peak position. Subtracting the background intensity from the measured total intensity of the characteristic peak gives the net characteristic X-ray intensity. This net intensity is directly proportional to the content of the analyte element; therefore, based on the quantitative model of electron probe microanalysis, the actual content of the corresponding element in the sample can be further calculated.

[0075] In summary, this method works by accurately acquiring continuous spectrum information and establishing a background fitting equation that conforms to actual variation patterns, thereby achieving accurate estimation of the characteristic peak background. Its core advantage lies in significantly reducing background estimation errors and improving the accuracy and stability of trace and low-content element determination.

[0076] like Figure 1 As shown, an embodiment of the present invention provides a method for determining the intensity of continuous X-ray background using fine spectral scanning, comprising the following steps:

[0077] S1, the spectral scan of the element to be tested A is obtained by using an electron probe through spectral scanning; the spectral scan can simultaneously and qualitatively determine whether there is spectral peak interference at different spectral positions.

[0078] S2, select a point on the continuous X-ray spectrum to the left of the peak in the spectral scan of element A that is free from interfering factors (such as interfering peaks, negative peaks, etc.). ( ≥1) Spectral position: Select the continuous X-ray section on the right side where there are no interfering factors (such as interfering peaks, negative peaks, etc.). ( ≥1) Spectral position, and All values ​​are integers, and the selected spectral positions must be free of interfering peaks. For example, the spectral band located on the left is... The spectral band on the right is .

[0079] S3, using an electron probe microanalysis unit to perform fine spectral scanning, the intensity variation spectral lines of continuous X-rays at each selected spectral position are measured. Assume the continuous X-ray intensities at these spectral positions are respectively... and If the scanned spectral lines contain interfering factors (such as interfering peaks, negative peaks, etc.), the data containing interfering factors can be removed.

[0080] S4, using the spectral band selected in step S2 and Using the x-axis as the basis, the continuous X-ray intensity values ​​measured in step S3 are quantitatively analyzed. and For the value of y, curve fitting is performed to obtain the background fitting equation for the element to be measured, A. Curve fitting methods include quadratic polynomials, exponential functions, power functions, and logarithmic functions. The fitting equation for a quadratic polynomial is: In the formula, The constant is ; the fitting equation for the exponential function is In the formula, The constant is ; the fitting equation for the power function is In the formula, The constant is ; the fitting equation for the logarithmic function is In the formula, It is a constant.

[0081] S5. Substitute the spectral position of the peak of element A into the background fitting equation to obtain the background intensity value of element A. .

[0082] S6. By using the background intensity value and the total peak intensity value of the element to be measured, the characteristic X-ray intensity value of the element to be measured can be obtained, and the content of the element to be measured can be accurately calculated.

[0083] Using the background intensity value of the element A to be measured obtained above The total peak intensity value of the analyte A can be used to calculate the content of analyte A in the sample, eliminating the influence of background intensity on the test results of trace element content. The specific process is as follows:

[0084] S6.1, The total X-ray intensity value at the peak position of the analyte element A is obtained by quantitative analysis using an electron probe microanalysis. ;

[0085] S6.2, based on the total X-ray intensity value at the peak position and background intensity value Calculate the characteristic X-ray intensity value of element A to be measured. Characteristic X-ray intensity value The calculation formula is: ;

[0086] S6.3, based on the characteristic X-ray intensity value of the element A to be measured. The content of element A to be tested is calculated using the following formula: .

[0087] In the formula, This represents the percentage content of element A to be measured in the unknown sample. This represents the percentage content of element A to be tested in the standard sample. The characteristic X-ray intensity value of element A to be measured in the unknown sample; The characteristic X-ray intensity value of element A to be tested in the standard sample; This is the matrix correction factor for analyte A in the unknown sample. This is the matrix correction factor for analyte A in the standard sample.

[0088] like Figure 2 As shown, it is a schematic diagram comparing the multi-point fitting method of the present invention with the traditional two-point background testing method. Figure 2 It can be seen that the background intensity value obtained by the traditional two-point background test method is significantly higher than the background intensity value obtained by the multi-point fitting method.

[0089] Traditional two-point background testing methods often result in overestimation of background intensity values, which can lead to a discrepancy of tens of ppm in the test results. While this has minimal impact on major element testing, it can significantly affect trace element testing (ranging from a few to hundreds of ppm). The method provided in this invention, through multi-point fitting, greatly eliminates the influence of background intensity values ​​on the trace element content test results in the sample. The method provided in this invention is simple to use, has a straightforward calculation process, and provides accurate background intensity values.

[0090] This experiment selected an international quartz standard sample, whose reference value for Al content is 154±15 ppm. Using a JEOL electron probe microanalyzer, the content of the trace element Al was tested using the method described above, as follows:

[0091] S1, the spectral scan of Al in quartz was obtained by using an electron probe microanalysis. Figure 3 ).

[0092] S2, select a spectral position 87-89mm to the left of the peak of the spectral scan of the element Al to be measured, and a spectral position 92-94mm to the right.

[0093] S3, using an electron probe microanalysis unit to perform fine spectral scanning, the intensity variation spectral lines of continuous X-rays at two selected spectral positions were measured respectively. (See...) Figure 4 .

[0094] S4. Using the spectral band selected in step S2 as the x-axis and the continuous X-ray intensity value obtained from the quantitative analysis in step S3 as the y-value, perform curve fitting. Taking the exponential function fitting method as an example, obtain the background fitting equation for the element Al to be measured, see... Figure 5 .

[0095] S5. Substitute the spectral position of the peak of the element Al to be measured, 90.661 mm, into the background fitting equation to obtain the background intensity value of the element Al to be measured, 81733 counts, corresponding to 3266.6 cps / μA.

[0096] S6. The content of the element to be measured is calculated using the background intensity value and the total peak intensity value of the element to be measured, Al. The specific process is as follows:

[0097] S6.1 The total X-ray intensity value at the peak position of the element Al to be tested was 4032.4 cps / μA (average of 10 points) obtained by quantitative analysis using an electron probe.

[0098] S6.2, The characteristic X-ray intensity value of the element Al to be measured is calculated as 383.2 cps / μA (average value of 10 points) based on the total X-ray intensity value and background intensity value at the peak position.

[0099] S6.3, based on the characteristic X-ray intensity value of element A, 383.2 cps / μA, the content of element Al was calculated using the formula in S6.3 above. The result was 150.7 ppm (average of 10 points), which is close to the reference value.

[0100] Example 1: Taking the continuous X-ray background quadratic polynomial fitting of trace Ti elements in quartz as an example

[0101] In this embodiment, trace amounts of Ti in the quartz of the geological sample were selected as the analyte A. First, a JEOL electron probe microanalyzer was used to perform a spectral scan of Ti in the Kα band, obtaining a complete spectral image. The scan image showed a continuous, interference-free background segment 84-86 mm to the left of the Ti main peak, and another continuous, interference-free background segment 90-92 mm to the right. Therefore, the left spectral segment was designated as the analyte. Set the right spectral band as Subsequently, a fine spectral scan was performed on the two spectral windows mentioned above, yielding the corresponding continuous X-ray intensity curves as follows: and Using the spectral position as x and the measured continuous background intensity as y, a quadratic polynomial is performed. A fitting equation was obtained through fitting. Substituting the center spectral position of the Ti peak, x0 = 88.15, into the background equation, the background intensity B = 621.8 cps was obtained. Quantitative analysis then yielded the total peak intensity P = 940 cps, from which the characteristic intensity S = P - B = 318.2 cps was calculated. Using standard Ti sample data, the Ti content in this quartz was calculated to be 55.6 ± 2.0 ppm, which is very close to the reference value of 57 ± 4 ppm.

[0102] Example 2: Power function background fitting using trace amounts of F in glass as an example

[0103] In this embodiment, the analyte is F, and the sample is silicate glass. Using a JEOL electron probe microanalyzer, a spectral scan of the Kα band of F revealed no interfering peaks in the regions 195.5–197 mm to the left of the main peak and 201.2–203 mm to the right. Therefore, these regions were selected as the spectral bands. With the right background spectral band The corresponding continuous X-ray intensity curves obtained through fine scanning are as follows: and Power function fitting was used. Background fitting was performed, and the peak position of element F (199.2 mm) was substituted into the equation to calculate the background intensity of F, B = 182 cps. Actual quantitative testing yielded a total peak intensity of F, P = 240 cps, therefore its characteristic intensity S = 58 cps. Finally, based on the characteristic intensity ratio and matrix correction factor, the F content in the glass was determined to be 342 ± 18 ppm, which is close to the reference value of 317 ± 59 ppm, and the error is significantly reduced compared to the traditional two-point background method.

[0104] Example 3: Logarithmic function background fitting using P element in zircon as an example

[0105] In this embodiment, trace amounts of phosphorus (P) were selected from a zircon sample. Using a JEOL electron probe microanalysis device, a coarse scan was performed, identifying interference-free background regions in the areas 194.5–196.6 mm to the left of the main peak and 197.6–198.5 mm to the right, thus obtaining the left background spectral band. With the right background spectral band The corresponding continuous X-ray intensity curves obtained through fine scanning are as follows: and Logarithmic function fitting was used. Substituting the peak position of element P (197.21 mm) into the equation, the background intensity of P is obtained as B = 304 cps. The total peak intensity of element P is P = 465 cps, therefore the characteristic intensity S = 161 cps. Combining this with the standard sample data, the P content in this zircon can be calculated to be 26 ± 4 ppm, which is close to the reference value of 24 ± 8 ppm, effectively eliminating the analytical bias caused by background fluctuations.

[0106] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for determining the intensity of a continuous X-ray background using a fine spectral scan, characterized in that, The method comprises the following steps: (1) obtaining a spectrum scanning graph of the element to be measured by an electron probe; (2) selecting at least one continuous X-ray position on both sides of the characteristic peak of the element to be measured in the spectrum scanning graph, the positions not containing interference peaks or negative peaks; (3) performing fine spectrum scanning on the positions by the electron probe, measuring the continuous X-ray intensity of each position, and removing the spectrum points containing interference signals; (4) establishing a fitting curve with the spectrum position as the independent variable and the corresponding intensity as the dependent variable to obtain a background fitting equation; (5) substituting the spectrum position corresponding to the characteristic peak into the background fitting equation to obtain the background intensity value of the position; (6) calculating the characteristic X-ray intensity according to the difference between the total intensity of the characteristic peak and the background intensity, and determining the content of the element to be measured.

2. The method of determining the continuous X-ray background intensity using fine spectral scanning as claimed in claim 1, wherein, The number of continuous spectrum points selected on the left side in step (2) is an integer not less than 1, and the number of continuous spectrum points selected on the right side is an integer not less than 1.

3. The method of determining the continuous X-ray background intensity using fine spectral scanning as claimed in claim 1, wherein, The judgment condition for removing the spectrum points containing interference signals in step (3) is that when the intensity of a single spectrum point deviates from the fitting curve by more than three times the square root value of the intensity of the fitting curve at the position of the spectrum point, it is determined as an interference point.

4. The method of determining the continuous X-ray background intensity using fine spectral scanning of claim 1, wherein, The model of the fitting curve in step (4) is one of a quadratic polynomial function, an exponential function, a power function or a logarithmic function, and the fitting model is automatically selected by the least residual principle.

5. The method of determining the continuous X-ray background intensity using fine spectral scanning as claimed in claim 1, wherein, In step (6), the characteristic X-ray intensity is obtained by subtracting the background intensity from the total intensity of the peak, and the content of the element to be measured is calculated by the ratio of the characteristic X-ray intensity of the unknown sample to the characteristic X-ray intensity of the standard sample combined with the matrix correction factor.

6. A system for determining the intensity of the continuous X-ray background using a fine spectral scan in a method according to any one of claims 1 to 5, characterized in that It comprises: a spectrum acquisition module for acquiring the spectrum signal of the sample to be measured; a spectrum point screening module for automatically identifying continuous spectrum points without interference and excluding abnormal data; a background fitting module for establishing a background fitting equation according to the spectrum point intensity; a data operation module for calculating the characteristic X-ray intensity and the element content.

7. The system for determining the continuous X-ray background intensity using fine spectral scanning according to claim 6, characterized in that, The background fitting module comprises a model selection unit and a residual check unit, the model selection unit is used for fitting optimization among multiple function models, and the residual check unit is used for verifying the fitting accuracy and correcting the background curve.

8. A computer device, comprising: The computer device comprises a memory and a processor, the memory stores a computer program, and the computer program is executed by the processor to make the processor execute the steps of the method for determining the continuous X-ray background intensity by fine spectrum scanning according to any one of claims 1-5.

9. A computer readable storage medium storing a computer program, the computer program being executed by a processor to make the processor execute the steps of the method for determining the continuous X-ray background intensity by fine spectrum scanning according to any one of claims 1-5.

10. An information data processing terminal, characterized by The information data processing terminal comprises the system for determining the continuous X-ray background intensity by fine spectrum scanning according to claim 7.

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