Energy calibration method of X-ray absorption spectrometry

Abstract

The present invention relates to an energy calibration method for an X-ray absorption spectrum, comprising: providing an X-ray absorption spectrometer, comprising a monochromator, a first ionization chamber, and a second ionization chamber; performing an X-ray absorption spectrum experiment on a sample to be tested to obtain a curve showing a change in absorption coefficient of the sample to be tested versus a monochromator angle and a corresponding curve showing a change in X-ray intensity measured by the first ionization chamber versus the monochromator angle; determining the monochromator angle at a glitch point of a monochromator crystal; determining the energy of monochromatic light corresponding to the monochromator angle at the glitch point of the monochromator crystal of the sample to be tested; determining the Bragg angle at the glitch point of the monochromator; a mapping relationship between the monochromator angle of the sample to be tested and the Bragg angle; determining a corresponding relationship between the monochromator angle of the sample to be tested and the energy of the monochromatic light; and converting the curve showing a change in absorption coefficient of the sample to be tested versus the monochromator angle into a curve showing a change in absorption coefficient of the sample to be tested versus the energy of the monochromatic light.

Description

Technical Field

[0001] The present invention relates to the technical field of X-ray absorption spectra, and more particularly to an energy calibration method for X-ray absorption spectra. Background Art

[0002] In the QXAFS (rapid X-ray absorption fine structure) experiment, the rapid oscillation motion of the monochromator crystal can lead to angular deviation and energy drift, so the monochromator angle must be energy scaled and calibrated in real time.

[0003] In the prior art, the "three-ionization chamber" method is usually used to calibrate the energy of the X-ray absorption spectrum. It includes three ionization chambers arranged in sequence. The first and second ionization chambers are used to place the sample to be tested, and a standard sample is placed between the second and third ionization chambers, thereby calibrating the energy of the X-ray absorption spectrum of the sample to be tested.

[0004] However, the existing "three-ionization chamber" method requires an additional ionization chamber and standard sample, which increases the experimental complexity and cost. Summary of the Invention

[0005] The object of the present invention is to provide an energy calibration method for X-ray absorption spectroscopy, which can achieve energy calibration without adding additional equipment, thereby reducing experimental complexity and cost.

[0006] Based on the above objectives, the present invention provides an energy calibration method for X-ray absorption spectroscopy, which comprises the following steps:

[0007] S100: Provide an X-ray absorption spectrometer, comprising a monochromator, a first ionization chamber, and a second ionization chamber sequentially arranged along an X-ray transmission direction;

[0008] S200: placing a sample to be tested between the first ionization chamber and the second ionization chamber, and performing an X-ray absorption spectrum experiment on the sample to be tested to obtain a curve of a change in the absorption coefficient of the sample to be tested versus a monochromator angle, and a curve of a change in the intensity of X-rays measured by the first ionization chamber corresponding to the sample to be tested versus the monochromator angle;

[0009] S300: determining the monochromator angle at the Glitch point of the monochromator crystal according to a curve of the intensity of X-rays measured by the first ionization chamber corresponding to the sample to be tested and the monochromator angle;

[0010] S400: determining the energy of the monochromatic light corresponding to the monochromator angle at the monochromator crystal Glitch point of the sample to be tested based on a pre-acquired energy database of the monochromator crystal Glitch point;

[0011] S500: determining the Bragg angle at the Glitch point of the monochromator crystal of the sample to be tested based on the energy of the monochromatic light corresponding to the monochromator angle at the Glitch point and the Bragg formula;

[0012] S600: Determine a mapping relationship between the monochromator angle and the Bragg angle of the sample to be tested based on the monochromator angle at the Glitch point of the monochromator crystal and the Bragg angle as a first mapping relationship;

[0013] S700: Determine a correspondence between a monochromator angle of the sample to be tested and the energy of the monochromatic light based on the Bragg formula and the first mapping relationship;

[0014] S800: Based on the correspondence between the monochromator angle of the sample to be tested and the energy of the monochromatic light, convert the curve of the absorption coefficient of the sample to be tested versus the monochromator angle into the curve of the absorption coefficient of the sample to be tested versus the energy of the monochromatic light.

[0015] Optionally, step S300 specifically includes:

[0016] Obtaining the trough of the curve of the X-ray intensity measured by the first ionization chamber corresponding to the sample to be tested versus the monochromator angle as the monochromator crystal glitch point;

[0017] The monochromator angle corresponding to the trough is obtained as the monochromator angle at the glitch point of the monochromator crystal.

[0018] Optionally, step S600 specifically includes:

[0019] Obtaining a difference between the Bragg angle at the Glitch point of the monochromator crystal and the monochromator angle as a first deviation;

[0020] The Bragg angle corresponding to each monochromator angle of the sample to be measured is determined according to the first deviation.

[0021] Optionally, step S800 specifically includes:

[0022] According to the correspondence between the monochromator angle of the sample to be tested and the energy of the monochromatic light, the energy of the monochromatic light corresponding to each monochromatic light angle in the curve of the change of the absorption coefficient of the sample to be tested versus the monochromator angle is obtained;

[0023] Each monochromator angle is replaced by the energy of the monochromatic light corresponding to the monochromator angle to obtain a curve of the absorption coefficient of the sample to be tested versus the energy of the monochromatic light.

[0024] Optionally, the energy database of the monochromator Glitch point includes the monochromator Glitch point and the energy of the monochromatic light corresponding to the monochromator Glitch point.

[0025] Optionally, the energy database of the monochromator glitch point is obtained by pre-measurement, and the measurement method includes:

[0026] Placing a standard sample between the first ionization chamber and the second ionization chamber, and performing an X-ray absorption spectrum experiment on the standard sample to obtain a curve of the absorption coefficient of the standard sample varying with the monochromator angle, and a curve of the intensity of X-rays measured by the first ionization chamber corresponding to the standard sample varying with the monochromator angle; wherein the X-ray absorption spectrum of the standard sample has a significant near-edge characteristic peak, and the energy of the monochromatic light corresponding to the near-edge characteristic peak is a fixed value;

[0027] Determining the correspondence between the monochromator angle of the standard sample and the energy of the monochromatic light based on a curve of the absorption coefficient of the standard sample varying with the monochromator angle and the energy of the monochromatic light corresponding to the near-edge characteristic peak;

[0028] Determine the monochromator crystal Glitch point and the monochromator angle at the monochromator crystal Glitch point based on a curve of X-ray intensity versus monochromator angle measured by the first ionization chamber corresponding to the standard sample;

[0029] The energy of the monochromatic light at the Glitch point of the monochromator crystal is determined according to the corresponding relationship between the monochromator angle of the standard sample and the energy of the monochromatic light.

[0030] Optionally, determining the correspondence between the monochromator angle of the standard sample and the energy of the monochromatic light based on a curve of a change in the absorption coefficient of the standard sample with the monochromator angle and the energy of the monochromatic light corresponding to the near-edge characteristic peak specifically includes:

[0031] Obtain the monochromator angle at the peak of the curve of the absorption coefficient of the standard sample varying with the monochromator angle, and use it as the monochromator angle of the near-edge characteristic peak;

[0032] Determine the Bragg angle corresponding to the near-edge characteristic peak based on the energy of the monochromatic light corresponding to the near-edge characteristic peak;

[0033] obtaining a difference between the Bragg angle of the near-edge characteristic peak and the monochromator angle of the near-edge characteristic peak as a second deviation;

[0034] determining a Bragg angle corresponding to each monochromator angle of the standard sample based on the second deviation;

[0035] The energy of the monochromatic light corresponding to each monochromator angle is determined based on the Bragg angle corresponding to each monochromator angle and the Bragg formula.

[0036] Optionally, the relationship between the Bragg angle and the energy of monochromatic light is:

[0037] ,

[0038] Where θ is the Bragg angle of the monochromator crystal, h is Planck's constant, c is the speed of light, d is the interplanar spacing of the monochromator crystal, and E is the energy of the monochromatic light.

[0039] The energy calibration method for X-ray absorption spectrum of the present invention realizes real-time energy calibration based on the Glitch phenomenon of the monochromator crystal. It does not require additional equipment and can significantly reduce the complexity and cost of the experiment. The calibration accuracy can reach ±0.1eV, meeting the requirements of high-precision experiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a flow chart of an energy calibration method for X-ray absorption spectra according to an embodiment of the present invention;

[0041] Figure 2 is a structural schematic diagram of an X-ray absorption spectrometer according to an embodiment of the present invention;

[0042] Figure 3 Schematic diagram of a curve showing a change in the absorption coefficient of zinc foil with the monochromator angle according to an embodiment of the present invention;

[0043] Figure 4 Schematic diagram of a curve showing a change in X-ray intensity as a function of the monochromator angle, measured by a first ionization chamber corresponding to a zinc foil according to an embodiment of the present invention;

[0044] Figure 5 Schematic diagram of a curve showing a change in the absorption coefficient of zinc foil according to an embodiment of the present invention as a function of the energy of monochromatic light;

[0045] Figure 6 Schematic diagram of a curve showing a change in the intensity of X-rays measured by a first ionization chamber corresponding to a zinc foil according to an embodiment of the present invention as a function of the energy of monochromatic light;

[0046] Figure 7 2 is a schematic diagram of a curve showing a change in the absorption coefficient of zinc oxide with the monochromator angle according to an embodiment of the present invention;

[0047] Figure 8 Schematic diagram of a curve showing a change in X-ray intensity as a function of the monochromator angle, measured by a first ionization chamber corresponding to zinc oxide according to an embodiment of the present invention;

[0048] Figure 9FIG. 4 is a schematic diagram of a curve showing a change in the absorption coefficient of zinc oxide with the energy of monochromatic light according to an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The preferred embodiments of the present invention are given below in conjunction with the accompanying drawings and described in detail.

[0050] like Figure 1 As shown, an embodiment of the present invention provides an energy calibration method for X-ray absorption spectroscopy, which includes the following steps:

[0051] S100: Provide an X-ray absorption spectrometer, such as Figure 2 As shown, the X-ray absorption spectrometer includes a monochromator 10, a first ionization chamber 20 and a second ionization chamber 30 which are sequentially arranged along the X-ray transmission direction.

[0052] The monochromator 10 is used to convert the X-rays emitted by the X-ray source into monochromatic light, and the first ionization chamber 20 and the second ionization chamber 30 are used to obtain the intensity of the X-rays incident thereon.

[0053] S200: placing the sample 40 to be tested between the first ionization chamber 20 and the second ionization chamber 30, and performing an X-ray absorption spectrum experiment on the sample 40 to be tested to obtain a curve of the absorption coefficient of the sample 40 to be tested varying with the monochromator angle, and a curve of the intensity of the X-rays measured by the first ionization chamber 20 corresponding to the sample 40 to be tested varying with the monochromator angle.

[0054] When an X-ray absorption spectrometer is used to conduct an X-ray absorption spectrum experiment on a sample 40 to be tested, the X-rays emitted by the X-ray source pass through the monochromator 10, which converts them into monochromatic light. The monochromatic light passes through the first ionization chamber 20, the sample 40 to be tested, and the second ionization chamber 30 in sequence. The first ionization chamber 20 is used to measure the intensity of the monochromatic light, and the second ionization chamber 30 is used to measure the intensity of the monochromatic light after passing through the sample 40 to be tested. During the experiment, the monochromator angle will be continuously adjusted. At each monochromator angle, the first ionization chamber 20 and the second ionization chamber 30 will measure an intensity signal. Assume that the monochromator angle is θ i , i is the serial number of the monochromator angle, i=1,2...n, n is the number of monochromator angles; at angle θ i Under the condition that the intensity of the monochromatic light measured by the first ionization chamber 20 is I 1,θi The monochromatic light I measured by the second ionization chamber 30 after passing through the sample 40 to be tested 2,θi , according to I 1,θi and I 2,θi The angle θ can be obtained i The absorption coefficient μ of the sample under test is 40 i , where μ i =ln(I 1,θi / I2,θi ). According to the angle θ of each monochromator i The corresponding absorption coefficient μ i The absorption coefficient of the sample 40 to be tested can be obtained as the monochromator angle θ i The variation curve of (for example, can be obtained by fitting using an existing fitting method (such as the least squares method)), according to the angle θ of each monochromator i The corresponding I 1,θi A curve showing the variation of the intensity of the X-rays measured by the first ionization chamber 20 with the monochromator angle can be obtained.

[0055] The principle of monochromator monochromatization of X-rays is Bragg diffraction. That is, when X-rays are irradiated on the monochromator crystal, Bragg diffraction will occur. The diffracted X-rays are monochromatic light of a specific energy. There is a one-to-one correspondence between the energy of the monochromatic light and the incident angle of the X-rays on the monochromator crystal (that is, the Bragg angle of the monochromator crystal). The relationship between the two can be calculated using the following formula:

[0056] (1)

[0057] Where θ is the Bragg angle of the monochromator crystal, h is Planck's constant, c is the speed of light, d is the interplanar spacing of the monochromator crystal, for example, for Si(111), d is 3.1356 Å, and E is the energy of the monochromatic light.

[0058] During an X-ray absorption spectrum experiment, the adjusted monochromator angle is not necessarily the Bragg angle of the monochromator crystal. For example, the monochromator angle may be the angle that deviates from the center of oscillation during the crystal oscillation process. Therefore, there is a fixed deviation between the monochromator angle and the Bragg angle of the monochromator crystal. If the monochromator angle is directly substituted into formula (1), the energy obtained is not the true energy of the monochromatic light. Energy calibration is to find the true energy of the monochromatic light corresponding to the monochromator angle, and then obtain the curve of the absorption coefficient of the sample 40 to be tested as a function of the energy of the monochromatic light (i.e., the X-ray absorption spectrum of the sample 40 to be tested).

[0059] S300: Determine the monochromator angle at the Glitch point of the monochromator crystal according to a curve of the intensity of the X-ray measured by the first ionization chamber 20 corresponding to the sample 40 to be tested and the monochromator angle.

[0060] The monochromator will produce a glitch (fault) phenomenon at a specific angle. That is, when multiple groups of crystal planes simultaneously satisfy the Bragg law, the X-ray intensity will drop sharply. Therefore, the curve of the change of the X-ray intensity measured by the first ionization chamber 20 corresponding to the sample 40 to be tested as the monochromator angle changes will have a sharp trough. The trough is the monochromator crystal glitch point, and the monochromator angle at the trough is the monochromator angle at the monochromator crystal glitch point.

[0061] Because the monochromator glitch point is an inherent physical property of the monochromator, its corresponding Bragg angle and energy remain unchanged. Regardless of the deviation of the monochromator angle, the shape of the X-ray intensity versus monochromator angle curve measured by the first ionization chamber 20 remains unchanged, and the energy corresponding to each trough remains unchanged. Therefore, energy calibration can be performed based on the monochromator glitch point. A monochromator may have multiple glitch points. During energy calibration, any monochromator glitch point can be selected and the monochromator angle at that glitch point can be obtained.

[0062] S400: Determine the energy of the monochromatic light corresponding to the monochromator angle at the monochromator crystal Glitch point of the sample to be tested 40 based on a pre-acquired energy database of the monochromator crystal Glitch point.

[0063] The energy database for monochromator crystal glitch points refers to the correspondence between monochromator crystal glitch points and the energy of monochromatic light. Specifically, it includes multiple monochromator crystal glitch points and the energy of the monochromatic light corresponding to each monochromator crystal glitch point. After obtaining a monochromator crystal glitch point, the energy of the monochromatic light corresponding to that point can be found in the energy database for monochromator crystal glitch points.

[0064] S500: Determine the Bragg angle at the Glitch point of the monochromator crystal of the sample to be tested 40 based on the energy of the monochromatic light corresponding to the monochromator angle at the Glitch point and the Bragg formula.

[0065] Substituting the energy of the monochromatic light corresponding to the monochromator angle at the Glitch point of the monochromatic light crystal into formula (1), the Bragg angle at the Glitch point of the monochromator crystal can be obtained.

[0066] S600: Determine a mapping relationship between the monochromator angle and the Bragg angle of the sample to be tested 40 based on the monochromator angle at the Glitch point of the monochromator crystal and the Bragg angle as a first mapping relationship.

[0067] Step S600 specifically includes the following steps S610 to S620:

[0068] S610: Obtain the difference between the Bragg angle at the glitch point of the monochromator crystal and the monochromator angle as a first deviation; the first deviation is the deviation between the Bragg angle and the monochromator angle during this measurement process.

[0069] S620: Determine the Bragg angle corresponding to each monochromator angle of the sample to be tested 40 according to the first deviation.

[0070] Assume that the first deviation is , the Bragg angle is , the calculation formula is:

[0071] (2)

[0072] In this way, the first mapping relationship can be obtained.

[0073] S700: Based on the Bragg formula and the first mapping relationship, determine the corresponding relationship between the monochromator angle of the sample to be tested 40 and the energy of the monochromatic light.

[0074] Through the first mapping relationship, the Bragg angle corresponding to each monochromator angle can be obtained, and then the energy of the corresponding monochromatic light can be calculated according to the Bragg angle. The specific calculation formula is as follows:

[0075] (3)

[0076] S800: Based on the correspondence between the monochromator angle of the sample 40 to be tested and the energy of the monochromatic light, convert the curve of the absorption coefficient of the sample 40 to be tested versus the monochromator angle into a curve of the absorption coefficient of the sample 40 to be tested versus the energy of the monochromatic light.

[0077] The specific conversion method is as follows:

[0078] Each absorption coefficient of the sample 40 to be tested corresponds to a monochromator angle, and the monochromator angle corresponds to the energy of a monochromatic light. Thus, the energy of the monochromatic light corresponding to each absorption coefficient can be obtained. By fitting each absorption coefficient and the corresponding energy of the monochromatic light, a curve of the absorption coefficient of the sample 40 to be tested versus the energy of the monochromatic light can be obtained, that is, the X-ray absorption spectrum of the sample 40 to be tested.

[0079] In step S400, the energy database of the monochromator glitch point can be obtained by pre-measurement. The measurement method is as follows:

[0080] A standard sample is placed between the first ionization chamber 20 and the second ionization chamber 30, and an X-ray absorption spectrum experiment is performed on the standard sample to obtain a curve of the absorption coefficient of the standard sample varying with the monochromator angle, and a curve of the intensity of the X-rays measured by the first ionization chamber 20 corresponding to the standard sample varying with the monochromator angle. A standard sample refers to a sample having a significant near-edge characteristic peak in the X-ray absorption spectrum. For example, the standard sample of the zinc (Zn) element is zinc foil, which is a physical property corresponding to a fixed energy value (for example, the K-edge white line peak energy of Zn is 9669 eV). Substituting it into the Bragg formula (1), the characteristic peak Bragg angle of the monochromator crystal corresponding to the characteristic peak energy can be obtained. , for a particular element, is a fixed value, such as Zn In the curve of the absorption coefficient of the standard sample changing with the monochromator angle, the absorption coefficient of the standard sample corresponding to the characteristic peak energy is the peak, and the monochromator angle corresponding to the peak of the curve of the absorption coefficient of the standard sample changing with the monochromator angle is the monochromator angle corresponding to the characteristic peak energy, which is recorded as , and Correspondingly, the difference between the two can be calculated , as the second deviation, the second deviation That is, the difference between the Bragg angle of the monochromator crystal and the monochromator angle of the standard sample. Based on this second deviation, all other monochromator angles can be converted into the Bragg angle of the monochromator crystal (that is, the Bragg angle of the monochromator crystal corresponding to the monochromator angle is obtained). The specific calculation formula is as follows:

[0081] (2)

[0082] in, is the monochromator angle The Bragg angle of the monochromator crystal is then Substituting into formula (1), we can get the monochromator angle The energy of the corresponding monochromatic light E j (That is, the correspondence between the monochromator angle of the standard sample and the energy of the monochromatic light).

[0083] Then, the monochromator angle corresponding to each trough of the curve of the X-ray intensity versus monochromator angle measured by the first ionization chamber 20 corresponding to the standard sample can be obtained, that is, the monochromator angle at each monochromator glitch point. Based on the corresponding relationship obtained above, the energy of the corresponding monochromatic light can be obtained, that is, the energy of the monochromatic light at each monochromator glitch point, thereby forming an energy database of the monochromator glitch points.

[0084] Next, the energy calibration method according to the embodiment of the present invention is used to perform energy calibration on zinc oxide (ZnO).

[0085] Before measuring the ZnO sample, the energy database of the monochromator crystal Glitch point can be obtained first. The specific method is as follows:

[0086] The X-ray absorption spectrum experiment of zinc foil was carried out to obtain the curve of the absorption coefficient of zinc foil changing with the angle of the monochromator (such as Figure 3 As shown) and the curve of X-rays measured by the first ionization chamber 20 corresponding to the zinc foil as the monochromator angle changes (as shown Figure 4 shown). Figure 3In the equation (1), the monochromator angle at the peak is -0.0374272°, and the energy of the corresponding monochromatic light is the characteristic peak energy of zinc, i.e., 9669 eV. Substituting this characteristic peak energy into formula (1), we can get the corresponding characteristic peak Bragg angle of 11.7986966°, from which the second deviation is 11.8361238°. Based on the second deviation, the remaining monochromator angles can be converted into Bragg angles, and then into the corresponding monochromatic light energy, thus obtaining the X-ray absorption spectrum of zinc foil (such as Figure 5 At the same time, you can Figure 4 Converted into the curve of the intensity (I0) of X-rays measured by the first ionization chamber 20 versus the energy (E) of monochromatic light (eg Figure 6 shown); Figure 6 There are multiple troughs in the , for example, four points numbered 1, 2, 3 and 4 can be obtained as monochromator crystal Glitch points, and their corresponding energies can be obtained to form an energy database of monochromator crystal Glitch points, wherein the energy corresponding to the monochromator crystal Glitch point numbered 1 is 9981.74 eV, the energy corresponding to the monochromator crystal Glitch point numbered 2 is 9800.31 eV, the energy corresponding to the monochromator crystal Glitch point numbered 3 is 9772.23 eV, and the energy corresponding to the monochromator crystal Glitch point numbered 4 is 9708.23 eV.

[0087] After obtaining the energy database of the monochromator crystal Glitch point, the X-ray absorption spectrum experiment can be performed on the ZnO sample to obtain the curve of the absorption coefficient of ZnO changing with the monochromator angle (such as Figure 7 As shown) and the X-ray curve measured by the first ionization chamber 20 corresponding to ZnO as the monochromator angle changes (as shown Figure 8 ). Compare Figure 8 and Figure 4 It can be seen that the two have the same shape. Figure 8 There are also four Glitch points numbered 1 to 4. Choose any Glitch point, for example, Glitch point numbered 4. Figure 6 The energy corresponding to the Glitch point 4 is 9708.23 eV. According to formula (1), the Bragg angle corresponding to the energy can be obtained. Then, according to Figure 8 It can be seen that the monochromator angle at Glitch point 4 is 0.5931400°. According to the Bragg angle and the monochromator angle, the first deviation can be obtained. Then, according to the first deviation, all other monochromator angles can be converted into Bragg angles, and the Bragg angles can be converted into the energy of monochromatic light. Thus, the relationship curve between the absorption coefficient of ZnO and the energy of monochromatic light can be obtained (such as Figure 9 ), which is the X-ray absorption spectrum of ZnO.

[0088] The energy calibration method for X-ray absorption spectrum in an embodiment of the present invention realizes real-time energy calibration based on the Glitches phenomenon of the monochromator crystal. It does not require additional equipment and can significantly reduce experimental complexity and cost. The calibration accuracy can reach ±0.1 eV, meeting the requirements of high-precision experiments.

[0089] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Various modifications are possible. In other words, any simple, equivalent changes and modifications made in accordance with the claims and description of the present invention are within the scope of protection of the patent claims. Anything not fully described in this invention constitutes conventional technology.

Claims

1. A method for energy calibration of X-ray absorption spectroscopy, characterized in that: The following steps are involved: S100: Provide an X-ray absorption spectrometer, comprising a monochromator, a first ionization chamber, and a second ionization chamber sequentially arranged along an X-ray transmission direction; S200: placing a sample to be tested between the first ionization chamber and the second ionization chamber, and performing an X-ray absorption spectrum experiment on the sample to be tested to obtain a curve of a change in the absorption coefficient of the sample to be tested versus a monochromator angle, and a curve of a change in the intensity of X-rays measured by the first ionization chamber corresponding to the sample to be tested versus the monochromator angle; S300: determining the monochromator angle at the Glitch point of the monochromator crystal according to a curve of the intensity of X-rays measured by the first ionization chamber corresponding to the sample to be tested and the monochromator angle; S400: determining the energy of the monochromatic light corresponding to the monochromator angle at the monochromator crystal Glitch point of the sample to be tested based on a pre-acquired energy database of the monochromator crystal Glitch point; S500: determining the Bragg angle at the Glitch point of the monochromator crystal of the sample to be tested based on the energy of the monochromatic light corresponding to the monochromator angle at the Glitch point and the Bragg formula; S600: Determine a mapping relationship between the monochromator angle and the Bragg angle of the sample to be tested based on the monochromator angle at the Glitch point of the monochromator crystal and the Bragg angle as a first mapping relationship; S700: Determine a correspondence between a monochromator angle of the sample to be tested and the energy of the monochromatic light based on the Bragg formula and the first mapping relationship; S800: Based on the correspondence between the monochromator angle of the sample to be tested and the energy of the monochromatic light, convert the curve of the absorption coefficient of the sample to be tested versus the monochromator angle into the curve of the absorption coefficient of the sample to be tested versus the energy of the monochromatic light.

2. The energy calibration method of X-ray absorption spectrum according to claim 1, characterized in that: Step S300 specifically includes: Obtaining the trough of the curve of the X-ray intensity measured by the first ionization chamber corresponding to the sample to be tested versus the monochromator angle as the monochromator crystal glitch point; The monochromator angle corresponding to the trough is obtained as the monochromator angle at the glitch point of the monochromator crystal.

3. The energy calibration method of X-ray absorption spectrum according to claim 1, characterized in that: Step S600 specifically includes: Obtaining a difference between the Bragg angle at the Glitch point of the monochromator crystal and the monochromator angle as a first deviation; The Bragg angle corresponding to each monochromator angle of the sample to be measured is determined according to the first deviation.

4. The energy calibration method of X-ray absorption spectrum according to claim 1, characterized in that: Step S800 specifically includes: According to the correspondence between the monochromator angle of the sample to be tested and the energy of the monochromatic light, the energy of the monochromatic light corresponding to each monochromatic light angle in the curve of the change of the absorption coefficient of the sample to be tested versus the monochromator angle is obtained; Each monochromator angle is replaced by the energy of the monochromatic light corresponding to the monochromator angle to obtain a curve of the absorption coefficient of the sample to be tested versus the energy of the monochromatic light.

5. The energy calibration method of X-ray absorption spectrum according to claim 1, characterized in that: The energy database of the monochromator Glitch point includes the monochromator Glitch point and the energy of the monochromatic light corresponding to the monochromator Glitch point.

6. The energy calibration method of X-ray absorption spectrum according to claim 5, characterized in that: The energy database of the monochromator Glitch point is obtained by pre-measurement, and the measurement method includes: Placing a standard sample between the first ionization chamber and the second ionization chamber, and performing an X-ray absorption spectrum experiment on the standard sample to obtain a curve of the absorption coefficient of the standard sample varying with the monochromator angle, and a curve of the intensity of X-rays measured by the first ionization chamber corresponding to the standard sample varying with the monochromator angle; wherein the X-ray absorption spectrum of the standard sample has a significant near-edge characteristic peak, and the energy of the monochromatic light corresponding to the near-edge characteristic peak is a fixed value; Determining the correspondence between the monochromator angle of the standard sample and the energy of the monochromatic light based on a curve of the absorption coefficient of the standard sample varying with the monochromator angle and the energy of the monochromatic light corresponding to the near-edge characteristic peak; Determine the monochromator crystal Glitch point and the monochromator angle at the monochromator crystal Glitch point based on a curve of X-ray intensity versus monochromator angle measured by the first ionization chamber corresponding to the standard sample; The energy of the monochromatic light at the Glitch point of the monochromator crystal is determined according to the corresponding relationship between the monochromator angle of the standard sample and the energy of the monochromatic light.

7. The energy calibration method of X-ray absorption spectrum according to claim 6, characterized in that: Determining the correspondence between the monochromator angle of the standard sample and the energy of the monochromatic light based on a curve of a change in the absorption coefficient of the standard sample with the monochromator angle and the energy of the monochromatic light corresponding to the near-edge characteristic peak specifically includes: Obtain the monochromator angle at the peak of the curve of the absorption coefficient of the standard sample varying with the monochromator angle, and use it as the monochromator angle of the near-edge characteristic peak; Determine the Bragg angle corresponding to the near-edge characteristic peak based on the energy of the monochromatic light corresponding to the near-edge characteristic peak; obtaining a difference between the Bragg angle of the near-edge characteristic peak and the monochromator angle of the near-edge characteristic peak as a second deviation; determining a Bragg angle corresponding to each monochromator angle of the standard sample based on the second deviation; The energy of the monochromatic light corresponding to each monochromator angle is determined based on the Bragg angle corresponding to each monochromator angle and the Bragg formula.

8. The energy calibration method of X-ray absorption spectrum according to claim 1, characterized in that: The relationship between the Bragg angle and the energy of monochromatic light is: , Where θ is the Bragg angle of the monochromator crystal, h is Planck's constant, c is the speed of light, d is the interplanar spacing of the monochromator crystal, and E is the energy of the monochromatic light.

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