X-ray diffraction based photon counting detector energy response calibration system

Abstract

The application discloses an X-ray diffraction-based photon counting detector energy response calibration system, comprising an X-ray source, a pencil collimator for forming pencil X-rays from the X-rays, a crystal sample, diffraction X-rays generated after the pencil X-rays irradiate the crystal sample, a transmission blocker for blocking transmission X-rays formed after the pencil X-rays transmit through the crystal sample, a photon counting detector for detecting characteristic diffraction energy of the diffraction X-rays, and a controller for adjusting X-ray source parameters to screen preset characteristic diffraction energy reaching the photon counting detector, and controlling the photon counting detector to translate so that the photon counting detector and diffraction angles of the diffraction X-rays continuously change within a preset angle range, measure detector energy response of the photon counting detector at each position under the preset characteristic diffraction energy, and perform photon counting detector energy response calibration. The system does not need to rely on simulation modeling and mathematical parameter models, and can directly perform energy response calibration of the detector.

Description

Technical Field

[0001] This application relates to the field of radiation imaging technology, and in particular to an energy response calibration system for a photon counting detector based on X-ray diffraction. Background Technology

[0002] X-ray imaging plays a crucial role in various fields such as medicine, security inspection, and industrial testing. In recent years, significant breakthroughs have been achieved in photon counting detector technology, which features flexible and adjustable multi-energy thresholds, bringing new impetus to X-ray imaging. In transmission imaging, photon counting detectors are key to computed tomography (CT), enabling better material identification based on equivalent atomic number and electron spatial density. In X-ray fluorescence imaging, photon counting detectors eliminate redundant Compton scattering interference through threshold settings and utilize X-ray fluorescence photons of specific energies. Energy dispersion-based X-ray diffraction material identification or X-ray diffraction tomography relies on high-energy-resolution photon counting detectors with multi-energy windows to obtain material diffraction spectra, placing higher demands on the performance of these detectors. Although photon counting detectors play an important role in various radiation imaging tasks, the broadening of the detector's measured energy spectrum due to statistical fluctuations of charge carriers within the photon counter, and the charge-sharing effect between different detector pixels caused by charge drift, all contribute to its challenges. These effects all cause the detector's measured energy spectrum to deviate from the true incident energy spectrum, thus affecting its performance in various missions. Effective detector energy response characteristic calibration methods are crucial for correcting non-ideal detector energy responses and improving detector performance.

[0003] Currently, the methods for obtaining energy response models for photon counting detectors can be broadly categorized into three types. The first type is detector response modeling based on simulation methods. These methods utilize key detector parameters such as thickness and material to obtain the detector response through analytical or Monte Carlo simulations. This type of method does not require actual experiments, and the obtained detector response model is stable. However, it demands strict accuracy in the simulation process and cannot model out detector-specific manufacturing processes. The second type is detector response calibration methods based on actual experiments. This type of method first models the detector response using parametric formulas, and then fits the parameters in the formulas through metal powder fluorescence experiments. Because this type of method uses actual measurement data for parameter calibration, the influence of detector manufacturing processes on performance is included, and the calibrated detector response is closer to reality. However, this method relies heavily on the design of parametric formulas, and the actual detector response function is usually non-analytical, so formulating it introduces additional errors. On the other hand, in the metal powder fluorescence calibration method, the fluorescence energy is discrete, and only a fixed number of fluorescent metals can be used for detector calibration. The energy cannot be continuously changed, and the sample size is small. The third type is the detector modeling method that combines simulation and experimental calibration. In the first step, the detector response is modeled using simulation. Then, the simulated detector response model is corrected using a parametric formula, and the formula parameters are fitted through metal powder fluorescence experiments. This method reduces the dependence of the detector response on the formula form and can incorporate the influence of detector process factors. However, it is more complicated to implement, and the problems of non-monochromaticity and energy discreteness of metal powder fluorescence experiments have not yet been solved. Summary of the Invention

[0004] This application provides a photon counting detector energy response calibration system and method based on X-ray diffraction, which can directly calibrate the energy response of the detector without relying on simulation modeling and mathematical parameter models.

[0005] The first aspect of this application provides an energy response calibration system for a photon counting detector based on X-ray diffraction, comprising:

[0006] An X-ray source used to generate X-rays;

[0007] A pencil beam collimator is used to shape the X-rays into a pencil beam X-ray;

[0008] A crystal sample is positioned in the propagation path of the pen beam X-ray so that the pen beam X-ray irradiates the crystal sample to generate diffraction X-rays.

[0009] A transmission blocker is used to block the transmitted X-rays formed after the pen beam X-rays pass through the crystal sample;

[0010] A photon counting detector is used to detect the characteristic diffraction energy of the diffracted X-rays;

[0011] The controller is used to adjust the X-ray source parameters to filter the preset characteristic diffraction energies reaching the photon counting detector, and to control the translation of the photon counting detector so that the diffraction angle between the pencil beam X-ray and the diffracted X-ray continuously changes within a preset angle range. It also receives multiple preset characteristic diffraction energies detected by the photon counting detector at different positions, measures the detector energy response of the photon counting detector at each preset characteristic diffraction energy, and performs energy response calibration of the photon counting detector.

[0012] Optionally, in one embodiment of this application, when the diffraction angle is θ, the characteristic diffraction energy E of the diffracted X-rays is... i (θ) is:

[0013]

[0014] Where, q i The characteristic diffraction lines of the crystal sample are denoted by h, which is Planck's constant, c is the speed of light, and θ is the diffraction angle between the pen beam X-ray and the diffracted X-ray.

[0015] Optionally, in one embodiment of this application, the controller is further configured to adjust the voltage of the X-ray source to a preset voltage range so that the photon counting detector detects only the preset characteristic diffraction energy.

[0016] Optionally, in one embodiment of this application, the preset voltage range is (E1(θ) / e, E2(θ) / e), where e is the electron charge.

[0017] Optionally, in one embodiment of this application, the detector energy response of the photon counting detector at each preset characteristic diffraction energy is:

[0018]

[0019] in, θ represents the probability that the photon counting detector detects an energy of h when the characteristic diffraction energy incident on the photon counting detector is monoenergetic E. max For the maximum diffraction angle, θ min For the minimum diffraction angle, E1(θ) max ) is the diffraction angle θ max The characteristic diffraction energy corresponding to the first-order characteristic diffraction line is E1(θ). min ) is the diffraction angle θ min The characteristic diffraction energy corresponding to the first-order characteristic diffraction line.

[0020] Optionally, in one embodiment of this application, the intensity of the first-order characteristic diffraction line of the crystal sample is greater than a preset intensity, and the difference between the position of the first-order characteristic diffraction line and the position of the second-order characteristic diffraction line is greater than a preset distance.

[0021] Optionally, in one embodiment of this application, the crystal sample is a powder crystal sample or a polycrystalline sample.

[0022] Optionally, in one embodiment of this application, the controller includes: a first correction component, configured to perform geometric modeling of the calibration system when the diffraction angle broadens, calculate the diffraction angle distribution of the photon counting detector at each position, and correct the detector energy response according to the diffraction angle distribution.

[0023] Optionally, in one embodiment of this application, the controller includes: a second correction component, configured to perform higher-order diffraction spectrum correction on the detector energy response from high energy to low energy when the photon counting detector detects a characteristic diffraction energy other than the preset characteristic diffraction energy, and to subtract the mixed higher-order diffraction spectrum.

[0024] A second aspect of this application provides a method for calibrating the energy response of a photon counting detector based on X-ray diffraction. Utilizing the aforementioned X-ray diffraction-based photon counting detector energy response calibration system, the calibration method includes the following steps: setting the X-ray source parameters such that the photon counting detector detects a preset characteristic diffraction energy of the diffracted X-rays; controlling the translation of the photon counting detector such that the diffraction angle between the pen-beam X-ray and the diffracted X-ray at the position of the photon counting detector continuously changes within a preset angle range; receiving multiple preset characteristic diffraction energies detected by the photon counting detector at different positions, and measuring the detector energy response of the photon counting detector at each preset characteristic diffraction energy, thereby calibrating the energy response of the photon counting detector.

[0025] The X-ray diffraction-based photon counting detector energy response calibration system and method of this application utilizes the characteristic peaks of crystal diffraction to generate characteristic monoenergetic X-rays from conventional continuous-energy incident X-rays. By continuously adjusting the position of the photon counting detector relative to the crystal to change the diffraction angle, the energy of the diffracted X-rays is changed, thereby achieving continuously adjustable energy response calibration. This is a new, accurate, and convenient X-ray photon counting detector energy response calibration method that does not rely on simulation modeling and mathematical parameter models.

[0026] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0027] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0028] Figure 1 This is a schematic diagram of the energy response calibration system for a photon counting detector based on X-ray diffraction, according to an embodiment of this application.

[0029] Figure 2 This is a schematic diagram of an energy response calibration system for a photon counting detector based on X-ray diffraction, according to an embodiment of this application.

[0030] Figure 3 This is a schematic diagram of the calibration process of an X-ray diffraction-based photon counting detector energy response calibration system according to an embodiment of this application;

[0031] Figure 4 This is a schematic diagram of the calibration results of an X-ray diffraction-based photon counting detector energy response calibration system provided in an embodiment of this application.

[0032] Figure 5 This is a flowchart of an energy response calibration method for a photon counting detector based on X-ray diffraction, according to an embodiment of this application. Detailed Implementation

[0033] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0034] Figure 1 This is a schematic diagram of the energy response calibration system framework for a photon counting detector based on X-ray diffraction, according to an embodiment of this application.

[0035] like Figure 1 As shown, the X-ray diffraction-based photon counting detector energy response calibration system 10 includes: an X-ray source 100, a pencil beam collimator 200, a crystal sample 300, a transmission blocker 400, a photon counting detector 500, and a controller 600.

[0036] X-ray source 100 is used to generate X-rays.

[0037] The pencil beam collimator 200 is used to form pencil beam X-rays.

[0038] A crystal sample 300 is disposed in the propagation path of the pen beam X-ray so that the pen beam X-ray irradiates the crystal sample 300 to generate diffracted X-rays.

[0039] Transmission blocker 400 is used to block the transmitted X-rays formed after the pen beam X-rays pass through the crystal sample 300.

[0040] The X-ray source can be a commonly used X-ray source in medical or security checks. For example... Figure 2 As shown, the X-ray source generates continuous energy X-rays, which are collimated by a pen beam collimator to form a pen beam X-ray. After the pen beam X-ray irradiates the crystal sample, it produces diffracted X-rays. The pen beam X-rays pass through part of the crystal sample to form transmitted X-rays. The transmitted X-rays are blocked by a transmission blocker to eliminate interference.

[0041] The photon counting detector 500 is used to detect the characteristic diffraction energy of diffracted X-rays.

[0042] The controller 600 is used to adjust the X-ray source parameters to filter the preset characteristic diffraction energy reaching the photon counting detector, and to control the translation of the photon counting detector so that the diffraction angle between the pencil beam X-ray and the diffracted X-ray continuously changes within a preset angle range. It also receives multiple preset characteristic diffraction energies detected by the photon counting detector at different positions, measures the detector energy response of the photon counting detector at each preset characteristic diffraction energy, and performs energy response calibration of the photon counting detector.

[0043] In the embodiments of this application, when the diffraction angle is θ, the characteristic diffraction energies of the diffracted X-rays are set as E1(θ), E2(θ), E3(θ),..., and the calculation formula is as follows:

[0044]

[0045] Where, q i The characteristic diffraction lines of the crystal sample are determined solely by the crystal structure, where h is Planck's constant, c is the speed of light, and θ is the diffraction angle between the pen beam X-ray and the diffracted X-ray.

[0046] In the embodiments of this application, the energy response calibration of the photon counting detector only utilizes the characteristic diffraction energy with energy E1(θ). In order to make the photon counting detector only detect the preset characteristic diffraction energy, the voltage of the X-ray source is adjusted by the controller to be within the preset voltage range. When only the characteristic diffraction energy with energy E1(θ) is utilized, the tube voltage of the X-ray source is set to be within the range of (E1(θ) / e, E2(θ) / e), where e is the electron charge.

[0047] After adjusting the tube voltage of the X-ray source, gradually shift the pixel p of the detector to be calibrated, so that the diffraction angle θ corresponding to the detector pixel is within [θ]. min ,θ max The range changes continuously, and the detector pixel p is measured in [E1(θ)]. max),E1(θ min The original detector energy response at each incident energy E between )] The meaning is the probability that the photon counting detector detects an energy of h when the characteristic diffraction energy incident on the photon counting detector is monoenergetic E.

[0048] In the embodiments of this application, the intensity of the first-order characteristic diffraction line of the crystal sample is greater than a preset intensity, and the difference between the position of the first-order characteristic diffraction line and the position of the second-order characteristic diffraction line is greater than a preset distance.

[0049] Specifically, the crystal sample can be a powder crystal sample or a polycrystalline sample, and the first-order diffraction line q1 of the crystal sample has a high intensity and a large interval between q1 and q2.

[0050] Final detector energy response R p (h,E),E∈[E1(θ max ),E1(θ min The form can be discrete. Let the number of detector windows (channels) be M, i.e., h∈{h... o1 ,h o2 ,h o3 ,...,h oM}. And the calibrated energy range [E1(θ max ),E1(θ min The energy is discretized into N incident energies at equal intervals, i.e., E∈{E i1 E i2 E i3 ,...,E iN In the discrete case, the detector energy response can be expressed as:

[0051]

[0052]

[0053] Similarly, the energy response of the original detector can be defined. discrete form And broaden the energy response of the correction detector Discrete form

[0054] In an embodiment of this application, the controller 600 includes: a first correction component, used to perform geometric modeling of the calibration system when there is broadening of the diffraction angle, calculate the diffraction angle distribution of the photon counting detector at each position, and correct the detector energy response according to the diffraction angle distribution.

[0055] It is understandable that when the pen beam collimator width is large, or the detector pixel size is large, the diffraction angle corresponding to the detector pixel will broaden to a certain extent. Diffraction angle broadening correction yields the energy response of the broadened corrected detector. If no diffraction angle broadening correction is performed, then directly set... like Figure 3 As shown.

[0056] Specifically, the diffraction angle broadening correction is as follows: Additional geometric modeling of the system is performed, and the diffraction angle distribution ρ(θ',θ) corresponding to the detector pixel at each acquisition position is calculated. ρ(θ',θ) represents the distribution of diffraction angle magnitudes at each position of the pixel when the diffraction angle at the center of the pixel is θ. Then:

[0057]

[0058] Where θ, θ' ∈ [θ min ,θ max Based on formula (3), the solution is obtained iteratively from... get

[0059] In an embodiment of this application, the controller 600 includes a second correction component, used to perform high-order diffraction spectrum correction on the detector energy response from high energy to low energy when the photon counting detector detects a characteristic diffraction energy other than a preset characteristic diffraction energy, and to subtract the mixed high-order diffraction spectrum.

[0060] In some experiments, to improve efficiency, the X-ray source voltage was not adjusted in real time to the (E1(θ) / e, E2(θ) / e) range as the diffraction angle position changed. The energy corresponding to q2 in the second-order diffraction spectrum of the crystal sample might enter the detector, requiring higher-order diffraction spectrum subtraction correction to obtain the final detector response R. p (h,E), if this situation does not exist, no higher-order diffraction spectrum subtraction correction is needed, then let R p (h,E) represents the final calibrated detector energy response, such as... Figure 3 As shown.

[0061] Specifically, the higher-order diffraction spectrum subtraction correction is performed by gradually adjusting the correction from high energy to low energy. Perform higher-order diffraction spectrum correction for the maximum energy R within the calibration range. p (h,E max ),think Then, according to the calibration energy E from high to low, first, the mixing coefficient α(E) of the higher-order diffraction spectrum is fitted using least squares. * E), that is The incident energy mixed in is E* The photon ratio. The fitting cost function is:

[0062]

[0063] After fitting, α(E) is obtained * After E), subtract the mixed higher-order diffraction patterns:

[0064]

[0065] Because the correction is performed gradually from high energy to low energy, in solving R... p When (h,E), R p (h,E * E * E is known.

[0066] The energy response calibration system of the photon counting detector based on X-ray diffraction of this application will be described in detail below through a specific embodiment.

[0067] The photon counting detector energy response calibration system in this embodiment uses a tungsten anode X-ray source with a tube voltage adjustable between 70kV and 150kV and a tube current adjustable between 0.3mA and 3mA (in this embodiment, the current is fixed at 3mA). The pencil beam collimator is a tungsten collimator with a depth of 200mm and an aperture of 0.5mm. The crystal sample is a pure iron sheet. The detector to be calibrated is a planar array cadmium zinc telluride detector with a pixel side length of 1.6mm and a pixel count of 16×64. The detector is 500mm away from the crystal sample.

[0068] This embodiment employs a discrete detector response. The detector's energy acquisition range is set to 21keV-120keV, with an energy window width of 1keV and a total of 100 energy windows, i.e., h∈{21keV,22keV,23keV,...,120keV}. In this embodiment, the calibration energy range is also set to 21keV-120keV, with a calibration energy step size of 1keV, i.e., E∈{21keV,22keV,23keV,...,120keV}.

[0069] To obtain the raw detector energy response, the detector was gradually moved to change the diffraction angle, and detector signals were collected under different diffraction characteristic energies. When E ≥ 70 keV, the optomechanical voltage was set to 150 kV, and a 1 mm thick iron sheet crystal sample was used. The detector was moved horizontally for scanning, with a movement range of [-100 mm, 100 mm] and a step size of 0.5 mm. When E < 70 keV, the optomechanical voltage was set to 80 kV, and a 0.3 mm thick iron sheet crystal sample was used. The detector was moved horizontally for scanning, with a movement range of [-200 mm, 200 mm] and a step size of 1 mm. The data collected from each pixel during the scanning process were arranged in descending order of diffraction angle (increasing diffraction energy) to obtain the raw detector energy response for that pixel.

[0070] right Discretization is obtained by resampling in the E-dimensional dimension. Original detector energy response Diffraction angle broadening correction was performed according to the correction method described in the above embodiments to obtain... Further The final detector energy response R is obtained by performing higher-order diffraction spectrum subtraction correction using the correction method described in the above embodiments. p The final energy response calibration results are as follows: Figure 4 As shown.

[0071] The X-ray diffraction-based photon counting detector energy response calibration system of this application does not rely on manual modeling or refined detector response simulation. Utilizing crystal X-ray diffraction, through reasonable incident energy spectrum settings, the crystal X-ray diffraction exhibits only a unique energy at each defined spatial location, resulting in excellent monochromaticity. By adjusting the diffraction angle, the energy of this monoenergetic X-ray diffracted X-ray continuously varies, providing a weaker form of laboratory synchrotron radiation. Besides its use in detector energy response calibration, it is also suitable for other tasks requiring a monoenergetic X-ray source.

[0072] Next, with reference to the accompanying drawings, a method for calibrating the energy response of a photon counting detector based on X-ray diffraction, according to an embodiment of this application, is described.

[0073] like Figure 5 As shown, the X-ray diffraction-based photon counting detector energy response calibration method utilizes the aforementioned X-ray diffraction-based photon counting detector energy response calibration system. The calibration method includes the following steps:

[0074] In step S101, the X-ray source parameters are set so that the photon counting detector can detect the preset characteristic diffraction energy of the diffracted X-rays.

[0075] In step S102, the photon counting detector is controlled to translate so that the diffraction angle of the pen beam X-ray and the diffracted X-ray at the position of the photon counting detector changes continuously within a preset angle range.

[0076] In step S103, multiple preset characteristic diffraction energies detected by the photon counting detector at different positions are received, and the detector energy response of the photon counting detector at each preset characteristic diffraction energy is measured to calibrate the energy response of the photon counting detector.

[0077] The photon counting detector energy response calibration method based on X-ray diffraction proposed in this application can directly calibrate the detector response based on conventional light sources experimentally, without relying on manual modeling or refined detector response simulation methods. It is a simple and robust detector response calibration method. Besides being used for detector energy response calibration, it is also applicable to other tasks requiring single-energy X-ray sources.

[0078] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0079] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0080] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0081] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0082] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

Claims

1. An energy response calibration system for a photon counting detector based on X-ray diffraction, characterized in that, include: An X-ray source used to generate X-rays; A pencil beam collimator is used to shape the X-rays into a pencil beam X-ray; A crystal sample is positioned in the propagation path of the pen beam X-ray so that the pen beam X-ray irradiates the crystal sample to generate diffraction X-rays. A transmission blocker is used to block the transmitted X-rays formed after the pen beam X-rays pass through the crystal sample; A photon counting detector is used to detect the characteristic diffraction energy of the diffracted X-rays; The controller is used to adjust the X-ray source parameters to filter the preset characteristic diffraction energies reaching the photon counting detector, and to control the translation of the photon counting detector so that the diffraction angle between the pencil beam X-ray and the diffracted X-ray continuously changes within a preset angle range. It also receives multiple preset characteristic diffraction energies detected by the photon counting detector at different positions, measures the detector energy response of the photon counting detector at each preset characteristic diffraction energy, and performs photon counting detector energy response calibration. At the diffraction angle is At that time, the characteristic diffraction energy of the diffracted X-rays for: in, q i The diffraction lines of the crystal sample are denoted as h, where h is Planck's constant and c is the speed of light. The diffraction angle between the pen beam X-ray and the diffracted X-ray is given.

2. The system according to claim 1, characterized in that, The controller is further configured to adjust the voltage of the X-ray source to a preset voltage range so that the photon counting detector detects only the preset characteristic diffraction energy.

3. The system according to claim 2, characterized in that, The preset voltage range is: ,in, This refers to the amount of electron charge.

4. The system according to claim 3, characterized in that, The energy response of the photon counting detector at each preset characteristic diffraction energy is: in, This indicates that the characteristic diffraction energy incident on the photon counting detector is monoenergetic. At that time, the energy detected by the photon counting detector was The probability, For the maximum diffraction angle, The minimum diffraction angle, The diffraction angle is The characteristic diffraction energy corresponding to the first-order characteristic diffraction line. The diffraction angle is The characteristic diffraction energy corresponding to the first-order characteristic diffraction line.

5. The system according to claim 1, characterized in that, The intensity of the first-order characteristic diffraction line of the crystal sample is greater than a preset intensity, and the difference between the position of the first-order characteristic diffraction line and the position of the second-order characteristic diffraction line is greater than a preset distance.

6. The system according to claim 5, characterized in that, The crystal sample is either a powder crystal sample or a polycrystalline sample.

7. The system according to any one of claims 1-6, characterized in that, The controller includes: The first correction component is used to perform geometric modeling of the calibration system when the diffraction angle broadens, calculate the diffraction angle distribution of the photon counting detector at each position, and correct the detector energy response according to the diffraction angle distribution.

8. The system according to any one of claims 1-6, characterized in that, The controller includes: The second correction component is used to perform higher-order diffraction spectrum correction on the detector energy response stepwise from high energy to low energy when the photon counting detector detects a characteristic diffraction energy other than the preset characteristic diffraction energy, and to subtract the mixed higher-order diffraction spectrum.

9. A method for calibrating the energy response of a photon counting detector based on X-ray diffraction, utilizing the energy response calibration system for a photon counting detector based on X-ray diffraction as described in any one of claims 1-8, characterized in that, The calibration method includes the following steps: The X-ray source parameters are set so that the photon counting detector can detect the preset characteristic diffraction energy of the diffracted X-rays; The photon counting detector is controlled to translate so that the diffraction angle between the pen beam X-ray and the diffracted X-ray at the position of the photon counting detector changes continuously within a preset angle range; The photon counting detector receives multiple preset characteristic diffraction energies detected at different positions, and measures the detector energy response of the photon counting detector at each preset characteristic diffraction energy to calibrate the photon counting detector energy response.

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