X-ray focusing detection system and manufacturing method of diffraction crystal of X-ray focusing detection system

Abstract

The invention relates to the field of X-ray spectrum detection, in particular to an X-ray focusing detection system and a manufacturing method of a diffraction crystal of the X-ray focusing detection system, and the system comprises an X-ray source, the diffraction crystal and an X-ray detector; the surface of the manufactured diffraction crystal is provided with a diffraction surface which is in an arc curved surface shape in the meridian direction and the sagittal direction, so that X-rays emitted by an X-ray source can be received and detected by an X-ray detector after being diffracted by the diffraction surface of the diffraction crystal according to the Bragg law. Receiving image points of X-rays on the detector are located on a Rowland circle which is in coplanar tangent with an arc line of the diffraction surface in the meridian direction of the diffraction surface, and the corresponding receiving image points of the X-rays with different energies on the X-ray detector and the position point of the X-ray source are located on the same straight line. And the surface of the diffraction crystal is a curved surface formed by rotating the arc line in the meridian direction by taking the straight line as an axis. According to the invention, the imaging quality and the detection precision of the X-ray spectrum are effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of X-ray spectrum detection, and in particular to an X-ray focusing detection system and a method for manufacturing a diffraction crystal thereof. Background Art

[0002] X-ray focusing crystal spectrometers have important applications in high-energy-density physics, inertial confinement fusion (ICF), and plasma diagnostics. Using the principle of Bragg diffraction, they enable high-resolution measurements of X-ray spectra and, combined with the focusing properties of crystals, provide spatially resolved spectral information. While conventional planar crystal spectrometers are simple and easy to implement, their lack of focusing functionality results in low photon collection efficiency and limited spectral resolution, making them difficult to meet the demands of high-precision measurements. Furthermore, when measuring high-energy X-rays, the brightness of the spectral lines of planar crystal spectrometers is relatively dim, making it difficult to resolve complex spectral features. In plasma diagnostics, particularly in measurements of warm dense plasmas (WDM) and high-temperature dense plasmas (HED), it is necessary to simultaneously acquire spectral information with both high spatial and spectral resolution, but existing technologies often struggle to meet both requirements. Furthermore, the difficulty of resolving complex spectra is a major bottleneck in existing technologies. In plasma spectral measurements, the spectral lines are complex and dense, making it difficult for conventional inhomogeneous dispersion spectrometers to achieve rapid and accurate spectral resolution, which limits our understanding of the physical processes within the plasma.

[0003] In inertial confinement fusion experiments, in order to accurately measure parameters such as the electron temperature, electron density, and opacity of the plasma, the spectrometer needs to have high spectral resolution (such as E / ΔE>10000) so that it can distinguish complex spectral lines. In addition, in order to meet the needs of complex spectral measurements, the spectrometer needs to achieve uniform dispersion over a wide spectral range to simplify the spectral analysis process. In practical applications, especially in measurements of low-brightness X-ray sources, the spectrometer also needs to have high photon collection efficiency to improve the signal-to-noise ratio. For example, in X-ray Thomson scattering measurements in shock compression experiments, due to the low brightness of the X-ray source, the high photon collection efficiency of the spectrometer is crucial for obtaining high-quality spectral data. In addition, with the development of experimental technology, higher requirements are placed on the real-time and dynamic measurement capabilities of the spectrometer. For example, in laser plasma experiments, the spectrometer needs to be able to respond quickly and record transient spectral changes to capture key information in the plasma evolution process.

[0004] To address the shortcomings of existing technologies, researchers have developed a variety of improved spectrometers. Curved crystals are the core dispersive elements in radiation diagnostics. Currently, a variety of surface-shaped crystals are used, including planar, cylindrical, elliptical, conical, spherical, and toroidal. Planar crystal structures lack focusing capabilities and suffer from low photon collection rates and dim spectral lines. Cylindrical crystals can reflect X-rays from multiple energy points onto the central axis of the cylinder. The measurable energy band range increases with crystal length, and all spectral lines incident on the cylindrical surface can be focused. However, they lack a Rowland circle structure, making the spectrometer's spectral resolution affected by the size of the light source and the thickness of the diffraction crystal. Because the radius of the off-axis cylinder of a conical crystal is not equal to the local radius of the cone, the paraxial approximation for off-axis X-rays can lead to the following problems: X-rays of the same wavelength experience defocusing on the imaging surface, affecting spectral resolution. X-rays of the same wavelength no longer focus to a point on the detection surface, but instead defocus into lines. This structural asymmetry affects the spectrometer's spectral resolution and spectral line intensity, resulting in a relatively narrow spectral range for conical structures. Continuous conical crystals can focus X-rays across a wide spectral range, but significant aberrations between different energy points still hinder spectral resolution. And like cylindrical diffraction, aberrations are affected by the size of the light source. Spherical and toroidal crystal structures suffer from John errors, resulting in a very narrow energy spectrum, allowing them to focus only within a single energy range.

[0005] In summary, existing X-ray spectrometers cannot solve the following key problems at the same time: the image points corresponding to X-rays of different energies are not on the same straight line, and the curved surface characteristics of the crystal imaging surface will introduce significant aberrations; the X-ray receiving point on the meridian plane deviates from the design position of the Rowland circle, and the light source size expansion effect and the influence of crystal thickness further increase the system aberrations. These factors together cause the spectral resolution to decrease and the photon collection efficiency to decrease, which seriously restricts the ability to obtain accurate spectral data in high-energy density physics research, and becomes the main technical bottleneck for improving the success rate of inertial confinement fusion experiments and the accuracy of plasma diagnosis. Therefore, an X-ray focusing crystal spectrometer that can achieve high spectral resolution and high photon collection efficiency over a wide spectrum range is invented to solve the problem of high spectral resolution and high photon collection efficiency that is difficult to achieve in the existing technology, thereby significantly improving the performance of X-ray spectral detection. Summary of the Invention

[0006] In response to the above-mentioned deficiencies in the prior art, the present invention provides an X-ray focused detection system, which solves the problem in the prior art of difficulty in achieving both high spectral resolution and high light collection efficiency, and significantly improves the performance of X-ray spectral detection.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention discloses an X-ray focusing detection system, comprising an X-ray source, a diffraction crystal and an X-ray detector; the surface of the diffraction crystal has a diffraction surface that is an arc-shaped surface in the meridional and sagittal directions, so that the X-rays emitted by the X-ray source can be received and detected by the X-ray detector after being diffracted by the diffraction surface of the diffraction crystal according to the Bragg law, and the receiving image points of the X-rays on the detector are located on a Rowland circle that is coplanar and tangent to the arc of the diffraction surface in its meridional direction, and the receiving image points corresponding to X-rays of different energies on the X-ray detector and the position point of the X-ray source are located on the same straight line, and the surface of the diffraction crystal is a curved surface formed by rotating the arc in the meridional direction with the straight line as the axis.

[0009] Preferably, the arc of the diffraction surface of the diffraction crystal surface in its meridional direction is an arc formed by connecting the arcs corresponding to X-rays of different energies; wherein, after the X-rays of each energy are diffracted through their corresponding arc positions, the receiving image point received by the X-ray detector is located on a Rowland circle that is coplanar and tangent to the arc, and the diameter of the Rowland circle is the same as the radius of the arc.

[0010] In a second aspect, the present invention further provides a method for manufacturing a diffraction crystal, which is used to manufacture the diffraction crystal in the above-mentioned X-ray focusing detection system, comprising the following steps:

[0011] S1. Construct an arc as a crystal diffraction surface, wherein the arc radius is R, and set an X-ray source S on one side of the arc;

[0012] S2. Obtain an intersection point C(x1, y1) where the X-rays emitted by the X-ray source S intersect the arc; draw a center O(x, y) of the curvature circle of the arc through the intersection point C, connect point C and point O to obtain a line segment OC; and draw a Rowland circle with a diameter R with the midpoint of the line segment OC as the circle center.

[0013] S3. Diffract the X-ray emitted by the X-ray source S through the line connecting the intersection point C(x1, y1) where the arc intersects to obtain an X-ray diffraction line; extend the X-ray diffraction line until it intersects the Rowland circle to obtain the receiving image point P(x′, y′);

[0014] S4. Determine the energy range according to the X-ray spectrum emitted by the X-ray source S, and calculate the initial Bragg angle α0 using the following formula: Where E′ represents the median of the energy range, and d represents the lattice parameter of the crystal;

[0015] S5. For multiple energy values ​​within the energy range, use The Bragg angle θ corresponding to each energy value is calculated, where E represents a specific energy value within the X-ray spectrum energy range. Based on the calculated Bragg angle θ corresponding to each energy value and the initial Bragg angle α0, the rotation angle φ of the crystal relative to the X-ray source S is calculated by the following formula: α0+β1·φ+β2·φ 2 =θ, where β1 and β2 represent the crystal plane curvature parameters;

[0016] S6. By adjusting the crystal plane curvature parameters β1 and β2, repeating steps S1 to S3, obtaining the distance ρ from the intersection point C to the X-ray source S corresponding to the minimum error value of the slope y′ / x′ of the X-ray diffraction line at different energies, and then determining the position of the intersection point C where the X-ray and the arc intersect at different energies and the position of the corresponding receiving image point P based on the corresponding rotation angle φ at different energies and the distance ρ, and then connecting the curves obtained by connecting the intersection points, and rotating the curve formed by the straight line formed by connecting the receiving image point P corresponding to the X-rays of different energies on the X-ray detector and the position of the X-ray source as the axis to form a curved surface, which is used as the diffraction surface shape of the crystal;

[0017] S7. Calculate the crystal length based on the upper and lower energy limits of the X-ray energy range and the slope y′ / x′ of the X-ray diffraction line at the corresponding energy values; process the diffraction surface of the crystal based on the crystal length and the crystal surface shape, and determine the positioning position of the X-ray detector based on the position of the receiving image point P corresponding to X-rays of different energies.

[0018] Preferably, in step S6, the distance ρ from the intersection point C to the X-ray source point S is calculated using the following formula:

[0019]

[0020] Where ρ0 is a configurable constant, which represents the distance from the intersection point C to the X-ray source point S when the rotation angle φ is 0.

[0021] Preferably, in step S3, according to the Rowland circle principle, the imaging receiving point P(x′, y′) on the Rowland circle is calculated by the following formula:

[0022] x′=ρcos(φ)+Rsin(θ)cos(2θ+φ);

[0023] y′=ρsin(φ)+Rsin(θ)sin(2θ+φ);

[0024] Where x′ and y′ represent the abscissa and ordinate of the receiving image point P, respectively, and ρ represents the polar radius corresponding to the intersection point C(x1,y1), that is, the distance from the intersection point C to the X-ray source S.

[0025] Preferably, in step S6, the curvature radius R corresponding to the intersection point C(x1, y1) with the arc is calculated by the following formula:

[0026]

[0027] Where ρ represents the polar radius corresponding to the intersection point C(x1,y1), that is, the distance from the intersection point C to the X-ray source S.

[0028] Preferably, the X-ray source S is positioned within the Rowland circle.

[0029] Preferably, the X-ray source S is positioned on the Rowland circle.

[0030] Preferably, the X-ray source S is positioned outside the Rowland circle.

[0031] Preferably, the crystal is one of crystalline materials such as quartz, Ge, and Si.

[0032] Compared with the prior art, the present invention has the following technical effects:

[0033] (1) The present invention dynamically determines the geometric shape of the diffraction crystal by optimizing the Bragg diffraction conditions and the curvature of the diffraction surface, thereby achieving X-ray focusing with high spectral resolution, significantly enhancing the light collection efficiency and improving the focusing performance. This optimized design enables the X-rays to be accurately focused to a predetermined point on the Rowland circle, overcoming the influence of the light source size on the spectral resolution, and rotating along a fixed line. According to the principle of rotational symmetry, the spectra of the same Bragg angle converge to the same point, thereby improving the imaging quality and detection accuracy.

[0034] (2) The design method of the present invention has good adaptability and can be customized according to different X-ray energy ranges and application requirements. The detector position determined by the Rowland circle principle optimizes the detection surface design, ensuring that the detector can receive the optimized X-ray signal, thereby improving detection efficiency and data quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to make the purpose, technical solutions and advantages of the invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings, in which:

[0036] Figure 1 Schematic diagram of spherical curved crystal imaging in the prior art;

[0037] Figure 2 Schematic diagram of conical curved crystal imaging in an X-ray focusing detection system;

[0038] Figure 3 A schematic diagram of the principle of determining the diffraction surface shape of a diffraction crystal in the X-ray focusing detection system of the present invention;

[0039] Figure 4 Schematic diagram of the relationship between components of the X-ray focusing detection system of the present invention.

[0040] Explanation of reference numerals: 100 - X-ray source; 101 - X-ray; 110 - diffraction crystal; 120 - X-ray detector; 130 - Rowland circle; 140 - section; 150 - arc. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but only represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0042] The present invention will be described in further detail below with reference to the accompanying drawings.

[0043] X-ray plasma spectroscopy plays an important role in the field of inertial confinement fusion (ICF), providing a powerful tool for studying the formation and evolution mechanism of plasma and diagnosing plasma conditions. Bragg diffraction-based curved crystal spectrometers are commonly used to study high-energy-density plasma sources. The measured X-ray spectrum can provide rich information on plasma parameters, including electron temperature and its gradient, electron density and its gradient, opacity, etc. Therefore, it is becoming increasingly important to study the state of matter under extreme conditions in high-energy-density plasmas. The requirements for these measurements are as follows: (1) high spectral resolution of E / dE = 10000 within the spectral energy range of 1keV; (2) high light collection efficiency to improve the signal-to-noise ratio; (3) elimination of the source size broadening effect that reduces the spectral resolution; (4) the detection system has a flat-field response characteristic. Currently available spectrometers cannot meet requirements (1)-(4) at the same time. These spectrometers use standard crystals, such as planar crystals, spherical crystals, cylindrical curved crystals, and traditional ring crystals bent into a constant major radius R and a constant minor radius r, so a new focusing crystal surface structure is required.

[0044] Embodiments provided herein fulfill at least some of the above requirements to provide accurate X-ray spectroscopy measurements.

[0045] In order to better understand the technology of the present invention, the background technology of the present invention is now explained in detail.

[0046] 1. Spherical curved crystal spectrometer

[0047] like Figure 1 The figure shows a schematic diagram of spherical curved crystal imaging. The imaging principle of spherical curved crystal is similar to that of spherical mirror imaging. The diffraction of X-rays on the crystal must meet the Bragg condition, namely:

[0048] 2dsinθ=nλ;

[0049] Where d is the lattice spacing and λ is the X-ray wavelength.

[0050] As can be seen from the above formula, the Bragg diffraction angle directly affects the imaging center energy point, thus placing extremely high demands on the Bragg diffraction angle of the crystal in the imaging system. From the perspective of imaging principles, at high magnifications, the spatial positioning of the backlight source and sample is extremely demanding. Therefore, spherical curved crystal systems require extremely high precision in the Bragg diffraction angle and the spatial positioning of the backlight source and sample, increasing the complexity and difficulty of debugging the system. Furthermore, strict requirements for the monochromaticity and stability of the backlight source limit its applicability under different experimental conditions. Spherical crystal structures are subject to John errors in imaging, and such structures have a very narrow energy spectrum, limiting focus to a single energy range.

[0051] 2. Conical curved crystal spectrometer

[0052] like Figure 2 The figure shows a schematic diagram of conical curved crystal imaging. A conical curved crystal spectrometer utilizes the Bragg diffraction principle of crystals. By bending the diffraction surface of the crystal into a cylindrical or conical surface, the spectrometer achieves partial focusing, thereby improving photon collection efficiency. Ray tracing is used to theoretically analyze and calculate key performance parameters of the spectrometer, such as dispersion characteristics, spectral resolution, and brightness. Optimized designs are then developed based on different structures (such as I-type and II-type) and the corresponding positional relationships between the light source, crystal, and detector.

[0053] However, although cylindrical and conical curved crystal spectrometers have shown significant performance advantages in spectral analysis, their technical implementation still faces some challenges. First, the design and manufacturing process of conical curved crystal spectrometers is relatively complex, requiring high-precision processing technology to achieve the ideal crystal curvature shape and geometric structure, which increases the manufacturing difficulty and cost. Second, when the incident light deviates from the central section or main section of the spectrometer, the system will experience defocus aberration, causing light of the same wavelength to be unable to focus on the imaging point, but instead defocus into a line, which will significantly affect the spatial and spectral resolution capabilities of the spectrometer. In addition, the actual performance of the spectrometer is also limited by external factors such as the size of the light source, off-axis imaging, and the spatial resolution of the detector. These factors may lead to a decrease in spectral resolution, thereby affecting the measurement accuracy of the spectrometer.

[0054] In summary, existing X-ray spectrometers cannot solve the following key problems at the same time: the image points corresponding to X-rays of different energies are not on the same straight line, and the curved surface characteristics of the crystal imaging surface will introduce significant aberrations; the X-ray receiving point on the meridian plane deviates from the design position of the Rowland circle, and the light source size expansion effect and the influence of crystal thickness further increase the system aberrations. These factors together cause the spectral resolution to decrease and the photon collection efficiency to decrease, which seriously restricts the ability to obtain accurate spectral data in high-energy density physics research, and becomes the main technical bottleneck for improving the success rate of inertial confinement fusion experiments and the accuracy of plasma diagnosis. Therefore, an X-ray focusing crystal spectrometer that can achieve high spectral resolution and high photon collection efficiency over a wide spectrum range is invented to solve the problem of high spectral resolution and high photon collection efficiency that is difficult to achieve in the existing technology, thereby significantly improving the performance of X-ray spectral detection.

[0055] Based on the above background technology and the technical problems to be solved, the present invention discloses a wide spectrum, high resolution and high collection rate X-ray focused detection system, such as Figure 3 As shown, it includes an X-ray source 100, a diffraction crystal 110 and an X-ray detector 120; the surface of the diffraction crystal 110 has a diffraction surface that is an arc-shaped surface in the meridional direction and the sagittal direction, so that the X-ray 101 emitted by the X-ray source 100 can be received and detected by the X-ray detector 120 after being diffracted by the diffraction surface of the diffraction crystal 110 according to the Bragg law. The receiving image point of the X-ray on the detector is located on a Rowland circle 130 that is coplanar and tangent to the arc 150 of the diffraction surface in its meridional direction, and the receiving image points corresponding to X-rays of different energies on the X-ray detector 120 and the position point of the X-ray source 100 are located on the same straight line (SP line). The diffraction surface on the surface of the diffraction crystal 110 is an arc-shaped rotating surface with the arc 150 in its meridional direction as the axis. The image points corresponding to X-rays of different energies lie on the same straight line. The curved crystal, formed with this line as the axis of rotation, ensures the same Bragg angle in the sagittal plane, enhancing the X-ray collection efficiency. Furthermore, the plane of this line serves as the imaging surface, reducing aberrations introduced by conventional curved crystal imaging surfaces. The X-ray receiving image point on the detector lies on a Rowland circle coplanar and tangent to the arc of the diffraction surface in its meridional direction, effectively minimizing aberrations caused by factors such as light source size expansion and crystal thickness.

[0056] Specifically, if Figure 3As shown, the arc 150 of the diffraction surface of the diffraction crystal 110 in its meridian direction is an arc formed by connecting the arcs corresponding to the X-rays of different energies; wherein, the receiving image point P received by the X-ray detector 120 after the X-rays of each energy are diffracted through the corresponding arc position is located on the Rowland circle 130 that is coplanar and tangent to the arc, and the diameter of the Rowland circle 130 is the same as the radius of the arc, both of which are R.

[0057] The present invention also correspondingly discloses a method for manufacturing a diffraction crystal, which is used to manufacture the diffraction crystal in the above-mentioned X-ray focusing detection system.

[0058] When this embodiment is specifically applied, the working principle of the present invention can be obtained by Figure 3 The mathematical derivation process is implemented, including:

[0059] In the polar coordinate system, the intersection point C is realized by rotating the angle φ and the polar radius ρ of the intersection point C, that is, x1 = ρcos(φ), y1 = ρsin(φ);

[0060] Next, solve the derivative at the intersection C(x1,y1), that is, the rate of change of y1 with respect to x1 is equal to the tangent of the Bragg angle, which reflects the slope of the diffraction surface, that is

[0061] Then, the rate of change of the Rowland circle radius ρ with respect to the rotation angle φ is solved, that is,

[0062] The functional relationship between α and φ can be expressed by the formula α-φ=α0+β1·φ+β2·φ 2 +β3·φ 3 +...+β n ·φ n express,

[0063] Among them, α0 is the initial Bragg angle, β1, β2…β n is the crystal plane curvature parameter;

[0064] Differentiating both sides gives:

[0065] The rotation angle φ here is small, and the higher-order terms β3…β can be omitted. n Then we get the rate of change of the Rowland circle ρ relative to the rotation angle φ, that is

[0066] Integrating both sides, we get: Among them, ρ0 is a configurable constant, which represents the distance from the crystal point to the origin when φ is 0;

[0067] Therefore, the curvature radius R corresponding to the intersection point C(x1,y1) intersecting the arc is expressed as:

[0068]

[0069] Finally, according to the Rowland circle principle, the imaging intersection point P can be obtained as:

[0070] x′=ρcos(φ)+Rsin(θ)cos(2θ+φ);

[0071] y′=ρsin(φ)+Rsin(θ)sin(2θ+φ);

[0072] Based on the above Figure 3 The mathematical derivation and formula derivation are performed based on the schematic diagram of the X-ray focusing detection system shown in the figure to determine the shape and curvature of the crystal surface, thereby achieving precise focusing of the X-rays. Therefore, the method for making the diffraction crystal proposed in this embodiment can be summarized as follows:

[0073] S1. Construct an arc as a crystal diffraction surface, wherein the arc radius is R, and set an X-ray source S on one side of the arc;

[0074] S2. Obtain an intersection point C(x1, y1) where the X-rays emitted by the X-ray source S intersect the arc; draw a center O(x, y) of the curvature circle of the arc through the intersection point C, connect point C and point O to obtain a line segment OC; and draw a Rowland circle with a diameter R with the midpoint of the line segment OC as the circle center.

[0075] S3. Diffract the X-ray emitted by the X-ray source S through the line connecting the intersection point C(x1, y1) where the arc intersects to obtain an X-ray diffraction line; extend the X-ray diffraction line until it intersects the Rowland circle to obtain the receiving image point P(x′, y′);

[0076] S4. Determine the energy range according to the X-ray spectrum emitted by the X-ray source S, and calculate the initial Bragg angle α0 using the following formula: Where E′ represents the median of the energy range, and d represents the lattice parameter of the crystal;

[0077] S5. For multiple energy values ​​within the energy range, use The Bragg angle θ corresponding to each energy value is calculated, where E represents a specific energy value within the X-ray spectrum energy range. Based on the calculated Bragg angle θ corresponding to each energy value and the initial Bragg angle α0, the rotation angle φ of the crystal relative to the X-ray source S is calculated by the following formula: α0+β1·φ+β2·φ 2 =θ, where β1 and β2 represent the crystal plane curvature parameters;

[0078] S6. By adjusting the crystal plane curvature parameters β1 and β2, repeating steps S1 to S3, obtaining the distance ρ from the intersection point C to the X-ray source S corresponding to the minimum error value of the slope y′ / x′ of the X-ray diffraction line at different energies, and then determining the position of the intersection point C where the X-ray and the arc intersect at different energies and the position of the corresponding receiving image point P based on the corresponding rotation angle φ at different energies and the distance ρ, and then connecting the curves obtained by connecting the intersection points, and rotating the curve formed by the straight line formed by connecting the receiving image point P corresponding to the X-rays of different energies on the X-ray detector and the position of the X-ray source as the axis to form a curved surface, which is used as the diffraction surface shape of the crystal;

[0079] S7. Calculate the crystal length based on the upper and lower energy limits of the X-ray energy range and the slope y′ / x′ of the X-ray diffraction line at the corresponding energy values; process the diffraction surface of the crystal based on the crystal length and the crystal surface shape, and determine the positioning position of the X-ray detector based on the position of the receiving image point P corresponding to X-rays of different energies.

[0080] The component relationship and working optical path of the X-ray focusing detection system of the present invention are finally obtained as follows: Figure 4 As shown, the X-ray focusing detection system is used to detect the X-rays emitted by the X-ray source after diffraction. The diffraction surface on the surface of the diffraction crystal can diffract all the X-rays emitted by the X-ray source and radiated to the diffraction surface and then be received and detected by the detector.

[0081] Specifically, the X-ray source S can be positioned on, outside or inside the Rowland circle.

[0082] In this way, the position of the X-ray source can be selected according to the specific application requirements and experimental objectives. Each configuration has its own specific advantages and limitations. Therefore, choosing the appropriate configuration can optimize the experimental results and improve the analysis accuracy.

[0083] Specifically, the crystal is one of quartz, Ge, Si and other crystal materials.

[0084] In a specific embodiment, the X-ray focused detection system further comprises a stage for positioning the diffraction crystal on the Rowland circle relative to the X-ray source so as to align at least one direction of the diffraction surface with the tangent plane. For example, the stage may comprise a linear motion stage configured to adjust the position of the diffraction crystal (e.g., along substantially perpendicular x, y, and z directions) and a rotational motion stage configured to adjust the orientation of the diffraction crystal.

[0085] In summary, the present invention dynamically determines the geometric shape of the diffraction crystal by optimizing the Bragg diffraction conditions and the curvature of the diffraction surface, achieving high-spectral-resolution X-ray focusing, significantly enhancing light collection efficiency and improving focusing performance. This optimized design enables X-rays to be precisely focused to a predetermined point on the Rowland circle, improving imaging quality and detection accuracy. Furthermore, this design method is highly adaptable and can be customized to suit different X-ray energy ranges and application requirements. The detector position, determined by the Rowland circle principle, optimizes the detection surface design, ensuring that the detector receives the optimal X-ray signal, thereby improving detection efficiency and data quality.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described with reference to the preferred embodiments of the present invention, it should be understood by those skilled in the art that various changes can be made in form and details without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. An X-ray focused detection system, characterized in that: The invention comprises an X-ray source, a diffraction crystal and an X-ray detector; the surface of the diffraction crystal has a diffraction surface that is an arc-shaped surface in the meridional direction and the sagittal direction, so that the X-rays emitted by the X-ray source can be received and detected by the X-ray detector after being diffracted by the diffraction surface of the diffraction crystal according to the Bragg law, the receiving image point of the X-ray on the detector is located on a Rowland circle that is coplanar and tangent to the arc of the diffraction surface in its meridional direction, and the receiving image points corresponding to X-rays of different energies on the X-ray detector and the position point of the X-ray source are located on the same straight line, and the surface of the diffraction crystal is a curved surface formed by rotating the arc in the meridional direction with the straight line as the axis.

2. The X-ray focus detection system according to claim 1, characterized in that: The arc of the diffraction surface of the diffraction crystal in its meridional direction is an arc formed by connecting the arcs corresponding to X-rays of different energies; wherein, after the X-rays of each energy are diffracted through the corresponding arc position, the receiving image point received by the X-ray detector is located on a Rowland circle that is coplanar and tangent to the arc, and the diameter of the Rowland circle is the same as the radius of the arc.

3. A method for manufacturing a diffraction crystal, used for manufacturing the diffraction crystal in the X-ray focusing detection system according to claim 1 or 2, characterized in that: The steps include: S1. Construct an arc as a crystal diffraction surface, wherein the arc radius is R, and set an X-ray source S on one side of the arc; S2. Obtain an intersection point C(x1, y1) where the X-rays emitted by the X-ray source S intersect the arc; draw a center O(x, y) of the curvature circle of the arc through the intersection point C, connect point C and point O to obtain a line segment OC; and draw a Rowland circle with a diameter R with the midpoint of the line segment OC as the circle center. S3. Diffract the X-ray emitted by the X-ray source S through the line connecting the intersection point C(x1, y1) where the arc intersects to obtain an X-ray diffraction line; extend the X-ray diffraction line until it intersects the Rowland circle to obtain the receiving image point P(x′, y′); S4. Determine the energy range according to the X-ray spectrum emitted by the X-ray source S, and calculate the initial Bragg angle α0 using the following formula: Where E′ represents the median of the energy range, and d represents the lattice parameter of the crystal; S5. For multiple energy values ​​within the energy range, use The Bragg angle θ corresponding to each energy value is calculated, where E represents a specific energy value within the X-ray spectrum energy range. Based on the calculated Bragg angle θ corresponding to each energy value and the initial Bragg angle α0, the rotation angle φ of the crystal relative to the X-ray source S is calculated by the following formula: α0+β1·φ+β2·φ 2 =θ, where β1 and β2 represent the crystal plane curvature parameters; S6. By adjusting the crystal plane curvature parameters β1 and β2, repeating steps S1 to S3, obtaining the distance ρ from the intersection point C to the X-ray source S corresponding to the minimum error value of the slope y′ / x′ of the X-ray diffraction line at different energies, and then determining the position of the intersection point C where the X-ray and the arc intersect at different energies and the position of the corresponding receiving image point P based on the corresponding rotation angle φ at different energies and the distance ρ, and then connecting the curves obtained by connecting the intersection points, and rotating the curve formed by the straight line formed by connecting the receiving image point P corresponding to the X-rays of different energies on the X-ray detector and the position of the X-ray source as the axis to form a curved surface, which is used as the diffraction surface shape of the crystal; S7. Calculate the crystal length based on the upper and lower energy limits of the X-ray energy range and the slope y′ / x′ of the X-ray diffraction line at the corresponding energy values; process the diffraction surface of the crystal based on the crystal length and the crystal surface shape, and determine the positioning position of the X-ray detector based on the position of the receiving image point P corresponding to X-rays of different energies.

4. The method for producing a diffraction crystal according to claim 3, wherein: In step S6, the distance ρ from the intersection point C to the X-ray source point S is calculated as follows: Where ρ0 is a configurable constant, which represents the distance from the intersection point C to the X-ray source point S when the rotation angle φ is 0.

5. The method for producing a diffraction crystal according to claim 3, wherein: In step S3, according to the Rowland circle principle, the imaging receiving point P(x′, y′) on the Rowland circle is calculated by the following formula: x′=ρcos(φ)+Rsin(θ)cos(2θ+φ); y′=ρsin(φ)+Rsin(θ)sin(2θ+φ); Where x′ and y′ represent the abscissa and ordinate of the receiving image point P, respectively, and ρ represents the polar radius corresponding to the intersection point C(x1,y1), that is, the distance from the intersection point C to the X-ray source S.

6. The method for producing a diffraction crystal according to claim 3, wherein: In step S6, the curvature radius R corresponding to the intersection point C(x1, y1) with the arc is calculated by the following formula: Where ρ represents the polar radius corresponding to the intersection point C(x1,y1), that is, the distance from the intersection point C to the X-ray source S.

7. The method for producing a diffraction crystal according to claim 3, wherein: The X-ray source S is positioned within the Rowland circle.

8. The method for producing a diffraction crystal according to claim 3, wherein: The X-ray source S is positioned on the Rowland circle.

9. The method for producing a diffraction crystal according to claim 3, wherein: The X-ray source S is positioned outside the Rowland circle.

10. The method for producing a diffraction crystal according to claim 3, wherein: The crystal is one of quartz, Ge, Si and other crystal materials.

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