An X-ray phase sensitivity resolution plate

Abstract

The invention discloses an X-ray phase sensitivity resolution plate, comprising a substrate and a phase structure; the size of the phase structure corresponds to the X-ray energy of the imaging system, and the phase structure is distributed in a spatial periodicity, the phase structure is a first phase structure arranged on the surface of the substrate; or the phase structure is a second phase structure formed by opening a cavity in the substrate; or the phase structure is a third phase structure formed by opening a cavity in the substrate and filling the cavity; the relationship between the phase structure and the spatial period satisfies: when the phase structure remains unchanged, the spatial period changes successively; when the spatial period remains unchanged, the phase structure changes successively; the substrate, the first phase structure, and the third phase structure adopt low atomic number materials, and the materials adopted by the substrate are different from those adopted by the first phase structure and the third phase structure. The invention can be used for the evaluation and experimental detection of the phase sensitivity and image resolution of the X-ray phase contrast imaging system.

Description

Technical Field

[0001] The invention belongs to the technical field of X-ray imaging, and relates to an X-ray device, and in particular to an X-ray phase sensitivity resolution plate used for image quality evaluation and detection of an X-ray phase contrast imaging system. Background Art

[0002] Since Roentgen discovered X-rays, X-ray imaging has been widely used to detect the internal structure of matter. Compared with X-ray absorption imaging, X-ray phase contrast imaging can obtain high-contrast images of light element materials. This is because the amount of change in the X-ray phase caused by such materials is 10 times the amount of change in its amplitude. 3 There are many types of light element materials, including carbon fiber, optical fiber and organic materials, as well as biological soft tissues and organs composed of them. Therefore, X-ray phase contrast imaging technology will be widely used in basic research fields such as materials science, life science and medicine, and can also be used in industrial non-destructive testing, safety inspection, biomedical imaging and biological archaeology.

[0003] Since the 1990s, X-ray phase contrast imaging has made great progress. According to different methods of obtaining phase information, it can be divided into various types such as crystal interferometry, diffraction enhancement, free space propagation and grating interferometry. However, since X-ray phase contrast imaging has high requirements on the coherence and brightness of the light source, early experimental studies need to use synchrotron radiation sources or microfocus sources to achieve it, which limits the application of these methods in practice. In 2006, F. Pfeiffer et al. realized grating phase contrast imaging experiments in ordinary laboratories using array X-ray sources based on the Talbot-Lau principle, breaking away from the limitations of synchrotron radiation sources and microfocus sources, and making people see the hope of grating phase contrast imaging technology moving towards practical application. Inspired and promoted by this work, many research groups at home and abroad have carried out relevant theoretical research and device development work on X-ray grating phase contrast imaging, and built experimental devices with unique characteristics. Some have even carried out research on medical imaging applications.

[0004] In China, a research team from Tsinghua University built an X-ray grating phase contrast imaging system based on the moiré deflection method. A research team from the Institute of High Energy Physics and the University of Science and Technology of China reconstructed the three-dimensional phase information of the object using a one-step exposure back-projection method. A research team from Shenzhen University proposed an absorption-free grating differential phase contrast imaging device based on a structured anode target X-ray source and a structured conversion screen. Researchers from the Shanghai Institute of Applied Physics built a grating phase contrast imaging system for biological imaging at the Shanghai Light Source.

[0005] Internationally, A. Momose et al. in Japan developed a grating phase contrast imaging prototype based on their original research to conduct experimental research on human arthritis, but its imaging field of view can only reach 6cm×6cm. C. David et al. in Switzerland used an X-ray grating phase contrast imaging device to conduct experimental research on human breast tissue specimens, and observed fine structures that conventional breast machines could not identify from their scattered images. F. Pfeiffer et al. developed a small X-ray grating phase contrast CT device at the Technical University of Munich in Germany and are exploring the application potential of this imaging device. Research groups from institutions such as the University of Wisconsin-Madison, the National Institutes of Health, the University of Zurich in Switzerland, and the University of Nuremberg-Erlangen in Germany have also built X-ray grating phase contrast imaging systems in their respective laboratories to carry out related research work.

[0006] The construction and experimental work of the above imaging devices have greatly promoted the research progress of X-ray grating phase contrast imaging technology, but in general, this imaging technology is still in its infancy, and there are many problems in imaging theory, device development and experimental technology, such as the limited imaging field of view and the energy used by X-rays, the difficulty in developing large-area, high aspect ratio absorption gratings, and the lack of means and technologies for imaging quality evaluation and verification, which restrict the development and application of this technology. The existing resolution plates used in traditional X-ray absorption imaging systems are fixed periodic structures made of strong absorption materials (such as gold), which cannot reflect the phase structure changes of weak absorption materials, and are therefore not suitable for the evaluation and detection experiments of the imaging quality of X-ray phase contrast imaging systems. Summary of the invention

[0007] The technical problem to be solved by the present invention is that, in view of the defect that the existing resolution plates used in traditional X-ray absorption imaging systems cannot reflect the phase structure information of weakly absorbing materials, and the problem of lack of means and technology for evaluating and verifying the imaging quality of X-ray phase contrast imaging systems, an X-ray phase sensitivity resolution plate with a relatively simple structure is provided, which can form a phase contrast for weak X-ray absorption and is very suitable for evaluation and detection experiments of the imaging quality of X-ray phase contrast imaging systems.

[0008] The technical solution adopted by the present invention to solve its technical problem is:

[0009] An X-ray phase sensitivity resolution plate, comprising a substrate and a phase structure for reflecting the phase sensitivity of the resolution plate; the size of the phase structure corresponds to the X-ray energy of the imaging system, and the phase structure is spatially periodically distributed;

[0010] The phase structure is a first phase structure arranged on the surface of the substrate; or the phase structure is a second phase structure formed by opening a cavity in the substrate; or the phase structure is a third phase structure formed by opening a cavity in the substrate and filling the cavity;

[0011] The relationship between the phase structure and the spatial period satisfies: when the phase structure remains unchanged, the spatial period changes successively; or when the spatial period remains unchanged, the phase structure changes successively;

[0012] The substrate, the first phase structure and the third phase structure are made of low atomic number materials, and the material used for the substrate is different from the material used for the filler in the third phase structure.

[0013] Furthermore, in the X-ray phase sensitivity resolution plate, preferably along the penetration direction of the X-ray, the phase structure is a cube structure, a wedge structure, a prism structure, a cone structure, a cylinder structure, a ring cylinder structure or a spherical structure.

[0014] Furthermore, in the X-ray phase sensitivity resolution plate, preferably, in the relationship between the phase structure and the spatial period, the phase structure remains unchanged means that the structure in the penetration direction of the X-ray remains unchanged.

[0015] Further, in the X-ray phase sensitivity resolution plate, the structure that is unchanged in the X-ray penetration direction is preferably: in a cube structure, the height in the X-ray penetration direction is unchanged; or in a wedge structure, the wedge angle corresponding to the X-ray penetration direction is unchanged; or in a prism structure, the prism angle corresponding to the X-ray penetration direction is unchanged; or in a cone structure, the cone angle corresponds to the X-ray penetration direction, and the cone angle is unchanged; or in a cylindrical structure, the radial direction of the cylinder corresponds to the X-ray penetration direction, and the radial radius of the cylinder is unchanged; or in a ring cylinder structure, the radial direction of the ring cylinder corresponds to the X-ray penetration direction, and the radial radius of the ring cylinder is unchanged; or in a spherical structure, the radius of the sphere is unchanged;

[0016] The phase structure changes successively as follows: in a cube structure, the height changes in the penetration direction of the X-rays; in a wedge structure, the wedge angle corresponding to the penetration direction of the X-rays changes; or in a prism structure, the prism angle corresponding to the penetration direction of the X-rays changes; or in a cone structure, the cone angle corresponds to the penetration direction of the X-rays, and the cone angle changes; or in a cylindrical structure, the radial direction of the cylinder corresponds to the penetration direction of the X-rays, and the radial radius of the cylinder changes; or in a ring cylinder structure, the radial direction of the ring cylinder corresponds to the penetration direction of the X-rays, and the radial radius of the ring cylinder changes; or in a spherical structure, the radius of the sphere changes.

[0017] Furthermore, in the X-ray phase sensitivity resolution plate, the spatial periodic distribution is preferably a grating-type spatial periodic distribution, a radiation-type spatial periodic distribution or a ring-type spatial periodic distribution.

[0018] Furthermore, in the X-ray phase sensitivity resolution plate, preferably, in the relationship between the phase structure and the spatial period, the successive change of the spatial period refers to: in the grating-type spatial period distribution, the periods are arranged from large to small or from small to large, and the interval distance between different period structures is the number of structures with the same period × the period, and the number of structures with the same period is 1 to 10; or in the radiation-type spatial period distribution, the period increases continuously from the center to the periphery; or in the annular spatial period distribution, the period increases continuously or decreases continuously from the center to the periphery.

[0019] Furthermore, in the X-ray phase sensitivity resolution plate, the spatial period distribution range is preferably 1 to 1000 μm.

[0020] Further, in the X-ray phase sensitivity resolution plate, when the grating type spatial periodic distribution is preferably selected, the X-ray energy is 0.2-500keV; the cube structure is 100-5000m long, 1-1000μm wide, and 1-1000μm high in the direction of X-ray penetration; or the wedge structure is 1-1000μm high in the direction of X-ray penetration, 0°<wedge angle≤90°; or the prism structure is 1-1000μm high in the direction of X-ray penetration μm, 0°<prism angle<180°; or the height of the cone structure in the direction of X-ray penetration is 1-1000μm, 0°<cone angle<180°; or the cylindrical structure is 100-5000μm high and the radius in the direction of X-ray penetration is 1-500μm; or the annular cylinder structure is 100-5000μm high and the radius in the direction of X-ray penetration is 1-500μm; or the spherical structure has a radius in the direction of X-ray penetration of 1-500μm.

[0021] Furthermore, in the X-ray phase sensitivity resolution plate, the low atomic number material is preferably at least one of beryllium, carbon single substance, silicon and light element compounds.

[0022] Furthermore, in the X-ray phase sensitivity resolution plate, it is preferred that the phase structure and the substrate are an integrated structure or the two are fixedly connected together.

[0023] The present invention has the following beneficial effects:

[0024] The present invention uses low atomic number materials as the base material or filling material for making X-ray phase sensitivity resolution plates, and the material used for the base is different from the material used for the filler in the third phase structure. The low atomic number material has a low density and exhibits weak absorption characteristics for X-rays; when X-rays pass through such materials, there will be a significant wavefront phase change, and a phase contrast for weak absorption of X-rays can be formed on the resolution plate. Therefore, the use of low atomic number materials to make X-ray phase resolution plates can reflect the phase structure changes of weakly absorbing materials, which is very suitable for the evaluation and detection experiments of the imaging quality of X-ray phase contrast imaging systems. X-ray phase contrast imaging technology is used to carry out imaging research and application of carbon fiber, optical fiber, organic materials and biological soft tissues and the organs they constitute, and quantitative image quality evaluation and detection can be performed. The size of the phase structure corresponds to the X-ray energy of the imaging system, and is applicable from soft X-rays to hard X-rays, so that the resolution plate can be used for both non-conventional X-ray source phase contrast imaging systems with small field of view and high resolution, and conventional X-ray source phase contrast imaging systems with large field of view and ordinary resolution. When the phase structure remains unchanged, the spatial period changes successively to form a discrete spatial period distribution. The number of line pairs corresponding to the corresponding period mark can be used to visually and roughly observe the range of the image resolution of the imaging system. When the spatial period remains unchanged, the phase structure changes successively and the spatial period is continuously distributed, which can quickly and accurately find the cutoff value of the image resolution of the imaging system.

[0025] The present invention designs a cube structure, a wedge structure, a prism structure, a cone structure, a cylindrical structure or a spherical structure as the phase structure of the phase resolution plate. The cube structure can directly provide the phase contrast of the internal structure of the resolution plate, the wedge structure, the prism structure or the cone structure can provide the phase gradient contrast of the internal structure of the resolution plate, and the cylindrical structure or the spherical structure can provide the continuously changing phase gradient contrast of the internal structure of the resolution plate. The X-ray phase contrast synthesis method can be divided into various types such as crystal interferometry, diffraction enhancement method, free space propagation method and grating interferometry according to its imaging principle, instrument and information acquisition method. The crystal interferometry method can obtain the phase contrast image of the internal structure of the object, the diffraction enhancement method and the grating interferometry method can obtain the phase first-order derivative contrast image of the internal structure of the object, and the free space propagation method can obtain the phase second-order derivative contrast image of the internal structure of the object. Phase resolution plates adopt different design structures and can be used in different X-ray phase contrast imaging systems. For example, the cube structure can be used in the imaging system of the crystal interferometry method, the wedge structure, prism structure and cone structure can be used in the imaging system of the diffraction enhancement method and grating interferometry method, and the cylindrical structure and spherical structure can be used in the imaging system of the free space propagation method.

[0026] The phase structure size of the resolution plate designed by the present invention corresponds to the X-ray energy of the imaging system. The X-ray energy is 0.2-500 keV; the cube structure is 100-5000 μm long, 1-1000 μm wide, and 1-1000 μm high; the wedge structure is 1-1000 μm high, and the wedge angle is 0-90°; the prism structure is 1-1000 μm high, and the prism angle is 0-108°; the cone structure is 1-1000 μm high, and the cone angle is 0-108°; the cylinder structure is 100-5000 μm high, and the radius is 1-500 μm; the sphere structure has a radius of 1-500 μm. The X-ray energy covers a range from soft X-rays to hard X-rays, and the phase structure size covers a range from microns to millimeters, so that the resolution plate can be used in a non-conventional X-ray source phase contrast imaging system with a small field of view and high resolution, and can also be used in a conventional X-ray source phase contrast imaging system with a large field of view and ordinary resolution.

[0027] The spatial periodic distribution arrangement of the phase structure of the resolution plate designed by the present invention includes grating-type spatial periodic distribution, radiation-type spatial periodic distribution and ring-type spatial periodic distribution, and the spatial periodic distribution range is 1 to 1000 μm. In the grating-type spatial periodic arrangement, the periods are arranged from large to small or from small to large, and the interval distance between different periodic structures is the number of structures with the same period × the period, and the number of structures with the same period is 1 to 10. The phase resolution plate with grating-type spatial periodic distribution has a discrete periodic distribution, and the number of line pairs corresponding to the corresponding periodic marks can intuitively and roughly observe the range of the image resolution of the imaging system. The radiation-type and ring-type spatial periodic arrangement modes continuously increase or decrease the period from the center of the resolution plate to the periphery, and their periodic distribution is continuous, which can quickly and accurately find the cutoff value of the image resolution of the imaging system.

[0028] The combination of the phase structure and the spatial period of the resolution plate designed by the present invention includes keeping the phase structure unchanged while the spatial period changes successively, or keeping the spatial period unchanged while the phase structure changes successively. In the phase sensitivity and image resolution detection experiment of the X-ray phase contrast imaging system, the image resolution of the imaging system can be measured by using a resolution plate with a constant phase structure and a successively changing spatial period; the phase sensitivity of the imaging system can be measured by using a resolution plate with a constant spatial period and a successively changing phase structure; and the two indicators of the imaging system can be measured successively by using the two successively.

[0029] The present invention designs a combination of the phase structure of the resolution plate and the substrate material in such a way that the phase structure is made on the surface of the substrate material, or the phase structure is embedded inside the substrate material. The resolution plate with the phase structure directly processed on the surface of the substrate material is realized by conventional mechanical processing technology or electrospark processing technology, which is simple, convenient, and low-cost, and is suitable for conventional X-ray source phase contrast imaging systems with large field of view and ordinary resolution. The resolution plate with the phase structure embedded inside the substrate material uses the emerging femtosecond laser processing technology or etching technology to process its internal structure, and then uses high-temperature melting filling technology, or electroplating filling technology, or nanoparticles to complete the filling of the material inside the substrate cavity. Its phase structure is complete and the period is precise, and it is suitable for unconventional X-ray source phase contrast imaging systems with small field of view and high resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0031] Figure 1a-1c It is a structural schematic diagram of a first implementation mode of a resolution panel in Example 1 of the present invention;

[0032] Figure 2 is a line logarithm distribution curve of the first implementation mode of the resolution panel in Example 1 of the present invention;

[0033] Figure 3 This is a curve showing the relationship between the structure height and the X-ray energy in the first implementation manner of the resolution plate in Example 1 of the present invention.

[0034] Figure 4 is a transmittance distribution diagram of the first implementation mode of the resolution plate in Example 1 of the present invention;

[0035] Figure 5 is a phase distribution diagram of the first implementation mode of the resolution panel in Example 1 of the present invention;

[0036] Figure 6a-6b is a schematic structural diagram of a second implementation of a resolution panel according to Example 2 of the present invention;

[0037] Figure 7 is a line logarithm distribution curve of the second implementation mode of the resolution panel of Example 2 of the present invention;

[0038] Figure 8 is a curve showing the relationship between the structural angle and the phase gradient in the second implementation manner of the resolution plate in Example 2 of the present invention;

[0039] Fig. 9 is a transmittance distribution diagram of a second implementation mode of a resolution plate in Example 2 of the present invention;

[0040] Fig.10 is a phase gradient distribution diagram of the second implementation mode of the resolution plate of Example 2 of the present invention;

[0041] Fig.11 is a schematic structural diagram of a third implementation of a resolution panel according to Example 3 of the present invention;

[0042] Fig.12 is a schematic structural diagram of a fourth implementation of a resolution panel according to Example 4 of the present invention;

[0043] Fig.13 is a schematic structural diagram of a fifth implementation manner of a resolution panel according to Example 5 of the present invention;

[0044] Fig.14 is a schematic structural diagram of a sixth implementation of a resolution panel according to Example 6 of the present invention;

[0045] Fig.15 is a schematic structural diagram of a seventh implementation manner of a resolution panel according to Example 7 of the present invention;

[0046] Figure 16a-16b is a schematic structural diagram of an eighth implementation manner of a resolution panel according to Example 8 of the present invention;

[0047] Figure 17a-17b is a schematic structural diagram of a ninth implementation manner of a resolution panel according to Example 9 of the present invention;

[0048] Fig.18 It is a structural schematic diagram of the tenth implementation manner of the resolution panel of Example 10 of the present invention. DETAILED DESCRIPTION

[0049] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0050] An X-ray phase-sensitive resolution plate comprises a substrate 100 and a phase structure 200 for reflecting the phase sensitivity of the resolution plate; the size of the phase structure 200 corresponds to the X-ray energy of the imaging system, and the phase structure 200 is spatially periodically distributed.

[0051] According to the different positions and structures of the phase structure 200, there are multiple implementation modes: the first implementation mode is that the phase structure 200 is a first phase structure arranged on the surface of the substrate 100, and the first phase structure is a solid structure; the second implementation mode is that the phase structure 200 is a second phase structure formed by opening a cavity in the substrate 100, and the second phase structure is a cavity structure; the third implementation mode is that the phase structure 200 is a third phase structure formed by opening a cavity in the substrate 100 and filling the cavity, and the third phase structure is a solid structure.

[0052] Furthermore, preferably, along the penetration direction of the X-ray, the phase structure 200 is a cube structure, a wedge structure, a prismatic structure, a cone structure, a cylindrical structure, a ring cylinder structure or a spherical structure, that is, the above structures are related to the direction, and the so-called structures are all shape structures obtained when viewed in the penetration direction of the X-ray. Among them, the cube structure refers to the shape of the phase structure 200: in the penetration direction of the X-ray, it is a rectangular parallelepiped or a cube; or the wedge structure refers to the shape of the phase structure 200: in the penetration direction of the X-ray, it is a wedge, and the wedge angle opening is facing away from the penetration direction of the X-ray; or the prismatic structure refers to the shape of the phase structure 200: in the penetration direction of the X-ray, it is a prism, and the prism angle opening is facing away from the penetration direction of the X-ray; or the cone structure refers to the shape of the phase structure 200: in the penetration direction of the X-ray, it is a cone, and the cone angle opening is facing the penetration direction of the X-ray; or the cylindrical structure refers to the shape of the phase structure 200: in the penetration direction of the X-ray, it is a cylindrical shape, and the radial direction (radial direction) of the cylinder is the penetration direction of the X-ray; or in the annular cylinder structure, the radial direction (radial direction) of the annular cylinder is the penetration direction of the X-ray; or the spherical structure refers to the shape of the phase structure 200 is a sphere, and the radius direction of the sphere is the penetration direction of the X-ray. Any of the shapes of the above-mentioned phase structure 200 is applicable to the present invention, and the shape of the phase structure 200 is selected according to the requirements of the X-ray source phase contrast imaging system. Among them, the first phase structure is a solid structure of the above-mentioned shape, the second phase structure is a cavity of the above-mentioned shape, and the third phase structure is a solid structure after the cavity of the above-mentioned shape is filled.

[0053] In the present invention, the use of a cube structure can directly provide the phase contrast of the internal structure of the resolution plate, the use of a wedge-shaped structure, or a prism structure, or a cone structure can provide the phase gradient contrast of the internal structure of the resolution plate, and the use of a cylindrical structure, or a ring cylindrical structure, or a spherical structure can provide the continuously changing phase gradient contrast of the internal structure of the resolution plate.

[0054] Since the X-ray phase contrast imaging method can be divided into various types such as crystal interferometry, diffraction enhancement, free space propagation and grating interferometry according to the imaging principle, instrument and information acquisition method, the crystal interferometry can obtain the phase contrast image of the internal structure of the object, the diffraction enhancement and grating interferometry can obtain the phase first-order derivative contrast image of the internal structure of the object, and the free space propagation can obtain the phase second-order derivative contrast image of the internal structure of the object. The phase resolution plate of the present invention can adopt the above-mentioned different phase structures 200, and be used for different X-ray phase contrast imaging systems respectively, such as the cube structure can be used for the imaging system of the crystal interferometry, the wedge structure, prism structure and cone structure can be used for the imaging system of the diffraction enhancement and grating interferometry, and the cylindrical structure, ring cylindrical structure and spherical structure can be used for the imaging system of the free space propagation method.

[0055] The substrate 100, the first phase structure, and the third phase structure are made of low atomic number materials, and the material used in the substrate 100 is different from the material used for the filler in the third phase structure. Since the present invention uses low atomic number materials as the material of the substrate 100 or the material of the phase structure 200 or the filler of the phase structure 200, the low atomic number material can be specifically selected from: at least one of beryllium, carbon single substance, silicon and light element compounds. This type of material has a low density and exhibits weak absorption characteristics for X-rays; and when X-rays pass through this type of material, there will be a significant wavefront phase change. The first phase structure and the substrate 100 are made of the same material; the substrate 100 corresponding to the second phase structure uses a material, and the second phase structure is a cavity; the substrate 100 corresponding to the third phase structure uses one of these materials, and the filler of the third phase structure is made of another of these materials as a filling material. The first phase structure, the second phase structure and the third phase structure can all form a phase contrast with weak absorption of X-rays on the resolution plate. Therefore, using this type of material to make X-ray phase resolution plates can reflect the 200° changes in the phase structure of weakly absorbing materials, and is very suitable for evaluation and detection experiments of imaging quality of X-ray phase contrast imaging systems. X-ray phase contrast imaging technology can be used to carry out imaging research and applications of carbon fiber, optical fiber, organic materials, biological soft tissues and the organs they constitute, and quantitative image quality evaluation and detection can be performed.

[0056] Carbon single substance is carbon single substance, and its main component is single carbon. Carbon single substance can be specifically selected from: diamond, graphite, C60 or graphene, and light element compound can be specifically selected from: PS (polystyrene), PMMA (polymethyl methacrylate) or PTFE (polytetrafluoroethylene).

[0057] The size of the phase structure 200 of the resolution plate designed by the present invention corresponds to the X-ray energy of the imaging system.

[0058] For example, when a grating type spatial periodic distribution is selected, the X-ray energy is 0.2-500 keV; the cube structure is 100-5000 m long, 1-1000 μm wide, and 1-1000 μm high in the direction of X-ray penetration; or the wedge structure is 1-1000 μm high in the direction of X-ray penetration, 0°<wedge angle≤90°; or the prism structure is 1-1000 μm high in the direction of X-ray penetration, 0°<prism angle<1 80°; or the cone structure has a height of 1 to 1000 μm in the direction of X-ray penetration, 0°<cone angle<180°; or the cylindrical structure has a height of 100 to 5000 μm and a radius of 1 to 500 μm in the direction of X-ray penetration; or the annular cylindrical structure has a height of 100 to 5000 μm and a radius of 1 to 500 μm in the direction of X-ray penetration; or the spherical structure has a radius of 1 to 500 μm in the direction of X-ray penetration. The above-mentioned phase structure 200 with different structures covers a size range from micrometers to millimeters, so that the resolution plate can be used for non-conventional X-ray source phase contrast imaging systems with small field of view and high resolution, and can also be used for conventional X-ray source phase contrast imaging systems with large field of view and ordinary resolution.

[0059] The distribution of the spatial periodic distribution of the phase structure of the resolution plate of the present invention can be: grating type spatial periodic distribution, radiation type spatial periodic distribution or ring type spatial periodic distribution, and the spatial periodic distribution range is 1 to 1000 μm. Among them, the grating type spatial periodic arrangement is arranged in intervals from large to small or from small to large, and the interval distance of different periodic structures is the number of structures with the same periodicity × the period, the number of structures with the same periodicity is 1 to 10, and the number of structures with the same periodicity is specifically set according to the requirements of the imaging system, and can be any one within the above numerical range. The phase resolution plate with grating type spatial periodic distribution has a discrete periodic distribution, and the number of line pairs corresponding to the corresponding periodic mark can intuitively and roughly observe the range of the image resolution of the imaging system. The phase resolution plate with radiation type spatial periodic distribution and ring type spatial periodic distribution has a spatial periodic arrangement in which the period continuously increases or decreases from the center of the resolution plate to the periphery. Since its periodic distribution is basically continuous, the cutoff value of the image resolution of the imaging system can be quickly and accurately found.

[0060] The above three spatial period distribution modes are all applicable to the present invention.

[0061] Different spatial period distribution modes can be selected according to different phase structures 200, and different spatial period structures also correspond to corresponding phase structures 200. The relationship between the phase structure 200 and the spatial period must satisfy: when the phase structure 200 remains unchanged, the spatial period changes successively; or when the spatial period remains unchanged, the phase structure 200 changes successively.

[0062] In the relationship between the phase structure 200 and the spatial period, according to the different structures and shapes of the phase structure 200, the phase structure 200 remains unchanged specifically in that: in a cube structure, the height in the penetration direction of the X-ray remains unchanged; or in a wedge structure, the wedge angle corresponding to the penetration direction of the X-ray remains unchanged; or in a prism structure, the prism angle corresponding to the penetration direction of the X-ray remains unchanged; or in a cone structure, the cone angle corresponds to the penetration direction of the X-ray, and the cone angle remains unchanged; or in a cylindrical structure, the radial direction of the cylinder corresponds to the penetration direction of the X-ray, and the cylindrical The radial radius of the body remains unchanged; or in the ring cylinder structure, the radial direction of the ring cylinder corresponds to the penetration direction of the X-ray, and the radial radius of the ring cylinder remains unchanged; or in the spherical structure, the spherical radius remains unchanged, and changes in other positions or the overall structure need to be determined according to the X-ray phase sensitivity resolution plate. For example, in the square structure, the height remains unchanged (the height direction is the penetration direction of the X-ray), and its length and width can be changed as needed. The same is true for phase structures 200 of other shapes. It is only necessary to keep one shape index in the penetration direction of the X-ray unchanged, and other shape indexes can be changed. The phase structure 200 changes successively specifically as follows: in a cube structure, the height changes in the penetration direction of the X-rays; in a wedge structure, the wedge angle corresponding to the penetration direction of the X-rays changes; or in a prism structure, the prism angle corresponding to the penetration direction of the X-rays changes; or in a cone structure, the cone angle corresponds to the penetration direction of the X-rays, and the cone angle changes; or in a cylindrical structure, the radial direction of the cylinder corresponds to the penetration direction of the X-rays, and the radial radius of the cylinder changes; or in a ring cylinder structure, the radial direction of the ring cylinder corresponds to the penetration direction of the X-rays, and the radial radius of the ring cylinder changes; or in a sphere structure, the radius of the sphere changes. Similar to the above principle, the phase structure 200 changes successively means that a shape or size indicator in the penetration direction of the X-rays changes, and other shapes or size indicators are not limited and may change or not.

[0063] In the relationship between the phase structure 200 and the spatial period, the successive change of the spatial period means that: in the grating-type spatial period distribution, the periods are arranged from large to small or from small to large, and the interval between different period structures is the number of structures with the same period × the period, and the number of structures with the same period is 1 to 10; or in the radiation-type spatial period distribution, the period increases continuously from the center to the periphery; or in the ring-type spatial period distribution, the period increases continuously or decreases continuously from the center to the periphery.

[0064] Furthermore, in the X-ray phase sensitivity resolution plate, the phase structure 200 and the substrate 100 are preferably an integral structure or the two are fixedly connected together. Specifically, the integral structure may be an integral structure in which the first phase structure and its substrate 100 are formed at one time, and the second phase structure is formed by opening a cavity on the substrate 100, and the two are also integral structures. The third phase structure is an integral structure formed by filling another low atomic number material on the basis of the second phase structure. For the first phase structure, it can also be fixedly connected to the substrate 100 by bonding, welding, etc.

[0065] The following is a detailed description through some specific embodiments:

[0066] Embodiment 1, as Figure 1a-1c As shown, this is a schematic structural diagram of a first specific implementation of an X-ray phase sensitivity resolution plate.

[0067] In this embodiment, the phase structure 200 selects the second phase structure, that is, the phase structure 200 is formed by a cavity opened in the substrate 100, and the second phase structure is embedded in the substrate 100 material. The material of the substrate 100 is organic glass (PMMA), and no filling material is used in the cavity. The second phase structure adopts a cubic structure, that is, a rectangular parallelepiped cavity structure along the penetration direction of the X-ray (z-axis direction), and the arrangement mode of the spatial period distribution of the phase structure is a grating-type spatial period distribution. The relationship between the phase structure 200 and the spatial period is: keep the phase structure 200 unchanged while the spatial period changes successively, from Figure 1a-1c It can be seen that in the cube structure, from right to left, the height in the Z-axis direction remains unchanged (the height in the X-ray penetration direction remains unchanged), the periods are arranged from large to small, and the interval between structures with different periods is the number of structures with the same period × the period, and the number of structures with the same period is 5. The length of the cube structure ( Figure 1a Y-axis direction) is 500μm, height ( Figure 1a z-axis direction) is 65μm, and the width ( Figure 1a The x-axis direction) changes with the period, from left to right, it is 250μm, 100μm, 50μm, and 25μm, respectively. Figure 2 The spatial resolutions are 2lp / mm, 5lp / mm, 10lp / mm, and 20lp / mm as shown.

[0068] The penetration direction of X-rays is the z-axis direction. By designing materials with different cubic structures and heights to meet the different X-ray energy and phase sensitivity requirements of the imaging system, Figure 3 This is a curve diagram showing the relationship between the resolution plate cube structure height and the X-ray energy. In this example, for an X-ray energy of 28keV, the cube structure height is designed to be 65μm so that the penetrating X-rays produce a π phase delay. Figure 4is a transmittance distribution diagram of the first implementation mode of the resolution plate in the embodiment of the present invention, Figure 5 It is a phase distribution diagram of the first embodiment of the resolution plate of the present invention. From Figure 4, it can be seen that the intensity of X-rays attenuates very weakly after passing through the resolution plate, and almost no absorption contrast of the internal structure is presented. Figure 5 It can be seen that the X-rays undergo a π phase delay when passing through the cube structure of the resolution plate, showing a significant phase contrast, the contrast of which is proportional to the height of the cube structure. This implementation directly provides the phase contrast of the internal structure of the resolution plate and can be used in the X-ray phase contrast imaging system of the crystal interferometry method. The large-period phase structure of the first implementation can be realized by mechanical processing technology, and the small-period phase structure can be realized by femtosecond laser processing technology.

[0069] Embodiment 2, as Figure 6a-6b As shown, this is a schematic structural diagram of a second embodiment of an X-ray phase sensitivity resolution plate.

[0070] The phase structure 200 of the second embodiment is also embedded in the substrate 100 material. The substrate 100 material is made of pure silicon wafer, and a cavity is made. The internal structure of the cavity does not use filling materials, which is a second phase structure. Figure 6a-6b As shown, the specific phase structure 200 adopts a prism structure, specifically a quadrangular prism shape, and the arrangement mode of the spatial period distribution of the phase structure 200 is also a grating type spatial period distribution. The arrangement mode of the second phase structure and the spatial period is also to keep the phase structure 200 unchanged while the spatial period changes successively. The figure shows that: in the penetration direction of the X-ray (z-axis direction), from right to left, the prism angle of the phase structure 200 remains unchanged, all at 90°, and the period is arranged from large to small, and the interval distance of different period structures is the number of structures with the same period × period, and the number of structures with the same period is 5. Design the length of the prism structure ( Figure 6b y-axis direction) 500μm, the prism angle is 90o, the height ( Figure 6a z-axis direction) and width ( Figure 6a The x-axis direction) changes with the period, from left to right, it is 250μm, 100μm, 50μm, and 25μm, corresponding to Figure 7 The spatial resolutions are 2lp / mm, 5lp / mm, 10lp / mm, and 20lp / mm as shown.

[0071] Figure 8 This is a graph showing the relationship between the prism angle of the resolution plate and the X-ray phase gradient. In this example, for an X-ray energy of 28 keV, the prism angle is designed to be 90 degrees so that the transmitted X-ray wavefront produces 9.6×10 4 The phase gradient changes. Fig. 9is a transmittance distribution diagram of the second implementation mode of the resolution plate in the embodiment of the present invention, Fig.10 It is a phase gradient distribution diagram of the second embodiment of the resolution plate of the present invention. As can be seen from Figure 9, the intensity of X-rays attenuates very weakly after passing through the resolution plate, and almost no absorption contrast of the internal structure is presented. Fig.10 It can be seen that the X-rays present significant phase gradient contrast when passing through the prismatic structure of the resolution plate. This embodiment provides a phase gradient contrast of the internal structure of the resolution plate, which can be used in X-ray phase contrast imaging systems of diffraction enhancement method and grating interferometry method. The small period part can be used in an unconventional X-ray source imaging system with a small field of view and high resolution, and the large period part can be used in a conventional X-ray source imaging system with a large field of view and ordinary resolution. The large period phase structure of the second embodiment can be made into a second phase structure of the cavity by laser processing, and the small period phase structure can be made into a second phase structure of the cavity by wet etching technology or dry etching technology.

[0072] Embodiment 3, as Fig.11 As shown, this is a schematic structural diagram of a third embodiment of an X-ray phase sensitivity resolution plate.

[0073] The phase structure 200 of the third embodiment selects the first phase structure, that is, the phase structure 200 is arranged on the substrate 100, and the phase structure 200 and the substrate 100 are fixed together by bonding. The material of the substrate 100 is organic glass (PMMA), and the material of the first phase structure is also organic glass (PMMA). Similar to the design of the first embodiment of Example 1, the first phase structure is a cubic structure, and the arrangement of the spatial periodic distribution of the phase structure is a grating-type spatial periodic distribution. The relationship between the phase structure 200 and the spatial period is: keep the phase structure 200 unchanged while the spatial period changes successively, from Fig.11 It can be seen from the figure that: from left to right (Z-axis direction), the height of the cube structure remains unchanged, the periods are arranged from large to small, and the interval between structures with different periods is the number of structures with the same period × the period, and the number of structures with the same period is 5. Design cube structure length ( Fig.11 Y axis direction) 500μm, height ( Fig.11 z-axis direction) 65μm, width ( Fig.11 The x-axis direction) changes with the period, from right to left, it is 250μm, 100μm, 50μm, and 25μm, corresponding to Figure 2The spatial resolutions shown are 2lp / mm, 5lp / mm, 10lp / mm, and 20lp / mm. The penetration direction of X-rays is the z-axis direction, and the materials and heights of different cube structures are designed to meet the requirements of different X-ray energies and phase sensitivities of the imaging system. In this example, for an X-ray energy of 28keV, the cube structure height is designed to be 65μm to cause a π phase delay in the penetrating X-rays. The intensity of X-rays is very weak after passing through the resolution plate, and almost no absorption contrast of the internal structure is presented. However, the X-rays undergo a π phase delay when passing through the cube structure of the resolution plate, presenting a significant phase contrast, the contrast of which is proportional to the height of the cube structure. This implementation directly provides a phase contrast for the internal structure of the resolution plate, and can also be used in X-ray phase contrast imaging systems of crystal interferometry.

[0074] Embodiment 4, as Fig.12 As shown, this is a schematic structural diagram of a fourth embodiment of an X-ray phase sensitivity resolution plate.

[0075] The phase structure 200 of the fourth embodiment selects the third phase structure. The phase structure 200 is embedded in the material of the substrate 100, and the internal structure uses a filling material. The material of the substrate 100 uses a pure silicon wafer, and the filling material of the third phase structure uses graphite nanoparticles. The phase structure 200 of this embodiment also adopts a cubic structure. The arrangement method of the spatial period distribution of the phase structure 200 is a grating type spatial period distribution. The combination method of the phase structure 200 and the spatial period is to keep the phase structure 200 unchanged while the spatial period changes successively, from Fig.12 It can be seen from the figure that: from left to right (z-axis direction), the height of the cube structure remains unchanged, the period is arranged from large to small, and the interval between structures with different periods is the number of structures with the same period × period, and the number of structures with the same period is 5. Design phase cube structure length ( Fig.12 Y axis direction) 500μm, height ( Fig.12 z-axis direction) 45μm, width ( Fig.12 The x-axis direction) changes with the period, from right to left, it is 250μm, 100μm, 50μm, and 25μm, corresponding to Figure 2The spatial resolutions shown are 2lp / mm, 5lp / mm, 10lp / mm, and 20lp / mm. The penetration direction of X-rays is the z-axis direction. By filling different materials in the phase cube structure and designing different heights of the cube structure, it is suitable for different X-ray energies and phase sensitivity requirements of the imaging system. In this example, the X-ray energy is 28keV, graphite material is filled in the phase cube structure, and the cube structure height is designed to be 45μm, so that the X-rays penetrating between the silicon material of the substrate 100 and the graphite material of the phase structure 200 produce a π phase delay. After passing through the resolution plate, the intensity attenuation of the X-rays is very weak, and almost no absorption contrast of the internal structure is presented. However, when the X-rays pass through the substrate 100 and the phase structure 200 of the resolution plate, a π phase delay occurs, showing a significant phase contrast, and the contrast is proportional to the height of the phase cube structure. This implementation directly provides the phase contrast of the internal structure of the resolution plate, and can also be used in X-ray phase contrast imaging systems of crystal interferometry. In the fourth embodiment, a cavity with an internal cubic structure can be firstly processed on the silicon substrate 100 by using dry or wet etching technology, and then graphite nanoparticles can be filled in the cavity.

[0076] Embodiment 5, as Fig.13 As shown, this is a schematic structural diagram of a fifth embodiment of an X-ray phase sensitivity resolution plate.

[0077] The arrangement of the phase structure spatial periodic distribution is a radial spatial periodic distribution. The relationship between the phase structure 200 and the spatial period is: the phase structure 200 is kept unchanged while the spatial period changes successively. The phase structure 200 adopts a wedge structure and keeps the height of the wedge ( Fig.13 The direction perpendicular to the paper plane) remains unchanged, and the period of the circular phase structure formed by the wedges gradually increases from the center to the periphery. In this embodiment, the phase structure 200 selects the second phase structure, that is, the phase structure 200 is formed by machining a cavity of a wedge-shaped structure in the substrate 100, and the substrate 100 is made of pure silicon wafers. The number of designed wedges is 36, and the wedge angle is 5o. The period of the circular phase structure formed by the wedges gradually increases from the center to the periphery, the period of the central circle is 900μm, the period of the phase structure in the central circle is 25μm, the period of the outermost circle is 9000μm, and the period of the phase structure in the outermost circle is 250μm, and the spatial resolution range from the center to the periphery is 20lp / mm to 2lp / mm. The penetration direction of X-rays is the height direction of the wedge (perpendicular to the attached Fig.13The different heights of the wedge structure are designed to meet the different X-ray energy and phase sensitivity requirements of the imaging system. In this example, for an X-ray energy of 28 keV, the height of the wedge structure is designed to be 38 μm, so that the X-rays that penetrate between the silicon material substrate 100 and the wedge structure produce a π phase delay. The intensity of the X-rays is very weak after passing through the resolution plate, and almost no absorption contrast of the internal structure is presented. However, the X-rays undergo a π phase delay between the resolution plate substrate 100 and the wedge structure, presenting a significant phase contrast, and the contrast is proportional to the height of the wedge. This embodiment directly provides the phase contrast of the internal structure of the resolution plate, and can also be used in the X-ray phase contrast imaging system of the crystal interferometry method, and can quickly obtain the cutoff value of the image resolution of the imaging system.

[0078] Embodiment 6, as Fig.14 As shown, this is a schematic structural diagram of a sixth embodiment of an X-ray phase sensitivity resolution plate.

[0079] The arrangement of the phase structure space period distribution is a ring-shaped space period distribution. The combination of the phase structure 200 and the space period is to keep the height of the phase structure 200 unchanged while the space period changes successively. The phase structure 200 adopts a circular cylinder structure, and the height of the circular cylinder is kept constant ( Fig.14 The phase structure period formed by the annular cylinders gradually decreases from the center to the periphery. In this embodiment, the phase structure 200 selects the second phase structure, that is, the phase structure 200 is formed by machining a cavity of annular cylinder structures arranged from the inside to the outside in the substrate 100, and the substrate 100 material adopts pure silicon wafers. The phase structure period formed by the annular cylinders gradually increases from the center to the periphery. The ring width of the central annular cylinder is designed to be 125μm, and the corresponding phase structure period formed by the central annular cylinder is 250μm. The ring width of the outermost annular cylinder is 12.5μm, and the corresponding phase structure period formed by the outermost annular cylinder is 25μm. The spatial resolution range from the center to the periphery is 2lp / mm to 20lp / mm. The penetration direction of the X-ray is the height direction of the annular cylinder. By designing different heights of the annular cylinder structure, it is suitable for the requirements of different X-ray energies and phase sensitivities of the imaging system. In this example, for an X-ray energy of 28 keV, the height of the circular cylinder structure is designed to be 38 μm, so that the X-rays penetrating between the silicon material substrate 100 and the circular cylinder structure produce a π phase delay. The intensity attenuation of the X-rays after passing through the resolution plate is very weak, and almost no absorption contrast of the internal structure is presented. However, the X-rays passing through the resolution plate substrate 100 and the wedge-shaped structure have a π phase delay, showing a significant phase contrast, and the contrast is proportional to the height of the circular cylinder. This implementation method directly provides the phase contrast of the internal structure of the resolution plate, and can also be used in the X-ray phase contrast imaging system of the crystal interferometry method to quickly obtain the cutoff value of the image resolution of the imaging system.

[0080] Embodiment 7, as Fig.15 As shown, this is a schematic structural diagram of the seventh implementation of the X-ray phase sensitivity resolution plate.

[0081] The arrangement mode of the phase structure spatial periodic distribution is a grating type spatial periodic distribution. The combination mode of the phase structure 200 and the spatial period is to keep the spatial period unchanged while the height of the phase structure 200 changes successively. The phase structure 200 adopts a cube structure, keeps the spatial period of the cube structure arrangement unchanged, and the cube height ( Fig.15 In the z-axis direction, the phase structure 200 increases from left to right. In this embodiment, the phase structure 200 selects the second phase structure, that is, the phase structure 200 is formed by machining a cavity of a cube structure in the substrate 100, and the substrate 100 is made of organic glass (PMMA). Four groups of cube structures with different heights are designed, and the spatial period of the cube structure arrangement is 60μm, corresponding to a spatial frequency of 8.3lp / mm, and the cube heights from left to right are 30μm, 40μm, 50μm, and 60μm, respectively. The penetration direction of X-rays is the cube height direction. By designing different heights of the cube structure, it is suitable for different X-ray energies and phase sensitivity requirements of the imaging system. In this example, for an X-ray energy of 28keV, the cube heights are designed to be 30μm, 40μm, 50μm, and 60μm, respectively, so that the phase delays generated by the X-rays penetrating between the PMMA material substrate 100 and the cube structure are 0.92π, 0.77π, 0.62π, and 0.46π, respectively. After the X-ray passes through the resolution plate, the intensity attenuation is very weak, and there is almost no absorption contrast of the internal structure. However, different phase delays occur between the X-ray substrate 100 and the cube structure when passing through the resolution plate, showing a significant phase contrast, and the contrast is proportional to the height of the cube. This embodiment directly provides different phase contrasts (such as 0.92π, 0.77π, 0.62π, 0.46π) of the internal structure of the resolution plate, which can be used in the X-ray phase contrast imaging system of the crystal interferometry method to measure the phase sensitivity of the imaging system at a specific spatial resolution (such as 8.3lp / mm).

[0082] Embodiment 8, as Figure 16a-16b As shown, this is a schematic structural diagram of an eighth embodiment of an X-ray phase sensitivity resolution plate.

[0083] The arrangement of the spatial periodic distribution of the phase structure is a grating type spatial periodic distribution. The combination of the phase structure 200 and the spatial period is to keep the spatial period unchanged while the height of the phase structure 200 changes successively. The phase structure 200 adopts a wedge structure, keeps the spatial period of the wedge structure arrangement unchanged, and the wedge height (z-axis direction in FIG. 16) increases from left to right. The wedge angle corresponding to the penetration direction of the X-ray decreases from left to right. In this embodiment, the phase structure 200 selects the first phase structure, that is, the phase structure 200 is the first phase structure fixed on the substrate 100, and the substrate 100 and the first phase structure material are PS (polystyrene). Four groups of wedge structures with different heights are designed. The spatial period of the wedge structure arrangement is 60 μm, and the corresponding spatial frequency is 8.3 lp / mm. The wedge heights from left to right are 30 μm, 40 μm, 50 μm, and 60 μm. The penetration direction of the X-ray is the wedge height direction. By designing different heights of the wedge structure, it is suitable for the requirements of different X-ray energies and phase sensitivities of the imaging system. In this example, the X-ray energy is 28 keV, and the wedge heights are designed to be 30 μm, 40 μm, 50 μm, and 60 μm, respectively, so that the phase gradients generated by the X-rays penetrating the PMMA wedge structure are 4.8×10 4 , 6.4×10 4 , 8.0×10 4 , 9.6×10 4 After the X-ray passes through the resolution plate, the intensity attenuation is very weak, and there is almost no absorption contrast of the internal structure. However, the X-ray passes through the wedge structure of the resolution plate and shows a significant phase gradient contrast, and the contrast is proportional to the height of the wedge. This embodiment provides different phase gradient contrasts of the internal structure of the resolution plate (such as 4.8×10 4 , 6.4×10 4 , 8.0×10 4 , 9.6×10 4 ) can be used in X-ray phase contrast imaging systems of diffraction enhancement method and grating interferometry method to measure the phase gradient sensitivity of the imaging system at a specific spatial resolution (such as 8.3lp / mm).

[0084] Embodiment 9, as Figure 17a-17b As shown, this is a schematic structural diagram of a ninth embodiment of an X-ray phase sensitivity resolution plate.

[0085] The arrangement mode of the phase structure spatial periodic distribution is a grating type spatial periodic distribution. The combination mode of the phase structure 200 and the spatial period is to keep the spatial period unchanged while the height of the phase structure 200 changes successively. The phase structure 200 adopts a cone structure, keeps the spatial period of the cone structure arrangement unchanged, and the cone height ( Fig.17aThe phase structure 200 increases from left to right in the direction of the cone angle corresponding to the penetration direction of the X-ray, and the cone angle decreases in sequence. In this embodiment, the phase structure 200 selects the third phase structure, that is, the phase structure 200 is formed by machining a cavity of a cone structure in the substrate 100, the substrate 100 material is PTFE (polytetrafluoroethylene), and the filling material is graphite. Four groups of cone structures with different heights are designed, and the spatial period of the cone structure arrangement is 60μm, corresponding to a spatial frequency of 8.3lp / mm, and the cone heights from left to right are 30μm, 40μm, 50μm, and 60μm, respectively. The penetration direction of the X-ray is the cone height direction. By designing different heights of the cone structure, it is suitable for the requirements of different X-ray energies and phase sensitivities of the imaging system. In this example, for an X-ray energy of 28keV, the cone heights are designed to be 30μm, 40μm, 50μm, and 60μm, respectively, so that the phase gradient generated by the X-ray penetrating the cone structure increases in sequence. After the X-ray passes through the resolution plate, the intensity attenuation is very weak, and there is almost no absorption contrast of the internal structure. However, the X-ray passes through the cone structure of the resolution plate and presents a significant phase gradient contrast, and the contrast is proportional to the height of the cone. This embodiment provides different phase gradient contrasts of the internal structure of the resolution plate, which can be used in X-ray phase contrast imaging systems of diffraction enhancement method and grating interferometry method to measure the phase gradient sensitivity of the imaging system at a specific spatial resolution (such as 8.3lp / mm).

[0086] Embodiment 10, as Fig.18 As shown, this is a schematic structural diagram of a tenth embodiment of an X-ray phase sensitivity resolution plate.

[0087] The arrangement of the spatial periodic distribution of the phase structure is a grating-type spatial periodic distribution. The combination of the phase structure 200 and the spatial period is to keep the spatial period unchanged while the height of the phase structure 200 changes successively. The phase structure 200 adopts a spherical structure, keeps the spatial period of the spherical structure arrangement unchanged, and the spherical radius increases from left to right. In this embodiment, the phase structure 200 selects the third phase structure, that is, the phase structure 200 is formed by machining a cavity of a spherical structure in the substrate 100. The substrate 100 material is PTFE (polytetrafluoroethylene), and graphite is selected as the filling material. Four groups of spherical structures with different radii are designed. The spatial period of the spherical structure arrangement is 60μm, and the corresponding spatial frequency is 8.3lp / mm. The spherical radii from left to right are 15μm, 20μm, 25μm, and 40μm, respectively. The penetration direction of the X-ray is Fig.18In the z-axis direction, the different radii of the spherical structure are designed to meet the different X-ray energy and phase sensitivity requirements of the imaging system. In this example, for an X-ray energy of 28 keV, the spherical radii are designed to be 15μm, 20μm, 25μm, and 30μm, respectively, so that the phase gradient generated by the X-rays penetrating the spherical structure decreases in sequence. The intensity of the X-rays is very weak after passing through the resolution plate, and almost no absorption contrast of the internal structure is presented. However, the X-rays present a significant phase gradient contrast when passing through the spherical structure of the resolution plate, and the contrast is inversely proportional to the radius of the sphere. This embodiment provides different phase gradient contrasts of the internal structure of the resolution plate, which can be used in X-ray phase contrast imaging systems of diffraction enhancement method and grating interferometry method to measure the phase gradient sensitivity of the imaging system at a specific spatial resolution (such as 8.3lp / mm).

Claims

1. An X-ray phase sensitivity resolution plate, characterized in that: It comprises a substrate and a phase structure for reflecting the phase sensitivity of a resolution plate; the size of the phase structure corresponds to the X-ray energy of the imaging system, and the phase structure is spatially periodically distributed; along the penetration direction of the X-ray, the phase structure is a cube structure, a wedge structure, a prism structure, a cone structure, a cylinder structure, a torus cylinder structure or a sphere structure; The phase structure is a first phase structure arranged on the surface of the substrate; Or the phase structure is a second phase structure formed by opening a cavity in a substrate; or the phase structure is a third phase structure formed by opening a cavity in a substrate and filling the cavity; The relationship between the phase structure and the spatial period satisfies the following two situations: when the phase structure remains unchanged, the spatial period changes successively; and when the spatial period remains unchanged, the phase structure changes successively; the resolution plates with the two relationships between the phase structure and the spatial period are used successively to successively measure the image resolution and phase sensitivity of the imaging system; The substrate, the first phase structure, and the third phase structure are made of low atomic number materials, and the material used in the substrate is different from the material used for the filler in the third phase structure, and the low atomic number material is at least one of beryllium, carbon single substance, silicon, and light element compounds; wherein the carbon single substance is selected from: diamond, graphite, C60 or graphene, and the light element compound is selected from: polystyrene, polymethyl methacrylate or polytetrafluoroethylene; In the relationship between the phase structure and the spatial period, the phase structure remains unchanged when: the structure in the penetration direction of the X-ray remains unchanged; The structure being unchanged in the penetration direction of the X-rays is: in a cube structure, the height in the penetration direction of the X-rays is unchanged; or in a wedge structure, the wedge angle corresponding to the penetration direction of the X-rays is unchanged; or in a prism structure, the prism angle corresponding to the penetration direction of the X-rays is unchanged; or in a cone structure, the cone angle corresponds to the penetration direction of the X-rays, and the cone angle is unchanged; or in a cylinder structure, the radial direction of the cylinder corresponds to the penetration direction of the X-rays, and the radial radius of the cylinder is unchanged; or in a ring cylinder structure, the radial direction of the ring cylinder corresponds to the penetration direction of the X-rays, and the radial radius of the ring cylinder is unchanged; or in a sphere structure, the radius of the sphere is unchanged; The phase structure changes successively as follows: in a cube structure, the height in the penetration direction of the X-ray changes; in a wedge structure, the wedge angle corresponding to the penetration direction of the X-ray changes; or in a prism structure, the prism angle corresponding to the penetration direction of the X-ray changes; or in a cone structure, the cone angle corresponds to the penetration direction of the X-ray, and the cone angle changes; or in a cylinder structure, the radial direction of the cylinder corresponds to the penetration direction of the X-ray, and the radial radius of the cylinder changes; or in a ring cylinder structure, the radial direction of the ring cylinder corresponds to the penetration direction of the X-ray, and the radial radius of the ring cylinder changes; or in a sphere structure, the radius of the sphere changes; The spatial periodic distribution is a grating type spatial periodic distribution, a radiation type spatial periodic distribution or a ring type spatial periodic distribution; In the relationship between the phase structure and the spatial period, the successive change of the spatial period means that: in the grating-type spatial period distribution, the periods are arranged from large to small or from small to large, and the interval distance between different period structures is the number of structures with the same period × the period, and the number of structures with the same period is 1 to 10; or in the radiation-type spatial period distribution, the period increases continuously from the center to the periphery; or in the ring-type spatial period distribution, the period increases continuously or decreases continuously from the center to the periphery.

2. The X-ray phase sensitivity resolution plate according to claim 1, characterized in that: The spatial period distribution range is 1-1000 μm.

3. The X-ray phase sensitivity resolution plate according to claim 1, characterized in that: When the grating type spatial periodic distribution is selected, the X-ray energy is 0.2~500 keV; the cube structure is 100~5000 m long, 1~1000 μm wide, and 1~1000 μm high in the direction of X-ray penetration; or the wedge structure is 1~1000 μm high in the direction of X-ray penetration, 0°<wedge angle≤90°; or the prism structure is 1~1000 μm high in the direction of X-ray penetration, 0°<prism angle<180°; or the cone structure is 1~1000 μm high in the direction of X-ray penetration, 0°<cone angle<180°; or the cylindrical structure is 100~5000 μm high, and the radius in the direction of X-ray penetration is 1~500 μm; Or the annular cylindrical structure has a height of 100 to 5000 μm and a radius of 1 to 500 μm in the penetration direction of the X-ray; Alternatively, the radius of the spherical structure along the penetration direction of the X-ray is 1-500 μm.

4. The X-ray phase sensitivity resolution plate according to any one of claims 1 to 3, characterized in that: The phase structure and the substrate are an integrated structure or the two are fixedly connected together.

Images