Focusing scintillator fiber faceplate of array micro-tab structure and method of manufacturing the same

Abstract

The application relates to a focusing type scintillator fiber panel with an array micro-platform structure and a preparation method thereof, and the preparation method comprises the following steps: drawing a fiber preform into a fiber monofilament; drawing a primary multifilament; drawing a secondary multifilament; preparing a fiber blank plate; heating, softening and stretching to obtain two platform fiber blank plates; preparing a first platform fiber panel; using a covering material to cover the surface of the large end face of the first platform fiber panel, then placing the first platform fiber panel in an acid liquid for acid etching to form a first platform fiber panel with a blind hole in the small end face; performing surface cleaning treatment on the first platform fiber panel to remove the surface covering layer of the large end face; and filling a scintillator material into the blind hole in the small end face by using a vapor deposition method or a vacuum melting filling method, so that a scintillator fiber panel with an array micro-platform structure is finally prepared. The scintillator fiber panel can obtain higher quality imaging results.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of scintillation screen production and manufacturing, in particular to a focusing type scintillator optical fiber panel with an array micro-platform structure and a preparation method thereof. BACKGROUND

[0002] The scintillator optical fiber panel, as a core component of an indirect X-ray detector, is usually composed of a scintillator film and a glass substrate. The scintillator is a functional material capable of emitting light after absorbing high-energy particles or rays. X-rays are converted into visible light by the scintillator film, and then imaged and detected by an image sensor. This technology is widely used in clinical medical imaging, security and industrial defect detection.

[0003] However, the indirect X-ray detector is usually applied to the hard X-ray energy region. When the X-ray light source irradiates the scintillation screen, not all X-rays can be completely converted into visible light. This results in a large amount of X-ray scattering and inevitable irradiation of the main radiation on the detector and other internal components, which can damage the detector and internal components and affect the performance and service life of the equipment. In addition, the visible light photons generated by the scintillator can cause a large amount of slow scattering on the glass substrate, resulting in the diffusion of the output visible light photons in the adjacent pixels of the image sensor, the generation of artifacts and non-uniform background noise, and the reduction of the imaging details and spatial resolution, which seriously deteriorates the imaging quality. Moreover, due to the low conversion efficiency of the scintillation screen, longer exposure time may be required in actual application, resulting in the decrease of image quality and the increase of patient radiation exposure.

[0004] The above-mentioned effects are superimposed on each other, which greatly affects the X-ray imaging quality and clinical application. SUMMARY

[0005] In view of the above-mentioned problems existing in the application of the scintillator optical fiber panel, the present application provides a focusing type scintillator optical fiber panel with an array micro-platform structure and a preparation method thereof, which can improve the imaging quality.

[0006] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0007] A preparation method of a focusing type scintillator optical fiber panel with an array micro-platform structure, comprising the following steps:

[0008] (1) combining a first peripheral material, a second peripheral material and a core material into an optical fiber preform rod, and then drawing the optical fiber preform rod into an optical fiber monofilament by an optical fiber drawing machine, wherein the first peripheral material surrounds the core material, and the second peripheral material surrounds the first peripheral material;

[0009] (2) arranging a plurality of optical fiber filaments in a row in a rowing die to form a primary multifilament rod, and then drawing the primary multifilament rod into a primary multifilament by means of a fiber drawing machine;

[0010] (3) arranging a plurality of primary multifilaments in a row in a rowing die to form a secondary multifilament rod of a desired structural design, and then drawing the secondary multifilament rod into a secondary multifilament by means of a fiber drawing machine;

[0011] (4) after cutting the secondary multifilament into a desired length, arranging the cut secondary multifilament in a row in a rowing die according to a certain structural design, loading the arranged blank plate into a hot-pressing die, and then placing the hot-pressing die into a vacuum hot-pressing furnace to perform vacuum fusion, thereby obtaining a fiber blank plate;

[0012] (5) placing the fiber blank plate in a fiber fusion tapering device to heat, soften and stretch the fiber blank plate, cooling and setting the stretched waist region after the stretching reaches the required stretching angle, and then cutting the stretched waist region to obtain two table body fiber blank plates;

[0013] (6) performing optical cold processing on the deformation region of the table body fiber blank plate to obtain a first table body fiber panel with a preset thickness and shape;

[0014] (7) using a covering material to cover the large end face of the first table body fiber panel, and then placing the first table body fiber panel in an acid solution to perform local acid etching, thereby forming a first table body fiber panel with a blind hole in the small end face;

[0015] (8) performing surface removal treatment on the first table body fiber panel with a blind hole to remove the surface covering layer of the large end face;

[0016] (9) filling a scintillator material into the blind hole in the small end face by means of a vapor deposition method or a vacuum fusion filling method, and then polishing the small end face, thereby finally preparing a scintillator fiber panel with an array micro table body structure.

[0017] The first peripheral material is an acid and alkali etching resistant optical glass material; the second peripheral material is an acid and alkali etching resistant high-lead-equivalent special optical glass material; and the core material is an acid-soluble optical glass material.

[0018] The refractive index of the core material is greater than the refractive index of the first peripheral material;

[0019] The difference between the thermal expansion coefficients of any two of the first peripheral material, the second peripheral material and the core material is less than or equal to 30%, and the drawing temperature ranges of any two of them overlap;

[0020] The fiber blank plate stretching temperature is higher than the glass transition temperature (Tg) of any one of the first peripheral material, the second peripheral material and the core material.

[0021] The drawing angle of the optical fiber blank is 0-13°; and the unit array period size of the optical fiber blank is 4-100 microns.

[0022] The covering material of the large end surface of the first bulk optical fiber panel is a material with acid and alkali resistance, adhesion and easy removal;

[0023] The acid liquid is at least one of nitric acid, hydrochloric acid and hydrofluoric acid;

[0024] During the acid etching, the temperature of the acid liquid is 20-60℃, preferably 20-40℃, and the acid etching time is 1-12 hours, preferably 2-6 hours.

[0025] The refractive index of the scintillator material is greater than the refractive index of the first peripheral material;

[0026] The scintillator material is one of cesium iodide, cesium iodide (thallium), sodium iodide, sodium iodide (thallium), aluminum oxide, gadolinium oxysulfide and gadolinium oxysulfide (terbium).

[0027] Cesium iodide (thallium) means that cesium iodide is doped with thallium elements, sodium iodide (thallium) means that sodium iodide is doped with thallium elements, and gadolinium oxysulfide (terbium) means that gadolinium oxysulfide is doped with terbium elements.

[0028] The thickness of the scintillator optical fiber panel is 0.5-10mm;

[0029] The filling height of the scintillator material is less than the thickness of the scintillator optical fiber panel;

[0030] The wall thickness of the second peripheral material of the scintillator optical fiber panel is greater than 0.3 microns.

[0031] The temperature for heating and softening the optical fiber blank is 500-900℃.

[0032] The wall thickness of the second peripheral material of the scintillator optical fiber panel is 0.3-500 microns.

[0033] The temperature for heating and softening the optical fiber blank is 760-780℃.

[0034] The covering material is acid-resistant ultraviolet light curing adhesive or protective paint.

[0035] The application also provides a focusing type scintillator optical fiber panel with an array micro-bulk structure prepared according to the preparation method.

[0036] The application also provides an application of the focusing type scintillator optical fiber panel with an array micro-bulk structure in medical CT imaging.

[0037] Through the above technical solutions, the application has at least the following advantages:

[0038] The present application fills the scintillator material into the blind hole at one end of the optical fiber panel in the structural design, forms the optical fiber structure, when X-ray irradiation, the light beam converted by the scintillator occurs total reflection in the first optical fiber structure, realizes the lossless transmission of the scintillator fluorescence to the output end surface, greatly improves the scintillator fluorescence collection efficiency, and provides more accurate and efficient imaging technology for the output end image sensor.

[0039] The present application directly internally couples the scintillator and the optical fiber panel, so that the fluorescence generated by the scintillator after being excited by the ray is further totally reflected and output in the second optical fiber structure, forms a double optical fiber passage, this design effectively reduces the lateral waveguide crosstalk of the fluorescence signal, improves the transmission efficiency and accuracy of the fluorescence signal, and has the advantages of no image distortion, high imaging speed and the like.

[0040] The present application efficiently separates the X-ray and the fluorescence in the optical path by adopting the second peripheral material design with high lead equivalent, absorbs the excess X-ray main ray and scattered ray, improves the signal-to-noise ratio of the output end detector, prevents the scattered photons of the irradiated object from reaching the detector, avoids the direct irradiation of the X-ray on the detector to cause radiation damage, and effectively ensures the service life and stability of the detector and the irradiated object.

[0041] The present application provides a scintillator optical fiber panel with a micro platform structure, which can enhance the transmission of optical signals, introduce more collimated optical signals between surface reflection and diffuse reflection, significantly reduce the valley effect, improve the optical density and contrast between the imaging center and the image edge, and obtain higher quality imaging results.

[0042] The above description is only a summary of the technical solutions of the present application, in order to more clearly understand the technical means of the present application, and the content of the specification can be implemented, the following is a preferred embodiment of the present application and the detailed description of the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 is a structural schematic diagram of an optical fiber preform provided by an embodiment of the present application;

[0044] Figure 2 is another structural schematic diagram of an optical fiber preform provided by an embodiment of the present application;

[0045] Figure 3 is a cross-sectional structural schematic diagram of an optical fiber blank provided by an embodiment of the present application;

[0046] Figure 4 is another cross-sectional structural schematic diagram of an optical fiber blank provided by an embodiment of the present application;

[0047] Figure 5 is a drawing of stretching of a fiber blank provided by an embodiment of the present application;

[0048] Figure 6 is a structural drawing of a fiber blank provided by an embodiment of the present application;

[0049] Figure 7 is a structural drawing of a fiber blank provided by an embodiment of the present application, in which the inner platform is a truncated cone after stretching;

[0050] Figure 8 is a structural drawing of a fiber blank provided by an embodiment of the present application, in which the inner platform is a truncated pyramid after stretching;

[0051] Figure 9 is a structural drawing of a fiber blank provided by an embodiment of the present application, in which the inner platform is an inclined platform after stretching;

[0052] Figure 10 is a structural drawing of a fiber blank provided by an embodiment of the present application, in which the inner platform is a truncated cone after stretching;

[0053] Figure 11 is a structural drawing of a fiber blank provided by an embodiment of the present application, in which the inner platform is a truncated cone after stretching;

[0054] Figure 12 is a structural drawing of a fiber blank provided by an embodiment of the present application, in which the inner platform is a truncated cone after stretching;

[0055] Figure 13 is a structural drawing of a fiber blank provided by an embodiment of the present application, in which the inner platform is a truncated cone after stretching;

[0056] Figure 14 is a structural drawing of a fiber blank provided by an embodiment of the present application, in which the inner platform is a truncated cone after stretching;

[0057] Figure 15 is a structural drawing of a fiber blank provided by an embodiment of the present application, in which the inner platform is a truncated cone after stretching;

[0058] Figure 16 is a structural drawing of a fiber blank provided by an embodiment of the present application, in which the inner platform is a truncated cone after stretching. DETAILED DESCRIPTION

[0059] To further clarify the technical means and effects taken by the present application to achieve the predetermined purposes, the specific embodiments, structures, features and effects of the present application are described in detail below in combination with the drawings and preferred embodiments. In the following description, different "an embodiment" or "embodiments" do not necessarily refer to the same embodiment. In addition, the specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0060] Embodiment 1

[0061] A method for preparing a focusing type scintillator fiber panel of an array micro-bulk structure, comprising the following steps:

[0062] (1) combining a first peripheral material, a second peripheral material and a core material into a fiber preform, and then drawing the fiber preform into a fiber monofilament by a fiber drawing machine, wherein the first peripheral material surrounds the core material, and the second peripheral material surrounds the first peripheral material; the first peripheral material is a special optical glass material resistant to acid and alkali etching; the second peripheral material is a high-lead-equivalent special optical glass material resistant to acid etching; the core material is an acid-soluble special optical glass material; the refractive index of the first core material is greater than that of the first peripheral material; the difference between the thermal expansion coefficients of any two of the first peripheral material, the second peripheral material and the core material should be less than or equal to 30%; the drawing temperature ranges of any two of them overlap;

[0063] The first peripheral material, the second peripheral material and the core material used in this embodiment are all purchased from China Building Material Scientific Research and Development Corporation Limited.

[0064] As shown in Figure 1 , it is a fiber preform 100 in the form of a sleeve, which is a circular surrounding structure, the first peripheral material 102 and the second peripheral material 103 are processed into a tube with a through-hole structure, and are directly sleeved outside the core material 101 in sequence, thereby forming an integral fiber preform 100;

[0065] (2) arranging a plurality of fiber monofilaments in a rod arranging mold to form a hexahedral primary multifilament rod, and then drawing the primary multifilament rod into a primary multifilament by a fiber drawing machine at 750℃;

[0066] (3) arranging a plurality of primary multifilaments in a rod arranging mold to form a hexahedral secondary multifilament rod, and then drawing the secondary multifilament rod into a secondary multifilament by a fiber drawing machine at 762℃;

[0067] (4) after cutting the secondary multifilament into a desired length, arranging the cut secondary multifilament in a plate arranging mold according to a certain structure design, loading the arranged blank plate into a hot-pressing mold, and then placing the hot-pressing mold into a vacuum hot-pressing furnace to perform vacuum fusion at 800℃ according to a designed compression ratio, thereby obtaining a fiber blank plate;

[0068] As shown in Figure 3 , it is a schematic diagram of the cross-sectional structure of a fiber blank plate, which is a hexahedral structure Figure 1The internal structure cross section of the optical fiber preform 100 shown in the figure is formed by multiple times of drawing, rod arranging and hot-pressing of the optical fiber blank plate 111. The internal structure of each optical fiber blank plate 111 is composed of hundreds of millions of optical fiber unit array periods, each of which is an independent optical fiber. Each independent optical fiber is in a column type and is arranged in the optical fiber blank plate 111 in an orderly manner. Each unit is placed parallel to each other. The unit array period size of the optical fiber blank plate 111 is 6 microns. The unit array period size refers to the optical fiber structure under a microscope.

[0069] (5) The optical fiber blank plate is placed in an optical fiber fusion tapering device, the middle region of the optical fiber blank plate is heated to soften at a temperature of 760°C, and the optical fiber blank plate is pulled on both sides. The middle region of the optical fiber blank plate gradually deforms. The pulling speed and temperature are adjusted to meet the requirement of a stretching deviation angle of 10°, then the waist region after stretching is cut to obtain two platform optical fiber blank plates;

[0070] Referring to Figure 5 and Figure 6 , in the stretching process of the optical fiber blank plate 111, the thinnest part formed in the middle is called a waist region 112. The region from the normal size of the optical fiber blank plate 111 to the size of the waist region 112 is called a transition region 113. The two platform optical fiber blank plates 131 are obtained by cutting along the middle cutting line 114 of the waist region 112. The optical cold processing can also be performed according to the required region.

[0071] Referring to Figure 6 , the stretching deviation angle θ is defined as the angle θ between the longitudinal axis of the optical fiber blank plate and the side surface of the platform optical fiber blank plate 131.

[0072] (6) The deformed region of the platform optical fiber blank plate is subjected to optical cold processing to obtain a first platform optical fiber panel with a preset shape and a thickness of 8 mm;

[0073] Referring to Figure 7 , Figure 8 and Figure 9 , after the optical fiber blank plate 111 is stretched, the internal optical fiber unit array changes from a cylindrical type to a platform type, which can be a circular platform structure, an angular platform structure or an inclined platform structure.

[0074] Referring to Figure 10The first embodiment of the present application provides a schematic diagram of a first bulk optical fiber panel structure. The upper end is a small end face 152, the lower end is a large end face 153, and the extension lines of the deflection angles of each array unit inside the first bulk optical fiber panel 151 converge at a focal point 154. The array units are parallel to the central axis of the X-ray or are oriented along the central axis of the X-ray and gradually tilt towards the periphery. Each array unit has a micro-bulk shape to match the beam divergence of a specific source-to-detector distance from the focal point 152 to the detector. The array units at the edge of the first bulk optical fiber panel 151 have a larger stretching deflection angle than the array units near the center.

[0075] (7) The large end face of the first bulk optical fiber panel is surface-coated with acid-resistant and ultraviolet (UV) light-resistant UV glue, and then the first bulk optical fiber panel is placed in a 30℃ hydrochloric acid solution for local acid etching. The acid etching time is 5 hours, forming a first bulk optical fiber panel with a small end face having blind holes.

[0076] In the present application, the side with larger array unit filament diameter is referred to as the large end, and the side with smaller array unit filament diameter is referred to as the small end. Alternatively, the side closer to the middle cutting line is defined as the small end, and the side farther away from the middle cutting line is defined as the large end.

[0077] (8) The first bulk optical fiber panel with blind holes is surface-cleaned in an acetone solution to remove the surface coating on the large end face.

[0078] Referring to Figure 11 and Figure 12 The first bulk optical fiber panel of the present application is coated and etched, and the structure after etching is shown in the schematic diagram. The covering material 161 is applied to the large end face of the first bulk optical fiber panel 151 to seal and protect the large end face from chemical reactions caused by acid etching. Then, the first bulk optical fiber panel 151 with the covering material 161 is placed in a hydrochloric acid solution. The acid etching is performed by stirring, ultrasonic wave, soaking, and spraying, etc. The small end core material 101 reacts with the hydrochloric acid, which has acid solubility, to gradually form regular array blind holes 163. The depth of the etched blind holes is related to the etching method, acid concentration, liquid temperature, and etching time. The etching parameters can be adjusted as needed. A higher acid concentration will accelerate the etching rate, while a lower acid concentration will require more acid additions to compensate for the reaction loss. Then, the sample is placed in a cleaning solvent to remove the covering material 161 on the large end of the sample surface, thereby forming a first bulk optical fiber panel 162 with a small end face having blind holes.

[0079] (9) Cesium iodide is filled into the blind holes of the small end face using a gas deposition method, and the small end face is polished, finally preparing a scintillator fiber panel with an array micro-bulk structure.

[0080] The refractive index of the cesium iodide is greater than that of the first peripheral material. Since it is a blind hole, the filling height of the cesium iodide is less than the thickness of the scintillator fiber panel, which is 8 mm. Considering the light tunneling effect, the wall thickness of the array unit inside the scintillator fiber panel is greater than 0.3 microns, preferably 0.3-500 microns, and the wall thickness of the second peripheral material in this embodiment is 0.5 microns.

[0081] Referring to Figure 13 The structure of the scintillator fiber panel after filling the scintillator is provided for the embodiment of the present application. The scintillator fiber panel 172 is composed of a scintillator material 171, a core material 101, a first peripheral material 102 and a second peripheral material 103, and the scintillator material 171 is filled in the first mesa fiber panel 162 with a blind hole on the small end face;

[0082] Referring to Figure 14 Because the refractive index of the scintillator material 171 is greater than that of the first peripheral material 102, they form a (core / cladding) fiber structure, which is called the first fiber structure 173, and the part not filled with scintillator material is called the second fiber structure 174, and the detector 175 is located on the large end face side.

[0083] When X-rays irradiate the scintillator fiber panel, X-rays are absorbed by atoms in the scintillator. The electrons in these atoms are excited to high energy levels, and then release visible light fluorescence through Auger effect. This fluorescence is confined within the first fiber structure, and the photons propagate along the first fiber structure when they are totally reflected, effectively reducing scattering noise and improving imaging quality. In addition, the small size and high density of the array micro-mesa structure enable it to form a high-density slit, achieving focusing of X-rays in a small area. The structure of the present application not only helps to transmit the visible light fluorescence generated by the scintillator to the output end face without loss, but also greatly improves the fluorescence collection efficiency. The fluorescence photons are confined within the fiber when they propagate, reducing energy loss and scattering, thereby improving imaging quality and increasing the collection efficiency of scintillator fluorescence. The design of the present application will bring better performance and application prospect to X-ray imaging technology.

[0084] The core material 101 and the first peripheral material 102 are also (core / cladding) fiber structures, such as Figure 14The visible fluorescence generated in the first optical fiber structure 173 can be transmitted to the output port without loss through the second optical fiber structure 174, forming a complete total reflection optical fiber system. This double optical fiber channel design effectively fixes most of the energy generated by X-ray excitation in the optical fiber channel, reduces the crosstalk phenomenon of the fluorescence signal in the transverse waveguide transmission process, and significantly improves the efficiency and accuracy of photon transmission. Compared with the traditional scintillator fiber panel, the transmission efficiency and accuracy are significantly improved. The traditional scintillator fiber panel is directly coated with a scintillator material on the surface of the fiber panel, resulting in a large amount of slow scattering phenomenon of the visible fluorescence generated by the scintillator on the surface. In this case, only a small amount of photons can enter the interior of the fiber panel for conduction, and most of the energy is lost in the form of radiation loss, fluorescence reflection, and the like in the environment around the fiber panel, thereby greatly reducing the efficiency of photon transmission. Through the design of the new total reflection optical fiber system of the present application, the transmission efficiency of the fluorescence signal is significantly improved, and the transverse waveguide crosstalk signal is effectively reduced, bringing higher accuracy and performance to the X-ray imaging technology.

[0085] Referring to Figure 15 A structure schematic diagram of a scintillator fiber panel for detection provided by an embodiment of the present application; the process of forming a projection X-ray image includes placing a radiation source and a detector 175 on opposite sides of the object to be detected 1. One side is a radiation source equipped with an X-ray tube 2, and the X-rays emitted by the radiation source are guided to the area equipped with a radiation-related detector 175 on the other side. A scintillator fiber panel 172 is placed on the side of the detector 175 for receiving and transmitting X-ray signals. When the X-ray beam (usually a cone beam) passes through the object to be detected 1 and reaches the detector 175, the X-ray beam will interact with different tissues or structures, resulting in different degrees of attenuation, thereby forming a shadow image on the detector 175. These shadow images record the absorption and scattering of X-rays inside the object to be detected 1, providing important information for medical imaging.

[0086] The X-ray beam generated by the X-ray tube 2 interacts with the atoms within the object under test 1 after entering the object under test 1 through direct radiation 3. Part of the X-rays will be absorbed by the object under test, and another part will be radiated into the environment. Among them, part of the photons will interact with the atoms in the body, causing the photons to deviate from the original propagation path and change in energy and direction. This scattered radiation 4 photon can eventually hit the image receiver (such as X-ray film, digital detector, etc.), and affect the acquisition of image data. The scattered radiation 4 forms a uniform gray mist layer on the image, causing the contrast of the image to decrease. This phenomenon weakens the contrast between different structures, making it difficult to distinguish clearly. Especially in structures with similar densities, some details and structures are difficult to identify due to the decrease in contrast. This contrast decrease can affect the diagnostic accuracy in medical imaging.

[0087] The scintillator fiber panel of the present application uses high lead equivalent material as the second peripheral material and is designed in an array matrix structure. The innovative design of the present application aims to improve the absorption efficiency of X-rays and reduce the occurrence of scattering phenomena, thereby further optimizing the quality and clarity of medical images. The high lead equivalent material as the second peripheral material has high X-ray absorption capacity and can effectively absorb the energy in the X-ray beam, reducing the useless transmission and scattering of X-rays. The design of the array matrix structure allows X-rays to be efficiently absorbed and attenuated when passing through the fiber panel, effectively reducing the impact of scattered photons on image quality, and thus improving the clarity and contrast of the image.

[0088] Referring to Figure 16 , the X-rays emitted by the X-ray tube 2 are scattered in a cone shape because X-rays are electromagnetic waves that follow the propagation rules of light waves and propagate in various directions in a manner similar to light waves, exhibiting wave-particle duality. According to Huygens' principle, the wave front of X-rays can be regarded as a combination of waves from numerous secondary sources. The waves emitted by these secondary sources propagate in various directions, forming a conical wave front with the X-ray source as the apex. The X-ray source is usually in the form of a point source or a focal point source, making the X-rays highly divergent, i.e., the X-rays radiate in all directions, forming a radiation cone. This cone-shaped radiation phenomenon causes X-rays to exhibit radiative scattering characteristics during propagation, thereby affecting medical imaging and other applications.

[0089] The internal array unit structure of the scintillator fiber panel of the present application is also conical, as shown in Figure 16 , the scintillator fiber panel 172 can selectively receive X-rays according to the scattering direction of the X-rays, allowing only X-rays in specific directions to pass through, which can effectively reduce the impact of scattered radiation.

[0090] The present application can achieve the characteristics of adapting to the X-ray divergence angle by reasonably designing the scintillator fiber panel, thereby selectively accepting X-rays in specific angle directions. The design scheme of the present application enables more primary radiation to be effectively guided to the detector, thereby improving the contrast, clarity and resolution of the image, and further improving the quality of medical images. By optimizing the structure and material of the scintillator fiber panel, efficient capture and guidance of X-ray radiation can be achieved, so that the key imaging information can be more fully utilized. The design of the present application not only helps to maximize the utilization of X-rays, but also effectively reduces the influence of scattering on image quality, improves the accuracy and reliability of imaging.

[0091] The valley effect refers to the phenomenon that the gray value at the edge of the object in the X-ray image is reduced. This phenomenon is partly caused by the interference of scattered radiation, which causes part of the X-rays to be scattered and cannot be completely received by the detector, so that the signal in the edge area of the image is weakened. Another part of the reason is that the current mainstream parallel scintillator fiber panel is located at a limited distance from the X-ray tube, so that the X-rays along the edge of the radiograph are more attenuated than the primary X-rays in the center, thereby causing the detector signal to be slightly weakened from the center to the edge of the radiograph exposed by the parallel scintillator fiber panel. The present application can make X-rays be more effectively captured and transmitted by optimizing the design of the micro-table structure scintillator fiber panel, solving the problem of more photons in the center and fewer photons in the edge, and thereby improving the signal strength and uniformity of the edge area of the image.

[0092] The scintillator fiber panel of the present application has lead wires that are oriented in parallel at the center (along the central axis of the X-ray) and gradually tilt outward to match the beam divergence of a specific source-to-detector distance from the focal point to the detector. The array units are not all placed parallel to each other, the array unit structures in the center of the scintillator fiber panel are parallel to each other, but the strips on both sides are at an angle, and the angle increases as the array unit structure approaches the side of the grid. The array units appear wider at the outer edge of the scintillator fiber panel because these grid strips have a larger angle than the strips near the center of the grid. Since the arrangement of the array units of the scintillator fiber panel matches the way primary radiation photons emerge from the X-ray tube, this cone-shaped scattered X-ray beam allows primary radiation photons near the center of the image to form a smaller angle when they reach the image receiver, increasing the number of photons at the edge and reducing the occurrence of the valley effect. Photons near the edge of the image receiver are more inclined to be distributed at an angle, and this arrangement makes the details of the image clearer and conducive to accurate diagnosis.

[0093] The application improves the imaging quality in X-ray imaging, reduces the influence of scattered radiation on the image, effectively reduces the valley effect, and makes the image clearer and higher in contrast, which is helpful for accurate diagnosis and analysis of the structure and characteristics of the target area.

[0094] Referring to Figure 15 , the focal distance L is the distance from the source to the image, which represents the distance from the X-ray beam source in the X-ray tube to the image forming point, i.e. the detector.

[0095] The array unit inside the scintillator fiber panel 172 has a specific angle and needs to be used at a focal distance L within a specific range to ensure the best imaging effect. If the focal distance is too far or too close, the image will show the case of grid blocking the X-ray beam, resulting in a decline in image quality. In order to achieve the best match, the focal distance range of the scintillator fiber panel 172 should be adapted to the divergence of the X-ray beam. In actual application, there is a certain tolerance range, so that the distance from the source to the image within the range is acceptable. This range is called the focal distance range, which represents the acceptable range of the distance from the source to the image of the scintillator fiber panel 172. If the position of the X-ray tube 2 is located outside the focal distance range, the grid cutoff phenomenon may occur, the grid edge blocks the X-ray beam, resulting in poor image quality.

[0096] Referring to Figure 16 , the application diagram of the scintillator fiber panel in medical CT imaging, the array micro-platform structure of the focusing type scintillator fiber panel is a device for optical system, used for controlling and adjusting the transmission of photons, focusing or dispersing properties, more accurately controlling the propagation direction and characteristics of light in the imaging process, bringing new possibilities and application prospects for detection technology and imaging.

[0097] Embodiment 2

[0098] A preparation method of an array micro-platform structure of a focusing type scintillator fiber panel is basically the same as that of embodiment 1, except that:

[0099] In step (1), the prepared optical fiber preform rod is as shown in Figure 2 , which is a square optical fiber preform rod 100, and the first outer material 102 and the second outer material 103 are processed into rods of the required specification. The rods are arranged in a certain order outside the core material 101 to form an integral optical fiber preform rod 100.

[0100] In step (4), as shown in Figure 4 , it is another cross-sectional structure diagram of the optical fiber blank plate, which is Figure 2The internal structure cross section of the optical fiber preform 100 shown in the figure is formed by multiple times of drawing, rod arranging and hot-pressing into an optical fiber blank plate 111, and the unit array period size of the optical fiber blank plate 111 is 20 microns;

[0101] In step (5), the temperature of heating and softening stretching is 780 DEG C, and the stretching bias angle is 13 DEG ;

[0102] In step (6), the thickness of the first bulk optical fiber panel is 0.5 mm;

[0103] In step (7), the acid liquid is hydrofluoric acid, the etching time is 6 hours, and the etching temperature is 20 DEG C; the covering material is a protective coating, and the protective coating is purchased from Yunnan Optical Auxiliary Material Co., Ltd. BHL-01 protective coating, and the protective coating is cleaned with anhydrous ethanol or according to the cleaning method described in the product description.

[0104] In step (9), the scintillator material is filled into the blind hole of the small end surface by a vacuum melting filling method, the scintillator material is sodium iodide, and the wall thickness of the second peripheral material is 500 microns.

[0105] Example 3

[0106] The preparation method of the array micro-bulk structure focusing scintillator optical fiber panel is basically the same as that in example 1, except that:

[0107] In step (4), the unit array period size of the optical fiber blank plate 111 is 100 microns;

[0108] In step (5), the temperature of heating and softening stretching is 770 DEG C, and the stretching bias angle is 0 DEG ;

[0109] In step (6), the thickness of the first bulk optical fiber panel is 10 mm;

[0110] In step (7), the acid liquid is a mixed acid of nitric acid and hydrochloric acid, the etching time is 2 hours, and the etching temperature is 40 DEG C;

[0111] In step (9), the scintillator material is aluminum oxide, and the wall thickness of the second peripheral material is 0.9 microns.

[0112] By limiting the thermal expansion coefficients of the first peripheral material, the second peripheral material and the core material and the drawing temperature range, the performance stability of the final optical fiber structure is ensured. In the process of drawing the optical fiber, the optical fiber is formed by heating and stretching to the required diameter and structure. If the thermal expansion coefficients of the materials constituting the optical fiber do not match, the stress in the stretching process will be uneven, and even the optical fiber will be broken or the structure will be unstable; if the common temperature range of the materials is not suitable, the optical fiber preform will not reach the same temperature in some areas when heated, which will cause the optical fiber material to have uneven temperature gradient, affecting the stability and performance of the optical fiber structure.

[0113] The above merely describes preferred embodiments of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed with the preferred embodiments as above, it is not intended to limit the present application, and any person skilled in the art can make some changes or modifications to the above disclosed technical contents to obtain equivalent embodiments with equivalent changes, as long as the changes or modifications do not depart from the technical solution of the present application. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application still falls within the scope of the technical solution of the present application.

Claims

1. A method of fabricating a focused scintillator fiber faceplate of an array of microtoms, characterized by, The method comprises the following steps: (1) combining a first peripheral material, a second peripheral material and a core material into an optical fiber preform, and then drawing the optical fiber preform into an optical fiber single yarn through an optical fiber drawing machine, wherein the first peripheral material surrounds the core material, and the second peripheral material surrounds the first peripheral material; (2) arranging a plurality of optical fiber single yarns in a rod arranging mold to form a primary multifilament rod, and then drawing the primary multifilament rod into a primary multifilament through the optical fiber drawing machine; (3) arranging a plurality of primary multifilaments in a rod arranging mold to form a secondary multifilament rod with a desired structural design, and then drawing the secondary multifilament rod into a secondary multifilament through the optical fiber drawing machine; (4) cutting the secondary multifilament into a desired length, arranging the cut secondary multifilament in a plate arranging mold according to a certain structural design, loading the arranged blank plate into a hot-pressing mold, and then placing the hot-pressing mold into a vacuum hot-pressing furnace to perform vacuum fusion, so as to obtain an optical fiber blank plate; (5) placing the optical fiber blank plate in an optical fiber fusion tapering device, heating and softening the optical fiber blank plate for stretching, cooling and setting after the stretching bias angle requirement is met, and then cutting the stretched waist region, so as to obtain two table body optical fiber blank plates; (6) performing optical cold processing on the deformation region of the table body optical fiber blank plate, so as to obtain a first table body optical fiber panel with a preset thickness and shape; (7) using a covering material to cover the large end surface of the first table body optical fiber panel, and then placing the first table body optical fiber panel in an acid solution for local acid etching, so as to form a first table body optical fiber panel with a blind hole on the small end surface; (8) performing surface removal treatment on the first table body optical fiber panel with the blind hole, so as to remove the surface covering layer of the large end surface; (9) filling a scintillator material into the blind hole of the small end surface by using a vapor deposition method or a vacuum fusion filling method, and then polishing the small end surface, so as to finally prepare a scintillator optical fiber panel with an array micro table body structure.

2. The production method according to claim 1, characterized by, The first peripheral material is an acid and alkali etching resistant optical glass material; the second peripheral material is a high lead equivalent special optical glass material resistant to acid and alkali etching; and the core material is an acid soluble optical glass material.

3. The preparation method according to claim 2, characterized in that, The refractive index of the core material is greater than the refractive index of the first peripheral material. The difference percentage of the thermal expansion coefficients of any two of the first peripheral material, the second peripheral material and the core material is less than or equal to 30%, and the drawing temperature ranges of any two of them overlap. The drawing temperature of the optical fiber blank plate is higher than the glass transition temperature (Tg) of any one of the first peripheral material, the second peripheral material and the core material.

4. The production method according to claim 2, characterized by, The drawing bias angle of the optical fiber blank plate is 0-13°, and the unit array period size of the optical fiber blank plate is 4-100 microns.

5. The preparation method according to claim 2, characterized in that, The covering material on the surface of the large end surface of the first table body optical fiber panel is a material with acid and alkali resistance, adhesion and easy removal; The acid solution is at least one of nitric acid, hydrochloric acid and hydrofluoric acid; During the acid etching, the temperature of the acid solution is 20-60℃, and the acid etching time is 1-12 hours.

6. The method of any one of claims 1-5, wherein, The refractive index of the scintillator material is greater than the refractive index of the first peripheral material. The scintillator material is one of cesium iodide, cesium iodide (thallium), sodium iodide, sodium iodide (thallium), aluminum oxide, gadolinium oxysulfide and gadolinium oxysulfide (terbium).

7. The production method according to claim 6, characterized by, The thickness of the scintillator fiber panel is 0.5-10mm; The filling height of the scintillator material is less than the thickness of the scintillator fiber panel; The wall thickness of the second peripheral material of the scintillator fiber panel is greater than 0.3 microns, The temperature for heating and softening the fiber blank is 500-900℃.

8. The production method according to claim 7, characterized by, The wall thickness of the second peripheral material of the scintillator fiber panel is greater than 0.3-500 microns; The temperature for heating and softening the fiber blank is 760-780℃. The covering material is acid-resistant ultraviolet light-resistant glue or protective paint.

9. A focused scintillator fiber faceplate of an array microtab structure, characterized by, Prepared by the preparation method according to any one of claims 1-8.

10. The application of the focusing scintillator fiber panel of the array micro-platform structure according to claim 9 in medical CT imaging.

Images