Light guide scintillator array

Abstract

The application discloses a light guide scintillator array, which comprises a plurality of scintillator units spliced in an array structure, and light is incident along a direction perpendicular to a cross section of the scintillator units, characterized in that the scintillator units comprise a first base layer to an n-th base layer which are diffused from a center to an outer layer along the cross section direction, and the refractive index of the first base layer to the n-th base layer gradually decreases. Through the above arrangement, the propagation path of part of light in the scintillator is changed by the decreasing change of the refractive index, so that the problem of light energy loss caused by refraction in the process of light propagation in the scintillator is improved, total reflection of light is realized, and the light output performance of the scintillator is improved.

Description

Technical Field

[0001] This invention relates to the field of scintillation detector technology, and in particular to a photoconductive scintillator array. Background Technology

[0002] A scintillation detector is a type of ionizing radiation detector widely used in fields such as medicine, defense, and security. The scintillator array is the core component of a scintillation detector; it is the conversion medium between high-energy rays and optical signals. It converts high-energy rays (X-rays / gamma rays) or charged particles into ultraviolet or visible light. This light is then converted into electrical signals by photon detection devices such as photomultiplier tubes, ultimately presenting the information about the interaction between the high-energy rays and the detected matter in the form of digital signals.

[0003] In the production process of scintillator arrays, the block-shaped scintillator medium first needs to be machined, that is, the scintillator medium is processed into several small basic units by cutting, grinding and other methods. Then, the basic units are filled into the mold, and a reflective layer is formed on the side of the basic units and the light-emitting surface of the array by potting glue.

[0004] Traditional scintillation ceramic basic structure is shown in the attached figure. Figure 1 As shown, the main body typically consists of a scintillator 1 (including a single-layer or multi-layer structure) and a reflective layer 2. Light propagation within the scintillator 1 relies on reflection from the outer reflective layer 2. Photons exiting from the light-emitting surface undergo multiple interface reflections between the scintillator 1 and the reflective layer 2. These interface reflections result in energy loss; the longer the scintillator, the greater the energy loss, which is detrimental to efficient photon extraction. Summary of the Invention

[0005] The purpose of this invention is to provide a photoguide scintillator array that achieves photon propagation confinement by setting a decreasing refractive index, thereby changing the propagation path of light and reducing light reflection loss.

[0006] To address the above problems, the present invention provides a light-guided scintillator array, comprising multiple scintillator elements arranged in an array structure, wherein light is incident along a direction perpendicular to the cross-section of the scintillator elements, characterized in that: the refractive index of the material of each scintillator element gradually decreases from the center to the outer layer along its cross-section.

[0007] Furthermore, each of the aforementioned scintillator units includes n base layers made of different materials, wherein the base layers include layers 1 to n stacked from the center outward along the cross-sectional direction; the refractive index of the materials of the layers 1 to n decreases stepwise, and n≥2.

[0008] Furthermore, the refractive index of the first to nth layers is between 1.0 and 3.0.

[0009] Furthermore, the substrate includes a matrix and activation ions doped in the matrix;

[0010] The matrix is ​​made of Lu2O3 transparent ceramic or single crystal, Lu3Al5O 12 Transparent ceramics or single crystals, Y3Al5O 12 Transparent ceramics or single crystals, (Gd x Lu 1-x )3(Al y Ga 1-y )5O 12 Transparent ceramics or single crystals, (Y a Lu b Gd c )2O3 transparent ceramics or single crystals, Gd2O2S transparent ceramics or single crystals, (Ca x Mg 1-x )3(Sc y Lu 1-y )2Si3O 12 One or more of the following: NaI(TI) single crystal material, CsI(Na) single crystal material, BaF2 single crystal material, CaF2(Eu) single crystal material, BGO single crystal material, CdWO4 single crystal material, PbWO4 single crystal material, YAP:Ce single crystal material, GSO:Ce single crystal material, and LSO:Ce single crystal material; wherein 0 < x < 1, 0 < y < 1; 0 < a < 1, 0 < b < 1, and a + b + c = 1;

[0011] The activating ions are selected from Ce. 3+ Pr 3+ 、Nd 3+ 、Sm 3+ Eu 2+ Dy 2+ Ho 2+ Er 2+ Tm 2+ Ti 2+ Cr 2+ and Mn 2+ One of them.

[0012] Furthermore, the various base layers of the scintillator unit are formed by casting or grouting followed by integral sintering; or by bonding the various base layers together with epoxy resin or a transparent adhesive to form the scintillator unit.

[0013] Furthermore, the sides and bottom of the scintillator elements are connected by a reflective medium or adhesive to form a scintillator array.

[0014] Furthermore, the scintillator unit is cylindrical or polygonal.

[0015] The beneficial effects of this invention are: by forming scintillator units through multiple base layers with decreasing discount rates, photon transmission confinement is formed within the scintillator, changing the propagation path of light after it enters the scintillator, improving the light energy loss caused by light reflection from the surface reflective medium, thereby improving the light output performance of the scintillator. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the light propagation path of a traditional scintillator element;

[0017] Figure 2 This is a schematic diagram of the structure of the scintillator unit in Embodiment 1 and Comparative Example 1 of the present invention;

[0018] Figure 3 This is a schematic diagram of the scintillator array according to Embodiment 1 of the present invention;

[0019] Figure 4 These are schematic diagrams of the scintillator units in Embodiments 2-3 and Comparative Examples 2-3 of the present invention;

[0020] Figure 5 This is a schematic diagram of the structure of a scintillator element in other embodiments of the present invention;

[0021] Figure 6 This is a schematic diagram of the propagation path of light in a scintillator element in an embodiment of the present invention. Detailed Implementation

[0022] The technical features and advantages of the present invention will be described in more detail below with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more explicit definition of the scope of protection of the present invention.

[0023] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0024] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0025] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] This invention provides a photoguide scintillator array, which is composed of multiple scintillator elements arranged in an array structure, and can be used in fields such as medical treatment, national defense, and security inspection detectors.

[0027] The scintillator element of the present invention can be cylindrical, polygonal, or other regular structural forms. Each scintillator element includes multiple layers stacked from the inside to the outside along its cross-sectional direction, and the refractive index of each layer gradually decreases from the center to the outer layer. By stacking multiple layers with decreasing refractive index, the transmission of photons is confined, the propagation path of light after it enters the scintillator element is changed, and the refractive index of light in the scintillator element is gradually changed, thereby improving the problem of light energy loss caused by refraction after light enters the scintillator and improving the light output performance of the scintillator.

[0028] The advantages of the present invention for improving the light output performance of scintillators will be explained in detail below through multiple embodiments and comparative examples.

[0029] Example 1

[0030] The scintillator unit of Embodiment 1 of the present invention has the following structure. Figure 2 Each scintillator unit comprises, along its cross-sectional direction, layers A, B, C, D, E, F, and G, which diffuse outward from the center. Each layer is made of a different material to form seven layers with refractive indices decreasing sequentially: refractive index of layer A > refractive index of layer B > refractive index of layer C > refractive index of layer D > refractive index of layer E > refractive index of layer F > refractive index of layer G.

[0031] The base layers A through G are successively made of Gd3Al2Ga3O 12 Gd3Al3Ga2O 12 Gd3Al4Ga1O 12 Gd3Al5O 12 Gd2YAl5O 12 GdY2Al5O 12 Y3Al5O 12 The scintillator unit is fabricated with its refractive index gradually decreasing from 1.9 at layer A to 1.82 at layer G, consisting of a total of 7 layers. Layer A is composed of Gd3Al2Ga3O 12It is made by incorporating activating ions, while the other components of the base layer do not contain activating ions. After weighing the above raw materials according to the stoichiometric ratio, each base layer is formed sequentially through slip casting, and then the structure is produced through processes such as sintering. Figure 2 The scintillator element shown is illustrated. Furthermore, a scintillator array can be formed by splicing multiple of the above-described scintillator elements. Adjacent scintillator elements are connected to each other and to their bottoms via a reflective medium. See [reference needed for the scintillator array structure]. Figure 3 As shown.

[0032] In this embodiment, the cross-section of each scintillator element is a square with a side length of 2mm, the height of each scintillator element is 2mm, and the thickness of each base layer in the scintillator element is approximately 0.285mm.

[0033] Example 2

[0034] The scintillator unit of Embodiment 2 of the present invention has the following structure. Figure 4 Each scintillator element comprises, along its cross-sectional direction, layers A and B that diffuse outward from the center. Each layer is made of a different material to form three layers with successively decreasing refractive indices, i.e., the refractive index of layer A is greater than that of layer B.

[0035] YAlO3 (YAP) was selected as the raw material to make base layer A, and Y3Al5O3 was selected as the raw material. 12 As a raw material for making base layer B, the refractive index decreases from YAlO3 (YAP) (refractive index 1.94) to Y3Al5O 12 (Refractive index 1.82), wherein activated ions are incorporated into the YAP of base layer A, while no activated ions are incorporated into the other base layer components. After weighing the above raw materials according to the stoichiometric ratio, base layers A and B are formed by slip casting, and then the structure is manufactured through processes such as sintering. Figure 4 The scintillator element shown; further, a scintillator array is formed by splicing multiple of the above-mentioned scintillator elements, and adjacent scintillator elements and the bottom of the scintillator elements are connected by epoxy resin incorporating a reflective medium or reflective film.

[0036] In this embodiment, the cross-section of each scintillator element is a square with a side length of 2mm, the height of each scintillator element is 2mm, and the thickness of each base layer in the scintillator element is approximately 1mm.

[0037] Example 3

[0038] The scintillator unit of Embodiment 3 of the present invention has the following structure. Figure 4 Each scintillator element comprises, along its cross-sectional direction, two layers: A and B, which diffuse outward from the center. Each layer is made of a different material to form two layers with successively decreasing refractive indices, i.e., the refractive index of layer A is greater than that of layer B.

[0039] Select Gd3Al2Ga3O 12 Y3Al5O was selected as the raw material for making base layer A. 12 As a raw material for making base layer B, base layer A (Gd3Al2Ga3O) 12 The refractive index of ) is 1.9, and the base layer B(Y3Al5O) 12 The refractive index of ) is 1.82, of which the A-base layer is Gd3Al2Ga3O 12 Activating ions are incorporated into the A layer, while no activating ions are incorporated into the B layer. After weighing the above raw materials according to the stoichiometric ratio, the A and B layers are sequentially formed by slip casting, and then the structure is manufactured through processes such as sintering. Figure 4 The scintillator element shown is further illustrated. A scintillator array is formed by splicing multiple of the aforementioned scintillator elements, with adjacent scintillator elements and the bottom of the scintillator elements connected by epoxy resin incorporating a reflective medium or reflective film.

[0040] In this embodiment, the cross-section of each scintillator element is a square with a side length of 2mm, the height of each scintillator element is 2mm, and the thickness of each base layer in the scintillator element is approximately 1mm.

[0041] Comparative Example 1

[0042] The scintillator primitive of Comparative Example 1 is shown in the figure below. Figure 2 It consists of 7 base layers from the inside out, using Gd3Al2Ga3O4. 12 The system uses Gd3Al2Ga3O as raw material, with the base layers A through G all consisting of Gd3Al2Ga3O 12 It is made of 7 layers in total, of which the A layer is Gd3Al2Ga3O 12 Activating ions are incorporated into the substrate, while the remaining substrate components are not. The refractive index of substrates A through G is 1.9. After weighing the above raw materials according to the stoichiometric ratio, the structure is fabricated through processes such as slip casting and sintering. Figure 2 The scintillator element shown is shown. Furthermore, a scintillator array can be formed by splicing multiple of the above-mentioned scintillator elements, with adjacent scintillator elements connected to each other and at their bottoms via a reflective medium.

[0043] In this comparative example, the cross-section of each scintillator element is a square with a side length of 2 mm, the height of each scintillator element is 2 mm, and the thickness of each base layer in the scintillator element is approximately 0.285 mm.

[0044] Comparative Example 2

[0045] The scintillator unit of Comparative Example 2 is shown in the figure below. Figure 5YAP was selected as the raw material. Both layers A and B were made of YAP, totaling two layers. The YAP in layer A was doped with activating ions, while the other layer components were not doped with activating ions. The refractive index of both layers A and B was 1.94. After weighing the above raw materials according to the stoichiometric ratio, the structure was fabricated through processes such as slurry casting and sintering. Figure 4 The scintillator element shown is further illustrated. A scintillator array is formed by splicing multiple of the aforementioned scintillator elements, with adjacent scintillator elements and the bottom of the scintillator elements connected by epoxy resin incorporating a reflective medium or reflective film.

[0046] In this comparative example, the cross-section of the scintillator element is a square with a side length of 2mm, the height of each scintillator element is 2mm, and the thickness of each base layer in the scintillator element is approximately 1mm.

[0047] Comparative Example 3

[0048] The scintillator unit of Comparative Example 3 is shown in the figure below. Figure 5 Gd3Al2Ga3O was selected. 12 Both substrates A and B are made of Gd3Al2Ga3O4 as raw materials. 12 It is made of two layers, with layer A being Gd3Al2Ga3O 12 Activating ions are incorporated into the substrate, while the remaining substrate components are not. The refractive indices of both substrates A and B are 1.9. After weighing the above raw materials according to the stoichiometric ratio, the structure is fabricated through processes such as grouting and sintering. Figure 4 The scintillator element shown is further illustrated. A scintillator array is formed by splicing multiple of the aforementioned scintillator elements, with adjacent scintillator elements and the bottom of the scintillator elements connected by epoxy resin incorporating a reflective medium or reflective film.

[0049] In this comparative example, the cross-section of the scintillator element is a square with a side length of 2mm, the height of each scintillator element is 2mm, and the thickness of each base layer in the scintillator element is approximately 1mm.

[0050] Based on the scintillator elements of Examples 1-3 and Comparative Examples 1-3, scintillator arrays of the same size were fabricated, and the optical output performance of each scintillator array was experimentally determined according to the measurement specifications in 5.1 of GB / T 13181-2002. The results are listed in Table 1.

[0051] Table 1 Comparison of optical output performance of various scintillator arrays

[0052]

[0053] As can be seen from Table 1, the present invention improves the overall light output performance of the scintillator unit by setting a decreasing refractive index within multiple layers of the scintillator unit.

[0054] In other embodiments of the present invention, the structure of the scintillator unit may also be as follows: Figure 5 The cylindrical shape shown includes n layers (n≥2) with decreasing refractive index from the center to the outer layer.

[0055] A schematic diagram of the propagation path of light after it enters the scintillator element of the structure of this invention can be found in [reference needed]. Figure 6 Figure a) shows the basic structure of a two-layer scintillator and the propagation path of light after incident; Figure b shows the basic structure of a multi-layer scintillator and the propagation path of light after incident. By changing the refractive index of each layer and stacking the layers, the propagation path of some light in the scintillator can be changed, thereby improving the reflection loss of light and improving the light output performance.

[0056] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A light-guided scintillator array, comprising a plurality of scintillator elements arranged in an array structure, wherein light is incident along a direction perpendicular to the cross-section of the scintillator elements, characterized in that: Each scintillator unit comprises, along its cross-sectional direction, seven layers diffused outward from the center: A-layer, B-layer, C-layer, D-layer, E-layer, F-layer, and G-layer. Each layer is made of a different material to form seven layers with refractive indices decreasing sequentially. The refractive index of layer A > the refractive index of layer B > the refractive index of layer C > the refractive index of layer D > the refractive index of layer E > the refractive index of layer F > the refractive index of layer G. The base layers A through G are successively made of Gd3Al2Ga3O 12 Gd3Al3Ga2O 12 Gd3Al4Ga1O 12 Gd3Al5O 12 Gd2YAl5O 12 GdY2Al5O 12 Y3Al5O 12 The fabrication process involves gradually decreasing the refractive index from 1.9 for substrate A to 1.82 for substrate G; substrate A is composed of Gd3Al2Ga3O 12 It is made by incorporating activating ions, while no activating ions are incorporated into the other components of the base layer; The method for preparing the scintillator array includes: weighing raw materials according to stoichiometric ratio, forming each base layer sequentially by slurry casting, and then forming scintillator units by sintering; forming a scintillator array by splicing multiple scintillator units, with adjacent scintillator units and the bottom of the scintillator units connected by a reflective medium.

2. The photoconductive scintillator array according to claim 1, wherein the scintillator element is cylindrical or polygonal.

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