CN217404541U - Microstructure-based scintillating optical fiber, optical fiber array and luminous scintillator - Google Patents

Abstract

The utility model discloses a scintillation optic fibre, fiber array and luminous scintillator based on micro-structure. The problems that the extraction efficiency of the scintillation light is low, the scintillation light is easy to diffuse in the propagation process, and the transmission mode is in Gaussian distribution, so that the imaging quality is reduced are solved. The scintillation optical fiber is characterized in that an optical fiber substrate made of a scintillation material is provided with an outer layer air hole group and an inner layer air hole array; the outer layer air hole group consists of a plurality of first air holes; connecting the centers of all the first air holes and enclosing the first air holes into a regular closed graph; the inner layer air hole array is composed of a plurality of second air holes, and all the second air holes are positioned in the regular closed graph; the aperture of the plurality of second air holes is gradually reduced from the center to the outside, and the aperture of the first air hole is larger than that of the second air hole at the center.

Description

Microstructure-based scintillation fiber, fiber array and luminescent scintillator

technical field

The utility model belongs to the fields of nuclear detection and ray and fast neutron imaging, in particular to a scintillation optical fiber, an optical fiber array and a luminescent scintillator based on a microstructure.

Background technique

Scintillation detection systems have important uses in high-energy physics experiments, nuclear physics experiments, nuclear medicine imaging, astronomical detection, prospecting logging, security inspection and other fields, often involving major scientific projects or major needs in the field of national security.

The scintillator is the core functional material in the scintillation detection system and belongs to the luminescent material, which can absorb incident high-energy particles (such as electrons, protons, neutrons, alpha particles, etc.) or high-energy photons (such as X-rays, γ-rays), and convert their energy It is converted into near-ultraviolet light or visible light, and then the detection of incident particles or rays is finally realized by photodetection devices such as photomultiplier tubes, photodiodes or CCDs. Common requirements for scintillators in detection systems include high light yield, fast decay, matching emission wavelengths with photodetector responses, stable physicochemical properties, and low cost, as well as high density for gamma-ray detection.

However, in practical applications, due to the high refractive index (about 1.6-2.2) of the inorganic scintillator, when the scintillator emits light, the scintillation photons inside the scintillator will be totally reflected at the exit interface, resulting in a large number of photons being limited. It cannot be emitted from the interior of the scintillator, even if the light less than the total reflection angle can be emitted, but because the emission angle covers the entire space, and the detector may be arranged in a certain direction, most of the light with the emission angle cannot enter the detector and be rejected. waste. At the same time, the scintillation light is easy to diverge during the propagation process, and the transmission mode is Gaussian. If the beam is not controlled, the imaging quality will still not be significantly improved. Therefore, improving the light output of the scintillator, controlling the directionality of its output, and regulating the transmission process are of great significance to improving the detection efficiency and sensitivity of the detection system, as well as the imaging quality.

Second, in the application of luminescent scintillators with macroscopic dimensions (millimeter to centimeter scale), the multiple reflections of the scintillation light at the scintillator interface after the scintillator is excited may lead to the dispersion of temporal characteristics, which will reduce the detection efficiency. time resolution.

Utility model content

In order to solve the problem of low extraction efficiency of scintillation light, easy divergence during propagation, and Gaussian distribution of transmission mode, resulting in low imaging quality, the utility model provides a scintillation optical fiber and an optical fiber array based on a microstructure.

At the same time, the utility model also provides a light-emitting scintillator based on a microstructure, which solves the problems that the scintillation light is repeatedly reflected at the scintillator interface after the luminescent scintillator is excited, which may lead to time characteristic dispersion and low emission efficiency of the scintillation light.

The concrete technical scheme of the present utility model is as follows:

A microstructure-based scintillation optical fiber is used for extracting and transmitting scintillation light. The improvement lies in that: an outer layer air hole group and an inner layer air hole array are opened on an optical fiber matrix made of a scintillation material;

The outer layer air hole group is composed of a plurality of first air holes; the centers of all the first air holes are connected to form a regular closed figure;

The inner layer air hole array is composed of a plurality of second air holes, and all the second air holes are located inside the regular closed pattern;

The diameters of the plurality of second air holes gradually decrease from the center to the outside, and the diameters of the first air holes are larger than the diameters of the second air holes at the center.

Further, the apertures of the above-mentioned plurality of second air holes gradually decrease in a spiral shape from the center to the outside.

Further, the closed figure of the above-mentioned rules is a circle or an ellipse or a regular polygon or a rectangle;

Further, the first air hole and the second air hole are circular or oval, regular polygon or rectangle.

Further, all the above-mentioned first air holes are filled with organic liquid scintillator material or solid scintillator material or noble gas with a lower refractive index than the optical fiber matrix material; all second air holes are filled with organic liquid scintillator materials with a lower refractive index than the optical fiber matrix material. Liquid scintillator material or solid scintillator material or noble gas.

Further, the above-mentioned optical fiber matrix adopts inorganic scintillator material or plastic scintillator material.

At the same time, the utility model also provides a microstructure-based scintillation fiber array, comprising a plurality of the above scintillation fibers, and stray light and nuclear radiation ray absorption isolation layers are arranged between the plurality of scintillation fibers and the periphery of the plurality of scintillation fibers.

Further, the above-mentioned scintillation fiber array is a regular polygon, a parallelogram or a circle.

In addition, the present invention also provides a light-emitting scintillator based on a microstructure for exciting visible light, the scintillator includes a block, and is characterized in that: the block is provided with an outer layer air hole group and an inner layer air hole array;

The outer layer air hole group is composed of a plurality of first air holes; the centers of all the first air holes are connected to form a regular closed figure;

The inner layer air hole array is composed of a plurality of second air holes, and all the second air holes are located inside the regular closed pattern;

The apertures of the plurality of second air holes gradually decrease from the center to the outside, and the apertures of the first air holes are larger than the apertures of the second air holes at the center;

All the first air holes and the second air holes are filled with organic liquid scintillator material or solid scintillator material or inert gas with a lower refractive index than the bulk material.

Further, the inside of the above-mentioned regular closed figure is a circle or an ellipse or a regular polygon or a rectangle; the first air hole and the second air hole are a circle or an ellipse or a regular polygon or a rectangle; the block is made of inorganic scintillator material. or plastic scintillator material.

Compared with the prior art, the advantages of the present utility model are:

1. In the present invention, the outer layer air hole group and the inner layer air hole array are arranged on the base of the scintillation fiber. The first air hole diameter of the layer air hole group makes the refractive index of the air hole part of the entire microstructure fiber interface present a low-high-low distribution, so that the scintillation light is confined in the fiber or fiber array during the transmission process, realizing flexible sealing The transmission is not easy to diverge, and the uniform regulation of the light field is achieved at the same time.

2. In the present invention, the outer layer air hole group and the inner layer air hole array are arranged on the light-emitting scintillator, and the diameter of all the second air holes in the inner layer air hole array gradually decreases from the inside to the outside in a gradient shape, and is smaller than the outer layer. The first air hole diameter of the layer air hole group, the design of the microstructure avoids the multiple reflections of the scintillation light at the interface of the luminescent scintillator after the luminescent scintillator is excited, which may lead to the dispersion of time characteristics, thereby reducing the time resolution of the detection system. At the same time, it solves the problem that the scintillation photons inside the scintillator will be totally reflected at the exit interface, resulting in a large number of photons being confined inside the scintillator and unable to exit, resulting in the inability to effectively extract the scintillation light.

3. The scintillation optical fibers and optical fiber arrays proposed by the present invention can realize flexible and bendable transmission of scintillation light, expand application scenarios, and have high imaging quality and resolution.

Description of drawings

FIG. 1 is a schematic structural diagram of this embodiment.

FIG. 2 is a schematic diagram of a refractive index distribution region of this embodiment.

FIG. 3 is a mode field diagram of scintillation light transmission in the optical fiber of the present embodiment.

FIG. 4 is a transmission mode field diagram of an optical fiber with a solid center.

FIG. 5 is a transmission mode field diagram of an optical fiber with a uniform air hole microstructure.

FIG. 6 is a graph showing a flat distribution of optical fiber transmission energy in the optical fiber of the present embodiment.

FIG. 7 is a schematic diagram of the microstructure of the cross-sectional microstructure of an optical fiber with air holes in a helical structure.

FIG. 8 is a structural diagram of a single scintillation fiber array in which the fibers are arranged in a regular hexagonal array.

FIG. 9 is a structural diagram of a single scintillation optical fiber array with optical fibers arranged in a square array.

FIG. 10 is a structural diagram of the scintillation fiber array after fusion and stretching by splicing.

The reference numbers are as follows:

1-fiber matrix, 2-outer layer air hole group, 3-inner layer air hole array, 21-first air hole, 31-second air hole, 4-scintillation fiber, 5-stray light and nuclear radiation ray absorption and isolation Floor.

Detailed ways

In order to make the above-mentioned purposes, features and advantages of the present utility model more obvious and easy to understand, the specific embodiments of the present utility model will be described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the present utility model. not all examples. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

In the following description, many specific details are set forth in order to fully understand the present utility model, but the present utility model can also be implemented in other ways different from those described herein, and those skilled in the art can do so without departing from the connotation of the present utility model. Therefore, the present invention is not limited by the specific embodiments disclosed below.

At the same time, in the description of the present utility model, it should be noted that the orientation or positional relationship indicated by "front, rear, inner and outer" in the terms is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of description. The present invention and the simplified description are not intended to indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first, second or third" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

Unless otherwise expressly specified and limited in this utility model, the term "installation, connection, connection" should be understood in a broad sense, for example: it may be a fixed connection, a detachable connection or an integrated connection: it may also be a mechanical connection, an electrical connection or a Direct connection, indirect connection through an intermediate medium, or internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

This embodiment provides a microstructure-based scintillation optical fiber and an optical fiber array prepared from the optical fiber. FIG. 1 is a cross-sectional view of the microstructured scintillation optical fiber. The microstructured scintillation optical fiber includes: an optical fiber matrix made of a scintillation material 1. Outer layer air hole group 2, inner layer air hole array 3;

The outer layer air hole group is composed of two or more first air holes 21; the centers of all the first air holes 21 are connected to form a regular closed figure; in this embodiment, the regular closed figure is a regular hexagon.

The inner layer air hole array 3 is composed of a plurality of second air holes 31, and all the second air holes 31 are located inside the regular closed pattern;

The hole diameter of the first air hole 21 is larger than that of the second air hole 31 ; the second air hole 31 at the center is the second air hole 31 with the largest hole diameter among the plurality of second air holes 31 , and the diameter of the plurality of second air holes 31 There is a decreasing trend from the center to the outside. It is assumed that the refractive index of the central area of the inner layer air hole array 33 is n ₁ (the area in the dotted circle A in FIG. 2 ), and the refractive index of the area formed by the outer air hole group 2 is n ₃ (the dotted circle B and The annular area between the dashed circles C), the refractive index of the area between them is n ₂ (the annular area between the dashed circles A and the dashed circles B in Figure 2), then there are n ₁ <n ₂ >n ₃ , the entire The refractive index of the air hole at the interface of the microstructured fiber exhibits a low-high-low distribution. This structure can realize the uniform regulation of the light field of the light beam. Specifically, as shown in Figure 3, the microstructure scintillation optical fiber designed by the utility model has a relatively uniform distribution of scintillation light energy during transmission, indicating that the light field of the light beam transmission is relatively uniform. , the structure can realize the uniformity control of the light field of the beam. Fig. 4 is the transmission mode field diagram of the fiber with the solid center, and Fig. 5 is the transmission mode field diagram of the fiber when all the air holes are set to a uniform aperture. Comparing Figures 4 and 5 with Figure 3, it can be seen that the energy transmission of the scintillation light in Figures 4 and 5 is a Gaussian distribution, and this mode affects the final imaging quality. FIG. 6 is a graph showing a flat distribution of the transmission energy of the optical fiber in the optical fiber, which further proves that the optical fiber designed by the present invention can realize uniform transmission of energy.

In addition to this embodiment, the regular closed figure may also be a circle or an ellipse or other regular polygons or rectangles. The air hole array in the inner layer can be a regular hexagon as shown in Figure 1, or it can be any shape such as a square, an ellipse, a circle or other regular polygons.

Preferably, in this embodiment, the apertures of the plurality of second air holes 31 gradually decrease in a spiral shape from the center to the outside, as shown in FIG. 7 .

The first air hole 21 and the second air hole 31 may also be any shape such as a circle, an ellipse, a square, a triangle, or other regular polygons. In this embodiment, the first air hole 21 and the second air hole 31 are circular.

The first air holes 21 and the second air holes 31 may be filled with an organic liquid scintillator having a lower refractive index than the optical fiber matrix material, or may be filled with a solid scintillator material having a lower refractive index than the optical fiber matrix material or an inert gas.

In this embodiment, the optical fiber matrix may be an inorganic scintillator material, including but not limited to: one or a combination of NaI(Tl), CsI(Tl), ZnS(Ag), BGO, etc., or a plastic scintillator material Body materials, including but not limited to: one or several combinations of EJ200, EJ230, NE213, ST401, NE102A, and NE104.

As shown in FIG. 8 , this embodiment provides a single scintillation fiber array composed of the above-mentioned scintillation fibers. The array includes a plurality of scintillation fibers 4 , between the plurality of scintillation fibers 4 and the periphery of the plurality of scintillation fibers 4 A stray light and nuclear radiation ray absorbing isolation layer 5 is provided, and the purpose of setting the stray light and nuclear radiation ray absorbing isolation layer 5 is to avoid crosstalk between the scintillation fibers.

The fabrication methods of the fiber array monomer are as follows:

The first method is to use multiple scintillation optical fibers to directly fabricate in a cutting-splicing method, but this method requires higher fabrication process and is more complicated to implement.

The second method is to insert a scintillation fiber with a larger diameter into a preform made of a porous scintillation fiber and a stray light composite isolation layer, and then stretch the preform to improve the image element of the fiber array. The stretched multiple fiber array monomers are cut-spliced-melted and stretched to increase the total number of pixels in the entire fiber array. This method solves the problem that the splicing method has high requirements on the manufacturing process, and splicing The disadvantages of cumbersome process.

The detection area of the scintillation fiber array can be a regular hexagon as shown in FIG. 8 , a square as shown in FIG. 9 , or a parallelogram, a polygon, a circle, and other shapes that are not limited to the above shapes. The structure shown is a scintillation fiber array with a larger matrix and higher resolution obtained by cutting-splicing-melting-drawing of the scintillation fiber array monomer shown in FIG. 8 .

Claims (10)

1. A microstructure-based scintillating optical fiber for extracting and transmitting scintillating light, characterized in that: an outer layer air hole group and an inner layer air hole array are arranged on an optical fiber substrate made of a scintillating material;

the outer layer air hole group consists of a plurality of first air holes; connecting the centers of all the first air holes and enclosing the first air holes into a regular closed graph;

the inner layer air hole array is composed of a plurality of second air holes, and all the second air holes are positioned in the regular closed graph;

the aperture of the plurality of second air holes is gradually reduced from the center to the outside, and the aperture of the first air hole is larger than that of the second air hole at the center.

2. The microstructure-based scintillating optical fiber of claim 1, wherein: the pore diameters of the plurality of second air holes are spirally and gradually reduced from the center to the outside.

3. The microstructure-based scintillating optical fiber of claim 1, wherein: the regular closed figure is a circle or an ellipse or a regular polygon or a rectangle.

4. The microstructure-based scintillating optical fiber of claim 1, wherein: the first air hole and the second air hole are circular or elliptical or regular polygonal or rectangular.

5. The microstructure-based scintillating optical fiber of claim 3, wherein: all the first air holes are filled with organic liquid scintillation materials or solid scintillation materials or inert gases with the refractive index lower than that of the optical fiber matrix materials; all the second air holes are filled with organic liquid scintillation materials or solid scintillation materials or inert gases with the refractive index lower than that of the optical fiber base materials.

6. The microstructure-based scintillating optical fiber of claim 1, wherein: the optical fiber substrate is made of inorganic scintillator material or plastic scintillator material.

7. A microstructure-based scintillating fiber array, characterized by: comprises a plurality of scintillating optical fibers according to claims 1-6, and stray light and nuclear radiation ray absorption isolation layers are arranged among the plurality of scintillating optical fibers and at the periphery of the plurality of scintillating optical fibers.

8. The microstructure-based scintillating optical fiber array of claim 7, wherein: the scintillation fiber array is regular polygon or parallelogram or round.

9. A microstructure-based luminescent scintillator for exciting visible light, the scintillator comprising a mass, characterized in that: the block body is provided with an outer layer air hole group and an inner layer air hole array;

the outer layer air hole group consists of a plurality of first air holes; connecting the centers of all the first air holes and enclosing the centers into a regular closed graph;

the inner layer air hole array is composed of a plurality of second air holes, and all the second air holes are positioned in the regular closed graph;

the aperture of the plurality of second air holes is gradually reduced from the center to the outside, and the aperture of the first air hole is larger than that of the second air hole at the center;

all the first air holes and the second air holes are filled with an organic liquid scintillation material or a solid scintillator material or an inert gas, wherein the refractive index of the organic liquid scintillation material is lower than that of the bulk material.

10. The microstructure-based luminescent scintillator of claim 9, wherein: the interior of the regular closed graph is circular or elliptical or regular polygonal or rectangular; the first air hole and the second air hole are circular, elliptic, regular polygonal or rectangular; the block body is made of an inorganic scintillator material or a plastic scintillator material.

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