Integrated liquid scintillation capillary array and method of making and using same, and a puller

Abstract

The application provides an integrated liquid flash capillary array, a preparation method and application thereof, and a pull-in equipment. The liquid flash capillary array comprises: an array substrate, which comprises an integrated straight area and a tapered area; the straight area is composed of a plurality of axis-parallel capillaries; the tapered area is formed by gradual shrinkage of the plurality of axis-parallel capillaries, each capillary is seamlessly and continuously extended to the tapered area and gradually shrunk synchronously; a liquid scintillator is filled in the internal channel of each capillary; a first sealing element is arranged at the end of the straight area, used for sealing the liquid scintillator and allowing fast neutron incidence; and a second sealing element is arranged at the end of the tapered area, used for sealing the liquid scintillator and allowing light signal output. The technical problem to be solved is how to provide the liquid flash capillary array, so that the straight area and the tapered area capillary are integrally formed, the pixel channel is one-to-one corresponding, the light transmission efficiency and the fast neutron imaging resolution are improved, the whole machine assembly is simplified, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of fast neutron detection technology, and in particular to an integrated liquid scintillator capillary array, its fabrication method and application, as well as a tapered device. Background Technology

[0002] In physical processes such as laser-driven inertial confinement fusion and Z-Pinch-driven inertial confinement fusion, the 14MeV fast neutrons released by the fusion nuclear reaction have strong penetrating power. Their spatial distribution can reflect information such as the size, shape, and uniformity of the fuel implosion compression zone. Therefore, fast neutron imaging systems are usually used to diagnose the fusion process.

[0003] Currently, the core detection structure of fast neutron imaging systems based on liquid scintillator capillary arrays commonly employs a combination of parallel liquid scintillator capillary arrays and optical cones. The liquid scintillator capillary array is a capillary array filled with liquid scintillator, with one end encapsulated in glass and the other in an optical fiber panel, used to convert fast neutrons into visible light signals. The optical cone is a gradually contracting array of glass fibers; its large-aperture end is coupled to the end face of the optical fiber panel of the liquid scintillator capillary array, while its small-aperture end is used to converge and transmit the visible light signal to the subsequent photodetector, ensuring efficient transmission of the optical signal to the detector for imaging.

[0004] However, this split structure of "liquid scintillation capillary array + light cone" has many inherent defects: First, as an independent component, the light cone needs to be precisely aligned and installed with the liquid scintillation capillary array at the sub-micron level. The high alignment accuracy requirement significantly increases the assembly difficulty and production cost of the system. Second, there is an unavoidable assembly gap between the light cone and the liquid scintillation capillary array, which will cause some visible light signals to leak and scatter during transmission, reducing the transmission efficiency of the light signals and thus affecting the detection sensitivity and imaging quality of the imaging system. Third, when the parallel liquid scintillation capillary array is coupled with the light cone, the pixel arrangement of the two cannot be strictly one-to-one, and the coupling process will cause a significant loss of spatial resolution. Summary of the Invention

[0005] The main objective of this invention is to provide an integrated liquid scintillation capillary array, its fabrication method and application, as well as a tapering device. The technical problem to be solved is how to overcome the defects of existing split liquid scintillation capillary arrays with independent optical cones, such as high assembly difficulty, high light transmission loss, and severe loss of imaging resolution. This invention eliminates the need for independent optical cone components, achieves integrated molding of the straight and tapered capillary regions, ensures one-to-one correspondence between pixel channels, improves light transmission efficiency and fast neutron imaging resolution, simplifies overall assembly, and reduces production costs.

[0006] The objective of this invention and the technical problem it solves are achieved through the following technical solution. According to this invention, an integrated liquid scintillation capillary array comprises: The array substrate includes an integrally formed straight region and a conical region; the straight region is composed of multiple capillaries with parallel axes; the conical region is formed by the gradual contraction of the multiple capillaries with parallel axes, and each capillary extends seamlessly and continuously from the straight region to the conical region and contracts synchronously. Liquid scintillator fills the internal channels of each capillary; The first seal, located at the end of the straight section, is used to seal the liquid scintillator and allow fast neutrons to enter; The second seal, located at the end of the conical section, is used to seal the liquid scintillator and allow optical signal output.

[0007] The objectives of this invention and the technical problems it addresses can be further achieved by the following technical measures.

[0008] Preferably, in the integrated liquid scintillation capillary array, a light-absorbing glass layer is provided between adjacent capillaries in the array substrate; the visible light transmittance of the light-absorbing glass layer is ≤1% at a thickness of 0.4 mm.

[0009] Preferably, the integrated liquid scintillation capillary array has a solid glass edging region surrounding the array substrate.

[0010] Preferably, in the integrated liquid scintillation capillary array, the shrinkage ratio of the conical region is greater than 1 and less than 10.

[0011] Preferably, in the integrated liquid scintillation capillary array, the inner diameter of a single capillary in the straight region is 20μm~500μm, and the length is ≥10cm.

[0012] Preferably, in the integrated liquid scintillator array, the liquid scintillator is a hydrogen-containing scintillator liquid with a hydrogen atom content ≥ 4 × 10⁻⁶. 22 pcs / cm 3 .

[0013] Preferably, in the integrated liquid scintillation capillary array, the capillary material is glass.

[0014] Preferably, in the integrated liquid scintillator array, the first sealing element is glass; the second sealing element is an optical fiber panel.

[0015] The objective of this invention and the technical problem it solves are achieved through the following technical solution. A method for fabricating an integrated liquid scintillation capillary array according to this invention includes the following steps: S1 involves drawing a glass preform tube twice to obtain a secondary multifilament. The secondary multifilament is then arranged, melted, rolled, and cut to obtain a first blank segment. The first blank segment includes multiple capillaries with parallel axes. S2 inserts the first billet into the zoned temperature-controlled heating furnace, aligning the billet axis with the furnace axis, continuously introducing protective gas into the capillary tube, and simultaneously applying tensile force along the billet axis to both ends to draw it, thus obtaining a second billet with a straight zone and a pre-formed conical zone; the zoned temperature-controlled heating furnace includes three temperature zones, with the center being a high-temperature zone and the two ends being secondary high-temperature zones. S3 cuts and cleans along the two end faces and the radial section in the middle of the second billet segment to obtain the third billet segment; the third billet segment includes a straight region composed of multiple capillaries with parallel axes and a conical region formed by the gradual contraction of the capillaries; S4 fills each capillary of the third blank section with liquid scintillation material, and then assembles the first seal at the end of the straight section and the second seal at the end of the conical section to complete the sealing.

[0016] The objectives of this invention and the technical problems it addresses can be further achieved by the following technical measures.

[0017] Preferably, in the preparation method, the protective gas introduced in step S2 is nitrogen or argon.

[0018] Preferably, in the preparation method, a light-absorbing glass layer is provided between adjacent capillaries in the first blank segment; the visible light transmittance of the light-absorbing glass layer is ≤1% at a thickness of 0.4 mm; and the outer periphery of the first blank segment is covered with a solid glass edging area.

[0019] Preferably, in the preparation method, the softening point temperature of the light-absorbing layer glass is 30°C to 60°C lower than that of the capillary glass, and the softening point temperature of the edge-sealing region glass is 20°C to 40°C lower than that of the light-absorbing layer glass.

[0020] Preferably, in the preparation method, in step S2, the temperature of the high-temperature zone is 20°C to 50°C higher than the softening point temperature of the capillary glass; and the temperature of the secondary high-temperature zone is 50°C to 150°C lower than the softening point temperature of the capillary glass.

[0021] The objective of this invention and the technical problem it solves are achieved through the following technical solution. According to this invention, an integrated liquid scintillation capillary array billet tapering device is provided, comprising: A zoned temperature-controlled heating furnace, the heating furnace including two opposing openings; a central high-temperature zone and secondary high-temperature zones arranged on both sides of the high-temperature zone along the stretching axis of the billet; Two clamping components are symmetrically arranged on the outside of the two openings of the heating furnace to clamp the billet segment passing through the heating furnace, so that its axis coincides with the axis of the heating furnace. A lead screw assembly is connected to two clamping members via a column; the lead screw can drive the two clamping members to translate towards or away from each other. The gas supply assembly includes a gas cylinder, a gas supply pipeline, and a hollow sealing element; the sealing element is assembled inside the clamping element and can fit against the end face of the edge area of ​​the billet segment to make the billet segment and the clamping element airtight; one end of the gas supply pipeline is connected to the gas cylinder, and the other end passes through the sealing element, and is used to supply gas into the capillary of the billet segment to form internal air pressure support.

[0022] The objective of this invention and the technical problem it solves are achieved by the following technical solution: An application of the aforementioned integrated liquid scintillator array in a fast neutron imaging system, according to this invention.

[0023] By utilizing the above technical solutions, the integrated liquid scintillation capillary array, its preparation method and application, and the tapering device proposed in this invention have the following beneficial effects: The integrated liquid scintillation capillary array, its fabrication method and application, and the tapering device proposed in this invention, by designing the straight and tapered regions as an integrally formed structure, allows each capillary to extend seamlessly and continuously from the straight region to the tapered region while simultaneously and gradually contracting. This eliminates the need for separate glass light cone components in existing technologies, and avoids the assembly structure of the liquid scintillation capillary array and the independent light cone, fundamentally preventing assembly gaps and coupling interfaces between the two. The resulting benefits include: 1. Improved optical transmission efficiency: Since the optical cone coupling interface is eliminated, visible light signal leakage and scattering caused by assembly gaps are avoided, while light reflection loss caused by multiple optical interfaces is also eliminated. Experimental data shows that the visible light transmittance of the embodiment of the present invention reaches 59.3% (@424nm), while that of the comparative example (split structure) is only 41.1%, indicating a significant improvement in optical transmission efficiency.

[0024] 2. Improved Spatial Resolution: The capillaries in the straight and conical regions are continuous deformations of the same channel, ensuring a strict one-to-one correspondence between each pixel channel and eliminating pixel misalignment or resolution loss caused by coupling. Experimental results show that the visible light spatial resolution of this embodiment reaches 4 lp / mm, and the fast neutron spatial resolution reaches 1.8 lp / mm, which are superior to the comparative examples of 2.24 lp / mm and 1.0 lp / mm, respectively.

[0025] 3. Simplified assembly process, reduced cost, and smaller overall size: The one-piece molded structure eliminates the need for a separate light cone component, saving the submicron-level precise alignment and installation process between the liquid scintillator array and the light cone, which greatly reduces the assembly difficulty and production cost of the system; at the same time, it eliminates the need for a separate light cone optical path, shortens the overall optical path length, and makes the probe structure more compact, which is suitable for the use scenarios of small diagnostic windows in fusion devices.

[0026] In summary, this invention achieves structural simplification and performance optimization while maintaining or even improving imaging performance, making it particularly suitable for high-precision detection applications such as fast neutron imaging systems.

[0027] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the cross-sectional structure of the integrated liquid scintillation capillary array of the present invention, wherein 1-straight region, 2-conical region, 3-capillary wall, 4-light absorption layer glass, 5-liquid scintillation, 6-first sealing element, 7-second sealing element, and 9-edge-sealing region. Figure 2 This is a schematic diagram of the integrated liquid scintillation capillary array arrangement structure of the present invention; wherein, 9 is the edging region and 10 is the array region; Figure 3 This is a schematic diagram of the tapered device structure used in the integrated liquid scintillation capillary array of the present invention; wherein, 11-bulk segment, 12-zone temperature-controlled heating furnace, 12-1-high temperature zone, 12-2-secondary high temperature zone, 13-clamping component, 14-sealing component, 15-screw assembly, 16-gas cylinder. Figure 4 The transmittance test results are for the integrated liquid scintillation capillary array prepared in Example 1; Figure 5 The transmittance test results are for the liquid scintillation capillary array prepared in Comparative Example 1 after coupling with an optical cone. Detailed Implementation

[0029] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the appendix and preferred embodiments, details the specific implementation and effects of an integrated liquid scintillation capillary array, its preparation method and application, and a tapered device according to the present invention. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, the results of one or more embodiments can be combined in any suitable manner. These embodiments are provided to make the invention thorough and complete, and to fully express the scope of the invention to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​described in these embodiments should be interpreted as merely exemplary and not as limiting.

[0030] This invention proposes an integrated liquid scintillation capillary array and its fabrication method, as shown in the appendix. Figure 1As shown, the liquid scintillator capillary array includes an array substrate, a liquid scintillator 5, a first sealing element 6, and a second sealing element 7. The array substrate is a monolithic structure comprising a connected straight region 1 and a conical region 2. The straight region consists of multiple capillaries with parallel axes, the capillary walls of which are indicated by reference numeral 3. The conical region is formed by the gradual contraction of the same group of capillaries. Each capillary extends seamlessly and continuously from the straight region to the conical region and contracts synchronously, ensuring that the capillary channels in the straight and conical regions correspond one-to-one, are homogeneous and continuous, and have no segmented connection structure. The internal channels of each capillary are filled with liquid scintillator. The first sealing element is assembled at the end of the straight region to seal the liquid scintillator and allow fast neutrons to enter the liquid scintillator capillary array. The second sealing element is assembled at the end of the conical region to seal the liquid scintillator and allow optical signal output. Fast neutrons incident on and bombard the liquid scintillator to generate fluorescence, and the generated fluorescence signal is transmitted along the capillary channel and output by the second sealing element.

[0031] In some specific embodiments of the present invention, as shown in the appendix Figure 1 As shown, a light-absorbing glass layer 4 is preferably provided between adjacent capillaries in the preferred array substrate; the visible light transmittance of the light-absorbing glass layer at a thickness of 0.4 mm is ≤1%. This light-absorbing glass layer can efficiently absorb crosstalk light between capillaries.

[0032] In some specific embodiments of the present invention, a solid glass edging region 9 is preferably formed around the outer periphery of the array substrate. The softening point temperature of the glass in this edging region is lower than that of the capillary wall material and the light-absorbing layer glass. Its function is to homogenize the pressure during melting and pressing, homogenize the tensile force during drawing, and provide mechanical strength.

[0033] In some specific embodiments of the present invention, the inner diameter of a single capillary in the straight region is preferably 20 μm to 500 μm and the length is ≥10 cm. This setting is because the detection target is a parallel fast neutron beam. The free path of high-energy fast neutrons is about 10 cm. Fast neutrons have strong penetrating power. If the length of the parallel capillary is short, the fast neutrons will penetrate multiple capillary tubes in the conical region, resulting in a decrease in resolution.

[0034] In some specific embodiments of the present invention, the cross-section of the array substrate is preferably a circular, tightly packed structure, and the cross-sectional size is set according to the imaging field of view requirements to ensure that the incident fast neutron signal can be fully received while ensuring the spatial resolution of the signal conversion.

[0035] In some specific embodiments of the present invention, the shrinkage ratio of the tapered region is preferably greater than 1 and less than 10. Tapered fibers inevitably suffer from light transmission loss; if the shrinkage ratio is too high, the light transmission loss will be excessive, and it will be detrimental to the fabrication process.

[0036] In some specific embodiments of the present invention, it is preferable that the cross-sectional size of the end of the conical region is comparable to the size of the input window of the imaging photoelectric detection module, so as to improve the utilization rate of light signals and imaging resolution.

[0037] In some specific embodiments of the present invention, the capillary material is preferably glass to ensure that the visible light signal can be transmitted by total internal reflection in the capillary, thereby reducing the loss of the light signal.

[0038] In some specific embodiments of the present invention, the liquid scintillator is preferably a hydrogen-containing scintillator liquid with a hydrogen atom content ≥ 4 × 10⁻⁶. 22 pcs / cm 3 This ensures that fast neutrons collide elastically with hydrogen atoms in the liquid scintillator to generate a sufficient number of recoil protons, which are then efficiently converted into visible light signals.

[0039] In some specific embodiments of the present invention, the first sealing element is preferably glass, and the second sealing element is an optical fiber panel.

[0040] The method for fabricating the integrated liquid scintillation capillary array of the present invention includes the following steps: First, the glass preform tube is drawn twice to obtain secondary multifilaments. After the secondary multifilaments are arranged and shaped, they are melted, pressed, rolled, and cut to obtain the first blank segment. The first blank segment includes multiple capillary tubes with parallel axes. The process from the glass preform tube to the first blank segment can refer to conventional processes in the field, and the present invention does not specifically limit it.

[0041] In some specific embodiments of the present invention, the preparation of secondary multifilaments specifically includes steps such as glass material preparation, preform preparation, and capillary drawing. Detailed explanations are as follows: In the first preform of the integrated liquid scintillation capillary array of the present invention, a light-absorbing glass layer is preferably provided between adjacent glass preforms, and during the secondary multifilament arrangement, a solid glass layer is wrapped around the outermost layer as an edge-sealing area. The glass preforms are processed into capillaries, hence the material is also called capillary glass.

[0042] When preparing the glass materials, it is preferable that the softening points of the capillary glass, the light-absorbing layer glass, and the solid glass in the edge region have a gradient. This gradient setting helps the light-absorbing layer glass soften and fuse first during drawing, even before the solid glass in the edge region is added, while the inner wall glass still maintains its circular shape. After adding the solid glass in the edge region, during capillary pressing, the edge region material softens and fuses first, while the array region capillary still maintains its circular shape, overcoming the problem of capillary deformation under high temperature. However, the softening point gradient of the above-mentioned glass should not be too large, especially the softening point of the edge glass should not be too low, otherwise it will cause the edge region to separate from the array region during subsequent tapering. Preferably, the softening point of the light-absorbing layer glass is 30°C to 60°C lower than that of the capillary glass, and the softening point of the solid glass in the edge region is 20°C to 40°C lower than that of the light-absorbing layer glass.

[0043] In some specific embodiments of the present invention, the capillary glass is processed into a glass tube with a circular cross-section, preferably with a wall thickness of 2-4 mm and an inner diameter of 20-50 mm. The light-absorbing layer glass is first processed into a glass tube with a circular cross-section, preferably with an inner diameter 0.5-1 mm larger than the outer diameter of the capillary glass tube and a wall thickness of 1-3 mm; then the light-absorbing glass tube is nested around the capillary glass tube to form a pre-formed tube, thereby enabling it to absorb crosstalk light in all directions at 360°.

[0044] In some specific embodiments of the present invention, the solid glass in the edge area is first processed into a glass rod with a regular hexagonal cross-section, preferably with a side-to-side distance of 20~50mm; then the glass rod is drawn into an edge-bound glass monofilament, preferably with a side-to-side distance of 0.5~2mm.

[0045] Regarding the selection of the aforementioned rod size, excessively thin dimensions will result in low material utilization, while excessively thick dimensions will lead to a large temperature difference between the center and periphery of the rod during drawing, resulting in poor uniformity of the capillary pore size. The wall thickness is set to ensure that the final capillary has the necessary strength, while not reducing the detection efficiency due to excessive wall thickness and low duty cycle.

[0046] In some specific embodiments of the present invention, capillary drawing is performed in two stages. The first stage involves drawing a pre-formed tube to obtain multiple circular primary multifilaments, preferably with a cross-sectional diameter of 0.5-2 mm. If the diameter of the primary multifilaments is too small, the subsequent bar arrangement operation will be more difficult; however, if the diameter is too large, the diameter accuracy during drawing will be difficult to control, resulting in significant deviations and more gaps during subsequent bar arrangement. Then, the obtained primary multifilaments are hexagonally stacked to obtain multifilament rods with a hexagonal cross-section. Preferably, the distance between opposite sides of the multifilament rod is 15-50 mm to meet the requirements for material utilization and temperature homogenization. A second stage of drawing is then performed, i.e., drawing the arranged multifilament rods to obtain secondary multifilaments. Preferably, the distance between opposite sides of the cross-section of the secondary multifilament is 0.5-2 mm to meet the requirements for accuracy control and subsequent array arrangement. After the two stages of drawing, the inner diameter of a single capillary within the obtained secondary multifilament is preferably 20 μm-500 μm.

[0047] In some specific embodiments of the present invention, preparing the secondary multifilament into a first blank includes steps such as array arrangement, melting and pressing, rounding, and cutting. Specific details are as follows: Hexagonal multifilaments and edge-wrapping glass monofilaments are arranged at fixed lengths to form a hexagonal blank segment, preferably 300-500 mm in length. This length is designed to form a conical region while ensuring a sufficient straight region. The central part of the array consists of a capillary bundle with an approximately circular cross-section, forming array region 10, as shown in the attached diagram. Figure 2 As shown, the outer perimeter is surrounded by multiple layers of monofilament glass to form the edging zone 9, with a preferred thickness of 5-20mm. The edging zone serves to soften the glass during the melting and pressing process to homogenize stress and protect the channel area during tapering. If the edging zone is too thin, the homogenization effect during melting and pressing will be ineffective, or it may crack under the clamping force during tapering. If it is too thick, it will result in unnecessary material waste. The array is arranged in a regular hexagonal shape to ensure compatibility with the shape of conventional melting and pressing molds.

[0048] The arranged array is loaded into a melting and pressing mold and melted at high temperature to form a blank. Generally, the melting and pressing temperature is set higher than the softening point of the light-absorbing layer glass and lower than the softening point of the capillary glass. This is because at this melting and pressing temperature, the light-absorbing layer glass is already in a softened state while the capillary glass is still not softened, so that the capillaries can still maintain their circular structure while being fused together by the light-absorbing layer glass.

[0049] The blank segment with the above-mentioned cross-section is rounded and cut. The six corners of the edge area are removed, and the two ends of the blank segment are cut flat to form the first blank segment with a circular cross-section, so that the heat and force are more uniformly transferred during the subsequent tapering process.

[0050] The second step is tapering, which involves inserting the first billet into a zoned temperature-controlled heating furnace, aligning the billet axis with the furnace axis, continuously introducing protective gas into the capillary, and simultaneously applying tension along the billet axis to both ends to draw it, thereby obtaining a second billet with a straight zone and a pre-formed conical zone. The zoned temperature-controlled heating furnace includes three temperature zones: a high-temperature zone in the center and secondary high-temperature zones at both ends.

[0051] The tapering step described above is a key step in the integral forming of the straight and tapered regions of this invention. In some specific embodiments of this invention, the tapering process is implemented using specially designed tapering equipment.

[0052] Specifically, the tapered device has a horizontal structure, as shown in the attached figure. Figure 3 As shown, it includes a zoned temperature-controlled heating furnace 12, which has two opposing openings for allowing the billet segments to pass through the furnace during installation. Along the tensile axis of the billet, the furnace is provided with at least a central high-temperature zone 12-1 and secondary high-temperature zones 12-2 located on both sides of the high-temperature zone. This three-zone temperature configuration allows the middle part of the first billet segment to soften while the two ends remain unsoftened, so that when tension is applied, only the diameter of a specific area in the middle narrows, while the radial dimensions of the two ends remain unchanged. In the middle region, the degree of softening of the glass varies at different locations, thus making the radial dimension of the narrowing area in the middle gradually change.

[0053] The tapered device also includes two clamping members 13, which are symmetrically arranged on the outside of the two openings of the heating furnace, for clamping the billet segment 11 that passes through the heating furnace, so that its axis coincides with the axis of the heating furnace.

[0054] The tapered device also includes a lead screw assembly 15, which is connected to two clamping members via a column; the lead screw can drive the two clamping members to translate towards or away from each other; when the two clamping members move away from each other in coordination with the lead screw, they can apply a pulling force to the clamped blank segment to reduce its diameter in the middle.

[0055] The tapering device also includes a gas supply assembly, comprising a gas cylinder 16, a gas supply pipeline, and a hollow sealing element 14. The sealing element is fitted inside the clamping element, with one side conforming to the clamping element and the other side conforming to the edge area of ​​the billet end to ensure an airtight seal between the billet and the clamping element. One end of the gas supply pipeline is connected to the gas cylinder, and the other end passes through the sealing element. The sealing element is tightly fitted to the outer wall of the gas supply pipeline to ensure an airtight seal, and is used to fill the capillary of the billet with gas to provide internal air pressure support for the array area, thereby ensuring the shape of the capillary is maintained. The tapering process specifically includes the following steps: A. The first billet segment is passed through a zone-controlled temperature heating furnace, ensuring that the axis of the first billet segment coincides with the axis of the heating furnace to guarantee uniform heating in all radial directions during heating. Both ends of the first billet segment are fixed to two adjustable clamping members. Hollow sealing elements are installed within the clamping members, which hold and fix the billet segment at both ends. The sealing elements are tightly fitted against the edge area of ​​the billet segment's end face, thus preventing gas exchange between the array area and the external environment. The edge area is solid, providing sufficient mechanical strength for clamping and sealing operations. The array area is hollow. The other end of the sealing element is connected to a gas supply line to a gas cylinder. The gas supply line passes through the sealing element and is tightly fitted against it to maintain airtightness. Since the purpose of gas filling is to support the shape, to avoid interaction between the gas and the glass, the gas used in this invention is preferably an inert gas such as nitrogen or argon.

[0056] B. The central region of the first billet is placed in the high-temperature zone, with the temperature set 20-50°C above the softening point of the capillary glass. The remaining regions of the first billet are placed in the secondary high-temperature zones on both sides and outside the furnace, with the secondary high-temperature zones set 50-150°C below the softening point of the capillary glass. Nitrogen or argon gas is introduced into the array area and reaches the capillary. The high-temperature zone temperature setting at this stage is to create a low-viscosity zone in the center of the first billet, facilitating tapering during the drawing process. If the high-temperature zone temperature is set too low, tapering will be difficult or take too long; if it is set too high, the glass will be too fluid, making it difficult to control the regularity of the tapered shape. The secondary high-temperature zone temperature setting is to allow the portion of the first billet near the center to complete the transition from the straight zone to the tapered zone. The side of the secondary high-temperature zone closer to the high-temperature zone forms a transition zone through the thermal radiation of the high-temperature zone, while the side farther from the high-temperature zone ensures the stability of the straight zone. If the secondary high-temperature zone temperature is set too low, a temperature drop may cause severe abrupt changes in the cone shape; if it is set too high, the stability of the straight zone cannot be guaranteed.

[0057] C. The movement of the lead screw assembly causes the two clamping parts to translate in opposite directions, causing the portion of the first blank section in the high-temperature zone to thin under tension. At high temperature, the gas inside the capillary expands, providing strong support for the capillary and ensuring that it maintains its round structure during deformation. As the two clamping parts move in opposite directions, the thinned blank section moves to the secondary high-temperature zone for cooling and solidification, resulting in a second blank section with a straight region and a pre-formed conical region. After tapering, the shrinkage ratio at the thinnest part of the cone is preferably greater than 1 and less than 10.

[0058] The third step is end-face processing. Specifically, after the second blank is removed from the clamping device, a cutting machine is used to cut along the radial cross-section of the second blank at both ends and the narrowest point in the middle, forming a flat surface. After cutting, each second blank becomes two cut pieces with one straight end and one tapered end. The cutting surface is perpendicular to the capillary axis, facilitating subsequent end-face encapsulation of lenses or fiber optic panels. Water is used as the coolant during cutting to facilitate subsequent cleaning. The cut pieces are then ultrasonically cleaned and dried to remove glass debris or cutting fluid impurities that entered the capillary during end-face processing, resulting in the third blank.

[0059] The fourth step is filling the liquid flash, which involves filling the array area of ​​the third billet section with liquid flash under the action of a peristaltic pump. Both the straight and conical areas are filled with liquid flash.

[0060] Finally, there is the encapsulation process, which involves using optical adhesive to seal the straight section end with glass and the tapered section end with an optical fiber panel. In other words, the first sealing element is assembled at the end of the straight section and the second sealing element is assembled at the end of the tapered section.

[0061] In some specific embodiments of the present invention, a solid glass edging region is preferably formed around the outer periphery of the array substrate. The softening point temperature of the glass in this edging region is lower than that of the capillary wall material and the light-absorbing layer glass. Its function is to homogenize the pressure during melting and pressing, homogenize the tensile force during drawing, and provide mechanical strength.

[0062] This invention also proposes an application of the aforementioned integrated liquid scintillation capillary array in a fast neutron imaging system. The dimensions of the second sealing element of the integrated liquid scintillation capillary array are matched with the dimensions of the light-receiving end of the photoelectric detection module in the application scenario, and are used to converge and conduct the visible light signal generated in the direct region, directly transmitting it to the photoelectric detection module.

[0063] The present invention will be further described below with reference to specific embodiments, but this should not be construed as a limitation on the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the above description of the present invention still fall within the scope of protection of the present invention.

[0064] Unless otherwise specified, all materials and reagents mentioned below are commercially available products well known to those skilled in the art; unless otherwise specified, all methods described are methods known in the art. Unless otherwise defined, the technical or scientific terms used should have the ordinary meaning understood by those skilled in the art to which this invention pertains.

[0065] Example 1 This embodiment describes the fabrication of an integrated liquid scintillation capillary array, with the following specific steps: 1) Glass Material Preparation: Three types of glass materials are selected: capillary glass, light-absorbing layer glass, and solid glass in the edging area. The capillary glass has a refractive index of 1.50 and a softening temperature of 606℃. The light-absorbing layer glass has a light transmittance of 0.2% at a thickness of 0.4mm and a softening temperature of 576℃. The solid glass in the edging area has a softening temperature of 556℃.

[0066] 2) Pre-formed tube preparation: The capillary glass is processed into a circular cross-section glass tube with a wall thickness of 2mm and an inner diameter of 42mm. The light-absorbing layer glass is processed into a circular cross-section glass tube with an inner diameter of 46.5mm and a wall thickness of 1mm. The solid glass in the edging area is processed into a glass rod with a regular hexagonal cross-section and a side-to-side distance of 20mm. The regular hexagonal glass rod is drawn into edging glass monofilaments with a side-to-side distance of 2mm. The light-absorbing glass tube is nested around the capillary glass tube to form the pre-formed tube.

[0067] 3) Capillary Drawing: The drawing process is performed in two stages. First, a pre-formed tube is drawn to obtain multiple primary multifilaments with a circular cross-section and a diameter of 1 mm. These primary multifilaments are then combined and arranged to obtain a multifilament rod with a regular hexagonal cross-section and a side-to-side distance of 18.5 mm. This multifilament rod is then drawn to obtain a secondary multifilament, which also has a regular hexagonal cross-section and a side-to-side distance of 2 mm. The inner diameter of each capillary within the secondary multifilament is 94 μm, and the center-to-center distance between holes is 109 μm.

[0068] 4) Array arrangement: The hexagonal secondary multifilament and edge-wrapping monofilament are cut into lengths of 380mm and arranged together to form a regular hexagonal blank segment with a cross-sectional side-to-side distance of 106.2mm. The middle part is a capillary bundle with a cross-section approximately 85mm in diameter, which constitutes the array area. The outer part is wrapped with edge-wrapping glass monofilament to form the edge-wrapping area, thus forming the blank segment.

[0069] 5) Melting and pressing: The billet is placed into the melting and pressing mold and melted and pressed at 580℃.

[0070] 6) Rounding: The blank segment with a regular hexagonal cross-section is rounded to form a blank segment with a circular cross-section of 96mm in diameter.

[0071] 7) Cutting: Cut the two ends of the billet segment flat to form a billet segment with a length of 360mm.

[0072] 8) Tapering: The billet segment is passed through the heating furnace in the tapering device, with the billet segment's axis coinciding with the furnace's axis. Both ends are fixed to two adjustable clamps. Hollow seals at both ends of the billet segment are fixed to the edge area, with the other end of the seals connected to a nitrogen cylinder. The heating furnace has an inner diameter of 120mm and is divided into a high-temperature zone and two sub-high-temperature zones. Along the furnace axis, the high-temperature zone is 35mm long, and each sub-high-temperature zone is 100mm long. The middle section of the billet segment is placed in the high-temperature zone, set at 636℃, while the remaining section is placed in the sub-high-temperature zone and outside the furnace, set at 456℃. Nitrogen gas is introduced into the array area, reaching the capillary tube. The distance between the two clamps is increased to complete the tapering of the billet segment. The narrowest point of the cone has a diameter of 40mm, and the effective array area has a diameter of 35mm.

[0073] 9) End Face Machining: Using a water-cooled cutting machine, the blank segment is cut at both ends and the narrowest point of the cone to form a flat surface. After cutting, the blank segment becomes two sections, each with a straight section at one end and a tapered section at the other. The straight section is 110 mm long, and the tapered section is 90 mm long. The inner diameter of a single capillary at the straight section end is 94 μm, and the center-to-center distance of the holes is 109 μm. The average inner diameter of the capillary at the tapered section end is 39 μm, and the average center-to-center distance of the holes is 45 μm. The blank segment is then ultrasonically cleaned and dried.

[0074] 10) Filling the liquid scintillator: The liquid scintillator is filled into the array area by a peristaltic pump, filling both the straight and conical areas completely. The liquid scintillator uses a hydrogen-containing scintillator liquid with a hydrogen atom content of 5.43 × 10⁻⁶. 22 pcs / cm 3 The refractive index of the liquid scintillator is 1.57.

[0075] 11) Packaging: The straight section end is sealed with quartz glass using optical adhesive, and the tapered section end is sealed with an optical fiber panel.

[0076] Imaging performance tests were conducted on the aforementioned integrated liquid scintillation capillary array. The visible light spatial resolution was 4 lp / mm, the fast neutron spatial resolution was 1.8 lp / mm, and the light transmittance was 59.3% at 424 nm. The transmittance test results are attached. Figure 4 As shown.

[0077] Comparative Example 1 In this comparative example, the liquid scintillation capillary array and the optical cone are separate structures that are then coupled together.

[0078] The liquid scintillator capillary array is a parallel capillary array structure filled with a liquid scintillator. The capillary walls are made of glass (refractive index 1.5), and light-absorbing glass is contained between the capillary walls. The light absorption performance is 0.4 mm thick, and the light transmittance is 0.2%. The liquid scintillator is a hydrogen-containing scintillator liquid with a hydrogen atom content of 5.43 × 10⁻⁶. 22 pcs / cm 3 The refractive index of the liquid scintillator is 1.57. Each capillary has an inner diameter of 94 μm and a length of 11 cm. The center-to-center distance between the capillary holes is 109 μm. The cross-section of the array, including the edging region, is a circle with a diameter of 96 mm, and the effective area of ​​the array has an approximate diameter of 85 mm. Both ends are sealed with quartz glass and fiber optic panels, respectively. The end with the quartz glass seal is the input end, and the end with the fiber optic panel seal is the output end.

[0079] The optical cone is a gradually shrinking glass fiber array structure. Its input end is coupled to the output fiber panel of the liquid scintillator capillary array. The cross-sectional dimension of the input end is a circle with a diameter of 85 mm. The core diameter of a single glass fiber at the input end is 94 μm, and the center-to-center distance between adjacent glass fibers is 109 μm. Each glass fiber gradually shrinks from the input end to the output end, with a shrinkage zone length of 90 mm. The cross-section at the output end is a circle with a diameter of 35 mm. The inner diameter of the glass fiber at the output end is 39 μm, and the average center-to-center distance between adjacent glass fibers is 45 μm.

[0080] Imaging performance tests were performed on the coupled components described above. The visible light spatial resolution was 2.24 lp / mm, the fast neutron spatial resolution was 1.0 lp / mm, and the light transmittance was 41.1%@424nm. The transmittance test results are attached. Figure 5 As shown.

[0081] The technical features in the claims and / or specification of this invention can be combined, and the combination is not limited to the combinations obtained through reference in the claims. Technical solutions obtained by combining the technical features in the claims and / or specification are also within the scope of protection of this invention.

[0082] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. An integrated liquid scintillation capillary array, characterized in that, include: The array substrate includes an integrally formed straight region and a conical region; the straight region is composed of multiple capillaries with parallel axes; the conical region is formed by the gradual contraction of the multiple capillaries with parallel axes, and each capillary extends seamlessly and continuously from the straight region to the conical region and contracts synchronously. Liquid scintillator fills the internal channels of each capillary; The first seal, located at the end of the straight section, is used to seal the liquid scintillator and allow fast neutrons to enter; The second seal, located at the end of the conical section, is used to seal the liquid scintillator and allow optical signal output.

2. The integrated liquid scintillation capillary array according to claim 1, characterized in that, A light-absorbing glass layer is provided between adjacent capillaries in the array substrate; the visible light transmittance of the light-absorbing glass layer is ≤1% at a thickness of 0.4 mm.

3. The integrated liquid scintillation capillary array according to claim 1, characterized in that, The array substrate is surrounded by a solid glass edging area.

4. The integrated liquid scintillation capillary array according to claim 1, characterized in that, The contraction ratio of the conical region is greater than 1 and less than 10.

5. The integrated liquid scintillation capillary array according to claim 1, characterized in that, The inner diameter of a single capillary in the straight region is 20μm~500μm, and the length is ≥10cm.

6. The integrated liquid scintillation capillary array according to claim 1, characterized in that, The liquid scintillator is a hydrogen-containing scintillator fluid with a hydrogen atom content ≥4×10⁻⁶. 22 pcs / cm 3 .

7. The integrated liquid scintillation capillary array according to claim 1, characterized in that, The capillary is made of glass.

8. The integrated liquid scintillation capillary array according to claim 1, characterized in that, The first sealing element is glass; the second sealing element is an optical fiber panel.

9. A method for fabricating an integrated liquid scintillation capillary array, characterized in that, Includes the following steps: S1 involves drawing a glass preform tube twice to obtain a secondary multifilament. The secondary multifilament is then arranged, melted, rolled, and cut to obtain a first blank segment. The first blank segment includes multiple capillaries with parallel axes. S2 inserts the first billet into the zoned temperature-controlled heating furnace, aligning the billet axis with the furnace axis, continuously introducing protective gas into the capillary tube, and simultaneously applying tensile force along the billet axis to both ends to draw it, thus obtaining a second billet with a straight zone and a pre-formed conical zone; the zoned temperature-controlled heating furnace includes three temperature zones, with the center being a high-temperature zone and the two ends being secondary high-temperature zones. S3 cuts and cleans along the two end faces and the radial section in the middle of the second billet segment to obtain the third billet segment; the third billet segment includes a straight region composed of multiple capillaries with parallel axes and a conical region formed by the gradual contraction of the capillaries; S4 fills each capillary of the third blank section with liquid scintillation material, and then assembles the first seal at the end of the straight section and the second seal at the end of the conical section to complete the sealing.

10. The preparation method according to claim 9, characterized in that, The protective gas introduced in step S2 is nitrogen or argon.

11. The preparation method according to claim 9 or 10, characterized in that, A light-absorbing glass layer is provided between adjacent capillaries in the first blank segment; the visible light transmittance of the light-absorbing glass layer is ≤1% at a thickness of 0.4mm; the outer periphery of the first blank segment is covered with a solid glass edging area.

12. The preparation method according to claim 11, characterized in that, The softening point temperature of the light-absorbing layer glass is 30°C to 60°C lower than that of the capillary glass, and the softening point temperature of the edge-sealing glass is 20°C to 40°C lower than that of the light-absorbing layer glass.

13. The preparation method according to claim 12, characterized in that, In step S2, the temperature of the high-temperature zone is 20°C to 50°C higher than the softening point temperature of the capillary glass; the temperature of the secondary high-temperature zone is 50°C to 150°C lower than the softening point temperature of the capillary glass.

14. An integrated liquid scintillation capillary array billet tapering device, characterized in that, include: A zoned temperature-controlled heating furnace, the heating furnace including two opposing openings; a central high-temperature zone and secondary high-temperature zones arranged on both sides of the high-temperature zone along the stretching axis of the billet; Two clamping components are symmetrically arranged on the outside of the two openings of the heating furnace to clamp the billet segment passing through the heating furnace, so that its axis coincides with the axis of the heating furnace. A lead screw assembly is connected to two clamping members via a column; the lead screw can drive the two clamping members to translate towards or away from each other. The gas supply assembly includes a gas cylinder, a gas supply pipeline, and a hollow sealing element; the sealing element is assembled inside the clamping element and can fit against the end face of the edge area of ​​the billet segment to make the billet segment and the clamping element airtight; one end of the gas supply pipeline is connected to the gas cylinder, and the other end passes through the sealing element, and is used to supply gas into the capillary of the billet segment to form internal air pressure support.

15. An application of the integrated liquid scintillation capillary array according to any one of claims 1 to 8 in a fast neutron imaging system.

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