Plastic wavelength-shifting fiber and method for making same

Abstract

To disclose a wavelength shift fiber and a production method thereof.SOLUTION: A wavelength shift fiber may comprise a plastic core and a coating surrounding the plastic core. The numerical aperture of the wavelength shift fiber may be at least about 0.53. A method for producing a wavelength shift fiber may comprise: heating and stretching a plastic core precursor to form a plastic core; coating the plastic core with liquid coating; and curing the liquid coating around the plastic core to for the wavelength shift fiber.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to scintillation articles and methods of forming the same, and more particularly to optical waveguides. This paper relates to a plastic wavelength-shifting fiber with a 1000 .ANG. [Background technology]

[0002] Radiation detection devices are used in a variety of applications. For example, scintillators are used in medical imaging. as well as for environmental monitoring, security applications, and well logging in the oil and gas industry. It can be used for nuclear physics analysis and applications. The manufacture of these sensors has traditionally been very challenging, as it has been limited by the properties of the materials used. Further improvements in the manufacturing of wavelength-shifting fibers are desirable. [Brief explanation of the drawings]

[0003] Embodiments are illustrated by way of example and not limitation in the accompanying figures. [Figure 1] 1 shows an illustration of a cross-sectional view of a plastic wavelength-shifting fiber according to one embodiment. [Figure 2] 1 illustrates a method of manufacturing a wavelength-shifting fiber according to one embodiment. [Figure 3] 10 includes an illustration of an end view of an article including a body and a wavelength-shifting fiber according to yet another embodiment.

[0004] Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and are not necessarily drawn to scale. It is understood that the dimensions of some of the elements in the drawings are not necessarily accurate. If an element is exaggerated relative to other elements to help improve understanding of the disclosed embodiment There is. DETAILED DESCRIPTION OF THE INVENTION

[0005] The following description in conjunction with the drawings will aid in understanding the teachings disclosed herein. The following discussion focuses on specific implementations and embodiments of the present teachings. This focus is provided to help explain the present teachings and is intended to provide a general overview of the present teachings. These terms should not be construed as limitations on scope or applicability.

[0006] As used herein, the group numbers corresponding to columns in the periodic table of elements are C RC Handbook of Chemistry and Physics, No. 81 It uses the "new notation" conventions found in the 2000-2001 edition.

[0007] The optical attenuation length of a wavelength-shifting fiber characterizes the amount of light detectable at the end of the fiber and its The optical attenuation length is measured on an optical bench that holds and supports the wavelength-shifting fiber. The optical bench includes a rail, on which are mounted: (1) a UV-Vis (ultraviolet-visible) (1) To support the photodiode, (2) the pump cavity, and (3) the rear end of the fiber The front end of the wavelength-shifting fiber is attached to a mechanical holder. The pump cavity is made up of 390 nm equally spaced laser diodes. The intensity of the excitation light is measured using an ED and a phototransistor. The carriage is mounted on a carriage that moves on an optical rail. The scale attached to the optical table can be read with an accuracy of better than ±5 mm. For details on setup and operation, see "A setup to measure the optical attenuation length of scintilla The video, titled "Chinese Physics Fibers," was released on May 12, 2015. This is described in the LHCb-PUB-2015-011 publication by the National Institute for Nuclear Research.

[0008] As used herein, "comprise" and "compris "ing", "include", "including", "having" The terms "has," "having," or any other variations thereof The term is intended to include a non-exclusive inclusion, e.g., a process that includes a list of features. The invention, method, article, or apparatus is not necessarily limited to those features expressly recited. Other features not disclosed or inherent in such process, method, article, or apparatus Furthermore, unless expressly stated otherwise, "or" may be used. " refers to an inclusive "or," not an exclusive "or." For example, if condition A or B is satisfied by one of the following: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and and both A and B are true (or exist).

[0009] The use of "a" or "an" refers to the elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This explanation is given to give one or more meanings unless it is clear that something else is meant. or at least one and the singular form should be read to include the plural, or vice versa. .

[0010] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by a person skilled in the art to which this invention pertains. The materials, methods, and examples are illustrative only and not intended to be limiting. To the extent not set forth herein, many details regarding specific materials and processing practices are set forth below. As mentioned above, textbooks and other information on scintillation technology and radiation detection technology can be seen in the source.

[0011] The wavelength shifting fiber is made of a plastic core and a fiber that surrounds the plastic core. a wavelength-shifting fiber including a coating for improving transmission of light along the radiation This ultimately increases the amount of light that can reach the detector.

[0012] In one embodiment, the wavelength-shifting fiber is a polymerized solid plastic scintillation fiber. The wavelength-shifting fiber includes a core and a cladding surrounding the core, and the numerical aperture of the wavelength-shifting fiber is at least 0. The larger the numerical aperture, the more light the detector can detect. By containing more light, the wavelength-shifting fiber allows more light to ultimately reach the detector. This allows the lens to reach a high numerical aperture, improving the output. The materials selected for the core and cladding are such that both the core and cladding are stretched simultaneously. This has been limited by the need for similar melting points and thermal properties to This has limited the numerical aperture of wavelength-shifting fibers. Furthermore, the presence of contaminants such as lubricants or dust particles may be a factor in determining the scintillation characteristics of the material. The dye impedes the transmission of photons along the length of the fiber, further increasing the loss of light. As used herein, cladding may include two or more distinct elements or layers. do.

[0013] Any of the wavelength-shifting fibers described below can be used in a variety of applications. Exemplary applications include gamma ray spectroscopy, isotope identification, single photon emission computed tomography ( SPECT) or Positron Emission Tomography (PET) analysis, X-ray imaging, oil well logging detectors, Medical imaging devices, network communication devices, high energy physics, small detectors, Network communications, broadcast receivers, wireless transmissions, augmented reality devices, broadcast networks, and This includes detecting the presence of radioactivity. Wavelength-shifting fibers can be used for other purposes, so The list is illustrative only and not exhaustive. Below are some specific applications: and explain.

[0014] The embodiments described and illustrated below will aid in understanding the concepts defined herein. The embodiments are provided for illustrative purposes only and are not intended to be limiting unless otherwise specified by the appended claims. As provided, it is not intended to limit the scope of the invention.

[0015] FIG. 1 shows an illustration of a plastic wavelength-shifting fiber 100 according to one embodiment. The synthetic wavelength-shifting fiber 100 may include a core 102 and a cladding 104. In one embodiment, the cladding 104 can be formed by a coating, In one embodiment, the core 102 is made of a plastic. The core 102 can be made of polystyrene (PS), polyvinyl toluene (PVT), or the like. (PVT), and polymethyl methacrylate (PMMA), polycarbonate, and The material may include a material selected from the group consisting of any combination thereof. In some embodiments, the core 102 may include a fluorescent dopant. The core 102 may be of various geometric shapes, such as a square, triangle, polygon, or hexagon. In one embodiment, the core 102 may have a diameter of at least 0.01 mm to 5 mm. Also 0.01mm diameter, for example, 0.1mm diameter, or 0.2mm diameter, or 0 In one embodiment, the diameter of the 0.5 mm diameter is 0.5 mm, or 1 mm diameter, or 2 mm diameter. , the core 102 may be at most 5 mm, for example at most 4.5 mm, or at most 4 mm, or may have a diameter of up to 3.5 mm.

[0016] The coating 104 may surround the core 102. In one embodiment, the coating 104 The coating 104 may surround the entire core 102. In one embodiment, the coating 104 may be In one embodiment, the coating 104 is in direct contact with the intervening material. For example, the core 102 may be in direct contact with the core 102 without a lubricant. In another embodiment, the coating 104 may comprise a single layer. In one embodiment, the coating 104 may include at least two layers. At least two layers can have different compositions of material. At least two layers of the coating 104 can be the same material. Alternatively, at least two layers of the coating 104 may be different materials. 104 may comprise an organic material. In one embodiment, the coating 104 is glycerol Ether acrylates, methacrylated polymers, fluoroacrylates, multifunctional acrylates The material may include materials selected from the group consisting of methyl methacrylate, ... In some embodiments, the coating 104 may include a dopant. The coating 104 may include additives to make the coating 104 more reflective. can be done.

[0017] In one embodiment, the coating 104 can have the same shape as the core 102. In another embodiment, the coating 104 may have a different shape than the core 102. For example, in one embodiment, the core 102 may be circular and the coating 104 may be square. In another embodiment, the coating 104 may be a liquid coating that can be radiation cured. In one embodiment, the coating 104 may be a radiation cured coating. In one embodiment, the coating 104 is a UV curable coating. In one embodiment, the coating 104 may be a heat-cured coating. In one embodiment, the coating 104 has a thickness of about 3 μm to about 1 mm. In one embodiment, the coating 104 may have a thickness of at least 3 μm. m, for example 25 μm, or for example 50 μm, or for example 75 μm, or for example 10 In one embodiment, the thickness of the core may be 0 μm or, for example, 500 μm. The coating 104 has a thickness of at most 600 μm, for example 700 μm, or for example 800 μm. The plastic fiber 10 may have a thickness of 1 μm or, for example, 1 mm. 0 is a numerical aperture of at least 0.53, for example a numerical aperture of at least 0.6, or at least In one embodiment, the plastic fiber 1 00 can be a wavelength shifting fiber.

[0018] FIG. 2 illustrates a method 200 for manufacturing wavelength-shifting fiber 100, according to one embodiment. In one embodiment, wavelength-shifting fiber 100 can be a scintillating fiber. In one embodiment, a mixture that can include a liquid monomer and a scintillation additive. to form a core precursor. In one embodiment, the core precursor comprises a plastic core In one embodiment, the core precursor may be a polystyrene (PS), polyvinyl Toluene (PVT), and polymethyl methacrylate (PMMA), polycarbonate and any combination thereof. In one embodiment, the core precursor can include a fluorescent dopant. The polymerization can be carried out in a geometrically shaped tube. For example, in one embodiment, the polymerization can be carried out in a cylindrical tube. In one embodiment, the scintillation core is formed in a circular tube. The core precursor has a refractive index of less than 1.60, for example, a refractive index of less than 1.59, or 1. having a refractive index of less than 57, or a refractive index of less than 1.55, or a refractive index of less than 1.50 In one embodiment, the core precursor may have a refractive index greater than 0.2. Cut.

[0019] In operation 210, the core precursor can be heated and stretched to form a core. In some embodiments, the core may be a plastic core. The plastic core may be similar to core 102 described above. In one embodiment, the plastic core is Diameters greater than 8 mm, for example, greater than 10 mm or greater than 12 mm In one embodiment, the plastic core precursor can be In one embodiment, the core precursor can have a diameter greater than 240°C. Temperatures, for example, above 260°C, above 270°C, or above 300°C The temperature can be increased to a desired value.

[0020] At operation 220, the plastic core can be coated with a liquid coating. In one embodiment, the liquid coating is glycerol ether acrylate, methacrylate acrylate polymer, fluoroacrylate, multifunctional acrylate, or combinations thereof In another embodiment, the liquid coating may comprise a material selected from the group consisting of: In another embodiment, the liquid coating may include a liquid coating. In one embodiment, the liquid coating may include additives to enhance the reflectivity of the coating. The coating may have a different melting point than the core precursor. The coating has a melting point at least 80° C. higher than the melting point of the core precursor, e.g., melting point at least 100°C higher than the melting point of the In one embodiment, the liquid coating has a melting point above 250°C, e.g. , above 300°C, or above 350°C, or above 400°C, or above 500°C In one embodiment, the liquid coating may have a melting point above 1. a refractive index of less than 50, for example, a refractive index of less than 1.48, or a refractive index of less than 1.45, or has a refractive index less than 1.42, or a refractive index less than 1.40, or a refractive index less than 1.35, etc. etc.

[0021] In operation 230, the liquid coating surrounding the plastic core is cured to form a wavelength-shifting film. In one embodiment, the plastic core can be formed into a fiber having its final length. After molding, a liquid coating that surrounds the plastic core is cured to form a protective cladding. In one embodiment, the liquid coating can be applied without the application of heat. In one embodiment, the liquid coating can be applied to a liquid core. It is applied directly to the plastic core so that there is no intervening material between the coating and the plastic core. In one embodiment, the liquid coating is cured using radiation. In one embodiment, the liquid coating is cured using ultraviolet radiation. In another embodiment, the liquid coating can be cured using thermal radiation. The liquid coating can be applied for a period not exceeding 30 seconds, for example, less than 5 seconds, or 3 It may be cured for a period of less than a second, or less than 1 second, or less than 0.5 seconds. After the first liquid coating has cured, a second liquid coating is applied to the first liquid coating. If multiple liquid coatings are applied, each coating must be applied separately. In one embodiment, the first liquid coating may be cured after the second liquid coating. In one embodiment, multiple liquid coatings may be applied to the surface of the substrate, and the surface may be cured in a shorter period of time than the application of the liquid coating. It may be applied to a plastic core. For example, three or more liquid coatings may be applied to a plastic core. In one embodiment, the first liquid coating may be applied to the second liquid core. In another embodiment, the first liquid coating may be different from the second liquid coating. In yet another embodiment, the first liquid coating may be thinner than the second liquid coating. In another embodiment, the first liquid coating may be thicker than the second liquid coating. The coating may have the same thickness as the second liquid coating. The first liquid coating uses a different type of radiation than the second liquid coating. In one embodiment, the plastic core is heated to its final length. After further stretching, multiple liquid coatings may be applied. Applying a coating eliminates the buildup that can occur with traditional core and cladding methods. Directly eliminates dust accumulation that is trapped at the core and cladding interface. Any dust or contamination that gets in can reduce the transmission of light along the fiber. By applying a liquid coating directly to the plastic core and curing it, The wavelength-shifting fiber has an increased transmission efficiency of light along the fiber.

[0022] After the wavelength-shifting fiber is formed, the wavelength-shifting fiber has an aperture ratio of at least 0.53. In one embodiment, the wavelength-shifting fiber can have a fiber optics ratio of at least 0.6. , for example at least 0.7.

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[0023] Figure 3 shows single photon emission computed tomography (SPECT) or step-through X-ray 3 illustrates an embodiment of a radiation detection device 300 that can be used for gamma ray analysis of devices such as As shown in FIG. 3, according to the embodiments described herein, radiation detection The device 300 includes a photosensor 301, an optical interface 303, and a scintillation The photo sensor 301, the optical interface 303, and the synchro sensor 304 may include a sensor device 305. Although the chilling devices 305 are illustrated in FIG. 3 as being separate from one another, According to certain embodiments, the photosensor 301 and the scintillation device 305 are: An optical interface 303 is provided between the photosensor 301 and the scintillation device 305. It will be understood that the optical interface 303 may be coupled to the optical interface 303 while the optical interface 303 is disposed in the optical path. According to another embodiment, the scintillation device 300 and the photosensor 301 are , using other known bonding methods such as the use of optical gels or bonding agents, or optically bonding The optical interface 303 may be optically coupled directly via molecular attachment of the attached elements.

[0024] According to yet another embodiment, the photosensor 301 may be a photomultiplier tube (PMT), a semiconductor body-based photomultipliers, hybrid photosensors, avalanche photodiodes, and As used herein, a semiconductor-based photomultiplier may be a semiconductor-based photomultiplier. The multiplier tube operates in Geiger mode, with each photodiode having a cell size of less than 1 mm. In practice, the term "photomultiplier tube" is intended to mean a photomultiplier tube containing a plurality of photodiodes. A semiconductor-based photomultiplier tube can contain over 1000 photodiodes. Each photodiode has a cell size ranging from 10 microns to 100 microns and a fixed gate. The output of a semiconductor-based photomultiplier tube is comparable to that of all Geiger-mode photodiodes. The semiconductor-based photomultiplier tubes include silicon photomultiplier tubes ( These may include photomultipliers based on SiPMs or other semiconductor materials. For applications (e.g., above 125°C), other semiconductor materials have wider bands than silicon. Exemplary materials include SiC, Ga-group V compounds, (e.g., GaN, GaP, Ga2O3, or GaAs). Balanche photodiodes are larger, with a light-sensitive area of ​​at least 1 mm2. and operates in proportional mode.

[0025] The photosensor 301 receives the scintillation device 304 via the input window 316. Receives photons emitted by the 05 and generates an electrical pulse based on the number of photons received. The photosensor 301 is electrically coupled to the electronic module 330. The electrical pulses are shaped, digitized, analyzed, or otherwise processed by the electronic module 330. Any combination of these may be performed, and the photons received by the photosensor 301 or other The electronic module 330 can provide count information. amplifier, discriminator, analog-to-digital signal converter, photon counter, pulse waveform analyzer or The photodetector may include a photodetector, a discriminator, another electronic component, or any combination thereof. Sensor 301 may be made of any suitable material, such as a metal, metal alloy, other material, or any combination thereof. The photo sensor 301, the electronic module 330, or a combination thereof may be protected. The device may be housed in a tube or housing made of a material that can

[0026] The scintillation device 305 may be a wavelength-shifting fiber 100 or other such fiber as previously described. The scintillation device 305 may include a wavelength-shifting fiber. chairs, isotope identification devices, and single photon emission computed tomography (SPECT) devices , Positron Emission Tomography (PET) analysis devices, X-ray imaging devices, oil well logging detectors, Medical imaging devices, network communication devices, small detectors, network communication devices broadcast receivers, wireless transmission devices, augmented reality devices, and broadcast network systems The wavelength-shifting fiber 100 can be included in a larger system such as a cable. The scintillation device 305 may be substantially surrounded by a wavelength scintillation The optical fiber 100 and the optical interface 303, the casing 313, or any of them to reduce relative motion between other elements of the radiation detection device 300, such as any combination of The device may include at least one stabilization mechanism adapted to

[0027] The optical interface 303 includes a photosensor 301 and a scintillation device 305. The optical interface 303 may also be adapted to be coupled between the photosensor 3 305。 Optical coupling between the optical fiber 301 and the scintillation device 305. The interface 303 is connected to the refractive index of the wavelength-shifting fiber 100 and the input window 316. It may include a polymer such as silicone rubber that is polarized to match the index. In this embodiment, the optical interface 303 is a gel or gel material containing a polymer and additional elements. can include a colloid.

[0028] The concepts described herein are not limited to the particular applications mentioned above. , and can be configured for other types of radiation. Many different aspects and embodiments are possible. Some of these aspects and embodiments are described herein. It may be according to any one or more of the embodiments listed below. Embodiment 1. The wavelength shifting fiber is a plastic core and a plastic core surrounding The wavelength-shifting fiber may include a coating. The numerical aperture of the wavelength-shifting fiber may be at least about 0.5. It can be set to 3. Embodiment 2. The numerical aperture is

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[0029] The doped polystyrene precursor rod was stretched in a stretching oven at 240 °C at a rate of 3 mm / min. The fiber diameter was determined by a commercially available multi-axis laser diameter converter. The coating process was controlled using a controller to within a diameter tolerance of + / - 0.010mm. The coating was started immediately after reaching 35°C. Immediately after the coating process, the coated The fiber was cured in a commercial 100 W / cm UV curing oven and placed in a 24-inch diameter slot. The wavelength-shifting fiber was spooled on a pool to form a wavelength-shifting fiber. NA) was measured to be 0.53.

[0030] The embodiments described herein are useful for inspecting cargo, vehicles, or other large objects, etc. In addition, high energy physics, medical imaging, small detectors, network communications, broadcast receivers, A relatively easy-to-use tool for research on wireless transmission, augmented reality devices, and broadcast networks. Larger radiation detectors are possible. Not all of the features are required, and some of the specific features may not be required. It should be noted that one or more functions in addition to the functions described above may be performed. However, the order in which the functions are listed is not necessarily the order in which they are performed.

[0031] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, benefits, advantages, solutions to problems, and any benefits, advantages, or Any or all of the features that may cause the solution to occur or become more pronounced should not be construed as a key, essential, or essential feature of the claims .

[0032] The specification and illustrations of the embodiments set forth herein are provided to provide a general understanding of the structure of the various embodiments. The specification and examples are intended to provide a thorough understanding of the structures or is a comprehensive and comprehensive description of all elements and features of apparatus and systems that use the method. Separate embodiments may also be combined into a single embodiment. Conversely, for the sake of brevity, the following may be provided in combination in the context of a single embodiment: The various features described herein may also be provided separately or in any subcombination. Further, references to values ​​stated in ranges are inclusive of the stated end-range values. Many other embodiments may be possible after reading this specification. Structural substitutions, logical substitutions, and other variations may be made without departing from the scope of the present disclosure. Other embodiments may be used from this disclosure, such that logical substitutions or other modifications may be made. Accordingly, the present disclosure should be considered illustrative rather than restrictive. is.

Claims

1. A wavelength-shifting fiber, comprising: a plastic core having a diameter of at least 0.5 mm; a cladding surrounding the plastic core, wherein the numerical aperture of the wavelength-shifting fiber is at least 0.6, the cladding comprises glycerol ether acrylate, a fluoroacrylate, a multifunctional acrylate, or a combination thereof, and the cladding surrounding the plastic core is a UV-cured cladding.

2. A wavelength-shifting fiber, comprising: a plastic core having a diameter of at least 0.5 mm; a cladding surrounding the plastic core, wherein the numerical aperture of the wavelength-shifting fiber is at least 0.6, the optical attenuation length of the wavelength-shifting fiber is at least 3 meters, the cladding comprises glycerol ether acrylate, fluoroacrylate, multifunctional acrylate, or a combination thereof, and the cladding surrounding the plastic core is a UV-cured cladding.

3. The numerical aperture [Equation 1] where n ｃｏｒｅ is the refractive index of the plastic core, and n ｃｌａｄ 3. The wavelength-shifting fiber of claim 1, wherein is the refractive index of said cladding.

4. 3. The wavelength-shifting fiber of claim 1, wherein the numerical aperture of the wavelength-shifting fiber is at least 0.

7.

5. 3. The wavelength-shifting fiber of claim 1, wherein the cladding has a thickness of at least 3 μm.

6. 3. The wavelength-shifting fiber of claim 1 or claim 2, wherein the cladding is in direct contact with the plastic core with no intervening material.

7. 3. The wavelength-shifting fiber of claim 1 or claim 2, wherein the plastic core comprises a material selected from the group consisting of polystyrene (PS), polyvinyl toluene (PVT), polymethyl methacrylate (PMMA), polycarbonate, and any combination thereof.

8. The wavelength-shifting fiber of claim 7 , wherein the plastic core contains a fluorescent dopant.

9. 3. The wavelength-shifting fiber of claim 1, wherein the cladding comprises an organic material.

10. 3. The wavelength-shifting fiber of claim 1, wherein the plastic core has a diameter of 5 mm or less.

11. The wavelength-shifting fiber of claim 10 , wherein the cladding further comprises a methacrylated polymer.

12. 1. A method of making a wavelength-shifting fiber, said method comprising: heating and stretching the plastic core precursor to form a plastic core having a diameter of at least 0.5 mm; coating the plastic core with a liquid coating, the liquid coating being in direct contact with the plastic core and comprising a glycerol ether acrylate, a fluoroacrylate, a multifunctional acrylate, or a combination thereof; and curing the liquid coating around the plastic core using UV light to form a wavelength-shifting fiber, wherein the wavelength-shifting fiber has a numerical aperture of at least 0.

6.

13. 13. The method of making a wavelength-shifting fiber of claim 12, wherein the numerical aperture is: [Equation 2] where n ｃｏｒｅ is the refractive index of the plastic core, and n ｃｌａｄ is the refractive index of the cured coating.

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