Rapid radiation imaging system and method based on fusion of optical imaging and coding hole technology

Abstract

The invention relates to the technical field of radiation imaging, and discloses a rapid radiation imaging system and method integrating optical imaging and coding hole technology, and the system comprises a spectral imaging subsystem and a gamma ray imaging subsystem. Wherein the spectral imaging subsystem and the gamma-ray imaging subsystem share a coding pore plate, the gamma-ray imaging subsystem further comprises a radiation detector, and the spectral imaging subsystem further comprises a first lens, a second lens, a dispersion prism, a third lens and a CCD detector; the first lens, the coding pore plate, the second lens, the dispersion prism and the third lens are sequentially arranged in the direction from a target to be detected to the radiation detector and the CCD detector. According to the invention, spectral imaging and radiation imaging can be carried out simultaneously, the complexity and cost of the system are reduced, and the working efficiency and safety are improved.

Description

Technical Field

[0001] The present invention relates to the field of radiation imaging technology, and in particular to a rapid radiation imaging system and method integrating optical imaging with coded aperture technology. Background Art

[0002] When implementing supervision on the utilization of mineral resources, it is required to complete the composition detection and radioactivity level monitoring of mineral raw materials, products or waste residues within a certain storage range safely and efficiently. In this process, it is necessary to conduct spectral and radioactive detection of mineral resources, which is conducive to the conduct of trade and the release of waste residues. On the one hand, the radioactive pollution existing in the imported industrial products and the radioactivity associated with the mineral waste residues are far higher than the natural radioactive background level. In the process of radioactive detection of metals and minerals, the different γ-ray energies emitted by different nuclides can identify the type of radioactive elements in the material and their relative content, and image the radioactivity distribution while obtaining information such as the type and energy spectrum of the radioactive nuclides. On the other hand, through spectral detection technology, not only can the geometric shape of the material be imaged, but also the spectral characteristics of the material can be obtained. Through the known mineral spectrum principle, spectral analysis can be performed to obtain mineral diagnostic characteristics for identification and classification, so as to achieve the purpose of facilitating supervision.

[0003] At present, the methods used for mineral resource monitoring are mainly divided into laboratory measurement and portable measurement. Laboratory measurement usually conducts random sampling of imported minerals or mineral waste to make it representative, but it has the problem of large equipment and lack of real-time performance; portable detection methods rely on staff to carry out radioactive inspections on site at close range with handheld instruments, which has the disadvantages of low work efficiency, high missed detection rate and threat to the health of detection personnel, and is not suitable for radioactive detection of imported minerals and mineral waste. In addition, the existing technology can usually only perform one type of imaging measurement at the same time, and cannot perform optical imaging and radiation imaging at the same time, resulting in longer measurement cycles and low work efficiency.

[0004] Therefore, there is an urgent need for a fast radiation imaging system and method that integrates optical imaging and coded hole technology, which can perform spectral imaging and radiation imaging simultaneously, reduce system complexity and cost, and improve work efficiency and safety. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a rapid radiation imaging system and method that integrates optical imaging and coded hole technology, which can perform spectral imaging and radiation imaging simultaneously, reduce system complexity and cost, and improve work efficiency and safety.

[0006] The present invention provides a rapid radiation imaging system integrating optical imaging and coded aperture technology, comprising: Spectral imaging subsystem and gamma ray imaging subsystem; The spectral imaging subsystem and the gamma-ray imaging subsystem share a coding aperture plate, the gamma-ray imaging subsystem further includes a radiation detector, and the spectral imaging subsystem further includes a first lens, a second lens, a dispersion prism, a third lens and a CCD detector; From the target to be measured to the radiation detector and the CCD detector, the arrangement order is the first lens, the coding aperture plate, the second lens, the dispersion prism and the third lens; The target to be measured is used to emit rays and diffusely reflect light; The first lens is used to form an image based on the light diffusely reflected by the target to be measured, so that the target to be measured is imaged on the coding hole plate through the first lens; The coding aperture plate is used to encode both the rays and the light simultaneously; The second lens is used to collimate the coded and modulated light onto the dispersion prism; The dispersion prism is used to split the collimated light into different wavelengths and inject it into the third lens; The third lens is used to converge the split light and image it onto the CCD detector; The radiation detector is used to receive the radiation emitted by the target to be detected; The CCD detector is used to receive the light after the third lens converges and forms an image.

[0007] Furthermore, the difference between the distance between the radiation detector and the target to be measured and the distance between the CCD detector and the target to be measured is less than or equal to a preset error value.

[0008] Furthermore, the CCD detector is arranged in parallel with the third lens.

[0009] Furthermore, the radiation detector is arranged in parallel with the coding aperture plate.

[0010] Furthermore, the CCD detector and the radiation detector are arranged on the same horizontal plane.

[0011] The present invention also provides a rapid radiation imaging method integrating optical imaging and coded hole technology, which is implemented based on the rapid radiation imaging system integrating optical imaging and coded hole technology described in any one of the above, and includes the following steps: S1, imaging the light diffusely reflected by the target through the first lens; S2, encoding and modulating the light imaged on the coding aperture plate through the coding aperture plate; S3, collimating the coded modulated light through a second lens; S4, splitting the aligned light through a dispersion prism; S5, the split light rays are respectively converged into images through the third lens; S6, receiving the split light through the CCD detector and converging the light into images to obtain a spectral information aliasing image; S7. Reconstruct the aliased image based on the spectral information by using a compressed sensing reconstruction algorithm to obtain three-dimensional data spectral information.

[0012] Furthermore, the method further comprises the following steps: S1.1. Encoding and modulating the rays radiated by the target to be measured on the coding aperture plate through the coding aperture plate; S1.2, receiving the coded modulated rays through the radiation detector to form a ray information aliasing image; S1.3. Reconstruct the aliased image of the radiation information through an image reconstruction algorithm to obtain a two-dimensional radiation source distribution image.

[0013] The present invention has the following technical effects: The present invention utilizes the same coding aperture plate to synchronously encode and modulate the light and rays of the target to be measured, receives the light and rays of the target to be measured through a CCD detector and a radiation detector respectively, and reconstructs the spectral image and gamma-ray image of the target to be measured respectively by using a compressed sensing reconstruction algorithm and an image reconstruction algorithm after measurement. The system structure of this scheme combines the functions of spectral imaging and radiation imaging into one, and simplifies the structure of the imaging system as much as possible to reduce the volume and weight. The imaging system is mounted on an unmanned robot platform, which can quickly complete the spectral and radioactive detection of mineral resources, maintain the high resolution of the measured image, and realize rapid imaging, while reducing the complexity and cost of the system, thereby improving the efficiency and safety of supervision work, and is conducive to the safe and comprehensive utilization of mineral resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 It is a schematic structural diagram of a rapid radiation imaging system integrating optical imaging and coded aperture technology provided by an embodiment of the present invention; Figure 2 is a structural schematic diagram of a spectral imaging subsystem provided by an embodiment of the present invention; Figure 3 is a structural schematic diagram of a gamma-ray imaging subsystem provided by an embodiment of the present invention; Figure 4 It is a structural schematic diagram of a coding hole plate provided by an embodiment of the present invention; Figure 5 is a schematic diagram of light being dispersed by a dispersion prism provided by an embodiment of the present invention; Figure 6 A target pattern and its spectrum spectrogram provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0017] The present invention proposes a rapid radiation imaging system that integrates optical imaging and coded aperture technology. Figure 1 is a schematic structural diagram of a rapid radiation imaging system integrating optical imaging and coded aperture technology provided by an embodiment of the present invention, Figure 2 is a schematic structural diagram of a spectral imaging subsystem provided by an embodiment of the present invention, Figure 3 is a structural schematic diagram of a gamma-ray imaging subsystem provided by an embodiment of the present invention, Figure 4 is a schematic diagram of the structure of a coding hole plate provided by an embodiment of the present invention, see Figure 1-Figure 4 , specifically including: Spectral imaging subsystem and gamma ray imaging subsystem; The spectral imaging subsystem and the gamma-ray imaging subsystem share a coding aperture plate, the gamma-ray imaging subsystem further includes a radiation detector, and the spectral imaging subsystem further includes a first lens, a second lens, a dispersion prism, a third lens and a CCD detector; From the target to be measured to the radiation detector and the CCD detector, the arrangement order is the first lens, the coding aperture plate, the second lens, the dispersion prism and the third lens; The target to be measured is used to emit rays and diffusely reflect light; The first lens is used to form an image based on the light diffusely reflected by the target to be measured, so that the target to be measured is imaged on the coding hole plate through the first lens; The coding aperture plate is used to encode both the rays and the light simultaneously; The second lens is used to collimate the coded and modulated light onto the dispersion prism; The dispersion prism is used to split the collimated light into different wavelengths and inject it into the third lens; The third lens is used to converge the split light and image it onto the CCD detector; The radiation detector is used to receive the radiation emitted by the target to be detected; The CCD detector is used to receive the light after the third lens converges and forms an image.

[0018] The structure of the coding aperture plate can be set according to the specific conditions of the target to be measured. The dispersion prism can change the path of the light while splitting the light, so that the rays and light can be measured at the same position with different detectors at the same time without interfering with each other.

[0019] Specifically, the parameters of the first lens, the second lens and the third lens can be set according to actual conditions; the first lens and the second lens can be the same size, but the third lens is generally an optical lens / lens with adjustable focal length, and, in some embodiments, the third lens can also be assembled with a CCD detector to facilitate image formation.

[0020] Furthermore, the difference between the distance between the radiation detector and the target to be measured and the distance between the CCD detector and the target to be measured is less than or equal to a preset error value.

[0021] Specifically, the distance between the radiation detector and the target to be measured is basically equal to the distance between the CCD detector and the target to be measured, which can ensure that the data collected by the radiation detector and the CCD detector are obtained under the same conditions, that is, ensuring spatial consistency and receiving time consistency, thereby reducing signal attenuation or viewing angle changes caused by distance differences, reducing data correction work, and thereby improving the accuracy and reliability of the final analysis results.

[0022] Furthermore, the CCD detector is arranged in parallel with the third lens.

[0023] Specifically, the focal length of the third lens or the distance between the third lens and the CCD detector can be adjusted so that the CCD detector can observe the complete coded aperture plate; There is no fixed relationship between the angle setting of the third lens and the dispersion prism. It is only necessary to adjust the position or angle of the third lens and the dispersion prism so that the CCD detector can observe the target and the coding aperture plate as clearly as possible.

[0024] Furthermore, the radiation detector is arranged in parallel with the coding aperture plate.

[0025] Furthermore, the CCD detector and the radiation detector are arranged on the same horizontal plane.

[0026] Specifically, the CCD detector and the radiation detector are arranged on the same horizontal plane (i.e., placed side by side), and their placement is not specifically limited, as long as the optical imaging information can be completely observed by the CCD detector. For example, in some embodiments, the dispersion prism can also be inverted, and the position of the CCD detector is adjusted to the other side of the radiation detector accordingly.

[0027] Specifically, Figure 5 is a schematic diagram of a light beam being dispersed by a dispersion prism provided by an embodiment of the present invention, see Figure 5 The dispersion prism can split the incident mixed light into different wavelengths, so that the split light falls on different pixels of the CCD detector.

[0028] Where l is the incident light, i is the incident angle, α is the vertex angle of the dispersion prism, γ1 is the refraction angle of the light entering the dispersion prism, γ2 is the refraction angle of the light when it exits the prism, θ is the exit angle, and Δl represents the imaging area of ​​the incident light projected on the CCD detector. The sum of the refraction angle γ1 and the refraction angle γ2 satisfies: ; The relationship between the incident angle i and the refraction angle γ1 satisfies: ; Where λ is the wavelength of the incident light, and n(λ) is the refractive index at different wavelengths; The relationship between the exit angle θ and the refraction angle γ2 satisfies: ; The relationship between the exit angle θ and the incident angle i satisfies: .

[0029] For example, Figure 6 is a target pattern and its spectral spectrogram provided by an embodiment of the present invention, see Figure 6 , select visible light in the range of 450nm-650nm, take 550nm light as the central wavelength of the selected equilateral prism, and calculate the exit angle of each wavelength as θ: ; From the above formula, it can be concluded that the incident angle i and refractive index n(λ) of the dispersion prism determine its output angle θ, and the distance at which light of different wavelengths falls on the detector and the output angle θ are related to the distance R from the dispersion prism to the detector.

[0030] The difference between the light emission angle of different wavelengths and the center wavelength is p, and the distance d between the position of the light image of different wavelengths on the detector and the position of the center wavelength is: .

[0031] Therefore, in order to make the imaging system compact and miniaturized, the distance between the dispersion prism and the CCD detector is set to R = 5 cm, and 10 discrete spectral segments with the same deflection angle between 450nm-650nm (450nm, 462nm, 475nm, 490nm, 508nm, 528nm, 551nm, 578nm, 608nm, 642nm) are selected as the spectral dimensions of the target spectral data cube. The spectral spectrogram of the target image can be obtained as shown in the figure. Figure 6 shown.

[0032] The present invention utilizes the same coding aperture plate to synchronously encode and modulate the light and rays of the target to be measured, receives the light and rays of the target to be measured through a CCD detector and a radiation detector respectively, and reconstructs the spectral image and gamma-ray image of the target to be measured respectively by using a compressed sensing reconstruction algorithm and an image reconstruction algorithm after measurement. The system structure of this scheme combines the functions of spectral imaging and radiation imaging into one, and simplifies the structure of the imaging system as much as possible to reduce the volume and weight. The imaging system is mounted on an unmanned robot platform, which can quickly complete the spectral and radioactive detection of mineral resources, maintain the high resolution of the measured image, and realize rapid imaging, while reducing the complexity and cost of the system, thereby improving the efficiency and safety of supervision work, and is conducive to the safe and comprehensive utilization of mineral resources.

[0033] The embodiment of the present invention also provides a rapid radiation imaging method integrating optical imaging and coded hole technology. The rapid radiation imaging system integrating optical imaging and coded hole technology described in the above embodiment is implemented. Figure 1-Figure 4 , the specific steps for optical imaging are as follows: S1. Forming an image through a first lens based on the light diffusely reflected by the target to be measured.

[0034] S2. Encode and modulate the light imaged on the coding aperture plate through the coding aperture plate.

[0035] S3. Collimate the coded modulated light through a second lens.

[0036] S4. Split the collimated light through a dispersion prism.

[0037] S5. The split light rays are converged into images through the third lens.

[0038] S6. The CCD detector receives the split light rays and converges them into images to obtain a spectral information mixed image.

[0039] S7. Reconstruct the aliased image based on the spectral information by using a compressed sensing reconstruction algorithm to obtain three-dimensional data spectral information.

[0040] Specifically, the three-dimensional data spectral information can reflect the reflection, absorption and transmission characteristics of the target under test at different wavelengths, thereby revealing its material composition, structural characteristics and chemical properties. The purpose of full-band hyperspectral imaging is to obtain detailed spectral information and image information of the target under test in a wider spectral range to improve recognition accuracy and achieve rapid detection and analysis.

[0041] The specific steps for performing radiation imaging are as follows: S1.1. Code and modulate the rays radiated by the target on the coding aperture plate through the coding aperture plate.

[0042] S1.2. A radiation information aliasing image is formed by receiving the coded modulated rays through a radiation detector.

[0043] S1.3. Reconstruct the aliased image of the radiation information through an image reconstruction algorithm to obtain a two-dimensional radiation source distribution image.

[0044] It should be noted that the terms used in the present invention are only for describing specific embodiments, rather than limiting the scope of the present application. As shown in the present specification, unless the context clearly indicates an exception, the words "one", "a", "a kind of" and / or "the" do not specifically refer to the singular, but may also include the plural. The terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method or device. In the absence of more restrictions, the elements defined by the sentence "include one..." do not exclude the presence of other identical elements in the process, method or device including the elements.

[0045] It should also be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. A fast radiation imaging system integrating optical imaging and coded aperture technology, characterized in that: include: Spectral imaging subsystem and gamma ray imaging subsystem; The spectral imaging subsystem and the gamma-ray imaging subsystem share a coding aperture plate, the gamma-ray imaging subsystem further includes a radiation detector, and the spectral imaging subsystem further includes a first lens, a second lens, a dispersion prism, a third lens and a CCD detector; From the target to be measured toward the radiation detector and the CCD detector, the arrangement order is the first lens, the coding aperture plate, the second lens, the dispersion prism and the third lens; The target to be measured is used to emit rays and diffusely reflect light; The first lens is used to form an image based on the light diffusely reflected by the target to be measured, so that the target to be measured is imaged on the coding hole plate through the first lens; The coding aperture plate is used to encode the rays and light simultaneously; The second lens is used to collimate the coded modulated light onto the dispersion prism; The dispersion prism is used to split the collimated light into different wavelengths and inject the light into the third lens; The third lens is used to converge the split light and form an image on the CCD detector; The radiation detector is used to receive the radiation emitted by the target to be detected; The CCD detector is used to receive the light after being focused and imaged by the third lens.

2. The rapid radiation imaging system integrating optical imaging and coded aperture technology according to claim 1, characterized in that: The difference between the distance between the radiation detector and the target to be measured and the distance between the CCD detector and the target to be measured is less than or equal to a preset error value.

3. The rapid radiation imaging system integrating optical imaging and coded aperture technology according to claim 2, characterized in that: The CCD detector is arranged in parallel with the third lens.

4. The rapid radiation imaging system integrating optical imaging and coded aperture technology according to claim 3, characterized in that: The radiation detector is arranged in parallel with the coding aperture plate.

5. The rapid radiation imaging system integrating optical imaging and coded aperture technology according to claim 1, characterized in that: The CCD detector and the radiation detector are arranged on the same horizontal plane.

6. A rapid radiation imaging method integrating optical imaging and coded hole technology, based on a rapid radiation imaging system integrating optical imaging and coded hole technology as described in any one of claims 1 to 5, characterized in that: The specific steps include: S1, imaging the light diffusely reflected by the target through the first lens; S2, encoding and modulating the light imaged on the coding aperture plate through the coding aperture plate; S3, collimating the coded modulated light through a second lens; S4, splitting the aligned light through a dispersion prism; S5, the split light rays are respectively converged into images through the third lens; S6, receiving the split light through the CCD detector and converging the light into images to obtain a spectral information aliasing image; S7. Reconstruct the spectral information aliasing image using a compressed sensing reconstruction algorithm to obtain three-dimensional data spectral information.

7. The rapid radiation imaging method combining optical imaging with coded aperture technology according to claim 6, characterized in that: The following steps are also included: S1.1, encoding and modulating the rays radiated by the target to be measured on the coding aperture plate through the coding aperture plate; S1.2, receiving the coded modulated rays through the radiation detector to form a ray information aliasing image; S1.

3. Reconstruct the aliased image of the radiation information through an image reconstruction algorithm to obtain a two-dimensional radiation source distribution image.

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