Radiation monitor

Abstract

The embodiment of the specification provides a radiation monitor, the radiation monitor comprises a shell, a scintillation crystal and a photomultiplier, one end of the scintillation crystal is connected with the photomultiplier, and the scintillation crystal and the photomultiplier are both arranged in the shell; the shell is provided with a channel used for enabling rays to enter the scintillation crystal, and the shell can reflect the rays emitted by the scintillation crystal.

Description

Technical Field

[0001] The present invention relates to the field of environmental monitoring technology, and in particular to a radiation monitor. Background Art

[0002] As people's living standards are getting higher and higher, higher requirements are also put forward for living conditions. In people's daily lives, there may be some radioactive objects. For example, marble is increasingly becoming the main force of home decoration because of its hard texture and beautiful appearance. Since the radiation (mainly caused by gamma rays) generated by marble (including other building materials) is colorless and odorless, people tend to ignore it when decorating their homes, so radiation monitors suitable for home environments (also suitable for other environments) came into being. At present, the most common radiation monitors in the domestic market are those based on Geiger-Mueller counters. However, since the price of radiation monitors based on Geiger-Mueller counters is relatively expensive overall, it is hoped that a radiation monitor can be provided that can improve measurement efficiency and measurement accuracy while reducing manufacturing costs. Utility Model Content

[0003] One or more embodiments of the present specification provide a radiation monitor, which includes a shell, a scintillation crystal and a photomultiplier tube, one end of the scintillation crystal is connected to the photomultiplier tube, and the scintillation crystal and the photomultiplier tube are both arranged in the shell; the shell is provided with a channel for allowing rays to enter the scintillation crystal, and the shell can reflect the light emitted by the scintillation crystal.

[0004] In some embodiments, the scintillation crystal is connected to the photomultiplier tube via a silicone oil layer, and the thickness of the silicone oil layer ranges from 0.2 mm to 0.8 mm.

[0005] In some embodiments, the photomultiplier tube is a silicon photomultiplier tube.

[0006] In some embodiments, the shell is an aluminum shell, and the thickness of the aluminum shell ranges from 0.2 cm to 0.5 cm.

[0007] In some embodiments, a reflective structure is disposed between the shell and the scintillation crystal, the reflective structure is wrapped around the scintillation crystal, the inner side of the reflective structure is in contact with the scintillation crystal, and the outer side of the reflective structure is in contact with the shell.

[0008] In some embodiments, the reflective structure includes a magnesium oxide powder layer, and the thickness of the magnesium oxide powder layer ranges from 0.1 cm to 0.4 cm.

[0009] In some embodiments, an elastic connecting layer is disposed between one end of the reflective structure close to the channel and the shell.

[0010] In some embodiments, the thickness of the elastic connecting layer ranges from 0.1 cm to 1 cm.

[0011] In some embodiments, the scintillator crystal is a yttrium lutetium silicate crystal, and the thickness of the yttrium lutetium silicate crystal ranges from 1 mm to 5 cm.

[0012] In some embodiments, the radiation monitor further includes a processing component and a display module, and the processing component is electrically connected to the photomultiplier tube and the display module. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0014] Figure 1 is an exemplary module diagram of a radiation monitor according to some embodiments of this specification;

[0015] Figure 2 is a cross-sectional view of a radiation monitor according to some embodiments of the present specification. DETAILED DESCRIPTION

[0016] In order to more clearly illustrate the technical solutions of the embodiments of this specification, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of this specification. For ordinary technicians in this field, this specification can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0017] It should be understood that the "system", "device", "unit" and / or "module" used herein are a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

[0018] As shown in this specification and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0019] Figure 1is an exemplary module diagram of a radiation monitor according to some embodiments of this specification; Figure 2 is a cross-sectional view of a radiation monitor according to some embodiments of the present specification.

[0020] Some embodiments of the present specification provide a radiation monitor, such as Figure 1-Figure 2 As shown, the radiation monitor 100 includes a housing 10, a scintillation crystal 20 and a photomultiplier tube 30, one end of the scintillation crystal 20 is connected to the photomultiplier tube 30, and the scintillation crystal 20 and the photomultiplier tube 30 are both arranged in the housing 10. The housing 10 is provided with a channel for allowing radiation to enter the scintillation crystal 20, and the housing 10 can reflect the light emitted by the scintillation crystal 20.

[0021] The housing 10 refers to the outer shell of the radiation monitor 100. In some embodiments, the housing 10 can be used to accommodate and fix other components or modules of the radiation monitor 100. For example, the scintillation crystal 20 and the photomultiplier tube 30 are both disposed in the housing 10. In some embodiments, the housing 10 can be designed in a variety of structural shapes. Exemplary structural shapes may include but are not limited to a rectangular parallelepiped, a cube, a cylinder, etc.

[0022] The channel is a passage for allowing radiation (such as gamma rays, etc.) in the environment to enter the scintillation crystal 20. The channel is provided on the housing 10. In some embodiments, the channel extends along the axial direction of the scintillation crystal 20 so that the radiation in the environment reaches the light receiving surface of the scintillation crystal 20. In some embodiments, the number of the channels may be one or more. When the number of the channels is one, the axis of the channel may be colinear with the axis of the scintillation crystal 20 so that the radiation in the environment can better enter the scintillation crystal 20. In some embodiments, the axial direction of the scintillation crystal 20 may be Figure 2 The X direction is shown.

[0023] In some embodiments, the housing 10 is an aluminum housing, and the thickness of the aluminum housing is in the range of L 1 In some embodiments, the thickness range of the aluminum shell is L 1 It can also be 0.15 cm to 0.25 cm. In some embodiments, the thickness range L of the aluminum shell is 1 It can also be 0.25cm to 0.6cm.

[0024] In some embodiments, the housing 10 may also be made of any other feasible material, such as iron, plastic, etc.

[0025] In some embodiments, since the aluminum shell is lighter and has better reflective performance than the shell 10 made of other materials (such as iron, etc.), the use of the aluminum shell as the shell 10 is not only conducive to reducing the overall weight of the radiation monitor 100, but also enables the light emitted by the scintillation crystal 20 to be reflected back to the surface of the photomultiplier tube 30, thereby improving the light collection efficiency of the photomultiplier tube 30. 1 By limiting the thickness of the aluminum shell to be within an appropriate range, the weight of the product can be reduced as much as possible, materials can be saved, and the quality of the product can be ensured.

[0026] The scintillation crystal 20 refers to a crystal that can convert the kinetic energy of high-energy particles such as gamma rays into visible light or light when hit by them.

[0027] In some embodiments, the scintillator crystal 20 is a lutetium yttrium silicate (LYSO) crystal, and the thickness of the lutetium yttrium silicate crystal ranges from L 2 In some embodiments, the thickness of the lutetium yttrium silicate crystal is in the range of L 2 In some embodiments, the thickness of the lutetium yttrium silicate crystal is in the range of L 2 It can also be 3mm to 5.5cm.

[0028] In some embodiments, the scintillation crystal 20 may also be any other feasible crystal, for example, the scintillation crystal 20 may include bismuth germanate (BGO), chromium tungstate (CdWO4), lead tungstate (PbWO4), and the like.

[0029] It can be understood that when the thickness of the scintillation crystal 20 is adjusted, the length of the housing 10 along the axial direction of the scintillation crystal 20 also needs to be adjusted accordingly to accommodate scintillation crystals 20 of different thicknesses.

[0030] In some embodiments of this specification, since the monitoring object is mainly gamma rays, the three mechanisms of interaction between gamma rays and substances (such as scintillation crystals 20) are photoelectric effect, Compton effect and electron pair effect, and these three mechanisms are positively correlated with the effective atomic coefficient of the substance. The more effective atomic coefficients of the substance, the better the effects of these three mechanisms. Lutetium yttrium silicate crystals have the characteristics of high light output, fast luminescence decay, many effective atomic coefficients, and high density, so they become the preferred material for monitoring gamma rays.

[0031] In some embodiments, the sensitivity of the radiation monitor 100 is positively correlated with the thickness of the scintillation crystal 20. The thicker the scintillation crystal 20 is, the higher the sensitivity of the radiation monitor 100 is. Therefore, by using yttrium lutetium silicate crystals of different thicknesses, radiation monitors 100 of different sensitivities can be obtained, thereby effectively expanding the scope of application.2 By limiting the range to 1 mm to 5 cm, the sensitivity of the radiation monitor 100 can be kept at a good level, so as to ensure the measurement accuracy of the radiation monitor 100 .

[0032] In some embodiments, radiation (such as gamma rays) in the environment can be incident on the surface of the scintillation crystal 20 through the channel on the housing 10 . The scintillation crystal 20 absorbs the radiation to generate visible light or light and guides it into the photomultiplier tube 30 .

[0033] In some embodiments, the scintillation crystal 20 may be directly or indirectly connected to the photomultiplier tube 30. For example, the scintillation crystal 20 may be directly disposed on an end of the photomultiplier tube 30 close to the channel, that is, an end of the scintillation crystal 20 away from the channel is directly connected to an end of the photomultiplier tube 30 close to the channel. For another example, an end of the scintillation crystal 20 away from the channel may be indirectly connected to an end of the photomultiplier tube 30 close to the channel through other media or substances (such as the silicone oil layer 40 described later).

[0034] The photomultiplier tube 30 is a component that can convert a weak light signal into an electrical signal. Exemplary photomultiplier tubes 30 may include high-temperature photomultiplier tubes, low-temperature photomultiplier tubes, and the like.

[0035] In some embodiments, the photomultiplier tube 30 is a silicon photomultiplier tube, which is a new type of photodetector device, composed of an avalanche diode array operating in Geiger mode, and has the characteristics of high gain, high sensitivity, low bias voltage, insensitivity to magnetic fields, and compact structure.

[0036] It can be understood that due to the characteristics of the silicon photomultiplier tube itself, its bias voltage is much lower than the bias voltage of the traditional photomultiplier tube (such as 1KV~2KV) and the bias voltage of the Geiger-Mueller counter tube (such as 400V). Therefore, the use of silicon photomultiplier tubes can ensure safer instrument operation on the one hand, and on the other hand, it can make the boost circuit simpler or even eliminate the need for a boost circuit, thereby effectively reducing the manufacturing cost of the radiation monitor.

[0037] In some embodiments, the amplification factor of the silicon photomultiplier tube is positively correlated with the bias voltage of the silicon photomultiplier tube. Therefore, by adjusting the bias voltage of the silicon photomultiplier tube, different amplification factors of the silicon photomultiplier tube can be obtained, thereby making the detection efficiency of the radiation monitor variable, the performance more stable and the application field more extensive.

[0038] In some embodiments, the photomultiplier tube 30 can receive the light emitted by the scintillation crystal 20 and convert the light into an electrical signal after amplifying the light.

[0039] For more information about radiation monitors, please refer to the relevant description below.

[0040] In some embodiments of this specification, a housing, a scintillation crystal and a photomultiplier tube are used as important components of a radiation monitor, wherein the housing can reflect the light emitted by the scintillation crystal, which can not only improve the light collection efficiency of the photomultiplier tube and the measurement efficiency of the radiation monitor, but also reduce statistical errors to a certain extent and improve the measurement accuracy of the radiation monitor. In addition, the radiation monitor adopts an integrated packaging structure, which is simple in structure, small in size, easy to carry and has low manufacturing cost, and has wide practicality.

[0041] In some embodiments, Figure 1-Figure 2 As shown, the scintillation crystal 20 is connected to the photomultiplier tube 30 through a silicone oil layer 40, and the thickness of the silicone oil layer 40 is in the range of L 3 It is 0.2mm~0.8mm.

[0042] The silicone oil layer 40 refers to an optical interface layer formed by silicone oil. Since silicone oil has not only high viscosity and stability, but also high refractive index and transparency, and can effectively transmit optical signals, the silicone oil layer 40 can effectively couple the light emitted by the scintillation crystal 20 to the photomultiplier tube 30 while connecting the scintillation crystal 20 and the photomultiplier tube 30, thereby improving the coupling efficiency of the photomultiplier tube, and further improving the measurement accuracy of the radiation monitor 100.

[0043] In some embodiments, the thickness range of the silicone oil layer 40 is L 3 In some embodiments, the thickness range L of the silicone oil layer 40 is 0.1 mm to 0.5 mm. 3 It can also be 0.5 mm to 0.9 mm. It can be understood that by adjusting the thickness range L of the silicone oil layer 40 3 The thickness of the silicone oil layer 40 is limited so as to be within a preferred range, which is beneficial to further improve the coupling efficiency of the photomultiplier tube.

[0044] In some embodiments, Figure 1-Figure 2 As shown, a reflective structure 50 is disposed between the housing 10 and the scintillation crystal 20 . The reflective structure 50 is wrapped around the scintillation crystal 20 . The inner side of the reflective structure 50 contacts the scintillation crystal 20 , and the outer side of the reflective structure 50 contacts the housing 10 .

[0045] The inner side of the reflective structure 50 refers to the surface of the reflective structure 50 close to the scintillation crystal 20 , that is, the inner surface of the reflective structure 50 ; the outer side of the reflective structure 50 refers to the surface of the reflective structure 50 away from the scintillation crystal 20 , that is, the outer surface of the reflective structure 50 .

[0046] The reflective structure 50 refers to a structure with reflective properties. In some embodiments, the reflective structure 50 may include a magnesium oxide powder layer, and the thickness of the magnesium oxide powder layer ranges from L 4It is 0.1cm~0.4cm.

[0047] The magnesium oxide powder layer refers to a structural layer composed of magnesium oxide powder. Since magnesium oxide powder is a reflector with excellent performance, the magnesium oxide powder layer is filled between the housing 10 and the scintillation crystal 20 to reflect the light emitted by the scintillation crystal 20 (such as lutetium yttrium silicate crystal) back to the surface of the photomultiplier tube (such as silicon photomultiplier tube), thereby further improving the light collection efficiency of the photomultiplier tube 30 and improving the measurement accuracy of the radiation monitor 100.

[0048] In some embodiments, the thickness range of the magnesium oxide powder layer is L 4 It can also be 0.08 cm to 0.2 cm. In some embodiments, the thickness range L of the magnesium oxide powder layer is 4 It can also be 0.2 cm to 0.5 cm. It can be understood that limiting the thickness of the magnesium oxide powder layer within a suitable range is conducive to ensuring the reflection effect of the magnesium oxide powder layer, thereby further improving the light collection efficiency of the photomultiplier tube 30 .

[0049] In some embodiments, the reflective structure 50 may also adopt other structural forms, such as a reflective coating (such as a magnesium oxide coating, an aluminum film, a silver film, a barium sulfate film, etc.), a reflective diaphragm, etc. It should be noted that the material of the reflective structure 50 may be any other feasible material in addition to magnesium oxide, and this specification does not limit this.

[0050] In some embodiments, the arrangement of the reflective structure 50 between the housing 10 and the scintillation crystal 20 is related to the structural shape of the reflective structure 50. For example, when the structure of the reflective structure 50 is a reflective coating, the reflective structure 50 is arranged on one or more outer surfaces of the scintillation crystal 20 that are not connected to the photomultiplier tube 30 (or the silicone oil layer 40). For another example, when the structure of the reflective structure 50 is a layer structure, the reflective structure 50 is arranged in a space formed by one or more outer surfaces of the scintillation crystal 20 that are not connected to the photomultiplier tube 30 (or the silicone oil layer 40) and the inner surface of the housing 10.

[0051] In some embodiments of the present specification, a reflective structure is provided between the housing and the scintillation crystal, which is beneficial for further reflecting the light emitted by the scintillation crystal back to the surface of the photomultiplier tube, thereby further improving the light collection efficiency of the photomultiplier tube.

[0052] In some embodiments, an elastic connection layer 60 is disposed between the end of the reflective structure 50 close to the channel and the housing 10. The elastic connection layer 60 refers to a structural layer with elasticity. For example, the elastic connection layer 60 may include a sponge layer, a foam layer, and the like.

[0053] In some embodiments, since the elastic connecting layer 60 is elastic, by arranging the elastic connecting layer 60 between one end of the reflective structure 50 close to the channel and the shell 10, other components in the shell 10 (such as the scintillation crystal 20 and the photomultiplier tube 30, etc.) can fit tightly, avoiding the generation of air light conduction between the scintillation crystal 20 and the photomultiplier tube 30, thereby further improving the light collection efficiency of the photomultiplier tube 30, reducing statistical errors, and improving the measurement accuracy of the radiation monitor 100.

[0054] In some embodiments, the thickness range L of the elastic connecting layer 60 is 5 In some embodiments, the thickness of the elastic connection layer 60 ranges from 0.1 cm to 1 cm. In some embodiments, the thickness of the elastic connection layer 60 ranges from 0.08 cm to 0.5 cm. In some embodiments, the thickness of the elastic connection layer 60 ranges from 0.5 cm to 1.2 cm.

[0055] It can be understood that by limiting the thickness range of the elastic connection layer 60 to be within the preferred range, its elasticity can be effectively guaranteed, thereby further ensuring a close fit between the scintillation crystal 20 and the photomultiplier tube 30 and improving the light collection efficiency of the photomultiplier tube 30 .

[0056] In some embodiments, Figure 1 As shown, the radiation monitor 100 further includes a processing component 70 and a display module 80 , and the processing component 70 is electrically connected to the photomultiplier tube 30 and the display module 80 .

[0057] The processing component 70 refers to a component for further processing the electrical signal output by the photomultiplier tube 30. In some embodiments, the processing component 70 may include a voltage divider, a potentiometer, an amplifier, a processor, and the like.

[0058] In some embodiments, the processing component 70 may be integrated on a chip and disposed at any feasible position in the housing 10 , such as below the photomultiplier tube 30 .

[0059] In some embodiments, the processing component 70 can receive the electrical signal output by the photomultiplier tube 30 , process and analyze the electrical signal to obtain measurement data, and transmit the measurement data to the display module 80 .

[0060] The display module 80 refers to a module for displaying measurement data to the user. For example, the display module 80 may include a liquid crystal screen, a touch screen, etc. The measurement data refers to the radiation data in the environment detected by the radiation monitor 100. For example, the measurement data may include but is not limited to radiation dose, radiation level, etc.

[0061] In some embodiments, a window structure for setting a display module 80 is provided on the housing 10. The display module 80 can be set in the housing 10 to display the measurement data to the user. In some embodiments, the connection between the display module 80 and the housing 10 can be sealed by a seal (such as a sealing ring) or bonding.

[0062] In some embodiments, the display module 80 can receive the measurement data transmitted by the processing component 70 and display it to the user.

[0063] In some embodiments, the display module 80 can display a user interface, and the user can perform relevant operations according to the user interface. It can be understood that by setting the display module 80, the measurement data can be intuitively displayed to the user so that the user can understand the detection results.

[0064] In some embodiments, the radiation monitor 100 may further include an early warning module (not shown in the figure), which is electrically connected to the processing component. The early warning module refers to a module for sending a warning signal to the user. The warning signal may include a warning sound, a warning light, a warning text, etc.

[0065] In some embodiments, the processing component 70 (such as a processor) can control the early warning module to issue an early warning signal by issuing an early warning instruction to the early warning module in response to the measurement data exceeding a preset threshold. The preset threshold refers to a pre-set parameter value. For example, the preset threshold may include a radiation dose threshold, etc.

[0066] As an example only, in response to the radiation dose in the environment exceeding the radiation dose threshold, the processor may send a warning instruction to the warning module, thereby controlling the warning module to issue a warning signal such as a warning sound.

[0067] In some embodiments, the radiation monitor 100 may further include an operation button. The operation button may be used for the user to input information. In some embodiments, the user may set a preset threshold value through the operation button.

[0068] In some embodiments of the present specification, when the radiation dose exceeds the radiation dose threshold, a warning signal is issued by the warning module, which can effectively remind the user to pay attention to the radiation risk, so as to protect individuals or the public from radiation hazards.

[0069] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements and corrections to this specification. Such modifications, improvements and corrections are suggested in this specification, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of this specification.

Claims

1. A radiation monitor, characterized in that: It comprises a shell, a scintillation crystal and a photomultiplier tube, one end of the scintillation crystal is connected to the photomultiplier tube, and the scintillation crystal and the photomultiplier tube are both arranged in the shell; The shell is provided with a channel for allowing rays to enter the scintillation crystal, and the shell can reflect the light emitted by the scintillation crystal.

2. The radiation monitor according to claim 1, characterized in that: The scintillation crystal is connected to the photomultiplier tube via a silicone oil layer, and the thickness of the silicone oil layer ranges from 0.2 mm to 0.8 mm.

3. The radiation monitor according to claim 2, characterized in that: The photomultiplier tube is a silicon photomultiplier tube.

4. The radiation monitor according to claim 1, characterized in that: The shell is an aluminum shell, and the thickness of the aluminum shell ranges from 0.2 cm to 0.5 cm.

5. The radiation monitor according to claim 1, characterized in that: A reflective structure is disposed between the shell and the scintillation crystal. The reflective structure is wrapped around the scintillation crystal. The inner side of the reflective structure is in contact with the scintillation crystal, and the outer side of the reflective structure is in contact with the shell.

6. The radiation monitor according to claim 5, characterized in that: The reflective structure comprises a magnesium oxide powder layer, and the thickness of the magnesium oxide powder layer ranges from 0.1 cm to 0.4 cm.

7. The radiation monitor according to claim 6, characterized in that: An elastic connection layer is arranged between one end of the reflective structure close to the channel and the shell.

8. The radiation monitor according to claim 7, characterized in that: The thickness of the elastic connecting layer ranges from 0.1 cm to 1 cm.

9. The radiation monitor according to claim 1, characterized in that: The scintillation crystal is a lutetium yttrium silicate crystal, and the thickness of the scintillation crystal ranges from 1 mm to 5 cm.

10. The radiation monitor according to claim 1, characterized in that: It also includes a processing component and a display module, wherein the processing component is electrically connected to the photomultiplier tube and the display module.

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