Gradient shielding camera based on radiation direction gradient and manufacturing method thereof

Abstract

The invention relates to a radiation environment monitoring camera, in particular to a gradient shielding camera based on a radiation direction gradient and a manufacturing method of the gradient shielding camera, and solves the problems that most of wall thicknesses are wasted, the light path adaptability is poor, and cameras of multiple specifications cannot be compatible in an existing shielding structure adopting a uniform wall thickness design. The device comprises a shell, a reflecting mirror, a lead shielding body and a camera movement, the position of a movement mounting cavity is positioned by calculating the thickness of a lead shielding layer, and the camera movement does not need to directly face a radiation field through reflection of the reflecting mirror, so that the influence of radiation on the camera movement is further weakened; due to the fact that the non-uniform wall thickness design is adopted in the lead shielding body, invalid loads are reduced, unnecessary material use is greatly reduced, the weight of the whole device is reduced, and meanwhile the manufacturing cost is reduced. The non-uniform wall thickness design is adopted, so that the position and the size of the window can be flexibly adjusted while necessary protection is ensured, and the device is suitable for camera movements of different sizes and types.

Description

Technical Field

[0001] This invention relates to radiation environment monitoring cameras, specifically to a gradient shielding camera based on radiation direction gradient and its manufacturing method. Background Technology

[0002] When monitoring radiation environments, cameras are typically equipped with shielding structures to prevent damage from radiation, as radiation can cause varying degrees of damage. These shielding structures are usually made of materials with inherent radiation-shielding properties, such as lead. The camera is placed inside the mounting cavity of the shielding structure. For ease of manufacturing, the shielding structure generally uses a uniform wall thickness design around the mounting cavity. However, the radiation field only has a high intensity in the main radiation direction, while the intensity is weak in other directions. Since lead has a relatively high density, a large portion of the shielding structure's wall thickness is wasted, typically resulting in more than 30% of the weight being unused. Furthermore, shielding structures with a uniform wall thickness design have poor optical path compatibility and are incompatible with various camera specifications. Summary of the Invention

[0003] The purpose of this invention is to solve the technical problems of existing shielding structures with uniform wall thickness design, which waste most of the wall thickness and have poor optical path adaptability, making them incompatible with cameras of various specifications. The invention provides a gradient shielding camera based on radiation direction gradient and its manufacturing method.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] A gradient-shielded camera based on radiation direction gradient, which is special in that:

[0006] This includes the outer casing, reflector, lead shield, and camera mechanism;

[0007] The outer shell is closed at both ends and hollow. A window is provided on the side wall of the outer shell near the upper end. The reflector is set on the inner top surface of the outer shell and the mirror surface of the reflector is set corresponding to the window.

[0008] The lead shield is disposed inside the outer shell and located below the reflector. The lead shield is a vertically arranged cylindrical structure, and a core mounting cavity is opened through the lead shield in the vertical direction. The camera core is installed in the core mounting cavity and is located in the reflected light path of the reflector.

[0009] The mechanism mounting cavity is configured to satisfy the following requirements:

[0010] The perpendicular distance between the tangent A of the cross section of the mechanism mounting cavity and the intersection point D of the main radiation direction and the lead shield is the thickness of the lead shield. The tangent A is perpendicular to the main radiation direction, and the center of the mechanism mounting cavity is located on the side of the tangent A away from the intersection point D of the main radiation direction and the lead shield.

[0011] The formula for calculating the thickness of the lead shielding layer is as follows:

[0012] exp ;

[0013] in: The thickness of the lead shielding layer, Radiation dose rate at the reference point The mass decay coefficient of lead. The density of lead, The energy of the incident radiation, The coordinates of the target's shielding location. The coordinates of the reference point The angle of incidence of the ray is the angle between the main radiation direction and the normal of the lead shielding layer.

[0014] Furthermore, both the reflector and the housing are made of stainless steel.

[0015] Furthermore, a communication interface is provided on the side wall near the bottom of the housing, which is used for electrical connection between the control terminal of the camera mechanism and an external control unit.

[0016] Furthermore, the window is provided with radiation-resistant glass.

[0017] Furthermore, the reflector is in the shape of an isosceles trapezoid, with its wider side positioned near the inner top surface of the outer shell and its narrower side positioned near the lead shield.

[0018] Meanwhile, the present invention also provides a method for manufacturing the above-mentioned gradient shielding camera based on radiation direction gradient, which is characterized by including the following steps:

[0019] S1. Establish a radiation field vector model and determine the main radiation direction;

[0020] S2. Radiation hotspot areas were determined using MCNP Monte Carlo simulation. The gradient distribution of the lead shielding layer was optimized using finite element analysis. Based on the functional relationship between the lead shielding layer thickness and the radiation dose rate, the thickness of the lead shielding layer was calculated. The formula for calculating the thickness of the lead shielding layer is as follows:

[0021] exp ;

[0022] in: The thickness of the lead shielding layer, Radiation dose rate at the reference point The mass decay coefficient of lead. The energy of the incident radiation, The coordinates of the target's shielding location. The coordinates of the reference point The incident angle of the rays is the angle between the main radiation direction and the normal to the lead shielding layer.

[0023] S3. Based on the calculated lead shielding layer thickness, process the mechanism mounting cavity on the lead shielding body, such that the perpendicular distance between the tangent A of the cross section of the mechanism mounting cavity and the intersection point D of the main radiation direction and the lead shielding body is the calculated lead shielding layer thickness, and the tangent A is perpendicular to the main radiation direction, while the center of the mechanism mounting cavity is located on the side of the tangent A away from the intersection point D of the main radiation direction and the lead shielding body.

[0024] S4. Install the camera module into the module mounting cavity and install the lead shield into the housing. Install the reflector on the inner top surface of the housing with the mirror surface corresponding to the window. The camera module is located below the reflector and simultaneously on the reflected light path of the reflector, thus completing the design of a gradient shielded camera based on the radiation direction gradient.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] (1) The present invention provides a gradient shielding camera based on radiation direction gradient, including a shell, a reflector, a lead shield and a camera core. The thickness of the lead shield is calculated to locate the mounting cavity of the core, and the reflection by the reflector makes the camera core not directly face the radiation field, further weakening the influence of radiation on the camera core. Since the lead shield adopts a non-uniform wall thickness design, the ineffective load is reduced, thereby greatly reducing unnecessary material use, reducing the overall weight of the equipment, and reducing the amount of precious metals such as lead used, directly reducing the manufacturing cost.

[0027] The gradient shielding structure is designed based on the directionality and intensity distribution of the radiation field. The shielding thickness is increased only in the locations where high protection is required, which can more effectively protect the camera mechanism from high-intensity radiation in specific directions and extend its service life.

[0028] Thanks to the non-uniform wall thickness design, the window position and size can be flexibly adjusted while ensuring necessary protection, adapting to camera mechanisms of different sizes and types, thus improving the system's versatility and flexibility.

[0029] (2) The gradient shielding camera based on radiation direction gradient provided by the present invention can adapt to different radiation levels by replacing different lead shields, thereby improving the ability to cope with complex radiation environments.

[0030] (3) The present invention provides a method for manufacturing a gradient shielded camera based on radiation direction gradient. It introduces the concept of directional gradient and applies the directional analysis results of the radiation field to the shielding design, which reflects the innovation in design concept and provides new ideas and technical references for the development of similar products in the future. Attached Figure Description

[0031] Figure 1 This is a front view of an embodiment of a gradient-shielded camera based on radiation direction gradient according to the present invention;

[0032] Figure 2 Figure 1 Sectional view along axis AA;

[0033] Figure 3 for Figure 1 Top view;

[0034] Figure 4 This is a top view of a lead shield in an embodiment of a gradient shielding camera based on radiation direction gradient according to the present invention;

[0035] Figure 5 Figure 4 BB-direction sectional view.

[0036] The annotations in the attached figures are explained as follows:

[0037] 1-Outer shell, 11-Window, 12-Communication interface; 2-Reflector, 3-Lead shield, 31-Mounting cavity for camera mechanism; 4-Camera mechanism. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and exemplary embodiments.

[0039] Reference Figures 1-5 The present invention provides a gradient shielding camera based on radiation direction gradient, comprising a housing 1, a reflector 2, a lead shield 3, and a camera mechanism 4.

[0040] The outer casing 1 is closed at both ends and hollow, and is made of stainless steel to ensure overall structural strength. A window 11 is provided on the side wall near the top of the outer casing 1. The window 11 is fitted with radiation-resistant glass to prevent discoloration or other damage in a radiation environment. A reflector 2 is located on the inner top surface of the outer casing 1, with its mirror surface corresponding to the window 11. The image is reflected by the reflector 2, preventing the camera module 4 from directly facing the radiation environment, further protecting the camera module 4. The reflector 2 is also made of stainless steel and is an isosceles trapezoid, with its wider side near the inner top surface of the outer casing 1 and its narrower side near the lead shield 3.

[0041] The lead shield 3 is set inside the outer shell 1 and located below the reflector 2. The lead shield 3 is a vertically arranged cylindrical structure, and a core mounting cavity 31 is opened through the lead shield 3 in the vertical direction. The camera core 4 is installed in the core mounting cavity 31 and is located in the reflected light path of the reflector 2.

[0042] To facilitate electrical connection between the camera mechanism 4 and the external control unit, a communication interface 12 is provided on the side wall of the housing 1 near the bottom. The control end of the camera mechanism 4 is electrically connected to the external control unit through a cable passing through the communication interface 12.

[0043] like Figure 4 As shown, the mechanism mounting cavity 31 is configured to satisfy the following conditions: the perpendicular distance between the tangent A of the cross section of the mechanism mounting cavity 31 and the intersection point D of the main radiation direction and the lead shield 3 is the thickness of the lead shield layer, and the tangent A is perpendicular to the main radiation direction, while the center of the mechanism mounting cavity 31 is located on the side of the tangent A away from the intersection point D of the main radiation direction and the lead shield 3.

[0044] The formula for calculating the thickness of the lead shielding layer is as follows:

[0045] exp ;

[0046] in: The thickness of the lead shielding layer, Radiation dose rate at the reference point The mass decay coefficient of lead. The density of lead, The energy of the incident radiation, The coordinates of the target's shielding location. The coordinates of the reference point The angle of incidence of the ray is the angle between the main radiation direction and the normal of the lead shielding layer.

[0047] Meanwhile, the present invention also provides a method for manufacturing the above-mentioned gradient shielding camera based on radiation direction gradient, comprising the following steps:

[0048] S1. Establish a radiation field vector model and determine the main radiation direction;

[0049] S2. Radiation hotspot areas were determined using MCNP Monte Carlo simulation. The gradient distribution of the lead shielding layer was optimized using finite element analysis. Based on the functional relationship between the lead shielding layer thickness and the radiation dose rate, the thickness of the lead shielding layer was calculated. The formula for calculating the thickness of the lead shielding layer is as follows:

[0050] exp ;

[0051] in: This refers to the thickness of the lead shielding layer;

[0052] The radiation dose rate at the reference point, also known as the cumulative dose, refers to the dose at the "reference point location" in the radiation field. The radiation intensity benchmark value at the "location", usually in units of Gy / h (dose rate) or Gy (cumulative dose), is the initial reference data for calculating the target shielding thickness;

[0053] is the mass attenuation coefficient of lead, which represents lead's ability to attenuate radiation of a specific energy level. In The density of lead, which is related to the incident radiation energy. The two main factors influencing the mass decay coefficient of lead vary with incident radiation energy. Changes, and related to the density of lead. Positive correlation, unit is cm² / g;

[0054] The energy of the incident radiation is expressed in MeV.

[0055] The coordinates of the target shielding location refer to the "spatial coordinates of the target point" that meet the shielding requirements, corresponding to the "path coordinates from the area to be protected to the radiation source" in the actual scenario;

[0056] To measure t The spatial coordinates of time, which are also the coordinates of the reference point and t Corresponding reference position coordinates;

[0057] The incident angle of the rays is the angle between the main radiation direction and the normal to the lead shielding layer.

[0058] This represents the difference in radiation path length from the reference point to the target point.

[0059] S3. Based on the calculated lead shielding layer thickness, a mechanism mounting cavity 31 is machined on the lead shield 3, such that the perpendicular distance between the tangent A of the cross section of the mechanism mounting cavity 31 and the intersection point D of the main radiation direction and the lead shield 3 is the calculated lead shielding layer thickness, and the tangent A is perpendicular to the main radiation direction, while the center of the mechanism mounting cavity 31 is located on the side of the tangent A away from the intersection point D of the main radiation direction and the lead shield 3.

[0060] S4. Install the camera mechanism 4 into the mechanism mounting cavity 31, and install the lead shield 3 into the housing 1. Install the reflector 2 on the inner top surface of the housing 1, with the mirror surface of the reflector 2 corresponding to the window 11. The camera mechanism 4 is located below the reflector 2 and simultaneously on the reflected light path of the reflector 2, thus completing the design of a gradient shielded camera based on the radiation direction gradient.

[0061] In summary, this invention not only solves the problems of excessive weight redundancy and poor optical path adaptability in existing technologies, but also improves the overall system performance through a series of innovative designs, possessing high practical value and technological advancement. These improvements are of great significance for enhancing the safety, efficiency, and economy of monitoring equipment in radiation environments.

[0062] The embodiments described above are merely illustrative of specific implementations of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A gradient shielding camera based on radiation direction gradient, characterized in that: comprising a shell (1), a mirror (2), a lead shielding body (3) and a camera core (4); the shell (1) is closed at both ends and hollow, a window (11) is arranged on the side wall near the upper end of the shell (1), and the mirror (2) is arranged on the inner top surface of the shell (1) and the mirror surface of the mirror (2) corresponds to the window (11); the lead shielding body (3) is arranged in the shell (1) and below the mirror (2), the lead shielding body (3) is a vertically arranged cylindrical structure, and a core mounting cavity (31) is arranged on the lead shielding body (3) in the vertical direction, the camera core (4) is mounted in the core mounting cavity (31), and the camera core (4) is located on the reflection light path of the mirror (2); the core mounting cavity (31) is arranged to satisfy: the vertical distance between the tangent A of the cross section of the core mounting cavity (31) and the intersection point D of the main radiation direction and the lead shielding body (3) is the thickness of the lead shielding layer, the tangent A is perpendicular to the main radiation direction, and the center of the core mounting cavity (31) is located on the side of the tangent A away from the intersection point D of the main radiation direction and the lead shielding body (3); the thickness of the lead shielding layer is calculated according to the following formula:

2. 2.The gradient shielding camera based on radiation direction gradient according to claim 1, characterized in that: the mirror (2) and the shell (1) are made of stainless steel. 3.The gradient shielding camera based on radiation direction gradient according to claim 2, characterized in that: a communication interface (12) is arranged on the side wall near the bottom of the shell (1), and the communication interface (12) is used for electrically connecting the control end of the camera core (4) and an external control unit. 4.The gradient shielding camera based on radiation direction gradient according to claim 3, characterized in that: a radiation-resistant glass is arranged on the window (11). 5.The gradient shielding camera based on radiation direction gradient according to claim 2, characterized in that: the shape of the mirror (2) is isosceles trapezoidal, the wide side is arranged near the inner top surface of the shell (1), and the narrow side is arranged near the lead shielding body (3). comprising the following steps: S1, establishing a radiation field vector model to determine the main radiation direction; exp ; wherein: is the thickness of the lead shielding layer, is the radiation dose rate at the reference point, is the mass attenuation coefficient of lead, is the density of lead, is the energy of the incident radiation, is the coordinate of the target shielding position, is the coordinate of the reference point, is the ray incidence angle, i.e. the angle between the main radiation direction and the normal to the lead shielding layer. S2, determining the radiation hot spot area by MCNP Monte Carlo simulation, optimizing the gradient distribution of the lead shielding layer by the finite element analysis method, calculating the thickness of the lead shielding layer according to the functional relationship between the thickness of the lead shielding layer and the radiation dose rate, and the thickness of the lead shielding layer is calculated according to the following formula: S3, according to the calculated thickness of the lead shielding layer, machining the core mounting cavity (31) on the lead shielding body (3), so that the vertical distance between the tangent A of the cross section of the core mounting cavity (31) and the intersection point D of the main radiation direction and the lead shielding body (3) is the calculated thickness of the lead shielding layer, the tangent A is perpendicular to the main radiation direction, and the center of the core mounting cavity (31) is located on the side of the tangent A away from the intersection point D of the main radiation direction and the lead shielding body (3). ​ ​ ​ ​ ​ ​ ​ 6. A method of fabricating a gradient shield camera based on the gradient of the direction of radiation according to any one of claims 1 to 5, characterized in that, ​ ​ ​ exp ; wherein: is the thickness of the lead shielding layer, is the radiation dose rate at the reference point, is the mass attenuation coefficient of lead, is the density of lead, is the energy of the incident radiation, is the coordinate of the target shielding position, is the coordinate of the reference point, is the ray incidence angle, i.e. the angle between the main radiation direction and the normal to the lead shielding layer; ​ S4, install the camera core (4) into the core installation cavity (31), and install the lead shielding body (3) into the shell (1), install the mirror (2) on the inner top surface of the shell (1) and the mirror surface of the mirror (2) corresponds to the window (11), the camera core (4) is below the mirror (2) and at the same time is on the reflected light path of the mirror (2), the production of the gradient shielding camera based on the radiation direction gradient is completed.

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