Radioactive element shielding block and radioactive source positioning device adopting same
By using a spirally thickened shielding block and detector components arranged vertically in the radiation source positioning device, the problem of inaccurate radiation source positioning in the prior art is solved, and accurate positioning in different directions and safe fixation of the detector are achieved.
Patent Information
- Application Number
- CN202422920228.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-28
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2034-11-28
AI Technical Summary
Existing methods for locating radioactive sources rely on single detection results, which are not precise enough, and lack shielding blocks that can provide shielding of different thicknesses in different orientations, resulting in inaccurate determination of the radioactive source's orientation.
Design a radioactive element shielding block with a spiral shape in which the thickness of the outer surface and the inner wall of the mounting through hole increases uniformly. Combined with two detector assemblies set at the top and bottom, one of the detectors is equipped with the shielding block. By comparing the data of the two detectors, the radiation attenuation coefficient is calculated to determine the orientation of the radiation source.
It achieves precise positioning under different shielding thicknesses, improves the accuracy of radiation source location determination and detector safety, and reduces the impact of shaking during transportation.
Smart Images
Figure CN223624431U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of radiation detection, specifically to a radioactive element shielding block and a radioactive source positioning device using the shielding block. Background Technology
[0002] With the continuous development of the nuclear industry, the application of radioactive sources is becoming increasingly widespread. Leaks and thefts of radioactive sources are frequent, seriously threatening people's health and safety. Therefore, the rapid search and removal of scattered radioactive contaminants is of great practical significance. Currently, the search for radioactive sources is generally conducted by nuclear technology professionals carrying radiation detectors and relying on their experience, or by using vehicles equipped with detectors to conduct a thorough search of the target area. These methods are inefficient and, in severe cases, may endanger the safety of the operators.
[0003] Chinese Patent Application No. 2024103808269 discloses a method and apparatus for locating a radioactive source. The method involves: using a detection device to collect radiation intensity information from the surrounding environment; obtaining first position information of the detection device; controlling the horizontal rotation and pitch deflection of the detection device to collect the first radiation intensity information from the surrounding environment; generating a first radiation intensity map based on the first radiation intensity information; determining a first azimuth angle of the radioactive source relative to the detection device based on the first radiation intensity map; obtaining second position information when the detection device is in a second position; collecting second radiation intensity information from the surrounding environment; generating a second radiation intensity map based on the second radiation intensity information; determining a second azimuth angle of the radioactive source relative to the detection device based on the second radiation intensity map; and determining the position information of the radioactive source based on the first azimuth angle, the second azimuth angle, and the distance between the first and second positions. This detection method uses a single detection device to collect radiation intensities at different positions and then determines the position information of the radioactive source by comparing the distance between the two detected radiation intensities and the position information. Although this measurement method obtains the position of the radioactive source by integrating the two azimuth angle information, the method of determining the azimuth angle by detecting the radiation intensity once with a single detector for each of the two azimuth angle acquisitions is not precise.
[0004] According to the formula for calculating the detector count rate, the count rate *n* is inversely proportional to the square of the distance to the source. Determining the location of a radioactive source by observing changes in the count rate is one of the most fundamental methods in existing technology. Furthermore, the gamma rays generated by the radioactive source propagate in a straight line and have directionality. When the rays pass through materials with different shielding thicknesses, they exhibit varying degrees of attenuation. Based on this, a positioning device capable of rapidly locating lost or leaking radioactive sources is considered. This device would perform real-time detection and shielding attenuation detection of the radioactive source in the suspected area. After comparing the shielding attenuation detection results with the real-time detection results, the incident angle of the radioactive source can be determined based on the thickness of the shielding material at the gamma ray incident position, thus determining the orientation of the radioactive source. Therefore, it is essential to provide a positioning device and shielding block that can accommodate different shielding thicknesses at different orientations, is easy to fix with the detector, and can simultaneously achieve both conventional and shielding detection results. By comparing the two detection results, the thickness of the shielding material at the shielding attenuation point can be obtained, thus enabling precise positioning of the radioactive source. Summary of the Invention
[0005] To address the aforementioned shortcomings of existing technologies, the purpose of this utility model is to provide a radioactive element shielding block and a radioactive source positioning device using the shielding block. This solves the problem that existing technologies rely solely on the detection results collected by a single detection device to determine the location of the radioactive source, which is not precise enough. Furthermore, existing technologies lack shielding blocks capable of providing different thicknesses of shielding at different locations detected by the detector.
[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0007] A radioactive element shielding block includes a shielding block body with a mounting through-hole in the center. The thickness of the outer surface of the shielding block body and the inner wall of the mounting through-hole increases uniformly in a spiral shape. The shielding block body is made of lead, tungsten, or a tungsten alloy. This design, with the mounting through-hole in the center of the shielding block body, facilitates its connection with the detector end of a detector, allowing it to be fitted onto the detector end and shield it. The spiral shape of the shielding block, with its uniformly increasing thickness from the outer surface to the inner wall of the mounting hole, results in different thicknesses in each corresponding region. This ensures that the attenuation coefficient of corresponding gamma rays penetrating the shielding block varies, facilitating subsequent calculations to determine the incident direction of the rays.
[0008] A radiation source locating device includes a protective housing. Two detector assemblies and a main control panel are installed inside the housing. The two detector assemblies are arranged vertically with their detection ends adjacent. A radiation element shielding block is mounted at the detection end of one of the detector assemblies, as described above. The two detector assemblies are communicatively connected to the main control panel, enabling real-time transmission of detection data. The main control panel receives the detection data from the two detector assemblies, compares the two sets of data, calculates the proportional relationship, determines the incident angle of the radiation source, and then determines and outputs the location of the radiation source. Thus, the locating device contains two detector assemblies arranged vertically, with a shielding block of uniformly increasing thickness mounted at the detection end of one of the detector assemblies. The adjacent detection ends of the two detector assemblies ensure consistent response to the same radiation source during detection. The vertical arrangement ensures no horizontal overlap between the detection end and the shielding block, and the detected data represents the current radiation intensity, unaffected by the shielding block. One detector is fitted with a shielding block, while the other is assembled normally. The radiation intensity detected by the detector with the shielding block is the shielded radiation intensity, while the radiation intensity of the gamma rays detected by the other detector is the radiation intensity emitted by the current radiation source. After the main control panel receives the shielded radiation intensity and the current radiation intensity, it can compare and calculate the gamma ray attenuation coefficient based on the ratio between the shielded and current radiation intensities. Based on the attenuation coefficient, the thickness at the gamma ray incident point can be calculated. Because the thickness of the shielding blocks increases uniformly and their installation orientation is fixed, after calculating the thickness at the incident point, the precise orientation of the gamma ray incident point can be obtained based on the corresponding thickness of the shielding blocks, thus determining the orientation of the radiation source. The compact structure of the two detectors minimizes the overall footprint, and the consistent environmental and interference conditions for detecting the radiation intensity received from the same radiation source result in more accurate results. The protective casing protects the detectors and the main control panel, preventing damage during transport.
[0009] Furthermore, both detector assemblies consist of a LaBr3 detector and a multichannel module. The two detector assemblies are fixedly mounted within a protective housing via an assembly cylinder. Inside the assembly cylinder and on each detector assembly, a shock-absorbing sleeve is fitted for protective positioning of the detector assemblies. This allows the LaBr3 detector to achieve higher detection accuracy compared to traditional detectors, effectively improving detection precision. The multichannel module can accurately calculate the radiation intensity of gamma rays and transmit the data to the main control panel via wireless communication. The assembly cylinder facilitates the positioning of the two detector assemblies, while the shock-absorbing sleeve fills the space between the assembly cylinder and the protective housing, preventing the shielding block and detector assemblies from shaking during transportation, thus avoiding impact on measurement accuracy. Specifically, the shock-absorbing sleeve is made of flexible materials such as foam or rubber.
[0010] Furthermore, the protective shell is cylindrical, comprising an outer cylinder, a top cover, and a bottom cover. The top cover is fitted onto the upper end of the outer cylinder and sealed to it. The bottom cover is detachably installed at the lower end of the outer cylinder. A main chamber and a battery mounting chamber are provided within the outer cylinder. A battery box is fixedly installed within the battery mounting chamber, and multiple batteries are mounted on the battery box. The output terminals of the batteries are electrically connected to the two detector assemblies and the main control panel, supplying power to them. Thus, the outer cylinder, top cover, and bottom cover together form a sealed shell with an internal cavity. The main chamber of the outer cylinder is used to assemble the two detectors, the mounting cylinder, the shock-absorbing cylinder, and the main control panel, while the battery mounting chamber is primarily used to assemble the batteries, which supply power to the detector assemblies and the main control panel.
[0011] Furthermore, the top cover is equipped with a display screen, a buzzer, and buttons, and a handle is provided on the outside of the top cover. Both the buzzer and the display screen are communicatively connected to the main control panel and electrically connected to the battery. The display screen is used to show the detection results and the location of the radiation source. This placement of the top cover close to the main control panel facilitates the wiring and installation of the display screen, buzzer, and buttons with the main control panel. The output results of the main control panel can be directly displayed on the screen, and the buzzer activates when the radiation intensity exceeds a set threshold, emitting a beeping sound.
[0012] Furthermore, a fixing component is installed at both the upper and lower ends of the main chamber, and the fixing component has a positioning cylinder in the middle; a connecting cylinder is sleeved on the multichannel module of each of the two detector assemblies, and the connecting cylinder is sleeved and fixed on the corresponding positioning cylinder. In this way, both detectors are connected to the positioning cylinder on the fixing component, and the connecting cylinder on the multichannel module of the two detector assemblies can protect the multichannel module and can be sleeved and fixed with the positioning cylinder.
[0013] Furthermore, a partition is provided in the middle of the assembly cylinder, dividing it into an upper cylinder and a lower cylinder. An isolation sleeve with a shielding block assembly space in the middle is provided on the side of the partition facing either the upper or lower cylinder. The radioactive element shielding block is fitted within the shielding block assembly space of the isolation sleeve. Thus, with the partition in the middle of the assembly cylinder, two assembly spaces are created, each for assembling one of the detector components. The isolation sleeve in one of these spaces allows the shielding block to engage with it for positioning, preventing displacement during transportation and ensuring the accuracy of the main control panel's judgment. The assembly cylinder's space is adapted to the shape of the detector components, facilitating their positioning. Attached Figure Description
[0014] Figure 1 This is a three-dimensional structural diagram of the radioactive element shielding block in the embodiment;
[0015] Figure 2 This is an exploded view of the radiation source locating device in the embodiment;
[0016] Figure 3 This is a cross-sectional structural diagram of the radiation source positioning device in the embodiment. Detailed Implementation
[0017] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely represents selected embodiments of the utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.
[0018] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. In addition, the terms "horizontal," "vertical," etc., do not indicate that the component is required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0019] like Figures 1-3 As shown, the radiation source locating device provided in this embodiment includes a protective housing 1. Two detector assemblies 2 and a main control panel 7 are installed inside the protective housing 1. The two detector assemblies 2 are arranged vertically and their detection ends are adjacent. A radiation element shielding block 3 is assembled at the detection end of one of the detector assemblies 2. The radiation element shielding block 3 includes a shielding block body with a mounting through hole 31 in the middle. The thickness between the outer surface of the shielding block body and the inner wall of the mounting through hole 31 increases uniformly and is spiral-shaped. It is made of lead. The two detector assemblies 2 are communicatively connected to the main control panel 7 and can transmit detection data to the main control panel 7 in real time. The main control panel 7 is used to receive the detection data of the two detector assemblies 2, compare the two sets of detection data, calculate the proportional relationship, determine the incident angle of the radiation source, and then determine and output the location of the radiation source. In this way, the positioning device is equipped with two detector components 2, arranged vertically. One of the detector components 2 has a shielding block of uniformly increasing thickness mounted on its detection end. The adjacent detection ends of the two detector components 2 ensure consistent response to the same radiation source during detection. The vertical arrangement ensures no horizontal overlap between the detection end and the shielding block, and the detected data represents the current radiation intensity, unaffected by the shielding block. With one component shielded and the other normally assembled, the radiation intensity obtained by the detector with the shield is the shielded radiation intensity, while the radiation intensity of the gamma rays detected by the other detector is the radiation intensity of the current radiation source itself. After receiving the shielded radiation intensity and the current radiation intensity, the main control panel 7 compares and calculates the two data. Based on the ratio between the shielded radiation intensity and the current radiation intensity, it converts the gamma ray attenuation coefficient and calculates the thickness at the gamma ray incident position based on the attenuation coefficient. Because the thickness of the shielding blocks increases uniformly and their installation orientation is fixed, once the thickness at the incident position is calculated, the precise orientation of the incoming radiation can be obtained based on the corresponding thickness of the shielding blocks, thus determining the orientation of the radiation source. The compact design of the two detectors minimizes the overall footprint, and the consistent environment and interference for detecting the radiation intensity received from the same radiation source result in more accurate results. The protective housing 1 protects the detectors and the main control panel 7, preventing damage during transport.
[0020] In this embodiment, one detector is unshielded and can directly measure the radiation intensity at its location. The other detector is shielded by a radioactive element shielding block 3, and the measured radiation intensity is the attenuation after the rays pass through the shielding block. According to the ray attenuation formula, the attenuation coefficient of rays passing through a material is related to the type and thickness of the material. Since the lead shielding thickness increases uniformly, the lead thickness varies in each direction. Therefore, the measured values of the lead-shielded detector will differ for γ-rays incident from different directions. By comparing the measurement results of the two detectors and calculating the proportional relationship, the incident angle of the γ-rays can be determined, thereby identifying the location of the radiation source. The γ-ray attenuation formula is as follows: where N0 can be measured by the unshielded detector assembly 2, N can be measured by the detector assembly 2 with the shielding block, u is the linear attenuation coefficient of the γ-rays in the shielding block, and d is the shielding thickness of the shielding block at the incident point. Transforming the attenuation formula, we get: By experimentally measuring N and N0, the thickness d at the incident position of the γ-rays can be calculated. After calculating the thickness at the incident point of the radiation, the orientation corresponding to that incident thickness is determined based on the installation orientation of the radiation element shielding block 3. Specifically, a marking line (multiple marking lines or a single marking line) can be made on the top cover 12. The length of the marking line corresponds to the thickness at the installation position of the shielding block, thereby quickly determining the incident orientation of the radiation at the corresponding thickness. Alternatively, the thickest position of the shielding block can be set to 0 degrees, and the incident orientation of the radiation can be determined by the calculated thickness relative to the 0-degree orientation. Specifically, in this embodiment, the main control panel 7 is equipped with a data transmission module and a data processing module. The data transmission module is used to receive and output information, while the data processing module is used to calculate the shielding thickness at which the radiation enters based on the radiation attenuation formula, and determine the incident orientation.
[0021] Specifically, in this embodiment, the shielding block can also be made of tungsten or tungsten alloy. The protective shell 1 is made of high-strength nylon material, which has low density, strong corrosion resistance, and high strength. While ensuring strength, the weight of the instrument is reduced as much as possible to meet the requirements of portability. At the same time, this material has a small radiation shielding effect, which can minimize the influence of the material on the radiation intensity measurement and make the orientation measurement results more accurate.
[0022] like Figure 1As shown, both detector assemblies 2 consist of a LaBr3 detector 21 and a multichannel module 22. The two detector assemblies 2 are fixedly installed inside the protective housing 1 via an assembly cylinder 5. A shock-absorbing cylinder 4 is fitted inside the assembly cylinder 5 and on each detector assembly 2 for protective positioning. Compared to traditional detectors, the LaBr3 detector 21 has higher detection accuracy, effectively improving detection precision. The multichannel module 22 can accurately calculate the radiation intensity of gamma rays and transmit the data to the main control panel 7 via data cable or wireless communication. The assembly cylinder 5 facilitates the positioning of the two detector assemblies 2, while the shock-absorbing cylinder 4 fills the space between the assembly cylinder 5 and the protective housing, preventing the shielding block and detector assembly 2 from shaking during transportation and affecting measurement accuracy. Specifically, the shock-absorbing cylinder 4 is made of a flexible material, such as foam or rubber.
[0023] Furthermore, the protective outer shell 1 is cylindrical, comprising an outer cylinder 11, a top cover 12, and a bottom cover 13. The top cover 12 is fitted onto the upper end of the outer cylinder 11 and is sealed to the outer cylinder 11. The bottom cover 13 is detachably installed at the lower end of the outer cylinder 11. A main chamber 11a and a battery mounting chamber 11b are provided inside the outer cylinder 11. A battery box 10 is fixedly installed in the battery mounting chamber 11b, and multiple batteries 101 are mounted on the battery box 10. The output terminals of the batteries 101 are electrically connected to the two detector assemblies 2 and the main control panel 7, providing power to the two detector assemblies 2 and the main control panel 7. Thus, the outer cylinder 11, the top cover 12, and the bottom cover 13 together form a sealed shell with an internal cavity. The main chamber 11a of the outer cylinder 11 is used to assemble the two detectors, the assembly cylinder 5, the shock-absorbing cylinder 4, and the main control panel 7, while the battery mounting chamber 11b is mainly used to assemble the battery, which powers the detector assembly 2 and the main control panel 7. In this embodiment, the battery box 10 has multiple battery placement slots, and the batteries are rechargeable batteries. A charging port for connecting to the external wiring of the battery box 10 is provided on the protective shell 1. In specific implementations, the rechargeable batteries can be replaced with rechargeable batteries such as lithium batteries.
[0024] Furthermore, the top cover 12 is equipped with a display screen 8, a buzzer 9, and buttons, and a handle is provided on the outside of the top cover 12. Both the buzzer 9 and the display screen 8 are communicatively connected to the main control panel 7 and electrically connected to the battery. The display screen 8 is used to display the detection results and the location of the radiation source. Thus, the top cover 12 is positioned close to the main control panel 7, facilitating the wiring and installation of the display screen 8, buzzer 9, and buttons with the main control panel 7. The output results of the main control panel 7 can be directly displayed on the display screen 8, and the buzzer 9 activates and emits a beeping sound when the radiation intensity exceeds a set threshold. The buttons include a power button and up / down selection buttons.
[0025] Furthermore, a fixing member 6 is installed at both the upper and lower ends of the main chamber 11a (the fixing member 6 can be fixedly connected to the outer cylinder 11 by fasteners), and the fixing member 6 has a positioning cylinder 61 in the middle; a connecting cylinder 23 is sleeved on the multi-channel module 22 of the two detector assemblies 2, and the connecting cylinder 23 is sleeved and fixed on the corresponding positioning cylinder 61. In this way, both detectors can protect the multi-channel module 22 by connecting to the positioning cylinder 61 on the fixing member 6, and the connecting cylinder 23 on the multi-channel module 22 of the two detector assemblies 2 can be sleeved and fixed to the positioning cylinder 61.
[0026] Furthermore, a partition 51 is provided in the middle of the assembly cylinder 5, dividing the assembly cylinder 5 into an upper cylinder and a lower cylinder. An isolation sleeve 52 with a shielding block assembly space in the middle is provided on the side of the partition 51 facing the upper or lower cylinder. The radioactive element shielding block 3 is fitted into the shielding block assembly space of the isolation sleeve 52. Thus, with the partition 51 in the middle of the assembly cylinder 5, two assembly spaces are created, each for assembling one of the detector components 2. The isolation sleeve 52 in one of the assembly spaces allows the shielding block to cooperate with it for positioning, preventing displacement of the shielding block during transportation and ensuring the judgment result of the main control panel 7. The space provided by the assembly cylinder 5 is adapted to the shape of the detector component 2, facilitating the positioning of the detector component 2.
[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of this utility model that do not depart from the spirit and scope of this technical solution should be covered within the scope of the claims of this utility model.
Claims
1. A radioactive element shielding block, characterized in that, The shielding block body includes a central mounting through hole for engaging with the detector end of a detector. The thickness of the outer surface of the shielding block body and the inner wall of the mounting through hole increases uniformly, and the outer surface of the shielding block body is spiral-shaped.
2. The radioactive element shielding block according to claim 1, characterized in that, The shielding block body is made of lead, tungsten, or tungsten alloy, with a thickness between 2-20 mm.
3. A radiation source positioning device employing a radioactive element shielding block, comprising a protective outer shell, characterized in that, Two detector assemblies and a main control panel are installed inside the protective housing. The two detector assemblies are arranged vertically and their detection ends are adjacent. A radioactive element shielding block is installed at the detection end of one of the detector assemblies, as described in claim 1 or 2. The two detector assemblies are communicatively connected to the main control panel and can transmit detection data to the main control panel in real time. The main control panel receives the detection data from the two detector assemblies, compares the two sets of detection data, calculates the proportional relationship, determines the incident angle of the radioactive source, and then determines and outputs the location of the radioactive source.
4. The radioactive source positioning device using a radioactive element shielding block according to claim 3, characterized in that, Both detector assemblies consist of a LaBr3 detector and a multichannel module. The two detector assemblies are fixedly installed inside the protective housing by an assembly cylinder. A shock-absorbing cylinder for protecting and positioning the detector assemblies is fitted inside the assembly cylinder and on each detector assembly.
5. The radioactive source positioning device employing a radioactive element shielding block according to claim 3 or 4, characterized in that, The protective shell is cylindrical and includes an outer cylinder, a top cover, and a bottom cover. The top cover is fitted onto the upper end of the outer cylinder and is sealed to the outer cylinder. The bottom cover is detachably installed at the lower end of the outer cylinder. A main chamber and a battery mounting chamber are provided inside the outer cylinder. A battery box is fixedly installed in the battery mounting chamber, and multiple batteries are assembled on the battery box. The output terminals of the batteries are electrically connected to the two detector assemblies and the main control panel to supply power to the two detector assemblies and the main control panel.
6. The radioactive source positioning device using a radioactive element shielding block according to claim 5, characterized in that, The top cover is equipped with a display screen, a buzzer, and buttons, and a handle is provided on the outside of the top cover; the buzzer and the display screen are both communicatively connected to the main control panel and electrically connected to the battery; the display screen is used to display the detection results and the location of the radiation source.
7. The radioactive source positioning device using a radioactive element shielding block according to claim 6, characterized in that, A fixing component is installed at both the upper and lower ends of the main chamber, and a positioning cylinder is provided in the middle of the fixing component; a connecting cylinder is sleeved on the multi-channel module of the two detector components, and the connecting cylinder is sleeved and fixed on the corresponding positioning cylinder.
8. The radioactive source positioning device employing a radioactive element shielding block according to claim 3, 4, 6, or 7, characterized in that, A partition is provided in the middle of the assembly cylinder, which divides the assembly cylinder into an upper cylinder and a lower cylinder. An isolation sleeve with a shielding block assembly space in the middle is provided on the side of the partition facing the upper or lower cylinder. The radioactive element shielding block is fitted inside the shielding block assembly space of the isolation sleeve.