Low background experiment measuring device and low background experiment system

Abstract

The invention relates to the technical field of radiation experiment measurement equipment, in particular to a low background experiment measurement device and a low background experiment system. The low background experiment measuring device comprises a main shell, a plurality of shielding layers and a plurality of shielding layers, wherein the plurality of shielding layers are encircled in the main shell to form a background shielding space; the diaphragm is arranged on the main shell and is coaxial with a beam outlet of a radioactive source of the low-background experiment system, and the diaphragm is suitable for introducing an external radioactive source into a detection area in the background shielding space in a collimation manner and providing different low-range dose rates for the interior of the device by virtue of a plurality of radioactive sources; the three-dimensional positioning mechanism is installed in the background shielding space and is suitable for driving the instrument to be detected to move into the detection area. The device can actively shield a natural background, reduce the interference of the natural background on the measurement of a low-range instrument, improve the measurement precision of the instrument, and realize the reliable measurement of an ionizing radiation low-background experiment; the device also can accurately adjust the measurement position of the instrument to be measured, thereby improving the measurement efficiency, precision, operability and safety.

Description

Technical Field

[0001] This invention relates to the field of radiation experimental measurement equipment technology, and in particular to a low-background experimental measurement device and a low-background experimental system. Background Technology

[0002] Low-background measurement technology refers to a series of methods used to reduce or eliminate the background noise of detectors. It aims to improve the detection sensitivity of extremely weak radioactive signals and reduce interference from cosmic rays, building materials, and electronic noise. The core solutions still lie in the optimization of material selection, shielding design, environmental control, and signal processing. In recent years, low-background measurement technology has had important applications in aerospace, environmental monitoring, radiomedicine, and dark matter detection.

[0003] To meet increasingly stringent radiation safety standards and the need for trace radioactivity analysis, low background radiation monitoring instruments are being rapidly updated and iterated. However, because they rely on advancements in detector materials, innovations in shielding technology, and optimization of signal processing algorithms, the reliability of low-range monitoring instruments is difficult to verify. Summary of the Invention

[0004] This invention provides a low-background experimental measurement device and a low-background experimental system to address the shortcomings of existing technologies where the reliability of low-range monitoring instruments is difficult to verify. During the calibration and measurement of the instrument under test, it can effectively and actively shield the natural background, reduce the interference of the natural background on the measurement of low-range instruments, and thus achieve efficient and accurate low-background experimental measurement of ionizing radiation.

[0005] This invention provides a low-background experimental measurement device, comprising: a main housing including multiple shielding layers, the multiple shielding layers forming a background shielding space within the main housing; an aperture disposed on the main housing, the aperture being adapted to be coaxially arranged with the exit port of an external radiation source, capable of collimating the external radiation source into a detection area, the detection area being formed within the background shielding space; and a three-dimensional positioning mechanism installed within the background shielding space, the three-dimensional positioning mechanism being adapted to move the instrument under test into the detection area.

[0006] According to the present invention, a low-background experimental measurement device includes a three-dimensional positioning mechanism comprising a bottom platform, a longitudinal movement component, a lateral movement component, a lifting component, and several worktables. The bottom platform is disposed within the background shielding space, and each of the worktables is sequentially connected above the bottom platform, with a first mounting position suitable for placing the instrument under test on the uppermost worktable. The longitudinal movement component, the lateral movement component, and the lifting component are respectively connected to each of the worktables. The longitudinal movement component is adapted to drive the worktable to perform longitudinal movement; the lateral movement component is adapted to drive the worktable to perform lateral movement; and the lifting component is adapted to drive the worktable to perform lifting movement.

[0007] According to a low-background experimental measurement device provided by the present invention, the plurality of workbenches include a first platform, a second platform and a third platform placed horizontally above the bottom platform from bottom to top; the longitudinal moving component connects the bottom platform and the first platform, the lifting component connects the first platform and the second platform, the lateral moving component connects the second platform and the third platform, and the third platform is provided with the first mounting position.

[0008] According to a low-background experimental measurement device provided by the present invention, the longitudinal movement component includes: a longitudinal track laid longitudinally on a bottom platform; a longitudinal slider slidably mounted on the longitudinal track and connected to the bottom of a first platform; and a longitudinal lead screw pair installed on the bottom platform and connected to the first platform, wherein the longitudinal lead screw pair drives the first platform to move along the longitudinal track through lead screw engagement; the transverse movement component includes: a transverse track laid transversely on a second platform; a transverse slider slidably mounted on the transverse track and connected to the bottom of a third platform; and a transverse lead screw pair installed on the second platform and connected to the third platform, wherein the transverse lead screw pair drives the third platform to move along the transverse track through lead screw engagement.

[0009] According to a low-background experimental measurement device provided by the present invention, the three-dimensional positioning mechanism further includes a plurality of vertically arranged support rods, each of which is connected to the first platform and movably connected to the second platform; wherein, the plurality of support rods includes at least one pair of threaded rods and a plurality of guide rods, each pair of threaded rods being movably connected to both ends of a diagonal line of the second platform; all the guide rods being movably connected to the second platform and spaced apart around each pair of threaded rods; the lifting assembly includes: a lifting positioning nut, fixed in the mounting hole of the second platform, the lifting positioning nut being engaged and sleeved on the corresponding threaded rod; and a belt drive mechanism, respectively connected between each pair of threaded rods, the belt drive mechanism driving each pair of threaded rods to rotate synchronously and in linkage through belt drive.

[0010] According to the present invention, a low-background experimental measurement device is provided, wherein the multilayer shielding layer comprises, from the inside out, a PMMA layer, a copper layer, a cadmium layer, a lead layer and a tungsten steel layer; wherein the tungsten steel layer constitutes the main shell, or the tungsten steel layer is connected to the inner wall of the main shell.

[0011] According to the present invention, a low-background experimental measurement device is provided, wherein the aperture includes: a plurality of light-blocking rings, each of the light-blocking rings being concentrically arranged, and each of the light-blocking rings being nested layer by layer from the inside out according to the diameter, thereby forming a light aperture arranged in a conical shape from the inside out; the center of the light aperture is adapted to allow γ-rays emitted by an external radiation source standard device to pass through.

[0012] According to the present invention, a low-background experimental measurement device further includes: a support frame connected to the bottom of the main housing; and a leveling support connected to the support frame and the main housing.

[0013] The present invention also provides a low background experimental system, comprising: the low background experimental measurement device as described above; and a radiation source standard device, the beam outlet of which is arranged toward the aperture of the low background experimental measurement device.

[0014] According to the present invention, a low-background experimental system further includes: a slide rail; a first base disposed at one end of the slide rail, wherein the low-background experimental measuring device is mounted on the first base, and the aperture of the low-background experimental measuring device is disposed on the axis of the radiation source outlet of the radiation source standard device; a second movable base assembled on the slide rail and movable along the slide rail, the second movable base being located between the first base and the radiation source standard device; the second movable base is provided with a second mounting position suitable for placing the instrument under test, the second mounting position being suitable for being disposed between the aperture of the low-background experimental measuring device and the radiation source outlet of the radiation source standard device, and the instrument under test placed on the second mounting position being disposed on the axis of the radiation source outlet of the radiation source standard device.

[0015] The low-background experimental measurement device (hereinafter referred to as the "experimental measurement device" or "device") provided by this invention includes a main housing, an aperture, and a three-dimensional positioning mechanism. The main housing includes multiple shielding layers, which together form a background shielding space within the main housing. An aperture is disposed on the main housing and is adapted to be coaxially aligned with the exit port of an external radiation source, enabling the external radiation source to be collimated and introduced into the detection area. The detection area is formed within the background shielding space, thus allowing multiple radiation sources to provide different low-range dose rates within the device. Furthermore, the aperture also reliably shields the environmental background, thereby perfecting the multi-layer shielding structure of the main housing. The three-dimensional positioning mechanism is installed within the background shielding space and is adapted to move the instrument under test into the detection area. This experimental measurement device actively shields the natural background by using multiple shielding layers and an aperture, thereby creating a low-radiation background environment within the device's internal space.

[0016] Using this experimental measurement device to measure the instrument under test can reduce the interference of natural background radiation on the measurement of low-range instruments, improve the measurement accuracy of the instruments, and achieve reliable measurement of ionizing radiation low-background experiments. It ensures that the internal air kerma background of the low-background environment does not exceed 30 nGy / h, which meets the needs of most current environmental level monitoring instruments for low-range testing. Furthermore, by changing the radiation source or adjusting the parameters of the radiation source, multiple radiation sources and / or adjusting the parameters of the radiation source standard device can be selected to provide different low-range dose rates within the device, increasing the experimental measurement range and diversity. Moreover, this low-background experimental measurement device can precisely adjust the measurement position of the instrument under test through a three-dimensional positioning mechanism, improving the precision of position adjustment and enabling fine-tuning of the three-dimensional position of the instrument under test, thereby improving measurement efficiency, accuracy, operability, and safety.

[0017] The present invention also provides a low-background experimental system (hereinafter referred to as the "experimental system" or "system"), including the low-background experimental measurement device as described above, and a radiation source standard device. The beam outlet of the radiation source standard device is arranged facing the aperture of the low-background experimental measurement device described above. By setting the experimental measurement device described above, the experimental system possesses all the advantages of the experimental measurement device described above, and the same parts will not be described in detail here. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1This is a front view of the low-background experimental measurement device provided by the present invention.

[0020] Figure 2 yes Figure 1 A partially enlarged schematic diagram of the middle shielding layer.

[0021] Figure 3 This is a schematic diagram of the three-dimensional positioning mechanism and aperture provided by the present invention.

[0022] Figure 4 This is a rear view of the low-background experimental measurement device provided by the present invention.

[0023] Figure 5 This is a schematic diagram of the low-background experimental system provided by the present invention.

[0024] Figure label: 1. Aperture; 11. Light-blocking ring; 2. Three-dimensional positioning mechanism; 201. First threaded rod; 202. Second threaded rod; 203. First guide rod; 204. Second guide rod; 20. Bottom platform; 21. First platform; 22. Second platform; 23. Third platform; 241. Longitudinal track; 242. Longitudinal slider; 243. Longitudinal lead screw pair; 251. Transverse track; 252. Transverse slider; 253. Transverse lead screw pair; 261. Belt drive mechanism; 262. Lifting and positioning nut; 263. Lifting control handle; 3. Main housing; 31. Front door panel; 32. Rear panel; 33. Top panel; 34. Bottom panel; 35. Side panel; 4. Lock; 5. Leveling bracket; 6. Support frame; 7. Control box; 8. Shielding layer; 81. Tungsten steel layer; 82. Lead layer; 83. Cadmium layer; 84. Copper layer; 85. PMMA layer; 9. First mounting position; 90. Slide rail; 91. First base; 92. Second movable base; 93. Fixed base; 94. Second mounting position; 100. Experimental measuring device; 200. Radioactive source standard device; 300. Instrument to be tested. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention 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 invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0026] The following is combined Figures 1-5 The low-background experimental measurement device 100 of the present invention is described.

[0027] like Figure 1As shown, the experimental measurement device 100 of this embodiment includes: a main housing 3, an aperture 1, and a three-dimensional positioning mechanism 2. The main housing 3 includes multiple shielding layers 8, which together form a background shielding space within the main housing 3. Preferably, the multiple shielding layers 8 consist of at least two shielding layers 8. More preferably, the shielding materials of each shielding layer 8 are different. By setting multiple shielding layers 8, the experimental measurement device 100 can actively shield the natural background radiation, achieve the use of multiple materials to shield different external radiation sources, and shield the background radiation from the outer shielding layers 8 with the help of the inner shielding layers 8, thereby creating a low-radiation background environment within the device's internal space.

[0028] In the experimental measurement device 100 described in this embodiment, the aperture 1 is disposed on the main housing 3, preferably on the rear plate 32 of the main housing 3. The aperture 1 is adapted to be coaxially disposed with the exit port of the external radiation source, and can be coaxial with the exit port of the external radiation source to collimate the external radiation source into the detection area. The detection area is formed within the background shielding space, thereby providing different low-range dose rates to the device interior with the help of multiple radiation sources; and the aperture can also reliably shield the background environment, thereby improving the structure of the multi-layer shielding layer 8 of the main housing. Preferably, the aperture includes at least two shielding layers 8. The two shielding layers are preferably a tungsten steel layer 81 and a lead layer 82 from the outside to the inside. The three-dimensional positioning mechanism 2 is installed within the background shielding space, and the three-dimensional positioning mechanism 2 is adapted to move the instrument under test 300 into the detection area.

[0029] This experimental measurement device actively shields the natural background by using multiple shielding layers 8 and an aperture 1 to create a low-radiation background environment within the device's internal space. Using this experimental measurement device 100 to measure the instrument 300 under test reduces the interference of the natural background on low-range instrument measurements, improves instrument measurement accuracy, and enables reliable measurement of ionizing radiation with a low background. It ensures that the internal air kerma background of this low-radiation background environment does not exceed 30 nGy / h, meeting the low-range testing requirements of most current environmental level monitoring instruments.

[0030] In a preferred embodiment of the invention, a radiation source standard device 200 is disposed outside the experimental measuring device 100. This radiation source standard device 200 can emit gamma rays into the experimental measuring device 100. An aperture 1 acts as a collimator to receive and introduce the radiation source, and collimates the radiation source, ensuring that the radiation source can form a detection area within the background shielding space of the experimental measuring device 100. The aperture 1 also enhances the active shielding effect of the main housing 3, achieving more complete and effective shielding of the internal space environment of the device, thereby reducing the influence of the natural background on the experiment. Furthermore, this low-background experimental measuring device 100 can precisely adjust the measurement position of the instrument under test 300 through the three-dimensional positioning mechanism 2, improving the precision of position adjustment and enabling fine-tuning of the three-dimensional position of the instrument under test 300, thereby improving measurement efficiency, accuracy, operability, and safety.

[0031] Understandably, during the experiment, the experimental measuring device 100 described in this embodiment of the invention can place the instrument under test 300 in the detection area within the background shielding space, thereby reducing or even completely eliminating the adverse effects of the environmental background on the measurement data of the instrument under test 300; and can also use the aperture 1 of the experimental measuring device 100 as a collimator for the radiation source to measure the instrument under test 300 placed in the external detection area, greatly improving the practicality and applicability of the experimental measuring device 100.

[0032] It is understood that the external radioactive source referred to in the embodiments of the present invention is an important component of the radioactive source standard device 200 and is stored within the radioactive source standard device 200.

[0033] Understandably, during the experiment, the experimental measurement device 100 described in this embodiment of the invention can use multiple radiation sources to provide different low-range dose rates to the device by changing the radiation source or adjusting the parameters of the radiation source standard device 200, thereby increasing the experimental measurement range and diversity.

[0034] In some embodiments, such as Figure 1 and Figure 2 As shown, the multi-layer shielding layer 8 includes, from the inside out, a PMMA layer 85 (also known as an acrylic layer or plexiglass layer), a copper layer 84, a cadmium layer 83, a lead layer 82, and a tungsten carbide layer 81. The tungsten carbide layer 81 forms the main housing 3, or it is connected to the inner wall of the main housing 3. The tungsten carbide layer 81 improves the overall structural strength of the main housing 3.

[0035] In some specific embodiments, to improve detection efficiency and reduce natural background levels, the shielding layer 8 of the device described in this embodiment preferably uses a lead layer 82 as the main shielding material layer, with a thickness of 20 mm. The outer layer of the lead layer 82 is preferably made of a tungsten steel layer 81 as the supporting material layer, with a thickness of 100 mm. Inside the main shielding material layer, a cadmium layer 83, a high-purity oxygen-free copper layer 84, and an organic glass layer are sequentially lined, and nitrogen is filled as the protective gas inside the shielding layer 8. The thickness of each of the above-mentioned lining layers is 10 mm. This utilizes multiple materials to shield different external radiation sources and, through the multi-layered materials of the lining layers, shields against background effects from the outer materials, thereby creating a low-radiation-background environment inside the device. The entire device is sealed and shielded using low atomic number materials, and nitrogen is used as the protective gas inside the shielding layer 8 to further reduce the radiation background contribution of radon and its decay products.

[0036] In some embodiments, such as Figure 1 and Figure 3 As shown, the aperture 1 includes several light-blocking rings 11. Each light-blocking ring 11 is concentrically arranged, and the rings are nested layer by layer from the inside out according to their diameter, thus forming a conical aperture from the inside out. The center of the aperture is suitable for allowing gamma rays emitted by an external radiation source standard device 200 to pass through. In this embodiment, preferably, the aperture 1 is constructed by nesting five rings of different diameters as light-blocking rings 11. Each light-blocking ring 11 is preferably a tungsten alloy ring with a design thickness of 15 mm. Preferably, the distance between adjacent light-blocking rings 11 is 10 mm, and the inner diameter of each ring 11 is 120 mm to 380 mm, arranged from largest to smallest. This arrangement, with multiple nested light-blocking rings 11 forming a conical aperture, ensures that the center of the aperture is aligned with the center of the radiation source. This allows the device to function as a collimator, providing different dose rate ranges in conjunction with the radiation source, thus improving the accuracy and reliability of the device.

[0037] In some embodiments, such as Figure 1 and Figure 3 As shown, the three-dimensional positioning mechanism 2 includes a bottom platform 20 and several worktables. The bottom platform 20 is located within the base shielding space. Each worktable is sequentially connected above the bottom platform 20, and the uppermost worktable has a first mounting position 9 suitable for placing the instrument under test 300.

[0038] In some specific embodiments, such as Figure 1 and Figure 3As shown, the three-dimensional positioning mechanism 2 also includes a longitudinal movement component, a lateral movement component, and a lifting component. The longitudinal movement component, lateral movement component, and lifting component are respectively connected to each worktable. The longitudinal movement component is adapted to drive the corresponding worktable to perform longitudinal movement. The lateral movement component is adapted to drive the corresponding worktable to perform lateral movement. The lifting component is adapted to drive the worktable to perform lifting movement. Utilizing the combined synergistic effect of the longitudinal movement component, lateral movement component, and lifting component, the position of the first mounting position 9 can be efficiently and accurately adjusted, and fine-tuning in the three-dimensional direction can be achieved. Under the driving and adjustment action of the three-dimensional positioning mechanism 2, the first mounting position 9 can move accurately and efficiently within the aforementioned background shielding space until it is located in the detection area, ensuring that the radiation source introduced into the background shielding space can accurately act on the instrument 300 under test on the first mounting position 9, thereby improving experimental efficiency and accuracy.

[0039] It should be noted that the reference Figure 3 As shown, the three-dimensional direction of this embodiment of the invention is based on... Figure 3 As shown, a rectangular coordinate system is established with the direction perpendicular to the drawing as the X-axis. Here, "vertical" refers to... Figure 3 The direction shown is perpendicular to the drawing, that is, the front-to-back direction; "horizontal" refers to... Figure 3 The left and right directions are shown; "vertical" or "vertical" or "rising and falling" refers to the up and down directions as shown in the figure.

[0040] In some specific embodiments, such as Figure 3 As shown, a plurality of workbenches include a first platform 21, a second platform 22, and a third platform 23, which are positioned horizontally above the bottom platform 20 from bottom to top. Each workbench is preferably arranged parallel to the bottom platform 20 within the base shielding space. Driven by a longitudinal moving component, a lateral moving component, and a lifting component, each workbench performs longitudinal, lateral, and lifting movements, respectively, thereby achieving reliable movement of the first mounting position 9 within the base shielding space. Preferably, to improve structural reliability and safety and avoid interference between the workbenches during movement, the longitudinal moving component connects the bottom platform 20 and the first platform 21, the lifting component connects the first platform 21 and the second platform 22, and the lateral moving component connects the second platform 22 and the third platform 23, with the first mounting position 9 provided on the third platform 23.

[0041] In some specific embodiments, such as Figure 3 As shown, preferably, both the longitudinal and transverse movement components described above are driven by precision lead screws to achieve reliable displacement of the worktable. In this embodiment, as... Figure 1 and Figure 3As shown, the longitudinal movement assembly includes a longitudinal track 241, a longitudinal slider 242, and a longitudinal lead screw pair 243. The longitudinal track 241 is laid longitudinally on the bottom platform 20. The longitudinal slider 242 is slidably mounted on the longitudinal track 241 and connected to the bottom of the first platform 21. The longitudinal lead screw pair 243 is mounted on the bottom platform 20 and connected to the first platform 21. The longitudinal lead screw pair 243 drives the first platform 21 to move along the longitudinal track 241 through lead screw engagement. The longitudinal track 241 and the longitudinal slider 242, through sliding engagement, drive the first platform 21 to perform longitudinal movement under the driving action of the longitudinal lead screw pair 243, thereby reliably controlling the movement of the first platform 21 and effectively improving the precision of longitudinal stroke control. Preferably, limit switches are provided at both ends of the longitudinal track 241 to control the movement range of the first platform 21, improving control accuracy and safety.

[0042] Similarly, the lateral movement assembly includes a lateral track 251, a lateral slider 252, and a lateral lead screw pair 253. The lateral track 251 is laid laterally on the second platform 22; the lateral slider 252 is slidably mounted on the lateral track 251 and connected to the bottom of the third platform 23; the lateral lead screw pair 253 is mounted on the second platform 22 and connected to the third platform 23, driving the third platform 23 to move along the lateral track 251 through lead screw engagement. The lateral track 251 and the lateral slider 252, through sliding engagement, drive the third platform 23 to perform lateral movement under the driving action of the lateral lead screw pair 253, thereby reliably controlling the movement of the first platform 21 and effectively improving the precision of lateral stroke control. Preferably, limit switches are provided at both ends of the lateral track 251 to control the movement range of the first platform 21, improving control accuracy and safety.

[0043] In some embodiments, such as Figure 1 and Figure 3As shown, the three-dimensional positioning mechanism 2 also includes several vertically arranged support rods. Each support rod is connected to the first platform 21 and movably passes through and connects to the second platform 22. The support rods provide support between the various worktables and guide and limit the lifting of the corresponding worktables, thereby improving the reliability and accuracy of the lifting assembly driving the worktables to rise and fall. The aforementioned support rods include at least one pair of threaded rods and multiple guide rods. Each pair of threaded rods movably passes through both ends of a diagonal line of the second platform 22. The diagonally arranged threaded rods ensure the diagonal synchronous lifting of the second platform 22 during the lifting process, improving the levelness of the second platform 22 during movement, thereby increasing the smooth movement of the instrument under test 300 on the first mounting position 9 above and reducing experimental errors. Preferably, all guide rods movably pass through the second platform 22 and are spaced apart around each pair of threaded rods. The spaced distribution of the guide rods increases the accuracy of the support rods guiding the lifting of the second platform 22 and improves the stability of the lifting of the second platform 22.

[0044] In some specific embodiments, such as Figure 3 As shown, the preferred lifting assembly includes a lifting positioning nut 262 and a belt drive mechanism 261. The lifting positioning nut 262 is fixed in the mounting hole of the second platform 22. The lifting positioning nut 262 is engaged with the corresponding threaded rod, and the threaded rod rotates to engage with the lifting positioning nut 262, thereby driving the second platform 22 to lift. The belt drive mechanism 261 is connected between each pair of threaded rods, and drives each pair of threaded rods to rotate synchronously through belt drive. To ensure smooth and reliable lifting of the second platform 22, it is preferable to use one of the threaded rods as the driving rod and the other as the driven rod. The driving rod rotates and engages with the corresponding lifting positioning nut 262 to drive the lifting of one corner of the second platform 22, and transmits power to the other threaded rod through the belt drive mechanism 261, driving the driven rod to rotate and engage with the corresponding lifting positioning nut 262 to drive the lifting of the other corner of the second platform 22, thereby ensuring synchronous lifting of the diagonal parts of the second platform 22 and improving the smoothness and safety of lifting the second platform 22.

[0045] In this embodiment, preferably, a pair of threaded rods and a pair of guide rods are vertically fixed diagonally at the four corners of the first platform 21, i.e., as shown in the example Figure 3The diagram shows a first threaded rod 201, a second threaded rod 202, a first guide rod 203, and a second guide rod 204. The second platform 22 has four mounting holes at its four corners. A pair of diagonally opposite mounting holes are fitted with lifting and positioning nuts 262, while the remaining mounting holes are through holes. The first threaded rod 201 and the second threaded rod 202 respectively engage with and pass through a pair of lifting and positioning nuts 262, and are connected by a belt drive mechanism 261. The first guide rod 203 and the second guide rod 204 respectively pass vertically through the remaining corresponding mounting holes. The third platform 23 is positioned within the area enclosed by the aforementioned first threaded rod 201, second threaded rod 202, first guide rod 203, and second guide rod 204. This structure ensures reliable limiting and precise adjustment of the lifting and lowering movement of the second platform 22 with minimal structural support, and improves guiding accuracy and the connection support strength between the first platform 21 and the second platform 22.

[0046] It should be noted that, in order to drive the aforementioned longitudinal moving component, lateral moving component, and lifting component more efficiently, stably, and accurately, it is preferable to install control handles at corresponding positions on the longitudinal moving component, lateral moving component, and lifting component, for example... Figure 3 As shown, the lifting control handle 263 is installed at the connection between the second threaded rod 202 and the belt drive mechanism 261; alternatively, the longitudinal movement component, the lateral movement component, and the lifting component can be connected to the electric control drive mechanism to achieve automatic control.

[0047] It should be noted that, in order to improve the lifting accuracy and reliability of the second platform 22, it is preferable to install limit switches at the upper and lower ends of the first threaded rod 201 and the second threaded rod 202 respectively to control the stroke within the required range.

[0048] In some embodiments, such as Figure 1 and Figure 4 As shown, the main housing 3 of the device is preferably constructed as a rectangular box structure. That is, the main housing 3 includes a front panel 31, a rear panel 32, a top panel 33, a bottom panel 34, and side panels 35. The top panel 33 and the bottom panel 34 are positioned vertically opposite each other. The top panel 33 and the bottom panel 34 are connected by the side panels 35 and the rear panel 32. The front panel 31 and the rear panel 32 are respectively installed between a pair of side panels 35, one in front of the other. The aforementioned aperture 1 is installed on the panel of the rear panel 32, that is, the center of the rear panel 32 protrudes outward to accommodate the conical aperture 1. The front panel is installed on the front surface of the main housing 3 by means of hinges and latches 4. Preferably, the front panel 31 is directly constructed of a transparent PMMA layer 85 to allow for easy observation of the status of the instrument under test 300 inside.

[0049] In some specific embodiments, such as Figure 1 and Figure 4As shown, to improve the leveling controllability of the entire device, the experimental measuring device 100 also includes a support frame 6 and leveling supports 5. The support frame 6 is connected to the bottom of the main housing 3. The leveling supports 5 are connected to the support frame 6 and the main housing 3. The support frame 6 is mainly used to reliably support the main housing 3 and, together with the leveling supports 5, to achieve fine adjustments of the main housing 3 in the horizontal direction. Preferably, the lower surface of the base plate 34 of the main housing 3 is connected to the support frame 6 through four leveling supports 5, which are preferably cylinders, hydraulic cylinders, or spring structures. Preferably, a stepper motor is installed under the base and connected to the leveling supports 5. By using the height fine-tuning of the leveling supports 5, the overall levelness of the main housing 3 can be finely adjusted, reducing the measurement experimental error of the instrument 300 under test inside the main housing 3 and improving experimental accuracy.

[0050] In some specific embodiments, such as Figure 1 As shown, the experimental measuring device 100 also includes a control box 7. The control box 7 houses a wired control unit. The control box 7 is connected to the stepper motors of the aforementioned three-dimensional positioning mechanism 2 and the leveling support 5 via control lines, thereby achieving precise automatic adjustment of the positions of the three-dimensional positioning mechanism 2 and the leveling support 5, and improving the level of automation control of the device.

[0051] The low-background experimental system provided by the present invention is described below. The low-background experimental system described below can be referred to in correspondence with the low-background experimental measurement device 100 described above.

[0052] like Figure 5 As shown, the experimental system provided by the present invention includes the low-background experimental measurement device 100 and the radiation source standard device 200 as described above. The beam outlet of the radiation source standard device 200 is positioned facing the aperture 1 of the low-background experimental measurement device 100. By setting the experimental measurement device 100 described above, the experimental system possesses all the advantages of the experimental measurement device 100 described above, and the identical parts will not be described in detail here.

[0053] Understandably, the radiation source standard device 200 preferably stores one or more radiation sources. By adjusting the parameters of the radiation source standard device 200, different low-range dose rates can be provided within the device. Especially when the radiation source standard device 200 stores multiple radiation sources, different radiation sources can be selected and switched through the control system to provide different low-range dose rates within the device; alternatively, different attenuators can be selected as described above to reduce the dose rate of the radiation sources under the same distance conditions, thereby achieving different low-range dose rates within the device. Therefore, the radiation source standard device 200 can provide different low-range dose rates within the device by switching multiple radiation sources and / or adjusting the relevant parameters of the radiation source standard device 200.

[0054] In some embodiments, the experimental system further includes a slide rail 90, a first base 91, and a second movable base 92. The first base 91 is disposed at one end of the slide rail 90, and the aforementioned experimental measuring device 100 is mounted on the first base 91. The aperture 1 of the experimental measuring device 100 is disposed on the axis of the radiation source outlet of the radiation source standard device 200. Preferably, the radiation source standard device 200 is mounted on a fixed base 93, which is disposed at the other end of the slide rail 90. The second movable base 92 is fitted to the slide rail 90 and is movable along the slide rail 90. Furthermore, the second movable base 92 is located between the first base 91 and the radiation source standard device 200. The second movable base 92 is provided with a second mounting position 94 suitable for placing the instrument under test 300. The second mounting position 94 is suitable for being positioned between the aperture 1 of the low background experimental measurement device 100 and the radiation source outlet of the radiation source standard device 200, and can ensure that the instrument under test placed on the second mounting position 94 is positioned on the axis of the radiation source outlet of the radiation source standard device 200. This setting can add a measurement position outside the background shielding space in the experimental system, namely the second mounting position 94. By moving the second movable base 92 along the slide rail 90, the distance of the instrument under test 300 to receive the radiation source can be flexibly adjusted, and the experimental measurement device 100 can use the aperture 1 to collimate the external radiation source, increasing the measurement accuracy of the instrument under test 300. The addition of the second movable base 92 can not only realize the measurement based on the environmental background in the unshielded state, but also simultaneously use the first mounting position 9 and the second mounting position 94, using the same system to realize accurate measurement of the instrument under test 300 under different environmental background conditions, improving experimental efficiency and controllability.

[0055] The following is a detailed implementation process of measurement using the experimental measurement device 100 and experimental measurement system of this embodiment.

[0056] First, place the environmental level instrument under test 300 in the first mounting position 9 of the third platform 23 and fix it. Use the three-dimensional positioning mechanism 2 to adjust the position of each workbench to ensure that the center of the instrument under test 300 is consistent with the center of the aperture 1. Turn on the instrument under test 300 and close the device shielding door.

[0057] After confirming all the above steps, begin reading the instrument data. Select integration mode for data acquisition, set each acquisition time to 20 seconds, and perform 10 measurements per group. Read and record the cumulative dose data. Due to the influence of factors such as temperature and air pressure, the measurement data needs to be corrected, and the corrected average value is used as the measurement value for that point.

[0058] After the background data measurement is completed, irradiation is carried out sequentially using radiation sources with different activity levels, or different attenuators are selected using the same radiation source to change the dose rate inside the low background device, and the above experiment is repeated.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-background experimental measurement device, characterized by, The utility model relates to a kind of three-dimensional positioning mechanism for detecting instrument, including: Main shell, including multilayer shielding layer, multilayer The shielding layer is enclosed to form background shielding space inside the main shell; Diaphragm, set on the main shell, the diaphragm is adapted to be coaxially arranged with external radiation source beam port, can be introduced into detection area to the external radiation source collimation, the detection area is formed in the background shielding space; Three-dimensional positioning mechanism, installed in the background shielding space, the three-dimensional positioning mechanism is adapted to drive the instrument to be measured to move into the detection area.

2. The low-background experimental measurement device of claim 1, wherein, The three-dimensional positioning mechanism includes a bottom platform, a longitudinal moving assembly, a transverse moving assembly, a lifting assembly, and a plurality of workbenches. The bottom platform is disposed in the background shielding space, each workbench is sequentially connected above the bottom platform, and the first mounting position adapted to place the instrument to be measured is provided on the uppermost workbench. Wherein, the longitudinal moving assembly, the transverse moving assembly and the lifting assembly are respectively connected to each workbench. The longitudinal moving assembly is adapted to drive the workbench to perform longitudinal movement. The transverse moving assembly is adapted to drive the workbench to perform transverse movement. The lifting assembly is adapted to drive the workbench to perform lifting movement.

3. The low-background experimental measurement apparatus of claim 2, wherein The plurality of workbenches includes a first platform, a second platform and a third platform placed horizontally above the bottom platform from bottom to top; the longitudinal moving assembly connects the bottom platform and the first platform, the lifting assembly connects the first platform and the second platform, the transverse moving assembly connects the second platform and the third platform, and the first mounting position is provided on the third platform.

4. The low-background experimental measurement apparatus of claim 3, wherein The longitudinal moving assembly includes: A longitudinal rail is laid along the longitudinal direction on the bottom platform. A longitudinal sliding block is slidingly assembled on the longitudinal rail and connected to the bottom of the first platform. A longitudinal screw pair is installed on the bottom platform and connected to the first platform. The longitudinal screw pair drives the first platform to move along the longitudinal rail through screw engagement. The transverse moving assembly includes: A transverse rail is laid along the transverse direction on the second platform. A transverse sliding block is slidingly assembled on the transverse rail and connected to the bottom of the third platform. A transverse screw pair is installed on the second platform and connected to the third platform. The transverse screw pair drives the third platform to move along the transverse rail through screw engagement.

5. The low-background experimental measurement apparatus of claim 3, wherein The three-dimensional positioning mechanism further includes a plurality of vertical support rods, each support rod is connected to the first platform and movably passes through the second platform. Wherein, the plurality of support rods includes at least one pair of threaded rods and a plurality of guide rods. Each pair of threaded rods movably passes through one diagonal line of the second platform. All guide rods movably pass through the second platform and are distributed around each pair of threaded rods. The lifting assembly includes: A lifting positioning nut is fixed in the mounting hole of the second platform. The lifting positioning nut is engaged and sleeved outside the corresponding threaded rod. A belt transmission mechanism is connected between each pair of threaded rods. The belt transmission mechanism drives each pair of threaded rods to rotate synchronously through belt transmission.

6. The low-background experimental measurement apparatus of any one of claims 1-5, wherein, The multilayer shielding layer comprises, from inside to outside, a PMMA layer, a copper layer, a cadmium layer, a lead layer and a tungsten steel layer; The tungsten steel layer constitutes the main housing, or the tungsten steel layer is connected to the inner wall of the main housing.

7. The low-background experimental measurement apparatus of any one of claims 1-5, wherein, The diaphragm comprises: A plurality of light blocking rings, each of the light blocking rings is concentrically arranged, and each of the light blocking rings is arranged in layers from inside to outside according to the diameter size, thereby forming a light hole arranged in a conical shape from inside to outside; The center of the light hole is adapted for the gamma rays emitted by the external radiation source standard device to pass through.

8. The low-background experimental measurement apparatus of any one of claims 1-5, wherein, Further comprising: A support frame connected to the bottom of the main housing; A leveling support connected to the support frame and the main housing.

9. A low-background experimental system, characterized by, Comprise: The low-background experimental measurement device according to any one of claims 1-8; A radiation source standard device, the beam outlet of which is directed towards the diaphragm of the low-background experimental measurement device.

10. The low-background experimental system of claim 9, wherein, Further comprising: A slide rail; A first base provided at one end of the slide rail, the low-background experimental measurement device is installed on the first base, and the diaphragm of the low-background experimental measurement device is arranged on the axis of the radiation source beam outlet of the radiation source standard device; A second movable base assembled on the slide rail and movable along the slide rail, the second movable base is located between the first base and the radiation source standard device; A second installation position adapted for placing a to-be-measured instrument is arranged on the second movable base, the second installation position is adapted to be arranged between the diaphragm of the low-background experimental measurement device and the radiation source beam outlet of the radiation source standard device, and the to-be-measured instrument placed on the second installation position is arranged on the axis of the radiation source beam outlet of the radiation source standard device.

Images