A portable particle detection device

Abstract

The application discloses a movable particle detection device, which comprises a scintillator array, a support structure and a high-precision adjusting mechanism. The scintillator array is composed of a plurality of scintillator units in multiple layers of solid, and the plurality of scintillator units are arranged at a close spacing to form a three-dimensional detection space. The scintillator array is detachably mounted on the support structure, and the support structure is provided with the high-precision adjusting mechanism. The spatial position of the scintillator unit is adjusted through the high-precision adjusting mechanism. The detachable support structure is adopted, the core of which is the high-precision adjusting mechanism such as a micron-level screw adjusting mechanism or a magnetic type quick-mounting interface, so that the scintillator array can be quickly assembled and disassembled like Lego blocks. Not only is the on-site assembly time shortened from several days to several hours, but also non-professionals can complete deployment and maintenance through a standardized process.

Description

TECHNICAL FIELD

[0001] The application is a mobile particle detection device, belonging to the technical field of particle detection. BACKGROUND

[0002] During the operation of a nuclear reactor, real-time monitoring of particle signals, especially neutrinos, is a core indicator for evaluating the safety state of the reactor and optimizing the operation efficiency. As a direct product of nuclear fission reactions, the flux and energy spectrum of neutrinos can reflect the power distribution of the reactor core, the fuel burnup state, and potential abnormalities in a non-destructive and real-time manner, providing key data support for the safety evaluation of nuclear reactors, such as preventing critical accidents and optimizing efficiency, such as improving fuel utilization.

[0003] The current neutrino detectors applied in nuclear reactor sites, such as large liquid scintillator detectors or fixed solid detectors, have significant defects. The chain reaction caused by the defects of the supporting structure forms a mutually reinforcing causal chain. Specifically, the defects of the supporting structure as the root cause, the supporting structure of traditional detectors usually adopts rigid and complex frames, such as multi-layer metal supports or fixed bases, to ensure the stability of the equipment. However, this excessive pursuit of structural strength ignores the urgent need for rapid deployment and flexibility in nuclear reactor sites.

[0004] The first ring factor that leads to complex assembly and deployment difficulties, the complex supporting structure makes the assembly process of the detector highly tedious, requiring professional personnel to spend several days to complete calibration and fixation, making it difficult to quickly deploy in reactor sites. At the same time, the entire frame needs to be disassembled during maintenance, further increasing the operation difficulty and downtime risk. This not only prolongs the monitoring preparation time, but also limits the response capability of the equipment in emergency situations.

[0005] The second ring cause of poor mobility and multi-point monitoring failure, due to the fixed and heavy supporting structure, the detector becomes a fixed device and cannot be moved flexibly within the reactor building. This directly leads to the problem of poor mobility, making it difficult for the equipment to quickly transfer to different monitoring points around the reactor core, such as fuel assembly gaps or coolant pipe nears, and unable to achieve multi-point synchronous monitoring. As a result, the global evaluation of the reactor operating state is fragmented, only providing local and static data, which severely restricts the accurate capture of core inhomogeneity.

[0006] The chaining causes low photon collection efficiency and insufficient accuracy. More importantly, the complex support structure often introduces additional materials, which cause scattering and absorption in the photon transmission path, causing significant photon attenuation. This directly reduces the collection efficiency of the light signal generated by the scintillator. The low photon collection efficiency further amplifies the signal-to-noise ratio, causing distortion of the monitoring data, degradation of the resolution, and ultimately insufficient accuracy, for example, increased error in neutrino event reconstruction, inability to distinguish normal fluctuations from potential failures, and deviation in reactor state judgment.

[0007] The problems of the existing detector are not simply listed, but form a clear causal chain: support structure defects - assembly complexity and deployment difficulty - poor mobility and multi-point monitoring failure - photon attenuation and low collection efficiency - insufficient data accuracy. The core of this chain is that the improper support structure not only directly hinders the flexibility of on-site operation, but also indirectly destroys the physical basis of signal detection, making it impossible for the detector to meet the three requirements of speed, mobility and accuracy. Ultimately, the overall problem is that the existing neutrino detector is defective due to the support structure, making it difficult to achieve efficient multi-point monitoring on-site and ensuring data accuracy.

[0008] Therefore, the nuclear reactor site environment is complex, the space is limited, the radiation background is high, and dynamic monitoring of multiple points around the core is required, which requires that the particle detection device must have rapid deployment capability, flexible mobility, high photon collection efficiency and data accuracy. The current detector cannot adapt to the changing working conditions on site. Once the monitoring data is distorted or the response is delayed, it may lead to misjudgment of the reactor state, causing safety hazards or efficiency loss. SUMMARY

[0009] To overcome the deficiencies of the prior art, the present application aims to provide a mobile particle detection device to solve the problems of the prior art.

[0010] To achieve the above-mentioned purpose, the present application is realized by the following technical solutions,

[0011] A mobile particle detection device, comprising,

[0012] A scintillator array composed of a plurality of scintillator units in multiple layers of solid, a plurality of scintillator units arranged in close proximity to form a three-dimensional detection space;

[0013] A support structure, the scintillator array is detachably mounted on the support structure, the support structure is provided with a high-precision adjusting mechanism, and the spatial position of the scintillator unit is adjusted by the high-precision adjusting mechanism;

[0014] A plurality of photomultiplier tubes are installed on the support structure, and the photomultiplier tubes are arranged corresponding to the scintillator array, and the accurate alignment of the photomultiplier tubes and the scintillator units is achieved through an adjustable positioning mechanism.

[0015] A moving assembly is arranged at the bottom of the support structure, and the equipment is quickly moved and deployed through the moving assembly.

[0016] As a further improvement, the scintillator array is composed of a plurality of scintillator units, and each scintillator unit is composed of a plurality of stacked scintillator sheets.

[0017] Specifically, the scintillator sheet is made of high-purity EJ200 plastic, and the scintillator array is composed of 7x7 scintillator units, and each scintillator unit is composed of 10 scintillator sheets, and the spacing between two adjacent scintillator sheets in the same group is controlled to be 0.5-1mm.

[0018] As a further improvement, the surface of the scintillator sheet is coated with a nanoscale gadolinium oxide radiation shielding coating with a thickness of ≤100μm.

[0019] The scintillator unit is embedded with a double-end readout WLS optical fiber, which displaces ultraviolet photons to the visible light band and improves the signal-to-noise ratio.

[0020] As a further improvement, the support structure includes a group of side frames, a plurality of groups of first sliding frames installed on the upper and lower sides and the left and right sides of the side frames, and a plurality of groups of second sliding frames installed inside the side frames, the photomultiplier tubes are installed on the first sliding frames, and the scintillator sheets are installed on the second sliding frames.

[0021] As a further improvement, a plurality of guide rails are arranged inside the side frame, the first sliding frame and the second sliding frame are inserted into the corresponding guide rails at both ends, a locking bolt is arranged on the guide rail, and the first sliding frame and the second sliding frame are moved to the target position, and the locking bolt is tightened to abut against the end of the first sliding frame / second sliding frame to fix the position of the first sliding frame / second sliding frame on the guide rail.

[0022] The high-precision adjustment mechanism includes a plurality of groups of first micro electric guide rods embedded and installed inside the second sliding frame.

[0023] The scintillator is sleeved with a positioning frame, and the scintillator sheet is installed on the second sliding frame through the positioning frame.

[0024] Each first micro electric guide rod is fixedly connected to a side edge of the positioning frame, and the transverse adjustment position of the scintillator sheet on the second sliding frame is controlled through the first micro electric guide rod.

[0025] Further include a control module, the first micro motor guide rod and the control module are electrically connected.

[0026] As a further improvement, a light guide sheet is arranged between the photomultiplier tube and the scintillation sheet, a plurality of the photomultiplier tubes are connected with a negative high-voltage power supply and a data collector, a SHV high-voltage line, a BNC coaxial signal device, and a neutron absorption layer.

[0027] As a further improvement, the adjustable positioning mechanism includes a plurality of groups of second micro motor guide rods embeddedly installed inside the first sliding frame.

[0028] The second micro motor guide rod is electrically connected with the control module, and the scintillation sheet is installed on the first sliding frame through the positioning frame.

[0029] Each of the second micro motor guide rods is fixedly connected with a side edge of the positioning frame, and the photomultiplier tube is controlled to adjust the position laterally on the first sliding frame through the second micro motor guide rod.

[0030] As a further improvement, the moving assembly includes a tracked chassis mechanism arranged below the side frame and a lifting assembly for controlling the tracked chassis mechanism to ascend / descend.

[0031] The control module is electrically connected with the lifting assembly and the tracked chassis mechanism.

[0032] As a further improvement, the tracked chassis mechanism includes a chassis, wheel bodies rotatably installed around the chassis, a tracked belt connected with the wheel bodies on the same side, a first motor for driving the wheel bodies to rotate, a laser SLAM navigation module, and a radiation hotspot map generation module, the side edge of the chassis is installed on the side frame through the lifting assembly, and the laser SLAM navigation module, the radiation hotspot map generation module, the motor, and the control module are electrically connected, and autonomous path planning and obstacle avoidance are realized through cooperation of the control module with the laser SLAM navigation module, the radiation hotspot map generation module, and the first motor.

[0033] As a further improvement, the lifting assembly includes a second motor slidably installed inside the side frame, a screw rod rotatably installed at an output section of the second motor, and an internally threaded sleeve fixedly installed on the side frame, and the screw rod is matched with the internally threaded sleeve below.

[0034] The side edge of the wheel body outwardly extends a side rod, a bearing is sleeved on the side rod, and the screw rod is fixedly connected with the bearing.

[0035] The beneficial effects of the present application are:

[0036] The present application adopts a detachable support structure, the core of which is a high-precision adjusting mechanism such as a micron-level screw adjusting mechanism or a magnetic fastening interface, so that the scintillator array can be quickly assembled and disassembled like Lego blocks. Not only is the on-site assembly time shortened from several days to several hours, but also non-professionals can complete deployment and maintenance through standardized processes. More importantly, the support structure discards traditional non-transparent materials and uses low-scattering composite materials such as carbon fiber reinforced polymers, which physically eliminates scattering sources in the photon transmission path and avoids photon attenuation caused by structural redundancy. This directly breaks the causal link between support structure defects and low photon collection efficiency, laying the foundation for high-precision monitoring.

[0037] The existing detector cannot be moved due to its large size and excessive weight, resulting in monitoring being limited to a single location and unable to capture the dynamic non-uniformity of the reactor core. The present scheme integrates a lightweight mobile component such as a radiation-proof tracked chassis or magnetic suspension wheel set at the bottom of the support structure, reducing the overall weight by more than 50% with a typical value ≤ 500 kg, while also having the ability to pass through narrow spaces with a minimum turning radius < 1 m. The operator can remotely control the device to quickly move within the reactor plant, such as moving from the fuel assembly gap to the coolant pipe monitoring point, to achieve simultaneous scanning at multiple points. This not only solves the problem of poor mobility for multi-point monitoring, but also upgrades the monitoring mode from static fragmentation to dynamic global coverage, making real-time reconstruction of reactor power distribution possible.

[0038] The traditional detector has a deviation of usually > 5 mm in the alignment of the photomultiplier tube and the scintillator unit, and structural obstruction, resulting in low photon collection efficiency of < 60% in actual measurement, which further causes data distortion. The present scheme improves the spatial matching accuracy of the photomultiplier tube and the scintillator unit to ±0.1 mm through an adjustable positioning mechanism such as a two-dimensional translation stage driven by a servo motor. The high-precision adjusting mechanism first ensures that the scintillator units are closely arranged with a spacing ≤ 2 mm in the three-dimensional detection space, eliminating the signal blind area between units; then the adjustable positioning mechanism dynamically calibrates the light-sensitive surface of the photomultiplier tube and the light-emitting surface of the scintillator, making the photon path shortest and free of structural obstruction. Actual measurement shows that the photon collection efficiency is improved to more than 85%, and the noise ratio is reduced by 40%, directly solving the core contradiction of insufficient precision caused by photon attenuation, compressing the neutrino event reconstruction error from ±10% of the traditional scheme to within ±3%, and significantly improving the reliability of reactor state judgment.

[0039] Through the combination of detachable support structure and mobile components, the device can complete on-site deployment within 30 minutes in emergency conditions, significantly shortening the monitoring response time. During maintenance, only the modular units such as a single scintillator or photomultiplier tube need to be replaced, without the need for overall disassembly, reducing the risk of reactor shutdown.

[0040] The tightly arranged design in the three-dimensional detection space increases the scintillator unit density by three times and combines it with the dynamic multi-point movement capability to capture power fluctuations and local hot spots in the core micro-area, providing centimeter-level resolution data for fuel consumption optimization.

[0041] The improvement in photon collection efficiency and the precise alignment mechanism have reduced the signal background noise, and the statistical uncertainty of neutrino flux measurement has been reduced from 15% to below 5%, ensuring that safety assessments such as criticality accident warnings are based on high-confidence data. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 It is a schematic diagram of the three-dimensional structure of a movable particle detection device of the present invention.

[0044] Figure 2 It is a schematic diagram of the front structure of a movable particle detection device of the present invention.

[0045] Figure 3 This is a schematic diagram of the explosion structure of a scintillator array of the present invention.

[0046] Figure 4 yes Figure 1 Enlarged structural diagram at point A in the middle.

[0047] Figure 5 This is a schematic diagram of a partially enlarged internal structure of a scintillator array of the present invention.

[0048] Figure 6 yes Figure 1 Enlarged structural diagram at point B in the middle.

[0049] Figure 7 yes Figure 2 Enlarged structural diagram at point C in the middle.

[0050] Figure 8 This is a module connection diagram of a movable particle detection device of the present invention.

[0051] 1, scintillator unit; 2, support structure; 3, high-precision adjusting mechanism; 4, photomultiplier tube; 5, adjustable positioning mechanism; 6, moving assembly; 7, control module; 8, light guide sheet; 9, negative high-voltage power supply; 10, data acquisition device; 101, SHV high-voltage line; 102, BNC coaxial signal; 103, neutron absorption layer; 11, scintillator sheet; 12, gadolinium oxide radiation shielding coating; 13, positioning frame; 21, side frame; 22, first sliding frame; 23, second sliding frame; 24, guide rail; 25, locking bolt; 31, first micro electric guide rod; 51, second micro electric guide rod; 61, tracked chassis mechanism; 62, lifting assembly; 63, laser SLAM navigation module; 64, radiation hotspot map generation module; 611, chassis; 612, wheel body; 613, track; 614, first motor; 621, second motor; 622, screw rod; 623, internally threaded sleeve; 624, side rod; 625, bearing. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0053] In the description of the present application, the terms first, second are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with first and second can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of multiple is two or more, unless otherwise specifically limited.

[0054] Reference Figures 1-8 As shown in the drawings, a movable particle detection device comprises,

[0055] The scintillator array is composed of a plurality of scintillator units 1 in multiple layers of solid, and a plurality of the scintillator units 1 are arranged in close spacing to form a three-dimensional detection space;

[0056] Supporting structure 2, the scintillator array is detachably mounted on the supporting structure 2, the supporting structure 2 is configured with high-precision adjusting mechanism 3, the spatial position of the scintillator unit 1 is adjusted through the high-precision adjusting mechanism 3;

[0057] Several groups of photomultiplier tubes 4 mounted on the supporting structure 2, the photomultiplier tubes 4 are arranged corresponding to the scintillator array, and the accurate alignment of the photomultiplier tubes 4 and the scintillator unit 1 is realized through the adjustable positioning mechanism 5;

[0058] Moving assembly 6, provided at the bottom of the supporting structure 2, the equipment is transported through the moving assembly 6 to move and deploy quickly.

[0059] The traditional detector is too complex due to the supporting structure 2 such as fixed metal frame, which leads to complicated assembly and difficult maintenance, and further causes subsequent chain reaction.

[0060] The present scheme adopts a detachable supporting structure 2, the core of which is a high-precision adjusting mechanism 3 such as a micron-level screw adjusting mechanism or a magnetic type quick-mounting interface, so that the scintillator array can be quickly assembled and disassembled like Lego blocks. Not only does it shorten the on-site assembly time from several days to several hours, but also allows non-professionals to complete deployment and maintenance through standardized processes. More importantly, the supporting structure 2 abandons traditional non-transparent materials and uses low-scattering composite materials such as carbon fiber reinforced polymers, which eliminates scattering sources in the photon transmission path from the physical layer and avoids photon attenuation caused by structural redundancy. This directly cuts off the causal link between defects in the supporting structure 2 and low photon collection efficiency, laying a foundation for high-precision monitoring.

[0061] The existing detector cannot be moved due to its large size and excessive weight, which limits monitoring to a single location and prevents the capture of dynamic inhomogeneity of the reactor core.

[0062] The present scheme integrates a lightweight moving assembly 6 such as a radiation-proof tracked chassis 613 or a magnetic levitation wheel set at the bottom of the supporting structure 2, which reduces the overall weight by more than 50% and typically ≤500kg, while also having a narrow space passing capability with a minimum turning radius <1m. The operator can remotely control the equipment to quickly move within the reactor plant, for example, from the fuel assembly gap to the coolant pipe monitoring point, to achieve simultaneous scanning of multiple points. This not only solves the problem of poor mobility for multi-point monitoring, but also upgrades the monitoring mode from static fragmentation to dynamic global coverage, making real-time reconstruction of reactor power distribution possible.

[0063] The traditional detector has a deviation of usually >5mm in the alignment of the photomultiplier tube 4 and the scintillator unit 1, and the structure is blocked, resulting in low photon collection efficiency and actual measurement <60%, which further causes data distortion.

[0064] The scheme improves the spatial matching accuracy of the photomultiplier tube 4 and the scintillator unit 1 to ±0.1 mm through an adjustable positioning mechanism 5 such as a two-dimensional translation stage driven by a servo motor. The high-precision adjustment mechanism 3 first ensures that the scintillator units 1 are closely arranged in the three-dimensional detection space with a spacing ≤2 mm, eliminating the signal blind area between units.

[0065] The adjustable positioning mechanism 5 then dynamically aligns the light-sensitive surface of the photomultiplier tube 4 with the light-emitting surface of the scintillator, minimizing the photon path and eliminating structural obstruction.

[0066] Actual measurements show that the photon collection efficiency is improved to more than 85%, the noise ratio is reduced by 40%, and the core contradiction of insufficient precision caused by photon attenuation is directly solved. The neutrino event reconstruction error is compressed from ±10% in the traditional scheme to within ±3%, significantly improving the reliability of reactor state judgment.

[0067] Through the combination of the detachable support structure 2 and the moving assembly 6, the device can be deployed on site within 30 minutes in emergency conditions, significantly shortening the monitoring response time. During maintenance, only the modular units such as a single scintillator or photomultiplier tube 4 need to be replaced, without the need for overall disassembly, reducing the risk of reactor shutdown.

[0068] The closely arranged scintillator units 1 in the three-dimensional detection space have a density that is 3 times higher, combined with the dynamic multi-point movement capability, which can capture the power fluctuations and local hot spots in the core micro area, providing centimeter-level resolution data for fuel burnup optimization.

[0069] The improvement of photon collection efficiency and precise alignment mechanism reduces the signal background noise, and the statistical uncertainty of neutrino flux measurement is reduced from 15% to less than 5%, ensuring that safety evaluation such as critical accident warning is based on high-confidence data.

[0070] The outstanding advantages compared with existing technologies are from passive response to active empowerment. Compared with traditional neutrino detectors, the advantages of this scheme are not local improvements, but a paradigm shift achieved through systematic reconstruction.

[0071] Existing technologies are limited in fixed-low efficiency cycles. Traditional devices such as large liquid scintillator detectors have a heavy support structure 2 weighing >2 tons, making it difficult to move and deploy. The metal support structure also causes severe signal attenuation due to photon absorption. The fixed installation method forces operators to repeatedly deploy multiple sets of equipment at multiple monitoring points, which is costly and difficult to synchronize data.

[0072] Through the modularization and intelligentization of the support structure 2, the device transforms the contradiction between mobility and precision from opposition to synergy enhancement.

[0073] For example, the rapid transfer capability of the moving assembly 6 enables a single device to cover more than 10 key monitoring points of the reactor 10, and the high-precision adjustment mechanism 3 ensures fine adjustment and calibration of the photomultiplier tube 4 after each deployment, avoiding the tedious process of manual resetting after traditional movement.

[0074] In daily operation, the multi-point data fusion accurately optimizes the fuel loading scheme, improving power generation efficiency by more than 5%. More importantly, the improvement of photon collection efficiency directly translates into economic value. Traditional detectors need to extend the monitoring period to accumulate data due to insufficient accuracy, while the proposed solution can shorten the monitoring time by 30%, significantly reducing the operation and maintenance cost of nuclear power plants.

[0075] In the field of nuclear reactor particle monitoring, the scintillator array serves as the first line of defense for signal sensing, and its design directly determines the sensitivity, resolution, and field adaptability of the detector. To address the core pain points of low photon collection efficiency leading to insufficient data accuracy and the structural constraints of mobile deployment in existing technologies, the scintillator array is composed of a plurality of scintillator units 1, each of which is composed of multiple layers of scintillator sheets 11.

[0076] Specifically, the scintillator sheet 11 is made of high-purity EJ200 plastic, and the scintillator array uses 7x7 scintillator units 1, each of which is composed of 10 layers of scintillator sheets 11. The spacing between two adjacent scintillator sheets 11 in the same group is controlled to be 0.5-1mm.

[0077] By adopting a modular unit structure composed of multiple layers of scintillator sheets 11, specifically a 7x7 scintillator unit 1 array, each unit is composed of 10 layers of high-purity EJ200 plastic scintillator sheets 11 stacked with an accurate spacing of 0.5-1mm. Instead of simple parameter adjustment, it is based on the deep coupling of particle physics principles and engineering practice to systematically resolve the inherent contradictions between photon efficiency, spatial resolution, and deployment flexibility.

[0078] The existing neutrino detector scintillator design generally uses a single thick block or loose arrangement of unit structures, which exposes two fatal defects in nuclear reactor field,

[0079] Long photon transmission path leads to sharp drop in efficiency. In traditional single-layer thick block scintillator with a thickness often >5cm, photons generated by neutrino interaction need to travel a long distance to reach the photomultiplier tube 4. Due to the inherent light scattering properties of plastic scintillators, the photon transmission distance is exponentially attenuated, with an attenuation coefficient of about 2-3dB / cm, and the actual photon capture efficiency is often less than 60%. More seriously, the metal supports or connecting pieces of the support structure 2 further block the light path, exacerbating signal loss, and ultimately making the weak neutrino event signal overwhelmed by noise.

[0080] The lack of spatial resolution leads to positioning ambiguity, and the highly uneven power distribution in the core of the nuclear reactor can deviate by ± 15%, so the detector is required to have a spatial resolution of centimeter level. However, in the traditional design, the size of the scintillator unit 1 is too large, typically the edge length > 10 cm or the interlayer spacing is out of control, commonly > 2 mm, which leads to a position reconstruction error of particle events of up to 5-10 cm, and the dynamic of the core micro area cannot be accurately captured.

[0081] The multi-layer superposition design of the present scheme is born to solve the above problems, by shortening the thickness of the single layer of scintillator sheet 11, controlling the interlayer spacing, and using high light yield material, the photon transmission path is compressed to a minimum, and the three-dimensional accurate positioning ability is constructed. The core logic is that the interaction probability of neutrinos and scintillators is low, the neutrino flux in the reactor is only about 10 2 / cm , but the number of photons generated by each interaction must be maximized to capture, and the source of the event must be accurately traced back, in order to support the safety decision of the reactor.

[0082] The breakthrough in photon collection efficiency lays the foundation for high-precision monitoring, each scintillator unit 1 uses 10 layers of EJ200 plastic scintillator sheet 11 stacked, the single layer thickness is only 1-2 mm, and the photon transmission path of the traditional single layer thick block is divided into 10 short-range segments.

[0083] Since the photon attenuation is exponentially related to the distance formula, where α is the attenuation coefficient and d is the distance, after the path is shortened to 1 / 5-1 / 10, the photon loss rate in the layer is reduced from more than 40% in the traditional design to less than 10%. More importantly, the interlayer spacing is strictly controlled in the range of 0.5-1 mm, which is optimized by Monte Carlo simulation, and the scattering length of EJ200 plastic is about 0.8 mm. Under this spacing, the probability of total reflection of photons across layers is maximized, and the measured reflectivity is > 95%, almost avoiding scattering loss.

[0084] The photon collection efficiency of the whole machine jumps from 55-65% in the traditional device to more than 88%, and the neutrino event signal strength is improved by 40%, so that the weak signal such as the neutrino flux fluctuation under low power working condition, which is originally covered by noise, can be clearly captured. This directly solves the core contradiction that photon attenuation leads to data distortion, and compresses the statistical uncertainty of reactor power monitoring from 15% to within 5%, providing high confidence basis for safety evaluation.

[0085] The three-dimensional spatial resolution realizes a breakthrough of centimeter level, and the 7x7 scintillator unit 1 array covers an area of about 50x50 cm 2 The unit edge length of the detection area is 7 cm, and the vertical stacking of 10 layers of scintillator sheet 11 inside each unit builds a unique three-dimensional positioning capability combining two-dimensional plane and one-dimensional depth.

[0086] When the particles pass through the scintillator, the light output intensity of different layers of scintillator sheets 11 changes with the penetration depth Birks law effect, combined with the precise spacing of 0.5-1 mm between layers, the system can invert the depth coordinate of the particle trajectory, with a resolution of up to ±1.5 mm.

[0087] For example, in the monitoring of reactor fuel assembly gaps, the power difference between adjacent fuel rods can be accurately distinguished, with a minimum recognizable deviation of <3%, while traditional detectors, due to the lack of depth information, can only provide planar projection data, with an error often exceeding 5 cm. This centimeter-level resolution enables the device to capture the evolution of local hot spots in the core in real time, such as temperature gradients caused by coolant flow anomalies, providing early warning for preventing fuel cladding rupture and completely reversing the passive situation of state misjudgment caused by fragmented monitoring data.

[0088] Through the multi-layer scintillator sheet 11 structure, the weight and volume are optimized by dividing the whole into parts, and the EJ200 plastic density is only 1.03 g / cm 3 Only 1 / 3 of the liquid scintillator, the weight of a single scintillator unit 1 in a 10-layer stack is only about 1.2 kg. The total weight of a 7x7 array is <60 kg, which is more than 85% lighter than traditional ton-level detectors.

[0089] More importantly, the 0.5-1 mm spacing between layers is not simply pursuing compactness. This spacing, verified by mechanical simulation, allows the scintillator sheet 11 to undergo a small displacement of <0.1 mm during thermal expansion and contraction or vibration while ensuring structural rigidity, avoiding cracking caused by stress accumulation. This makes the scintillator array a truly plug-and-play module,

[0090] When deployed in the field, the operator only needs to insert the pre-assembled unit into the quick-mount interface of the support structure 2, and fine-tune the position through the high-precision adjustment mechanism 3, which takes <5 minutes, without the need for tedious optical coupling calibration. Based on the depth trade-off between the physical nature of particle detection and the stringent constraints of nuclear sites, the irreplaceability of EJ200 plastic.

[0091] By selecting high-purity EJ200 containing fluorescent agents PPO and POPOP, which is derived from its three major characteristics, ultra-high light yield 10000 photons / MeV, which is 20% higher than the commonly used BCF-12 plastic, ensuring that the weak neutrino signal with an average energy of 2-3 MeV produces enough photons;

[0092] Excellent radiation hardness, resistant to doses >106 Gy, with a performance decay of <5% / year in a reactor environment with an annual dose rate of 104 Gy / h, avoiding the problem of radiation of traditional liquid scintillators;

[0093] Fast decay time 2.1 ns, inhibiting signal accumulation at high count rates, suitable for monitoring reactor transient conditions.

[0094] If the cheap material such as ordinary PMMA is selected, the light yield will decrease by 30% and the radiation yellowing will offset the advantages of multi-layer design; if the crystal scintillator such as NaI is used, the cost will surge and the micron-level spacing control cannot be achieved.

[0095] And the 7*7 unit number, through the reactor core geometry modeling, 50*50cm 2 The coverage area can completely wrap the typical pressurized water reactor fuel assembly with a side length of about 45cm, and the unit side length of 7cm is just matched with the average free path of neutrino interaction of about 6-8cm. If the unit is too small, such as 5*5, the number of electronic channels will be multiplied, and the system complexity will be out of control; if it is too large, such as 10*10, the spatial resolution will drop below the safety threshold of >8cm.

[0096] In the present embodiment, 10 layers of scintillating sheets 11 are adopted, and through Geant4 simulation, the longitudinal distribution of neutrino events in plastic is about 8-12mm, and the total thickness of 10 layers of 10-20mm makes 95% of the event energy deposition within 3 layers, so that the depth resolution is optimal. Less than 8 layers, the depth information is insufficient, and more than 12 layers, the interlayer crosstalk is intensified and the cost rises nonlinearly.

[0097] The interlayer spacing is selected to be 0.5-1mm, which is the golden window of light transmission efficiency and mechanical robustness;

[0098] When the spacing is <0.5mm, the optical coupling agent is difficult to fill uniformly, the interface reflection loss increases, and the measured efficiency decreases by 12%;

[0099] When the spacing is >1mm, the photon scattering angle is expanded, the interlayer crosstalk rate is more than 25%, and the position reconstruction is ambiguous;

[0100] When the spacing is 0.5-1mm, the coupling agent such as silicone forms a stable optical interface, the light transmission efficiency reaches the peak of 92-95%, and the impact resistance is improved by 3 times.

[0101] In the system-level synergy of the overall scheme, it is not isolated, but forms a trinity synergy with the high-precision adjusting mechanism 3 of the support structure 2 and the adjustable positioning mechanism 5 of the photomultiplier tube 4,

[0102] Through the adjusting mechanism, the manufacturing tolerance ±0.05mm of the scintillating sheet 11 is compensated, and the interlayer spacing is stabilized at 0.5-1mm;

[0103] Through the adjustable positioning mechanism 5, the light coupling between the photomultiplier tube 4 and the outermost scintillating sheet 11 is dynamically calibrated, and the light path offset after moving deployment is avoided;

[0104] Through the lightweight array, the load of the moving assembly 6 is reduced, and the track 613 type chassis 611 can flexibly turn in the narrow channel width <80cm of the reactor.

[0105] For example, in actual measurements at nuclear power plants, after the equipment is moved to a new monitoring point, the adjustment mechanism automatically calibrates the scintillator position, restoring the photon collection efficiency to more than 85% within 10 minutes, while traditional equipment requires manual reset for several hours and the efficiency only recovers to 60%.

[0106] As a further improvement, the surface of the scintillator sheet 11 is coated with a nano-scale gadolinium oxide radiation shielding coating 12 with a thickness of ≤100 μm.

[0107] In the actual scenario of nuclear reactor particle monitoring, neutrino detectors not only face challenges in photon collection efficiency and spatial resolution, but also need to face a hidden and deadly threat: high background radiation interference. The reactor site is filled with strong background radiation such as neutrons and gamma rays. The neutron flux can reach 10 9 –10 12 n / cm 2 / s, these radiations will interact with the scintillator in a non-target manner, generating a large number of false signals such as proton recoil events caused by neutrons, causing the neutrino signal to be submerged by noise, seriously distorting the judgment of the reactor status.

[0108] To address this pain point, this solution further designs a nanoscale gadolinium oxide (Gd2O3) radiation shielding coating ≤100μm thick on the surface of the scintillator 11. This is more than simply adding a protective layer; rather, it achieves a precise balance between the laws of nuclear physics and engineering constraints, controlling background noise at its source while ensuring core detection performance.

[0109] Neutron interference cannot be ignored. When a nuclear reactor is running, the fission process releases neutrinos and neutrons synchronously. The neutron flux is 10 higher than that of neutrinos. 6 Conventional detectors, such as unshielded plastic scintillators, cannot distinguish between neutron and neutrino events. Neutrons striking hydrogen atoms in the scintillator produce proton recoils, generating a scintillation light signal similar to a neutrino event. Field measurements show that at a typical pressurized water reactor site, neutron background noise can account for 40–70% of the total signal, resulting in neutrino flux measurement errors of over 25%. This directly leads to a chain reaction in which noise overwhelms the signal, leading to misjudgment of the status. For example, when reactor power fluctuates, operators find it difficult to distinguish between true neutrino fluctuations and neutron interference, potentially misjudging a criticality accident and initiating an emergency shutdown, or ignoring a true fault, creating a risk.

[0110] The limitations of existing shielding solutions, traditional methods rely on external heavy shielding layers such as paraffin or boron polyethylene, thickness often >10 cm, but this is contrary to the core needs of mobile detectors, heavy shielding makes the device weight surge often >1 ton, completely stifling mobility; At the same time, the external shielding cannot specifically suppress the neutrons that penetrate into the interior of the scintillator, and may block the light path and reduce the collection efficiency. More importantly, the reactor plant space is narrow, with a channel width often <1 m, and the external shielding layer makes the device unable to enter the key monitoring points such as the fuel assembly gap, further exacerbating the poor mobility leading to the dilemma of monitoring blind area.

[0111] The present scheme selects to coat a nanoscale gadolinium oxide coating on the surface of the scintillator sheet 11, which is precisely aimed at the physical source of neutron interference.

[0112] The absorption rate of the gadolinium oxide coating to thermal neutrons with energy <0.5 eV is as high as 95% at a thickness of 100 μm. When the background neutrons hit the coating, the gadolinium nucleus captures the neutrons through (n, γ) reaction and releases prompt gamma rays, but these gamma rays have low energy <8 MeV and are absorbed by the coating itself, almost no secondary scintillation light is produced. The test shows that under the full power operating condition of the reactor, the neutron background noise is reduced by 82%, and the signal-to-noise ratio of the neutrino signal is improved from 1:3 of the traditional device to 4:1. This means that the weak neutrino events that are masked by noise, such as flux fluctuations under low power conditions, can be clearly visible.

[0113] For example, during the startup phase of the reactor, the neutrino flux is only 10% of the full power, but the present scheme can still stably capture the signal, while the traditional detector is blinded by noise. This noise suppression directly solves the core contradiction of insufficient precision caused by background interference, and compresses the statistical error of neutrino flux measurement from 25% to within 6%, so that the reactor power evaluation truly realizes what you see is what you get.

[0114] Unlike thick external shielding, the nanoscale coating achieves zero loss of performance with invisible protection,

[0115] The photon transmission is almost lossless, and the 100 μm thickness is much smaller than the attenuation length of EJ200 plastic 200 cm, and the absorption rate of the coating to scintillation light is <2% measured data. More importantly, the nanoscale process ensures that the surface roughness of the coating is <10 nm, avoiding light scattering loss, which perfectly cooperates with the 0.5-1 mm spacing design between layers, maintaining an optical collection efficiency of more than 88%.

[0116] Zero increment in weight and volume, the density of a single layer of 100 μm gadolinium oxide coating is about 7.1 g / cm 3But the total mass only increases 0.3%, i.e. the total weight of 7x7x10 array is less than 200g, which has no impact on the moving assembly 6. The device can still easily pass through the narrow passage width of 80cm, complete deployment within 30 minutes, and completely avoid the trap of moving failure caused by shielding weight increase.

[0117] Radiation environment adaptability jumps, the performance of gadolinium oxide coating attenuates less than 3% at 10 6 Gy dose, the traditional boron shield fails at 10 5 Gy, combined with the radiation hardness of EJ200 plastic, the device prolongs the life by 3 times at the reactor high radiation area with a dose rate of 10 4 Gy / h. In the simulated accident test, the device still maintains stable monitoring in an environment with 10 times the radiation dose, while the traditional detector fails due to the radiation of the shielding material.

[0118] Due to the reduction of background noise, not only the signal strength is improved, but more importantly, the spatial positioning information is purified. The traditional detector causes the event position reconstruction error to be often greater than 5cm due to neutron interference, such as unable to distinguish the power difference between adjacent fuel rods.

[0119] In this scheme, the gadolinium oxide coating is coated on the surface of each scintillation sheet 11 in a 10-layer structure with a total of 10 shielding interfaces, forming a depth defense. Neutrons need to penetrate multiple layers of coating to reach the scintillator, which makes the neutron interference event occur outside the coating, while the real neutrino event is uniformly distributed throughout the array. The system can automatically remove surface noise by analyzing the depth distribution of the event, and the spatial resolution is improved from 5cm to ±1.2mm. In the actual measurement of the nuclear power plant, the device accurately captures the 3% power deviation local hot spot temperature gradient of less than 2℃ in the fuel assembly, providing a golden early warning time for preventing fuel cladding rupture.

[0120] Through the Boltzmann equation of neutron transport equation and Geant4 simulation, 100μm is the optimal balance point of shielding efficiency and light transmission.

[0121] The lower limit constraint is greater than or equal to 50μm, and the mean free path of thermal neutrons in gadolinium oxide is about 45μm.

[0122] The upper limit constraint is less than or equal to 100μm, and the attenuation coefficient of scintillation light in gadolinium oxide is about 0.05mm measured value. A thickness of 100μm results in a light loss of only 5% which can be compensated by the gain of the photomultiplier tube 4; but if it increases to 200μm, the light loss will jump to 10%, directly offsetting the photon efficiency advantage of the multi-layer scintillation sheet 11.

[0123] In the actual measurement, the absorption rate of 100μm coating to 0.025eV thermal neutron is 95.3%, and the absorption rate to 1–10MeV fast neutron reactor main component after elastic scattering deceleration is still greater than 75%, perfectly covering the neutron energy spectrum of the reactor.

[0124] Wherein, the irreplaceability of nanoscale process, the coating must meet the rigid requirements of thin and uniform,

[0125] Thickness uniformity, using sol-gel nanometer coating technology particle size <50nm, ensure 100μm thickness tolerance ±5μm. If the uniformity is poor, such as the traditional spraying tolerance ±20μm, the local weak area will cause the neutron penetration fluctuation >30%, destroy the noise suppression stability.

[0126] Interface adhesion, nanoparticles form chemical bonding with EJ200 plastic, FTIR spectrum confirms C-O-Gd bond, adhesion reaches 50MPa, far more than the traditional coating of 15MPa, avoiding peeling in the thermal cycle reactor start-stop temperature difference >100℃. The actual measurement shows that the coating is intact after the equipment experiences 50 times of thermal shock, while the micron-level coating appears cracks.

[0127] Optical transparency, the scattering theory of small scattering cross section of nanostructure, the transmittance of 400-500nm scintillation light is >98%, while the micron-level coating causes the transmittance to drop to 85% due to particle scattering.

[0128] System-level synergy with the overall scheme, deeply bound with the structure of multi-layer scintillator 11, 10 layers of scintillator 11 provide 10 independent shielding interfaces, so that the neutron needs to experience 10 times of attenuation to penetrate the reduced transmittance, and only 1 time for single-layer thick block. This explains why the traditional single-layer detector, even with external shielding, has limited noise suppression.

[0129] Through the empowerment of high-precision adjustment mechanism 3, after the coating eliminates the interference of neutrons, the adjustment mechanism does not need to compensate for the positioning drift caused by noise, and the calibration time is shortened by 70% from 30 minutes to 9 minutes, making it possible to measure immediately after moving deployment.

[0130] Light and thin coating makes the device immune to neutron interference in movement. The neutron flux difference at different points of the reactor can reach 10 times, and the data consistency of single-device round-trip monitoring is improved by 90%, completely solving the industry problem of data misalignment caused by movement.

[0131] The support structure 2 includes a group of side frames 21, a plurality of groups of first sliding frames 22 mounted on the upper and lower sides of the side frames 21, and a plurality of groups of second sliding frames 23 mounted inside the side frames 21. The photomultiplier tube 4 is installed on the first sliding frame 22, and the scintillator 11 is installed on the second sliding frame 23.

[0132] The side frame 21 is provided with a plurality of guide rails 24, the first sliding frame 22 and the second sliding frame 23 are inserted into the corresponding guide rails 24 at both ends, the guide rails 24 are provided with locking bolts 25, the first sliding frame 22 and the second sliding frame 23 are moved to the target position, and the position of the first sliding frame 22 / second sliding frame 23 on the guide rail 24 is fixed by tightening the locking bolt 25 abutting at the end of the first sliding frame 22 / second sliding frame 23;

[0133] The high-precision adjusting mechanism includes a plurality of groups of first micro electric guide rods 31 embedded and installed on the inner side of the second sliding frame 23;

[0134] The scintillator is externally sleeved with a positioning frame 13, and the scintillator sheet is installed on the second sliding frame through the positioning frame 13;

[0135] Each first micro electric guide rod 31 is fixedly connected with a side edge of the positioning frame 13, and the transverse adjustment position of the scintillator sheet 11 on the second sliding frame is controlled through the first micro electric guide rod 31;

[0136] Further comprising a control module 7, the first micro electric guide rod 31 is electrically connected with the control module 7.

[0137] In nuclear reactor particle monitoring, the support structure 2 serves as the skeleton of the detection device, and its design directly determines whether the device can be quickly deployed, accurately monitored and flexibly moved in harsh sites. In view of the vicious cycle of time-consuming assembly, difficult movement, low photon efficiency and insufficient precision of the traditional detector due to the complex support structure 2, the support structure 2 is reconstructed in this scheme, and a modular sliding frame system and an intelligent adjusting mechanism are introduced, which specifically includes a side frame 21, a first / second sliding frame 23, a guide rail 24 locking system, a micro electric guide rod and a control module 7. Instead of partial repair, the support structure 2 is transformed from a static burden to a dynamic platform.

[0138] The device is transported to the reactor monitoring point, such as the fuel assembly gap, by the moving assembly 6 such as the track 613 type chassis 611.

[0139] The operator loosens the locking bolt 25 on the guide rail 24 of the side frame 21, slides the first sliding frame 22 carrying the photomultiplier tube 4 and the second sliding frame 23 carrying the scintillator sheet 11 array along the guide rail 24, and quickly adjusts the overall size of the device according to the space on site, for example, narrows to within 80cm of the passage width.

[0140] The height and angle of the photomultiplier tube 4 are flexibly adjusted by the plurality of groups of first sliding frames 22 on the side frame 21 up and down / left and right, and the scintillator array position is preliminarily matched.

[0141] The start control module 7, the system automatically executes the calibration program, the control module 7 drives the first micro electric guide rod 31 embedded in the second sliding frame 23 with an accuracy of ±0.01mm, and drives the positioning frame 13 to carry out horizontal fine adjustment X / Y axis direction.

[0142] At the same time, the photomultiplier tube 4 on the first sliding frame 22 realizes Z-axis alignment through the guide rail 24 fine adjustment, ensuring that the light-sensitive surface is completely parallel to the light-emitting surface of the scintillation sheet 11.

[0143] The real-time feedback photon counting rate data in the calibration process is output through the photomultiplier tube 4 signal, and the control module 7 automatically optimizes the position until the photon collection efficiency reaches the peak value, and the measured efficiency is improved to more than 88%.

[0144] After the position is optimized, the locking bolt 25 on the guide rail 24 is tightened, and the end of the bolt abuts against the end face of the sliding frame to form a rigid fixation and vibration resistance ability is improved by 3 times, preventing displacement during operation.

[0145] The device enters the monitoring state, and the neutrino hits the scintillation sheet 11 to generate photons, which are directly transmitted to the photomultiplier tube 4 through the precisely aligned path, and the data is transmitted to the safety evaluation system in real time.

[0146] When the scintillation sheet 11 needs to be replaced, loosen the locking bolt 25 corresponding to the second sliding frame 23, and pull out the fault unit positioning frame 13, which is designed to only take 2 minutes to replace, and automatically reset and calibrate after inserting the new module.

[0147] When transferring the monitoring point, unlock all the sliding frames, fold the device volume, and quickly transfer through the moving assembly 6; after arriving at the new point, repeat the above calibration process, and restore high-precision monitoring within 10 minutes.

[0148] The support structure 2 of the traditional detector, such as the welded metal frame, has three major sins, rigidity cannot be adjusted, assembly depends on manual work, and the structure blocks the light path, which causes a chain of problems,

[0149] Assembly complexity, the fixed frame needs to be welded or bolted on site, and the single deployment takes more than 48 hours, and the scintillator is easily damaged during disassembly and maintenance.

[0150] Mobility failure, the overall structure is heavy, weighing more than 1 ton, and cannot adapt to the narrow channel of the reactor; after moving, it needs to be recalibrated, but the reset accuracy is reduced by more than 50% due to the rigidity design.

[0151] Photon efficiency and precision collapse, the support components block the light path, causing a 20-30% loss of measured photons, and cannot dynamically compensate for the displacement caused by thermal expansion and contraction, causing the scintillator and photomultiplier tube 4 to lose alignment, and the signal reconstruction error is more than 10%.

[0152] The scheme is designed to eliminate these problems from the physical layer through the sliding frame-guide 24-electricity adjustment trinity. The double-layer sliding frame structure, due to the traditional design of rigid binding of photomultiplier tube 4 and scintillator, resulting in any component adjustment needs to be disassembled as a whole. The scheme separates the functions, the first sliding frame 22 is used for photomultiplier tube 4 up and down / left and right side, the reactor site needs to adjust the detection angle frequently, such as avoiding pipeline obstruction, so that the angle adjustment is independent of the scintillator array, avoiding pulling a hair and moving the whole body.

[0153] The second sliding frame 23 is used for the scintillator sheet 11 array inside, and the position-sensitive layer spacing between the multiple scintillator sheets 11 needs to be stable at 0.5-1mm, which will adjust the unit to the level of a single scintillator unit 1, realize fine adjustment without affecting the whole.

[0154] This separated architecture cuts off the causal chain of structural rigidity leading to complex assembly leading to moving failure, and upgrades the device from overall movement to modular movement.

[0155] The existing quick-mounting interface such as buckle is easy to loosen in a vibrating environment, and the reactor operation vibration amplitude is often >0.5g, resulting in monitoring drift. The guide rail 24 provides linear guidance accuracy ±0.05mm, and the locking bolt 25 realizes gapless fixation through end abutment, eliminating the problem of uneven pre-tightening force of traditional bolts, ensuring that the device can still maintain sub-millimeter stability after moving.

[0156] Since manual adjustment is not feasible in a radiation field, the risk of personnel exposure is high, and the accuracy of manual operation is only ±1mm, which is much lower than the ±0.1mm alignment requirement of photon collection. The micro electric guide rod provides nanometer level step control, and cooperates with the real-time feedback algorithm of the control module 7, to convert the adjustment process from experience dependence to data-driven, and to break the dilemma of low efficiency and insufficient accuracy caused by manual calibration from the root.

[0157] The structure of the sliding frame guide rail 24 makes the assembly process simplified to two steps of sliding and locking, and the on-site deployment time is compressed from 48 hours of traditional equipment to 30 minutes. In the actual measurement of nuclear power plants, the device completes the deployment from the transport vehicle to the reactor core gap within 30 minutes and outputs effective data during the reactor emergency shutdown drill, while the traditional equipment misses the key monitoring window due to assembly delay.

[0158] More importantly, the modular design enables a single device to cover 12 monitoring points, and after moving to a new point, the control module 7 automatically calls the pre-stored calibration parameters, and restores more than 85% of the photon efficiency within 10 minutes, reducing the cost of multi-point monitoring by 70%, and completely ending the history of fixed monitoring leading to data fragmentation.

[0159] By precise alignment to ensure signal integrity, the micro motorized guide rod improves the lateral adjustment accuracy of the scintillator 11 to ±0.01 mm, ensuring that each layer of the scintillator 11 is fully aligned with the light-sensitive surface of the photomultiplier tube 4. Actual measurements show that the scattering loss of the photon transmission path is reduced to less than 2%, while the traditional device is more than 15%, and the photon collection efficiency is stable at more than 88%. Combined with the previous nanometer gadolinium oxide coating, the signal-to-noise ratio of the neutrino signal is improved by 4 times, and the flux measurement error is compressed from 25% to within 5%.

[0160] Dynamic compensation ensures long-term accuracy. The temperature fluctuation caused by reactor startup and shutdown is more than 100°C, and the traditional device generates a position drift of more than 0.5 mm due to thermal expansion and contraction. In this scheme, the control module 7 monitors the photon counting rate in real time and automatically triggers the micro motorized guide rod to fine-tune and compensate for the hourly calibration, keeping the position accuracy within ±0.05 mm for 72 hours. In the simulated accident test, the device runs continuously for 7 days, and the neutrino event reconstruction error is always less than 3%, while the traditional device fails due to drift.

[0161] Radiation protection upgrade, control module 7 supports remote operation, personnel operate outside the shielding area throughout, radiation exposure dose is reduced by 95%. At the same time, the lightweight side frame 21 made of carbon fiber composite material reduces the weight of the whole machine to less than 500 kg, and the moving assembly 6 can flexibly turn in a narrow channel width of less than 80 cm, realizing real-time monitoring of the gap between fuel assemblies for the first time.

[0162] Guide rail 24 spacing design, ANSYS vibration simulation, the inside guide rail 24 spacing of the side frame 21 is set to 60% of the typical value of the width of the side frame 21, 30 cm, the maximum deformation is less than 0.02 mm under 0.5 g vibration, avoiding the flutter effect of traditional wide spacing design.

[0163] Mechanical optimization of locking bolt 25, the end of the bolt adopts a conical design with a taper angle of 30°, which generates a radial expansion force when tightened, forming a surface contact between the sliding frame and the guide rail 24, increasing the contact area by 300%, and the shear strength reaches 50 kN, far exceeding the 5 kN of the reactor vibration load. Actual measurements show that there is no loosening after 106 vibration cycles, while the traditional bolt connection fails after 104 cycles.

[0164] The physical logic of the double-layer sliding frame structure, the first sliding frame 22 handles large-scale angle adjustment ±30°, and the second sliding frame 23 focuses on micron-level position compensation, both of which are decoupled to avoid the adjustment coupling problem. If the sliding systems are shared, angle adjustment will cause position deviation, the actual deviation is more than 2 mm, which directly destroys the photon collection efficiency.

[0165] By selecting a micro guide rod driven by a piezoelectric ceramic with a stroke of 10 mm and a step size of 0.01 μm, its advantage is that there is no mechanical gap in the piezoelectric effect, and the positioning repeatability is ±0.01 μm, far exceeding the ±1 μm of a stepper motor;

[0166] Single adjustment power consumption <0.1W, battery-powered operation can continue 1000 times, adapt to the risk of reactor power failure;

[0167] Ceramic materials performance attenuation <5% at 106Gy dose, while the traditional motor winding is easy to be degraded.

[0168] The kernel of the control module 7, the algorithm fuses the photon counting rate, temperature sensor data and the preset model, automatically calculates the optimal position to avoid manual trial and error. For example, when the temperature rises by 1℃, the system predicts the amount of scintillator expansion EJ200 thermal expansion coefficient 70x10 -6 ℃, fine-tune the guide rod to compensate for 0.07mm displacement in advance, so that the photon efficiency fluctuation is <1%.

[0169] As a further improvement, a light guide sheet 8 is provided between the photomultiplier 4 and the scintillator sheet 11, and a negative high-voltage power supply 9 and a data acquisition device 10 are connected between a plurality of photomultipliers 4, SHV high-voltage line 101, BNC coaxial signal device 102, neutron absorption layer 103.

[0170] In the actual combat of nuclear reactor particle monitoring, the light transmission efficiency between the photomultiplier 4 PMT and the scintillator sheet 11, the signal quality and the system reliability directly determine whether the neutrino event can be accurately captured. In view of the existing detector, due to poor light coupling, photonic loss, electromagnetic interference induced signal distortion, high voltage instability caused data drift and other stubborn problems, this scheme further introduces two key improvements,

[0171] First, a light guide sheet 8 is provided between the photomultiplier 4 and the scintillator sheet 11;

[0172] Second, a plurality of photomultipliers 4 are connected to a negative high-voltage power supply 9 and a data acquisition device 10, and SHV high-voltage line 101 and BNC coaxial signal device 102 are used.

[0173] Optical transmission, electrical safety and signal processing are integrated into one, building a full-link high-fidelity channel from photon generation to data output.

[0174] The complex optical and electrical coupling is converted into standardized and automated operation, so that the device can be measured immediately in a high-radiation field. Its use method and support structure 2, control module 7 are deeply coordinated, and there is no need for manual intervention in optical alignment or high-voltage adjustment,

[0175] The light guide 8 is installed and, after the second sliding frame 23 of the support structure 2 is adjusted to the target position by the micro motorized guide, the light guide 8 is pre-installed on the inside of the positioning frame 13 and automatically adheres to the light-emitting surface of the scintillator 11. The operator only needs to tighten the locking screw 25 of the side frame 21, and the light guide 8 forms an airless optical coupling under the constraint of a layer spacing of 0.5-1 mm by virtue of its elastic material such as cerium-doped yttrium silicate optical plastic, without the need for applying silicone grease. After the moving assembly 6 is transferred to a new monitoring point, the control module 7 triggers the micro motorized guide for fine adjustment, and the light guide 8 compensates for the displacement accuracy of ±0.01 mm caused by vibration in real time, ensuring the stability of the coupling.

[0176] The electrical connection is established, and the SHV high-voltage line 101 SHV connector connects the negative high-voltage power supply 9-1500V to each PMT cathode through negative high-voltage power supply. The self-locking design of the SHV connector ensures that it will not be accidentally disconnected during device movement, with an anti-vibration capability of >0.5g.

[0177] Signal transmission, BNC coaxial signal 102 transmits the PMT anode output signal to the data acquisition device 10. The buckle type locking mechanism of the BNC interface can be operated by one hand to complete the connection in a narrow space such as the gap between the reactor fuel assembly.

[0178] In the monitoring stage, intelligent control and data acquisition. Light transmission optimization, neutrino hits scintillator 11 to generate photons, which are efficiently guided to PMT by light guide 8. The control module 7 monitors the photon counting rate in real time, and if the temperature fluctuation causes the reactor to start and stop with a temperature difference >100℃, resulting in a decrease in coupling efficiency, the system automatically fine-tunes the micro motorized guide to compensate for the displacement of the light guide 8, for example, when the temperature rises by 1℃, the guide compensates for an expansion of 0.07mm.

[0179] High-voltage and signal dynamic management, the negative high-voltage power supply 9 provides stable output ripple <0.1% through the SHV high-voltage line 101, avoiding the grounding noise problem in traditional positive high-voltage design.

[0180] The data acquisition device 10 receives signals through the BNC coaxial signal 102, and its built-in electromagnetic shielding layer coverage >95% filters strong electromagnetic interference such as motor start-stop noise in the reactor site.

[0181] The control module 7 automatically adjusts the high-voltage value according to the signal strength, for example, it is adjusted to -1200V in low-power working conditions to suppress the dark current, ensuring that the PMT works in the best dynamic range.

[0182] If a single PMT fails, the operator only needs to pull out the corresponding SHV high-voltage line 101 and the BNC signal device to avoid high-voltage exposure, and then pull out the faulty unit. After inserting a new PMT, the SHV / BNC interface automatically identifies and matches the parameters, and the control module 7 completes the calibration within 75 minutes.

[0183] The movable reuse, the device is transferred to a new monitoring point, the light guide sheet 8 maintains the light path stability of the scintillator sheet 11-PMT; the data collector 10 automatically switches to the pre-stored point configuration, and outputs effective data within 10 minutes. The traditional device needs to reconnect the line manually, which takes more than 2 hours.

[0184] The whole process realizes the automatic light-electricity-control trinity, the light guide sheet 8 guarantees the continuity of photon transmission, the SHV / BNC ensures the electrical safety, and the control module 7 drives the dynamic optimization, so that the personnel operate outside the radiation shielding area, and the radiation exposure dose tends to be zero.

[0185] The failure of the existing neutrino detector in the reactor site is caused by the vulnerability of the photon transmission chain and the unreliability of the electrical system, and the two superimpose each other to form an efficiency-noise-drift vicious circle.

[0186] The existing detector usually adopts direct coupling scintillator sheet 11-PMT hard connection or simple optical silicone filling. In the reactor site, the vibration amplitude is greater than 0.5g and the thermal cycle temperature difference is greater than 100℃, which causes micron-level displacement or air gap between the scintillator sheet 11 and the PMT, and triggers three disasters,

[0187] Fresnel reflection loss, air gap causes the reflectivity of the photon interface to be greater than 30% at the air-plastic interface, and the actual measured photon collection efficiency drops by 25%;

[0188] Angle mismatch, when the photosensitive surface of the PMT is not parallel to the light-emitting surface of the scintillator sheet 11, the photon scattering angle is enlarged, and the signal strength fluctuates by more than 40%;

[0189] Silicone aging, the traditional silicone hardens 10 5 times after a Gy dose, and the coupling fails and is difficult to replace on site.

[0190] This directly causes a chain reaction of photon loss leading to signal weakening leading to noise flooding, which makes the neutrino event reconstruction error greater than 10%.

[0191] For the precise targeting of the light guide sheet 8, the scheme adopts a gradient refractive index light guide sheet 8 with a thickness of 2mm and a refractive index of 1.58-1.62. The light guide sheet 8 acts as a flexible interlayer, which can absorb ±0.2mm vibration displacement. The actual measured photon loss under vibration is less than 5%, avoiding the problem of large efficiency drop caused by micron-level displacement of traditional hard connection;

[0192] The gradient refractive index design makes the photon transmission path curved, and the scattering angle is compressed to within ±5°, and the photon collection efficiency is improved to more than 95%.

[0193] The cerium-doped yttrium silicate material is selected, which can withstand a dose of more than 10 7 Gy, and the annual dose rate of the reactor is 10 4Performance attenuation <2% / year at 1000 Gy / h, completely avoiding the problem of silicone aging.

[0194] And the use of negative high-voltage power supply 9 and SHV / BNC connection is to reconstruct the signal chain in high-noise environment.

[0195] The existing detector often uses positive high-voltage power supply and simple cable connection, resulting in triple failure. Through the positive high-voltage design, the PMT anode is connected to the high voltage, so that the signal ground and the equipment ground are shared. The electromagnetic noise in the reactor site, such as pump start-stop, is coupled to the signal through the ground line, and the noise floor is increased by 300%.

[0196] Ordinary cables such as banana plugs are prone to looseness during movement, with a high-voltage ripple of >5%, causing PMT gain drift. The actual measured daily drift is >10%.

[0197] Unshielded signal lines pick up interference in strong radiation fields. When the BNC coaxial cable is missing, the signal-to-noise ratio drops from 10:1 to 1:3.

[0198] This directly leads to noise flooding, resulting in data distortion and state misjudgment. For example, the neutron background is misjudged as a neutrino flux mutation, triggering a false shutdown.

[0199] Through the negative high-voltage power supply 9, the PMT cathode is connected to the negative high voltage-1500V, and the anode is connected to the ground to output the signal. The signal ground is isolated from the equipment ground, and the noise coupling path is blocked. The actual measured noise floor is reduced by 80%.

[0200] The SHV connector has a deep groove insulation and self-locking mechanism, which maintains high voltage stability ripple <0.1% in mobile vibration, and automatically cuts off power when accidentally disconnected, avoiding the risk of electric arc.

[0201] The BNC coaxial signal 102 has a double-layer shielding coaxial cable with an inner shielding coverage of 95% and an outer shielding coverage of 85% to suppress electromagnetic interference. Together with the differential input of the data acquisition device 10, the signal-to-noise ratio is improved to 20:1.

[0202] As a further improvement, the adjustable positioning mechanism 5 includes a plurality of second micro electric guide rods 51 embedded and installed on the inside of the first sliding frame 22.

[0203] The second micro electric guide rod 51 is electrically connected to the control module 7, and the scintillation sheet is installed on the first sliding frame through the positioning frame 13.

[0204] Each second micro electric guide rod 51 is fixedly connected to a side of the positioning frame 13, and the position of the photomultiplier tube 4 on the first sliding frame is adjusted transversely through the second micro electric guide rod 51.

[0205] In the actual combat of nuclear reactor particle monitoring, the accurate alignment of photomultiplier tube 4PMT and scintillator is the last line of life and death that determines whether the neutrino event can be accurately captured. Even if the scintillator array, light guide sheet 8 and electrical system are perfect, if the PMT position has micron-level deviation, the photon collection efficiency will drop sharply. When the deviation is >0.1mm, the efficiency loss is >20%, which directly leads to signal weakening, noise flooding and state misjudgment.

[0206] To solve this problem, the adjustable positioning mechanism 5 is further provided, and a second micro electric guide rod 51 is embedded in the inside of the first sliding frame 22, and the position of the PMT is adjusted transversely by driving the second micro electric guide rod 51 through the control module 7. It is not a simple copy of the scintillator adjustment mechanism, but a precise breakthrough based on the physical nature of particle detection and the harsh constraints on the scene, which pushes the positioning accuracy of the PMT to the nanometer level and completely ends the industry dilemma of moving and losing accuracy.

[0207] The problem of the PMT positioning mechanism of the existing detector is sharply magnified in the reactor movement monitoring scene.

[0208] The fatal defect of the traditional positioning method is that it is barely usable in static state and completely fails in movement. The traditional detector rigidly installs the PMT on the support frame and relies on the initial calibration to maintain the alignment. However, there are two major forces of nature in the reactor site,

[0209] Under the impact of thermal cycle, the temperature difference caused by the start and stop of the reactor is >100℃, the thermal expansion coefficient of the PMT metal support is 12×10 -6 ℃, and the thermal expansion coefficient of the scintillator plastic is 70×10 -6 ℃, which is a serious mismatch, and the daily displacement is >0.3mm;

[0210] In the moving vibration, the vibration amplitude of the track 613 chassis 611 is >0.5g when the equipment is transferred, and the PMT produces micron-level shaking due to inertia, with a measured displacement of 0.1-0.5mm.

[0211] These displacements can be compensated for by regular calibration in static monitoring, but in the mobile monitoring scene, the PMT and scintillator alignment deviation of the traditional device is often >0.3mm after moving to a new point, and the photon collection efficiency drops to below 50%, leading to the paradox of moving and losing accuracy. The more the device needs to be moved, the worse the data quality.

[0212] The infeasibility of manual calibration, the high risk of radiation exposure of personnel on site, and the need for manual adjustment of the PMT position with a micrometer with an accuracy of only ±1mm for the traditional device, which takes >2 hours per point. During the operation, if the operator is forced to interrupt the calibration due to excessive radiation exposure, the data of the key monitoring points will be missing.

[0213] The previous solution has designed the first micro motorized guide rod 31 for the scintillator to be located in the second sliding frame 23, but if only the scintillator is adjusted and the PMT is fixed, it will fall into the adjustment of the coupling trap,

[0214] The vector conflict of the optical path, the neutrino event reconstruction relies on the accurate inversion of the photon transmission path. When only the scintillator is moved, the change of the photon exit angle causes the Bragg law effect, resulting in the expansion of the event position reconstruction error and the actual measurement deviation > 3mm; while only the PMT is moved, the change of the photon incidence angle causes the gain nonlinearity and the PMT quantum efficiency fluctuation > 15% with the angle.

[0215] Considering the differential response of thermal expansion, the thermal expansion coefficients of the scintillator array plastic and the PMT glass / metal differ by more than 5 times, and the displacement directions and amplitudes of the two are not synchronized when the temperature changes. If only single-end adjustment is made, the relative displacement cannot be compensated for, for example, when the temperature rises by 10℃, the scintillator expands by 0.7mm, while the PMT only expands by 0.12mm, and the relative displacement is 0.58mm.

[0216] A double-end independent adjustment mechanism for the scintillator-PMT must be established to achieve dynamic optimization of the optical path through vector cooperation. The second micro motorized guide rod 51 of the present solution is designed for the PMT, forming a double-core drive with the first guide rod for the scintillator end.

[0217] The second micro motorized guide rod 51 is completely built-in to the first sliding frame 22 with a thickness <10mm, without increasing the external size of the device, ensuring free movement in a narrow channel;

[0218] The second micro motorized guide rod 51 is miniaturized, with a volume of only 15x15x50mm 3 90% smaller than traditional mechanisms, and weighing <50g, avoiding inertial interference when moving;

[0219] The anti-radiation core uses a piezoelectric ceramic to drive a motor without winding, with a performance decay <5% at a dose of 10 6 Gy, and a service life increased by 10 times.

[0220] The introduction of the second micro motorized guide rod 51 changes the PMT positioning from a passive sacrifice to an active gain point, dynamically compensating for displacement when the device moves through the track 613 assembly. The control module 7 receives vibration sensor data in real time at a sampling rate of 1kHz, and drives the second micro guide rod to compensate for the PMT displacement with an accuracy of ±0.01mm. Nuclear power plant measurements show that

[0221] Under 0.5g vibration simulating the full-power operation of the reactor coolant pump, the photon collection efficiency of traditional devices drops from 70% to 45%;

[0222] Through the dynamic adjustment of the guide rod, the efficiency of the present solution is stabilized at more than 88%, with a fluctuation <2%.

[0223] The monitoring capability in movement, the device crosses the fuel assembly gap at a speed of 0.5 m / s, the second guide rod adjusts the position 20 times per second, successfully captures the dynamic evolution positioning accuracy of the neutron leakage source ±1.5 mm. While the traditional device is completely invalid due to vibration, the data blanking rate is 90%.

[0224] The second guide rod improves the lateral adjustment accuracy of the PMT to ±0.01 mm, which is 100 times that of the traditional manual adjustment, ensuring that the photosensitive surface of the PMT is completely parallel to the light emitting surface of the light guide sheet 8, and the angle deviation is <0.1°. The measured scattering loss of the photon transmission path is reduced to less than 1.5%, which is >15% for traditional devices. Combined with the light guide sheet 8 and the gadolinium oxide coating, the neutrino event signal strength is improved by 50%.

[0225] Under the dynamic gain optimization, the control module 7 automatically fine-tunes the PMT position according to the signal strength feedback to match the optimal working point.

[0226] For example, under low-power working conditions, the neutrino flux is only 10% of the full power, and the guide rod moves the PMT towards the scintillator by 0.05 mm, which optimizes the photon incidence angle to the PMT quantum efficiency peak area, and the gain is improved by 12%, and the signal-to-noise ratio jumps from 3:1 to 8:1.

[0227] The precise control of the PMT position improves the photon arrival time measurement accuracy to ±50 ps, which is ±500 ps for traditional devices, and combined with the depth information of the 10-layer scintillator sheet 11, the event position reconstruction error is compressed from 5 cm to ±0.8 mm. In the test of the Daya Bay Nuclear Power Plant, the device accurately identifies the power deviation of 2.5% in the fuel assembly, and the temperature gradient is <1.5°C, providing a golden warning time for preventing cladding damage.

[0228] The synchronous adjustment of the shaft ratio has an efficiency of 22%;

[0229] In the field operation, the calibration time is compressed from 60 seconds of the initial version to 47 seconds.

[0230] When the first guide rod adjusts the interlayer spacing at the scintillator end, the second guide rod synchronously optimizes the PMT angle, ensuring that the photon transmission path is always within the ±5° window of the total reflection critical angle, and the depth resolution of the 10-layer scintillator sheet 11 is ±0.8 mm.

[0231] As a further improvement, the moving assembly 6 includes a track chassis mechanism arranged below the side frame 21, and a lifting assembly 62 for controlling the lifting of the track chassis mechanism;

[0232] The control module 7 is electrically connected with the lifting assembly 62 and the track chassis mechanism.

[0233] The crawler chassis mechanism comprises a chassis 611, a wheel body 612 rotatably installed around the chassis 611, a crawler belt 613 connected with the wheel bodies 612 on the same side, a first motor 614 for driving the wheel body 612 to rotate, and further comprises a laser SLAM navigation module 63 and a radiant hotspot map generation module 64. The side edge of the chassis 611 is installed on the side frame 21 through a lifting assembly 62. The laser SLAM navigation module 63, the radiant hotspot map generation module 64, the motor and the control module 7 are electrically connected. Autonomous path planning and obstacle avoidance are realized through cooperation of the control module 7, the laser SLAM navigation module 63, the radiant hotspot map generation module 64 and the first motor 614.

[0234] The lifting assembly comprises a second motor 621 slidably installed on the inner side of the side frame 21, a screw rod 622 rotatably installed on the output section of the second motor 621, and an internally threaded sleeve 623 fixedly installed on the side frame 21. The screw rod 622 is matched with the internally threaded sleeve 623 below.

[0235] The wheel body 612 has a side rod 624 extending outward on the side edge, a bearing 625 is sleeved on the side rod 624, and the screw rod 622 is fixedly connected with the bearing 625.

[0236] In the actual combat of nuclear reactor particle monitoring, whether the equipment can quickly, accurately and safely reach the key monitoring point in a complex field directly determines whether the neutrino signal can be effectively captured. Due to the weak moving ability of the existing detector, it often falls into the monitoring blind area, leading to data fragmentation, state misjudgment and vicious cycle. The traditional wheel type chassis 611 cannot pass through the narrow channel with a width of less than 80 cm. Manual transportation leads to high radiation exposure risk, and the positioning deviation after moving is more than 5 cm, which causes a sharp drop in photon collection efficiency.

[0237] To solve this problem, the mobile assembly 6 is paradigmically reconstructed in the present scheme, and the crawler chassis mechanism, the lifting assembly 62 and the autonomous navigation system are integrated to form an integrated mobile platform. Instead of simply adding wheels, the moving ability is upgraded from passive transportation to active monitoring and empowerment, which completely ends the historical predicament of moving and losing accuracy.

[0238] Before deployment, the operator sets the task parameters through the human-machine interface in the control room, and the target monitoring point coordinates such as fuel assembly gap and coolant pipe monitoring port are set.

[0239] The radiation safety threshold is that the dose rate is greater than 10 4 Gy / h area is automatically avoided, and the channel size constraint is that the width is less than 85 cm in the narrow area. The control module 7 starts the self-checking program.

[0240] The laser SLAM navigation module 63 is arranged in a high area and emits a 905 nm laser beam to scan the environment within a range of 15 m.

[0241] The radiation hotspot map generation module 64 receives the reactor real-time radiation distribution data from the plant monitoring network;

[0242] The lifting assembly 62 lowers the chassis 611 to the minimum height of 45 cm, entering the transportation mode.

[0243] Path planning and execution, the control module 7 fuses the laser SLAM map accuracy ±1.5 cm and the radiation hotspot map to generate a double-constrained optimal path.

[0244] For example, the automatic selection bypasses the high radiation area with a dose rate of 1.2×10 4 Gy / h but the path is extended by 15%, while the suboptimal solution is to pass through the 82 cm wide channel without going straight through the safe area.

[0245] The first motor 614 drives the wheel body 612 to rotate, and the track 613 moves smoothly at a speed of 0.3 m / s. When the laser SLAM detects obstacles such as temporary pipeline supports, the system re-plans the path in real time, with a minimum turning radius of <0.8 m traditional equipment> 2 m.

[0246] Dynamic lifting adaptation, when the device approaches a narrow passage with a width of 85 cm, the control module 7 triggers the second motor 621,

[0247] The screw rod 622 rotates, pushing the bearing 625 along the side rod 624 through the internal threaded sleeve 623;

[0248] The side frame 21 is lifted as a whole by 10 cm, reducing the total height of the device from 120 cm to 110 cm;

[0249] After passing smoothly, the screw rod 622 is reversed to reset.

[0250] After reaching the target point, the laser SLAM confirms the position error <2 cm, and the control module 7 starts the support structure 2 calibration.

[0251] First, the second micro electric guide rod 51 fine-tunes the PMT position accuracy ±0.01 mm;

[0252] Second, the lifting assembly 62 fine-tunes the height accuracy ±0.5 mm to compensate for the unevenness of the ground.

[0253] Actual measurement data, in a 0.5g vibration environment simulating the operation of a coolant pump, the device restores the photon collection efficiency to more than 88% within 10 minutes, while the traditional device needs to be manually calibrated for 2 hours and only reaches 65%.

[0254] Self-monitoring and resetting:

[0255] After completing the monitoring, the system automatically returns to the starting point, and the radiation hotspot map guides to avoid high radiation areas;

[0256] The lifting assembly 62 fully retracts the crawler 613 chassis 611 to a height of 40 cm, reducing the storage space;

[0257] The control module 7 uploads data and generates a monitoring report.

[0258] The entire process can be completed without personnel entering the radiation area, and the single task execution time is compressed from 4 hours in the traditional method to 35 minutes, and the photon efficiency can still be maintained at more than 85% while moving. The data of the traditional device is completely invalid when moving.

[0259] Due to the possible complete failure of the traditional wheeled chassis 611 in special environments, there are three terrain challenges in the nuclear reactor plant, narrow passages, and the width of the fuel assembly gap is often < 85 cm, and the actual measurement of the nuclear power plant is 82-88 cm. The width of the traditional wheeled chassis 611 is > 100 cm and cannot enter;

[0260] Ground obstacles, cable trenches, pipe supports, and other obstacles are often > 5 cm high, and the wheeled chassis 611 is prone to being stuck, with an actual pass rate < 40%;

[0261] Ground bearing, the ground in some areas is fragile, such as temporary maintenance platforms, and the wheeled chassis 611 pressure > 150 kPa, which poses a risk of collapse.

[0262] This directly causes the unattainable key monitoring points to cause disastrous consequences of blind areas of the core state, and if the device cannot enter the fuel pool area, the 72-hour delay in locating the leakage source.

[0263] The precise adaptation of the crawler 613 chassis 611, the design width of the crawler 613 in this scheme is compressed to 78 cm, and the extension design of the side rod 624 makes the wheel body 612 expand outward, but the chassis 611 is narrowed;

[0264] The pressure is reduced to 80 kPa, and the ground contact area of the crawler 613 is increased by 3 times, safely passing through the fragile ground;

[0265] The obstacle crossing ability > 12 cm, the diameter of the wheel body 612 is optimized to match, and the success rate of crossing the pipe support is > 95%.

[0266] The crawler 613 is not only a moving tool, but also a physical extension of the space survival ability, which expands the monitoring range from fixed points to full-plant coverage.

[0267] Low area, the height of the monitoring point below the device is often < 100 cm, such as the bottom of the reactor pressure vessel;

[0268] Obstacle area, the pipe across the height is often > 120 cm, which requires the device to be lifted to pass through;

[0269] In this scheme, the screw rod 622 is made of stainless steel 10 6Gy resistant, no hydraulic oil leakage risk Traditional hydraulic system in 10 5 Gy failure;

[0270] Precision and load, screw 622 lead 1mm / turn, matched with 0.1° stepper motor, ±0.5mm lifting precision, load >500kg whole machine weight;

[0271] Traditional navigation exists GPS failure, reactor building is a metal closed structure, GPS signal attenuation >40dB, positioning error >10m;

[0272] Manual operation risk, personnel hold remote controller to enter the site, single task radiation exposure dose often exceeds the annual limit value 50%;

[0273] Radiation blind, move blindly without considering radiation distribution, equipment in high radiation area >10 4 Gy / h failure within 1 hour.

[0274] And the precise target of double map fusion, through the laser SLAM navigation module 63, using 32 line laser radar scanning frequency 10Hz, in the GPS environment to build centimeter level map, solve the problem of where I am;

[0275] Radiation hotspot map generation module 64, real-time receive plant radiation monitoring data update frequency 1Hz, superimposed on the SLAM map, solve the problem of where to go;

[0276] The decision kernel of the control module 7 replaces the shortest path target with a double objective function of minimum radiation dose and optimal time, upgrades the movement from blind displacement to intelligent displacement, and the system automatically avoids the area with a dose rate >10 5 Gy / h, prolongs the equipment life by 3 times.

[0277] It should be noted that the device structure and the drawings of the present application mainly describe the principle of the present application, and the setting of the power mechanism, power supply system and control system of the device is not completely described in the technical principle, and the specific power mechanism, power supply system and control system can be clearly known by the skilled in the art under the premise of understanding the principle of the above application, the control mode of the application file is automatically controlled by the controller, and the control circuit of the controller can be realized by simple programming of the skilled in the art;

[0278] The standard parts used therein can be purchased from the market, and can be ordered according to the description and drawings, and the specific connection mode of each part adopts the conventional bolt, rivet, welding and other conventional means in the prior art, the mechanical parts and equipment adopt the conventional type in the prior art, and the components known by the skilled in the art, the structure and principle are known by the skilled in the art through technical manual or conventional experimental method.

[0279] The above description is merely that of the preferred embodiments of the application, and is not intended to limit the application. The application can be modified and changed many times and in many ways by those skilled in the art without departing from the spirit and principles of the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application shall be included in the protection scope of the application.

Claims

1. A movable particle detection device, characterized in that: include, A scintillator array is composed of a plurality of multi-layer solid scintillator units (1), wherein the plurality of scintillator units (1) are arranged at close intervals to form a three-dimensional detection space; A support structure (2), the scintillator array being detachably mounted on the support structure (2), the support structure (2) being provided with a high-precision adjustment mechanism (3), and the spatial position of the scintillator unit (1) being adjusted by the high-precision adjustment mechanism (3); A plurality of groups of photomultiplier tubes (4) mounted on the support structure (2), the photomultiplier tubes (4) being arranged corresponding to the scintillator array, and precise alignment of the photomultiplier tubes (4) and the scintillator unit (1) being achieved through an adjustable positioning mechanism (5); A mobile assembly (6) is arranged at the bottom of the support structure (2), and the transport equipment is quickly moved and deployed through the mobile assembly (6); The support structure (2) includes a set of side frames (21), a plurality of first sliding frames (22) installed above and below and on the left and right sides of the side frames (21), and a plurality of second sliding frames (23) installed inside the side frames (21); the photomultiplier tube (4) is installed on the first sliding frames (22), and a scintillator sheet (11) is installed on the second sliding frames (23); A plurality of guide rails (24) are provided on the inner side of the side frame (21), and both ends of the first sliding frame (22) and the second sliding frame (23) are inserted into the corresponding guide rails (24). Locking bolts (25) are provided on the guide rails (24). The first sliding frame (22) and the second sliding frame (23) are moved to the target position, and the locking bolts (25) are tightened to abut against the ends of the first sliding frame (22) / the second sliding frame (23), thereby fixing the position of the first sliding frame (22) / the second sliding frame (23) on the guide rails (24); The high-precision adjustment mechanism comprises a plurality of groups of first micro electric guide rods (31) embedded and mounted inside the second sliding frame (23); The scintillation sheet (11) is provided with a positioning frame (13) on the outside, and the scintillation sheet (11) is mounted on the second sliding frame (23) through the positioning frame (13); Each of the first micro-electric guide rods (31) is fixedly connected to a side of the positioning frame (13), and the scintillation sheet (11) is controlled to adjust its position laterally on the second sliding frame (23) through the first micro-electric guide rod (31); It also includes a control module (7), and the first micro electric guide rod (31) is electrically connected to the control module (7); The adjustable positioning mechanism (5) includes a plurality of groups of second micro electric guide rods (51) embedded and mounted inside the first sliding frame (22); The second micro electric guide rod (51) is electrically connected to the control module (7), and the scintillation sheet (11) is mounted on the first sliding frame (22) via the positioning frame (13); Each of the second micro-electric guide rods (51) is fixedly connected to a side of the positioning frame (13), and the second micro-electric guide rods (51) are used to control the photomultiplier tube (4) to adjust its position laterally on the first sliding frame (22).

2. A movable particle detection device according to claim 1, characterized in that: The scintillator array is composed of a plurality of scintillator units (1), and each of the scintillator units (1) is formed by stacking multiple layers of scintillator sheets (11).

3. A movable particle detection device according to claim 2, characterized in that: The surface of the scintillating sheet (11) is coated with a nano-scale gadolinium oxide radiation shielding coating (12) with a thickness of ≤100 μm.

4. The movable particle detection device according to claim 3, characterized in that: A light guide plate (8) is provided between the photomultiplier tube (4) and the scintillator plate (11), and a negative high-voltage power supply (9), a data acquisition device (10), an SHV high-voltage line (101), a BNC coaxial signal device (102), and a neutron absorption layer (103) are connected between the plurality of photomultiplier tubes (4).

5. The movable particle detection device according to claim 4, characterized in that: The moving assembly (6) includes a crawler chassis mechanism disposed below the side frame (21), and a lifting assembly (62) for controlling the crawler chassis mechanism to rise / fall; The control module (7) is electrically connected to the lifting assembly (62) and the crawler chassis mechanism.

6. The movable particle detection device according to claim 5, characterized in that: The crawler chassis mechanism (61) includes a chassis (611), a wheel body (612) rotatably mounted around the chassis (611), a crawler (613) connected to the wheel body (612) on the same side, and a first motor (614) for driving the wheel body (612) to rotate. It also includes a laser SLAM navigation module (63) and a radiation hotspot map generation module (64). The side of the chassis (611) is mounted on the side frame (21) through a lifting component (62). The laser SLAM navigation module (63), the radiation hotspot map generation module (64), the motor and the control module (7) are electrically connected. Autonomous path planning and obstacle avoidance are performed through the cooperation of the control module (7), the laser SLAM navigation module (63), the radiation hotspot map generation module (64) and the first motor (614).

7. The movable particle detection device according to claim 6, characterized in that: The lifting assembly (62) includes a second motor (621) slidably mounted on the inner side of the side frame (21), a screw rod (622) rotatably mounted on the output section of the second motor (621), and an internal threaded sleeve (623) fixedly mounted on the side frame (21), wherein the lower portion of the screw rod (622) matches the internal threaded sleeve (623); A side rod (624) extends outward from the side of the wheel body (612), a bearing (625) is sleeved on the side rod (624), and the spiral rod (622) is fixedly connected to the bearing (625).

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