Embedded fission chamber assembly and method for realizing delayed neutron monitoring

Abstract

The invention is suitable for the technical field of nuclear detection and embedded systems, and provides an embedded fission chamber assembly and a method for monitoring delayed neutrons thereof.The embedded fission chamber assembly comprises an outer cylinder, the outer cylinder serves as a shell structure of the assembly, a fission chamber body is arranged in the outer cylinder and fixedly installed in the outer cylinder, and the fission chamber body is arranged in the outer cylinder; and the fission chamber main body forms a basic framework of the detection core chamber. The fission chamber main body is internally provided with a gas filling chamber, and the gas filling chamber is used for filling working gas; a collecting electrode and a high-voltage electrode penetrating through the head and the tail are assembled on the collecting electrode in the gas filling chamber, the high-voltage electrode serves as an electric field applying end, and the collecting electrode serves as a signal output end; the outer wall of the collecting electrode and the inner wall of the high-voltage electrode are plated with high-concentration uranium 235 layers; the uranium plating layer serves as a fission material coating and directly participates in nuclear fission reaction caused by neutrons, a large number of fission fragments are generated, and ionization signals are remarkably enhanced. The design of the uranium plating layer can reduce the covering effect of the gamma-ray background on the neutron signal and improve the signal-to-noise ratio of the signal. Double electromagnetic shielding is achieved through the staggered design of the inner shielding layer and the outer shielding layer, external radiation interference and electromagnetic noise are restrained, and the signal distortion rate is reduced.

Description

Technical Field

[0001] The present invention belongs to the field of nuclear detection technology and embedded system technology, and in particular relates to an embedded fission chamber component and a method for realizing delayed neutron monitoring thereof. Background Art

[0002] An embedded fission chamber is a neutron detector designed based on the principle of nuclear fission. Its core function is to indirectly measure the neutron flux or nuclear material properties by monitoring the fragments or secondary particles (such as delayed neutrons) produced during the fission process.

[0003] Existing embedded delayed neutron detection assemblies lack sufficient radiation resistance. High gamma background can cause signal distortion and even make it impossible to distinguish between neutrons and gamma signals, potentially leading to misjudgments during reactor intermediate-range monitoring. High gamma background can trigger false counts in the fission chamber, drowning out the neutron signal with the gamma signal, resulting in artificially high or abnormally fluctuating neutron flux. For example, during reactor startup or power regulation, if prompt neutrons cannot be distinguished from the gamma background, a power anomaly may be misjudged, triggering unnecessary reactor shutdown protection. For example, in a BF3 delayed neutron detector, the BF3 gas within it decomposes under strong radiation to produce electronegative free radicals, which absorb electrons and reduce detection efficiency. To address these issues, it is necessary to design an embedded fission chamber assembly and a method for implementing delayed neutron monitoring. Summary of the Invention

[0004] The present invention provides an embedded fission chamber assembly and a method for implementing delayed neutron monitoring thereof, so as to solve the above-mentioned problems in the prior art.

[0005] The present invention is implemented as follows: an embedded fission chamber assembly includes an outer cylinder, which serves as the outer shell structure of the assembly. A fission chamber body is arranged inside the outer cylinder and is fixedly installed in the outer cylinder. The fission chamber body constitutes the basic frame of the detection core chamber.

[0006] A gas-filled chamber is provided inside the fission chamber body, and the gas-filled chamber is used to fill the working gas; a collecting electrode is passed through the inside of the gas-filled chamber, and the collecting electrode serves as a signal output end; a high-voltage electrode is provided between the collecting electrode and the fission chamber body, and the high-voltage electrode serves as an electric field application end, and is used to achieve the voltage required for the operation of the fission chamber body; a three-coaxial MI cable connector assembly is provided at the outer end of the outer cylinder, and the three-coaxial MI cable connector assembly is connected to the collecting electrode and the outer cylinder, and the three-coaxial MI cable connector assembly is used for signal transmission and power supply, the inner wall of the gas-filled chamber is covered with a uranium plating layer, the outer wall of the collecting electrode and the inner wall of the high-voltage electrode are provided with a high-concentration uranium layer, and the inside of the gas-filled chamber is filled with a mixture of single atoms and polyatomic gases.

[0007] Furthermore, the triaxial MI cable connector assembly includes a central signal conductor, an inner shielding layer, an outer shielding layer and an insulating layer, and the triaxial MI cable connector assembly is used to achieve isolated transmission of the detection signal and the power supply.

[0008] Furthermore, the center signal conductor is arranged in the innermost layer of the three-coaxial MI cable connector assembly, the inner shielding layer is arranged on the outer layer of the center signal conductor, an outer shielding layer is arranged outside the inner shielding layer, the outer shielding layer and the inner shielding layer are arranged alternately, and the insulating layer is wrapped around the outer shielding layer.

[0009] Furthermore, the gas filled in the gas-filled chamber is a mixture of an inert gas and a quenching gas in equal proportions. The mixed filling gas in the gas-filled chamber is used to optimize the amplification and shaping characteristics of the ionization signal.

[0010] Furthermore, the outer cylinder is made of high-strength metal material, and a shielding layer structure is provided on its surface, and the shielding layer structure is used to reduce the influence of external radiation interference on the detection signal.

[0011] Furthermore, the outer cylinder is made of stainless steel.

[0012] Furthermore, the shielding layer structure is a multi-layer composite structure: The outermost anti-radiation layer is made of zirconium alloy or nickel-based alloy with a thickness of 2-3 mm to shield external radiation and reduce radiation damage to the material; A heat-insulating layer provided in the middle layer, the heat-insulating layer is filled with alumina ceramic fiber and has a thickness of 5-10 mm to reduce heat conduction; The support layer is provided in the inner layer. The support layer is made of stainless steel with a thickness of 1-2 mm and is rigidly connected to the fission chamber body to ensure structural stability. Spiral heat dissipation fins are processed on the outer surface of the outer cylinder to improve the natural convection heat dissipation efficiency; a microchannel liquid cooling tube with a diameter of 1 mm is embedded between the thermal insulation layer and the support layer, and a fluorinated liquid coolant circulates in the microchannel liquid cooling tube to transfer internal heat to the outside.

[0013] A method for realizing delayed neutron monitoring uses an embedded fission chamber component, and a signal processing module, a power supply module and a data acquisition module connected to the component to realize delayed neutron detection and data analysis.

[0014] Furthermore, it includes a neutron source, a source detection device and a source detection base. The neutron source is mainly composed of a radioactive source, a neutron source cladding and a counterweight, and is used to generate neutron rays required for detector calibration; the source detection device mainly includes a source shaking device, a shielding body and a shielding tank, which are used to shield the neutron source in a non-calibrated state and to import and export the neutron source in a calibrated state; the source detection base is mainly used to support the source detection device.

[0015] Compared with related technologies, the embedded fission chamber assembly and the method for implementing delayed neutron monitoring provided by the present invention have the following beneficial effects: The uranium coating, a fissile material coating, directly participates in neutron-induced nuclear fission reactions, producing a large number of fission fragments and significantly enhancing the ionization signal. Compared to traditional ionization chambers, fission chambers offer higher neutron sensitivity, making them particularly suitable for use in high-radiation environments. The energy of fission fragments is significantly higher than that of secondary electrons produced by gamma rays, making their signature more easily distinguishable using pulse amplitude analysis or pulse shape discrimination techniques. The uranium coating design reduces the masking effect of the gamma-ray background on the neutron signal, improving the signal-to-noise ratio.

[0016] The staggered design of inner and outer shielding layers achieves dual electromagnetic shielding, suppressing external radiation interference and electromagnetic noise, significantly reducing signal distortion. The outer cylinder utilizes a multi-layer composite shielding structure, with an anti-radiation layer that enhances gamma-ray shielding efficiency and reduces the risk of radiation-induced material embrittlement. An alumina ceramic fiber insulation layer reduces external heat conduction and protects internal electronic components. A support layer rigidly connects the fission chamber body, ensuring structural stability in high-temperature and vibration environments. This provides enhanced impact resistance, making it suitable for scenarios such as nuclear accident emergency monitoring.

[0017] The heat dissipation enhancement design features spiral fins that increase surface area and improve natural convection cooling efficiency, reducing surface temperatures. Microchannel liquid cooling tubes circulate fluorinated coolant to remove heat, improving thermal conductivity and enabling long-term stable operation at high temperatures. The outer cylinder and shield are constructed of stainless steel and zirconium alloy, offering corrosion resistance and a long service life, making them suitable for harsh environments such as nuclear power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the embedded fission chamber assembly of the present invention; Figure 2 Schematic diagram of the structure of the method for implementing delayed neutron monitoring of the present invention; Figure 3 For the present invention Figure 2 A top-down plan view; Figure 4 It is a partial structural schematic diagram of the triaxial MI cable connector assembly of the present invention; Figure 5 is a cross-sectional view of a triaxial MI cable connector assembly according to the present invention; Figure 6 For the present invention Figure 1 A in the middle is an enlarged structural diagram; Figure 7 It is a three-dimensional outline drawing of the inspection source device; Figure 8 This is a diagram of the composition of the inspection source device; Figure 9 It is a three-dimensional structural diagram of the source detection device and the source detection base; Figure 10 Design a simple diagram for the neutron source; Figure 11 This is a cross-sectional diagram of the inspection source device; Figure 12 This is the dimensional drawing of the inspection source device; Figure 13 This is a schematic diagram of the composition of a single delayed neutron detection channel; Figure 14 This is the structural principle diagram of the fission ionization chamber.

[0019] In the figure: source detection device 1, source detection base 2, outer cylinder 101, fission chamber body 102, gas-filled chamber 103, collecting electrode 104, high-voltage electrode 105, triaxial MI cable connector assembly 106, uranium plating layer 107, center signal conductor 108, inner shielding layer 109, outer shielding layer 110, insulating layer 111, shielding layer structure 112, anti-radiation layer 113, thermal insulation layer 114, supporting layer 115, high-voltage electrode uranium layer 116, uranium layer collector 117. DETAILED DESCRIPTION

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0021] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0022] The preferred embodiment of the embedded fission chamber assembly and the method for implementing delayed neutron monitoring provided by the present invention is as follows: Figures 1 to 14 As shown: An embedded fission chamber assembly includes an outer cylinder 101, which serves as the outer shell structure of the assembly. A fission chamber body 102 is arranged inside the outer cylinder 101 and is fixedly installed in the outer cylinder 101. The fission chamber body 102 constitutes the basic frame of the detection core chamber.

[0023] A gas-filled chamber 103 is provided inside the fission chamber body 102, and the gas-filled chamber 103 is used to fill the working gas; a collecting electrode 104 is passed through the gas-filled chamber 103, and the collecting electrode 104 serves as a signal output terminal; a high-voltage electrode 105 is provided between the collecting electrode 104 and the fission chamber body 102, and the high-voltage electrode 105 serves as an electric field application terminal, and is used to achieve the voltage required for the operation of the fission chamber body 102; a three-coaxial MI cable connector assembly 106 is provided at the outer end of the outer cylinder 101, and the three-coaxial MI cable connector assembly 106 is connected to the collecting electrode 104 and the outer cylinder 101, and the three-coaxial MI cable connector assembly 106 is used for signal transmission and power supply, and the outer wall of the collecting electrode 104 and the inner wall of the high-voltage electrode 105 are provided with high-concentration uranium layers 116 and 107, and the gas-filled chamber 103 is filled with a mixture of monatomic and polyatomic gases. The ejection trajectory of fission fragments in the fission ionization chamber can be referred to Figure 14 As shown, which shows the schematic diagram of the fission ionization chamber structure.

[0024] The triaxial MI cable connector assembly 106 includes a center signal conductor 108 , an inner shielding layer 109 , an outer shielding layer 110 , and an insulating layer 111 . The triaxial MI cable connector assembly 106 is used to achieve isolated transmission of detection signals and power.

[0025] The center signal conductor 108 is arranged in the innermost layer of the triaxial MI cable connector assembly 106, the inner shield layer 109 is arranged on the outer layer of the center signal conductor 108, and the outer shield layer 110 is arranged outside the inner shield layer 109. The outer shield layer 110 and the inner shield layer 109 are arranged alternately, and the insulation layer 111 is wrapped around the outer shield layer 110.

[0026] The gas filled in the gas-filled chamber 103 is a mixture of an inert gas and a quenching gas in equal proportions. The mixed filling gas in the gas-filled chamber 103 is used to optimize the amplification and shaping characteristics of the ionization signal.

[0027] The outer cylinder 101 is made of high-strength metal material, and a shielding layer structure 112 is provided on the surface thereof. The shielding layer structure 112 is used to reduce the influence of external radiation interference on the detection signal.

[0028] The outer cylinder 101 is made of stainless steel.

[0029] The shielding layer structure 112 is a multi-layer composite structure: The outermost radiation-resistant layer 113 is made of zirconium alloy or nickel-based alloy with a thickness of 2-3 mm, and is used to shield external radiation and reduce radiation damage to the material. A heat insulation layer 114 is provided in the middle layer. The heat insulation layer 114 is filled with alumina ceramic fibers and has a thickness of 5-10 mm to reduce heat conduction. The support layer 115 is provided in the inner layer. The support layer 115 is made of stainless steel with a thickness of 1-2 mm and is rigidly connected to the fission chamber body 102 to ensure structural stability. Spiral heat dissipation fins are processed on the outer surface of the outer cylinder 101 to improve the natural convection heat dissipation efficiency; a microchannel liquid cooling tube with a diameter of 1 mm is embedded between the insulation layer 114 and the support layer 115, and fluorinated liquid coolant circulates in the microchannel liquid cooling tube to transfer internal heat to the outside.

[0030] A method for realizing delayed neutron monitoring uses an embedded fission chamber component, and a signal processing module, a power supply module and a data acquisition module connected to the component to realize delayed neutron detection and data analysis.

[0031] It includes a neutron source, a source detection device and a source detection base. The neutron source is mainly composed of a radioactive source, a neutron source cladding and a counterweight, and is used to generate the neutron rays required for detector calibration; the source detection device mainly includes a shaking source device, a shielding body and a shielding tank, which are used to shield the neutron source in non-calibration conditions and to import and export the neutron source in calibration conditions; the source detection base is mainly used to support the source detection device.

[0032] In this embodiment, the embedded fission chamber assembly is the core detection unit for implementing the delayed neutron monitoring method. The two are functionally integrated through modules such as signal transmission, power supply, and structural support to jointly complete the neutron detection task. The specific connection relationship and collaboration mechanism are as follows: The embedded fission chamber assembly, as the core detection unit, is the heart of the delayed neutron monitoring method. When a nuclear reaction occurs, the charged particles produced will ionize within the counter tube, generating detectable electrical signals. These signals form the basis for subsequent data acquisition and analysis.

[0033] Signal transmission and processing connection: The electrical signals generated by the detection components need to be transmitted via cables or signal transmission modules to the signal processing unit used to implement the delayed neutron monitoring method. This signal processing unit may include a preamplifier, a main amplifier, and a discriminator, which amplify, filter, and discriminate the weak electrical signals to improve the signal-to-noise ratio and detection accuracy.

[0034] Power supply connection: Detection components require a stable power supply for proper operation. Power modules are often integrated into delayed neutron monitoring systems, providing the necessary high and low voltage power to the detector components via cables. The stability and quality of the power supply directly impact the performance and lifespan of the detector components.

[0035] Structural support and shielding connection: The detector assembly must be installed within the structural framework of the delayed neutron monitoring method to ensure stability and safety. Furthermore, to reduce the impact of environmental radiation and electromagnetic interference on detection results, a shielding layer is typically installed around the detector assembly. This shielding layer must be well connected and grounded to the detector assembly and system structure.

[0036] Data collection and transmission connection: After signal processing, the data needs to be digitized by the data acquisition module and transmitted to the host computer or data center through a data transmission interface (such as USB, Ethernet, etc.) for further analysis and processing. This connection relationship enables communication and data sharing between the detection system and external devices.

[0037] Because fission fragments produced by fissile materials like uranium-235 under neutron bombardment have much higher energy than secondary particles produced by gamma rays, their ionization effect is significant. Uranium coatings, as fissile material coatings, enhance neutron detection sensitivity through the strong ionization signal of fission fragments while reducing interference from gamma-ray background signals.

[0038] The fission chamber's response to neutrons is based on nuclear fission reactions, while gamma rays primarily produce ionization through Compton scattering or the photoelectric effect. The uranium coating effectively distinguishes neutrons from gamma rays by optimizing the ratio of the fission fragment signal intensity to the gamma ray ionization signal.

[0039] Therefore, the uranium coating, as a fissile material coating, can directly participate in neutron-induced nuclear fission reactions, producing a large number of fission fragments and significantly enhancing the ionization signal. Compared to traditional ionization chambers, fission chambers offer higher neutron sensitivity, making them particularly suitable for use in high-radiation field environments. The energy of fission fragments is much higher than that of secondary electrons produced by gamma rays, making their signature more easily distinguishable using pulse amplitude analysis or pulse shape discrimination techniques. The uranium coating design reduces the masking effect of the gamma-ray background on the neutron signal, improving the signal-to-noise ratio.

[0040] The staggered design of inner and outer shielding layers achieves dual electromagnetic shielding, suppressing external radiation interference (such as gamma rays) and electromagnetic noise, significantly reducing signal distortion. The outer cylinder 101 utilizes a multi-layer composite shielding structure. The anti-radiation layer 113 improves gamma ray shielding efficiency and reduces the risk of radiation-induced material embrittlement. The alumina ceramic fiber insulation layer 114 reduces external high-temperature conduction and protects internal electronic components. The support layer 115 rigidly connects the fission chamber body, ensuring structural deformation in high-temperature and vibration environments. This provides enhanced impact resistance, making it suitable for scenarios such as nuclear accident emergency monitoring.

[0041] The heat dissipation enhancement design features spiral fins that increase surface area and improve natural convection cooling efficiency, reducing surface temperatures. Microchannel liquid cooling tubes circulate fluorinated coolant to remove heat, improving thermal conductivity and enabling long-term stable operation at high temperatures. The outer cylinder and shield are constructed of stainless steel and zirconium alloy, offering corrosion resistance and a long service life, making them suitable for harsh environments such as nuclear power plants.

[0042] As shown in Figure 10, the delayed neutron monitoring system test source device mainly includes the following parts: 1) One 238Pu-Be neutron source, neutron emission rate > 5×10 4 n / s; 2) One source detection device; 3) One source inspection base.

[0043] Among them, the source detection device includes a shaking source device and a shielding source tank.

[0044] Design plan: The delayed neutron monitoring system inspection source device is mainly composed of a neutron source, a source inspection device and a source inspection base. Among them, the neutron source is mainly composed of a radioactive source, a neutron source cladding and a counterweight, which is used to generate the neutron rays required for detector calibration; the source inspection device mainly includes a shaking source device, a shielding body and a shielding tank, which are used to shield the neutron source under non-calibration conditions and to import and export the neutron source under calibration conditions; the source inspection base is mainly used to support the source inspection device and ensure that the neutron source can be accurately introduced into the calibration source channel.

[0045] Neutron source: according to EJ 855-1994, emission rate 5×10 4 The outer core of the n / s Pu-Be neutron source measures 10 mm x 14 mm. The source core is enclosed in a cylindrical cladding that suspends the source. This cladding measures 14 mm x 20 mm and has a wall thickness of 1 mm. The cladding is counterweighted with approximately 100 g to ensure overall stability during source lifting and lowering. The hoisting rope is a 1 mm diameter steel wire rope.

[0046] The source detection device mainly includes a source shaking device, a shielding body, and a shielding source tank. The source shaking device is used to raise and lower the neutron source to the shielding position or working position. It consists of a crank handle, a winding reel, and a support rod. The neutron source is moved up and down by manually turning the crank handle.

[0047] Working position: When using the neutron source, place the source detection base above the vertical well plug base, align the quick alignment boss below the shielding cylinder with the calibration source channel of the vertical well plug base, and make the cutting surface of the shielding cylinder face the detector channel. The operator operates directly behind the cutting surface of the shielding cylinder. Place the source detection device above the source detection base, pull out the radiation source baffle, and then slowly shake the handle to lower the neutron source at a uniform speed. The length of the wire rope is about 8.1m. When the wire rope is fully released, the neutron source and the center of the sensitive area of ​​the neutron detector are basically at the same horizontal height. Using MCNP for simulation calculation, it is found that the maximum dose equivalent rate value at the operator's position when the neutron source moves in the shielding cylinder is less than 8uSv / h.

[0048] Shielding position: When the neutron source is used up, the wire rope is retracted by shaking the handle, and the neutron source is returned to the source detection device. The source detection device is equipped with a high-density polyethylene shielding body of about 150mm thick, which can basically completely shield the neutron ray emission in the shielding state. The outer diameter of the shielding tank is 320mm and the height is 185mm. Its cross-section diagram and specific dimensions are as follows Figure 5 and Figure 6 As shown. Furthermore, the source detection base should be placed upside down on a clean medium surface when not in operation to ensure stability. MCNP simulations show that the maximum dose equivalent rate at the center directly above the source detection device is approximately 12 uSv / h, while the maximum dose equivalent rate at other locations is less than 3 uSv / h.

[0049] The source detection base mainly consists of a shielding cylinder and a fixed support for the source detection device. The shielding cylinder is made of high-density polyethylene, with an outer diameter of 120mm and a height of about 245mm. There is a φ16mm neutron source introduction hole in the center.

[0050] In this design, the upper and lower ends of the source detection base shielding cylinder are respectively provided with guide bosses for rapid alignment with the source detection device and the vertical well plug base, so as to achieve rapid and accurate alignment on site.

[0051] Design parameters: Source detection device size: φ320mm×485mm (from the bottom of the source detection device to the top of the reel); Source detection device weight: ~20kg; Source inspection base dimensions: Height 200mm. Center polyethylene cylinder diameter φ120mm, height ~245mm; Source inspection base weight: ~7.5kg.

[0052] The preamplifier circuit mainly consists of seven parts, namely high-voltage filter circuit, integral amplifier, secondary amplifier, tertiary amplifier, signal conditioning circuit, test pulse generation circuit and test switching control circuit, as follows: a) The high-voltage filter circuit is mainly used to filter the interference signal in the high-voltage power supply, and then provide it to the detector after high-voltage filtering; b) Integral amplifier, secondary amplifier and tertiary amplifier are three-stage amplifiers used to amplify the weak negative pulse signal from the boron-coated proportional counter tube; c) The signal conditioning circuit mainly filters, shapes and drives the amplified signal to output voltage pulses of different frequencies with a pulse width less than 1us and an amplitude greater than 1V; d) The test pulse generating circuit generates a 100kHz test signal according to the test enable signal value provided by the signal processing device, so as to check whether the preamplifier has any fault; e) The test switching control circuit selects the output signal of the boron-coated proportional counter tube or the test signal as the input signal of the integral amplifier according to the test enable signal value from the signal processing device.

[0053] It is worth noting that the circuits, electronic components and modules involved in the present invention are all existing technologies and can be fully implemented by those skilled in the art. Needless to say, the content protected by the present invention does not involve improvements to software and methods.

[0054] In the several embodiments provided in this application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the above-mentioned units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be in the form of telecommunications or other forms.

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of protection of the invention. Obviously, the embodiments described are only some embodiments of the present invention, rather than all embodiments. Based on these embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field can still combine, add, delete or make other adjustments to the features in the various embodiments of the present invention according to the circumstances without conflict, without making creative work, so as to obtain different other technical solutions that do not deviate from the concept of the present invention in essence, and these technical solutions also fall within the scope of protection of the present invention.

Claims

1. An embedded fission chamber assembly, characterized in that: The outer cylinder (101) is used as a shell structure of the component. A fission chamber body (102) is provided inside the outer cylinder (101). The fission chamber body (102) is fixedly installed in the outer cylinder (101). The fission chamber body (102) constitutes a basic frame of the detection core chamber. A gas-filled chamber (103) is provided inside the fission chamber body (102), and the gas-filled chamber (103) is used to fill the working gas; a collecting electrode (104) is passed through the gas-filled chamber (103), and the collecting electrode (104) serves as a signal output end; a high-voltage electrode (105) is provided between the collecting electrode (104) and the fission chamber body (102), and the high-voltage electrode (105) serves as an electric field application end, and is used to achieve the voltage required for the operation of the fission chamber body (102); The outer end of the outer cylinder (101) is provided with a triaxial MI cable connector assembly (106), the triaxial MI cable connector assembly (106) is connected to the collecting electrode (104) and the outer cylinder (101), and the triaxial MI cable connector assembly (106) is used for signal transmission and power supply. The outer wall of the collecting electrode (104) and the inner wall of the high-voltage electrode (105) are provided with high-concentration uranium layers (116) and (107), and the gas-filled chamber (103) is filled with a mixture of monatomic and polyatomic gases.

2. The embedded fission chamber assembly according to claim 1, wherein: The triaxial MI cable connector assembly (106) comprises a central signal conductor (108), an inner shielding layer (109), an outer shielding layer (110), and an insulating layer (111). The triaxial MI cable connector assembly (106) is used to achieve isolated transmission of a detection signal and a power supply.

3. The embedded fission chamber assembly according to claim 2, wherein: The center signal conductor (108) is arranged in the innermost layer of the triaxial MI cable connector assembly (106), the inner shielding layer (109) is arranged in the outer layer of the center signal conductor (108), an outer shielding layer (110) is arranged outside the inner shielding layer (109), the outer shielding layer (110) and the inner shielding layer (109) are arranged alternately, and the insulating layer (111) is wrapped around the outer shielding layer (110).

4. The embedded fission chamber assembly according to claim 1, wherein: The gas filled in the gas-filled chamber (103) is a mixed gas of an inert gas and a quenching gas, which are mixed in equal proportions. The mixed filling gas in the gas-filled chamber (103) is used to optimize the amplification and shaping characteristics of the ionization signal.

5. The embedded fission chamber assembly according to claim 1, wherein: The outer cylinder (101) is made of a high-strength metal material, and a shielding layer structure (112) is provided on its surface. The shielding layer structure (112) is used to reduce the influence of external radiation interference on the detection signal.

6. The embedded fission chamber assembly according to claim 5, wherein: The outer cylinder (101) is made of stainless steel.

7. The embedded fission chamber assembly according to claim 5, wherein: The shielding layer structure (112) is a multi-layer composite structure: The outermost radiation-resistant layer (113) is made of zirconium alloy or nickel-based alloy and has a thickness of 2-3 mm, shielding external radiation and reducing material radiation damage; A heat insulation layer (114) is provided in the middle layer, the heat insulation layer (114) is filled with alumina ceramic fibers and has a thickness of 5-10 mm, and is used to reduce heat conduction; A support layer (115) is provided in the inner layer, wherein the support layer (115) is made of stainless steel and has a thickness of 1-2 mm and is rigidly connected to the fission chamber body (102) to ensure structural stability; Spiral heat dissipation fins are processed on the outer surface of the outer cylinder (101) to improve the natural convection heat dissipation efficiency; a microchannel liquid cooling tube (1 mm in diameter) is embedded between the thermal insulation layer (114) and the support layer (115), and a fluorinated liquid coolant circulates in the microchannel liquid cooling tube to conduct internal heat to the outside.

8. A method for implementing delayed neutron monitoring, characterized in that: The embedded fission chamber assembly according to any one of claims 1 to 4, as well as a signal processing module, a power supply module and a data acquisition module connected to the assembly are used to jointly realize the detection and data analysis of delayed neutrons.

9. The method for implementing delayed neutron monitoring according to claim 8, wherein: It includes a neutron source, a source detection device and a source detection base. The neutron source is mainly composed of a radioactive source, a neutron source cladding and a counterweight, and is used to generate neutron rays required for detector calibration; the source detection device mainly includes a source shaking device, a shielding body and a shielding tank, which are used to shield the neutron source in non-calibration conditions and to import and export neutrons in calibration conditions; the source detection base is mainly used to support the source detection device.

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