A SiC-based neutron detection system for radiation-resistant reactor cores

Abstract

This invention discloses a SiC-based neutron detection system for a radiation-resistant reactor core, comprising a detection device, a wireless communication device, and an industrial control computer. The wireless communication device includes a transmitter module, an antenna module, and a receiver module. The transmitter communicates wirelessly with the receiver through the antenna module, which includes a millimeter-wave transmitting antenna array and a receiving antenna array. The transmitter module converts logic-level pulse train signals into microwave signals and outputs the microwave signals to the millimeter-wave transmitting antenna array. The millimeter-wave transmitting antenna array outputs corresponding millimeter-wave signals that penetrate the reactor core wall and reach the receiving antenna array. The receiver module receives the penetrating signals through the receiving antenna array, amplifies, filters, detects, and shapes them, and then outputs them to the industrial control computer for processing and display. The neutron detection system provided by this invention ensures that the wireless communication device can operate stably for extended periods under high radiation fields, essentially overcoming the signal interference problem of wireless communication technology.

Description

Technical Field

[0001] This invention relates to the field of reactor neutron detection system technology, and more particularly to a SiC-based radiation-resistant reactor core neutron detection system. Background Technology

[0002] In the new century, nuclear energy has seen increasing applications due to rising energy demands. While nuclear energy is a low-carbon, safe, and efficient energy source, reactor operation generates large amounts of radioactive material and poses a potential risk of leakage. Therefore, to ensure stable reactor operation and the safety of personnel and the environment, it is necessary to monitor the neutron flux within the reactor.

[0003] Currently, reactor neutron flux detection is mainly divided into core neutron detection and external neutron detection. Because the external environment of the reactor has a low temperature and low neutron flux density, conventional neutron detectors can meet the detection requirements. However, the reactor core environment has a high temperature and extremely strong radiation, so most neutron detectors cannot meet the detection requirements for parameters such as core neutron flux. Furthermore, reactor core neutron monitoring plays a crucial role in reactor startup and operation; therefore, developing a high-temperature resistant and radiation-resistant neutron detection system is essential. Simultaneously, transmitting the detected signals outside the reactor for data analysis is also crucial for maintaining safe reactor operation. However, due to the reactor's enclosed environment and radiation exposure, wired communication technology is insufficient to meet the requirements for safe and effective communication. Therefore, it is necessary to develop a low-power, low-error-rate, high-precision wireless communication technology suitable for the complex reactor environment.

[0004] Currently used plastic scintillator detectors suffer from low sensitivity and are susceptible to environmental interference, while silicon detectors are not radiation-resistant and therefore cannot meet the requirements for reactor core detection. In contrast, SiC, a third-generation semiconductor material with a wide bandgap, has advantages such as radiation resistance, high temperature resistance, and fast response time, and can be applied to the detection and communication needs of high-temperature, high-radiation fields in reactor cores.

[0005] The above background information is provided only to assist in understanding the inventive concept and technical solution of this invention. It does not necessarily belong to the prior art of this patent application, nor does it necessarily provide technical teaching. In the absence of clear evidence that the above information was disclosed before the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, this invention provides a SiC-based neutron detection system for radiation-resistant reactor cores, the specific technical solution of which is as follows:

[0007] A SiC-based neutron detection system for a radiation-resistant reactor core is provided, comprising a detection device, a wireless communication device, and an industrial control computer. The detection device includes a SiC detector, a preamplifier, a shaping circuit, a multi-stage amplification circuit, and a pulse extension circuit connected in sequence. The detection device is used to convert the neutron signals detected in the reactor core into logic-level pulse train signals. The wireless communication device includes a transmitter module, an antenna module, and a receiver module. The transmitter communicates wirelessly with the receiver through the antenna module. The antenna module includes a millimeter-wave transmitting antenna array and a receiving antenna array. The millimeter-wave transmitting antenna array and the transmitter are disposed inside the reactor core, while the receiving antenna array and the receiver module are disposed outside the reactor core.

[0008] The transmitting module converts the logic level pulse train signal into a microwave signal using DRO technology and drain modulation technology, and outputs the microwave signal to the millimeter-wave transmitting antenna array. The millimeter-wave transmitting antenna array outputs a millimeter-wave signal that passes through the core wall and reaches the receiving antenna array. The receiving module receives the through-wall signal through the receiving antenna array, and after amplification, filtering, detection and shaping, outputs it to the industrial control computer for processing and display.

[0009] Furthermore, the transmitting module includes a frequency source, an SPDT microwave switch, a pulse driving circuit, a first isolator, and a second isolator. The frequency source, the first isolator, the SPDT microwave switch, the second isolator, and the millimeter-wave transmitting antenna array are connected in sequence. The frequency source adopts DRO technology. The pulse driving circuit is connected to the SPDT microwave switch. The pulse driving circuit drives the SPDT microwave switch to operate according to the received logic level pulse train signal.

[0010] Furthermore, the transmitter module also includes an LDO unit, which is connected to the frequency source and the pulse drive circuit respectively.

[0011] Furthermore, the detection device also includes a signal discrimination circuit, which is disposed between the preamplifier and the shaping circuit. The industrial control computer is equipped with an FPGA microcontroller, through which a signal discrimination algorithm is pre-written to the signal discrimination circuit. The signal discrimination circuit is used to distinguish neutron signals in electrical signals from signals generated by other rays, and retains the valid neutron signals filtered by the signal discrimination algorithm. The FPGA microcontroller collects and stores the signals received from communication at a fixed clock frequency through the signal acquisition port to obtain the valid neutron pulse signals recorded per unit time, and then calculates the neutron count rate.

[0012] Furthermore, the industrial control computer is equipped with a human-machine interface. The FPGA microcontroller calculates the true neutron fluence rate and neutron dose rate based on the neutron count rate. The human-machine interface can display the neutron count rate, true neutron fluence rate, and neutron dose rate at the SiC detector deployment point in real time. The true neutron fluence rate is a multiple of the neutron count rate, obtained through a fixed coefficient conversion. The neutron dose rate is calculated based on the fluence-dose conversion factor of neutrons with different energies, combined with the proportion between neutrons of different energies indicated by the neutron energy spectrum, to obtain the average fluence-dose conversion factor of the reactor monitored by the SiC detector. Finally, the determined true neutron fluence rate is multiplied by the average fluence-dose conversion factor to derive the neutron dose rate at the SiC detector deployment point.

[0013] Furthermore, the millimeter-wave transmitting antenna array is a two-dimensional area array, which adopts a microstrip array antenna scheme, and its transmitting power is ≥20dBm.

[0014] Furthermore, the SiC detector has a conversion layer in front of its built-in SiC material, and the material of the conversion layer is... 6 LiF or 10 B4C, the conversion layer is used to react with neutrons and produce alpha particles, the SiC detector detects the alpha particles produced by the reaction to obtain an electrical signal and transmit it to the preamplifier.

[0015] Furthermore, the receiving module includes an amplifier circuit, a superheterodyne receiver, an active filter, and a radio frequency detector connected in sequence. The superheterodyne receiver is used to change the signal frequency to a predetermined frequency, and the active filter is used to filter out clutter signals outside the frequency point of the signal frequency.

[0016] Furthermore, the millimeter-wave signal output by the millimeter-wave transmitting antenna array has a frequency band of 5–6 GHz.

[0017] Furthermore, the reactor is one or more of a thermal neutron reactor, a medium-energy neutron reactor, and a fast neutron reactor.

[0018] Compared with the prior art, the present invention has the following advantages: it can work stably for a long time in the reactor core environment of strong radiation and high temperature, ensuring that the wireless communication device can operate stably for a long time under high radiation field, and basically overcoming the signal interference problem of wireless communication technology. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the circuit topology of the detection device in the SiC-based radiation-resistant reactor core neutron detection system provided in an embodiment of the present invention;

[0020] Figure 2This is a schematic diagram of the transmitter module circuit topology in the SiC-based radiation-resistant reactor core neutron detection system provided in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the receiver module circuit topology in a SiC-based radiation-resistant reactor core neutron detection system provided in an embodiment of the present invention. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0023] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0024] In one embodiment of the present invention, a SiC-based radiation-resistant reactor core neutron detection system is provided, comprising a detection device, a wireless communication device, and an industrial control computer. The detection device is used to convert the neutron signals detected in the reactor core into logic-level pulse train signals; see also Figure 1 The detection device includes a SiC detector, a preamplifier, a discrimination circuit, a shaping circuit, a multi-stage amplification circuit, and a pulse extension circuit, which are connected in sequence.

[0025] The SiC detector has a conversion layer in front of its built-in SiC material, and the material of the conversion layer is... 6 LiF or 10 In B4C, the conversion layer reacts with neutrons to produce alpha particles; the SiC detector detects the alpha particles produced by the reaction to obtain an electrical signal, which is then transmitted to the preamplifier; the preamplifier amplifies the electrical signal; the signal discrimination circuit distinguishes between neutron signals and signals generated by other rays in the electrical signal; the shaping circuit filters out noise signals in the electrical signal; the multi-stage amplification circuit improves the signal-to-noise ratio of the signal and converts the electrical signal to a logic level signal; and the pulse extension circuit extends the pulse of the logic level signal to obtain a pulse signal, which is then transmitted to the wireless communication device.

[0026] The wireless communication device includes a transmitter module, an antenna module, and a receiver module. All radio frequency devices inside the transmitter module and antenna module use silicon carbide chips, and the internal digital circuit devices are radiation-resistant products. The transmitter communicates wirelessly with the receiver through the antenna module, transmitting reactor irradiation and temperature information. The antenna module includes a millimeter-wave transmitting antenna array and a receiving antenna array. The millimeter-wave transmitting antenna array and the transmitter are located inside the reactor core, while the receiving antenna array and the receiver module are located outside the reactor core.

[0027] The transmitting module converts the logic level pulse train signal into a microwave signal using DRO (Drain-Output) and drain-modulation (DEM) technologies, and outputs the microwave signal to the millimeter-wave transmitting antenna array. The millimeter-wave transmitting antenna array outputs a millimeter-wave signal that passes through the reactor core wall to reach the receiving antenna array. The receiving module receives the through-wall signal through the receiving antenna array, amplifies, filters, detects, and shapes it, and then outputs it to the industrial control computer for processing and display. It should be noted that the reactor applicable to this embodiment can be one or more of the following: thermal neutron reactor, medium-energy neutron reactor, and fast neutron reactor.

[0028] The transmitting module includes a frequency source, an SPDT microwave switch, a pulse drive circuit, an LDO unit, a first isolator, and a second isolator. (See [link to relevant documentation]). Figure 2 The frequency source, first isolator, SPDT microwave switch, second isolator, and millimeter-wave transmitting antenna array are connected sequentially. The frequency source employs DRO technology. The pulse drive circuit is connected to the SPDT microwave switch, and drives the SPDT microwave switch to operate based on the received logic level pulse train signal. The LDO unit is connected to both the frequency source and the pulse drive circuit. The LDO unit is a low-dropout linear regulator used for circuit protection and voltage regulation. Specifically, to ensure the radiation resistance of the transmitting circuit, the frequency source uses mature DRO technology, achieving a frequency stability of ±1MHz across the entire temperature range and a phase noise of ≤-105dB@10KHz. The logic level pulse train is applied to the SPDT microwave switch via the pulse drive circuit. A drain modulation circuit is used, and the SPDT microwave switch has a modulation depth >60dB, enabling the modulation of microwave signals. The modulated microwave signal is amplified by a power amplifier and output to the millimeter-wave transmitting antenna array with a transmit power ≥20dBm. All RF devices use SiC-based chips, and the digital circuit devices are radiation-resistant products.

[0029] The antenna module outputs a millimeter-wave signal in the 5GHz–6GHz frequency band. The antenna module includes a millimeter-wave transmitting antenna array and a receiving antenna array. The millimeter-wave transmitting antenna array is a two-dimensional planar array with 16 channels. To improve gain and reduce sidelobes, a microstrip array antenna scheme is used. For ease of RF circuit integration, a flat microstrip antenna structure is adopted. The antenna's overall dimensions are 150mm. The antenna measures 120mm x 3mm and features a 4x4 multi-layer patch structure with a bandwidth approaching 10%. Its center frequency is 5.5GHz, and its bandwidth exceeds 300MHz. It employs a parallel-feed design with a sidelobe level of 13dB. The antenna gain G ≥ 17dB, and the beamwidth is 22°. Considering practical engineering applications, the antenna aperture determines the beamwidth, and the system size primarily considers the antenna dimensions. At 10 meters, the theoretical radius of the 3dB radiating "spot" is 3.8 meters, facilitating easy alignment between transmitter and receiver, and ensuring suitable gain. The receiving antenna array is a high-gain, low-sidelobe antenna array. It should be noted that the same antenna can be used as both a transmitting and receiving antenna for bidirectional communication; antennas with sidelobe levels below -30dB are typically referred to as low-sidelobe antennas.

[0030] The receiver module includes an amplifier circuit, a superheterodyne receiver, an active filter, and an RF detector, all electrically connected in sequence. The amplifier circuit is a low-noise amplifier. The receiver module uses a low-noise amplifier and a superheterodyne receiver to achieve optimal receiving sensitivity. The receiver module receives weak microwave through-wall signals transmitted from the reactor core via a low-sidelobe array antenna and further processes the signals. Signal processing includes data acquisition, filtering, noise interference suppression, shaping, and spurious signal detection. The judgment and processing of the detected information are implemented through an industrial control computer. The receiver module can also achieve interface matching with the user terminal system. See also Figure 3 The receiving module includes multiple amplifier circuits and multiple filters to achieve multi-level signal processing.

[0031] In one embodiment of the present invention, SiC material is a third-generation semiconductor, a ceramic-like compound formed by silicon atoms and carbon atoms bonded by covalent bonds, possessing excellent properties such as high temperature resistance and radiation resistance. It is a wide bandgap semiconductor, and due to its large bandgap, high breakdown electric field strength, high displacement threshold energy, and good thermal stability, it can meet the requirements for use in reactor cores in high-radiation, high-temperature environments. The SiC material can be one or more common allotropes such as 3C-SiC, 4H-SiC, and 6H-SiC. SiC material has the following characteristics: high carrier mobility, high sensitivity, fast response speed, wide bandgap, high displacement threshold energy, and high temperature resistance and radiation resistance. The thickness of the SiC detector varies depending on the neutron energy of different reactors, ensuring it remains within the range of charged particles. The SiC detector's packaging is customized according to the dimensions used, and the packaging material is radiation-resistant metals such as copper or stainless steel, or ceramics. When a SiC detector detects neutron flux, a conversion layer that reacts with neutrons is placed in front of the SiC material in the detector. This conversion layer is primarily used for... 6 LiF or 10 Materials such as B4C, utilizing their... 6 Li or 10 B reacts with neutrons. For example, when the conversion layer is... 6 When using LiF materials, through 6 The Li(n, α) reaction produces charged particles, which are then detected by a SiC detector to obtain a voltage level signal, which is then transmitted to a preamplifier.

[0032] The preamplifier connects the SiC detector to the signal discrimination circuit. The nuclear pulse signal output by the SiC detector has a very small amplitude and is easily drowned out by noise in subsequent circuits. The preamplifier amplifies the measured voltage signal, making it easier to distinguish in subsequent circuits. Since the reaction of neutrons with matter is often accompanied by the generation of other rays such as gamma rays, the signal discrimination circuit distinguishes the neutron signal from the signals generated by other rays. Then, the shaping circuit filters out noise signals, making the detection results more accurate. Then, the signal-to-noise ratio is improved again by a multi-stage amplification circuit and a signal conditioning circuit. At the same time, the voltage signal is converted into a logic level signal. At this time, the signal is a narrow pulse. Finally, the pulse extension circuit is used to extend the narrow signal pulse. Finally, by analyzing the pulse signal, the purpose of monitoring the neutron flux in the reactor core can be achieved.

[0033] Specifically, the preamplifier consists of a sensitive amplification circuit, a pulse shaping circuit, and an output drive circuit, which are connected in sequence. The sensitive amplification circuit amplifies the weak input voltage signal into a pulse signal; the pulse shaping circuit converts the amplified pulse signal into a square wave signal; and the output drive circuit converts the square wave signal into a square wave signal with driving capability.

[0034] In one embodiment of the present invention, the process of using a neutron detection system in a radiation-resistant reactor core is as follows:

[0035] Step S1: Neutrons in the reactor enter the SiC detection sensitive area through the conversion layer and generate an electrical signal. The electrical signal is amplified and filtered by the preamplifier, and then enters the shaping circuit for noise filtering. The multi-stage amplification circuit amplifies the voltage signal and converts it into a logic level signal. The output narrow pulse signal is extended by the pulse extension circuit.

[0036] Specifically, the incident neutrons come from one or more of the following: thermal neutron reactors, medium-energy neutron reactors, and fast neutron reactors. Among these, lower-energy neutrons readily react with the neutrons in the conversion layer covered by the SiC detector. 6 Li or 10 Botanical atoms undergo an (n, a) reaction to produce charged particles. Higher-energy neutrons can directly react with C or Si atoms in the sensitive layer of the SiC detector through multiple reaction channels, generating various heavy charged particles. At random locations in the conversion layer covering the SiC detector, charged particles generated by low-energy neutrons penetrate the conversion layer of a certain thickness with sufficient energy, enter the sensitive region of the SiC detector, and generate a large number of electron-hole pairs in the junction region. These electron-hole pairs drift towards the two electrodes under the electric field created by the bias voltage applied to the electrodes at both ends of the SiC detector and are collected by the electrodes, generating a weak electrical signal. The generated weak electrical signal is amplified and shaped by a preamplifier through a three-stage circuit. The first-stage sensitive amplifier circuit consists of JFETs, MOS, resistors, capacitors, and other devices. It receives the weak electrical signal output from the SiC probe as input and outputs an amplified pulse signal. The second-stage pulse shaping circuit consists of MOS, capacitors, and other devices. It receives the amplified pulse signal output from the sensitive amplifier circuit as input and outputs a square wave signal. The third-stage output drive circuit consists of MOS and other devices. It receives the square wave signal output from the pulse shaping circuit as input and outputs a square wave signal with driving capability. This signal is then extended by a pulse extension circuit to output a logic level pulse train.

[0037] Step S2: The pulse output by the detection device is input to the transmitting module of the wireless communication device. After the microwave signal is modulated by the pulse output by the detection device, it is amplified and output to the millimeter-wave transmitting antenna array.

[0038] Specifically, in order to ensure that the logic level pulse train output by the SiC detector that directly monitors the neutron flux in the reactor inside the concrete wall can be correctly transmitted through various circuits such as sensitive amplification, pulse shaping, output driving, multi-stage amplification, and pulse extension, the attenuation characteristics of electromagnetic waves passing through different walls are considered. In combination with the significant attenuation of high-frequency electromagnetic waves by the concrete wall, and taking into account the size and performance of the system, a millimeter-wave array communication system is adopted to complete the overall signal transmission.

[0039] Step S3: The receiving module receives the signal through the receiving antenna array and amplifies, filters and detects it. The detected pulse waveform is amplified, filtered and shaped before being sent to the signal processing circuit for data processing.

[0040] Specifically, to receive the weak through-wall signal from the transmitter, which is severely attenuated by the concrete wall, the receiving antenna array is a low-sidelobe antenna array with high gain characteristics. After the through-wall signal is received, it is amplified by a low-noise amplifier (LNA) circuit, and a superheterodyne receiver is used to change the signal frequency to a predetermined frequency to achieve optimal receiving sensitivity. The pre-processed signal is further passed through a high-Q, extremely narrow-band low-pass active filter to effectively filter out clutter signals outside the signal frequency range, improving the signal-to-noise ratio (SNR) of the channel processing. The high SNR microwave signal is then passed through a high-sensitivity, high-dynamic-range radio frequency detector to complete the detection, measurement, and conversion of the input signal. The processed amplitude-modulated microwave signal is converted into a baseband signal for wired transmission, which improves the detection sensitivity and reduces the false alarm probability. The multi-stage processed signal is finally sent to an industrial control computer for further processing.

[0041] Step S4: After signal processing to remove interference and noise, calculate the number of effective pulses per unit time, as well as the neutron fluence rate and dose rate, and transmit them to the industrial control computer in real time.

[0042] Specifically, the industrial control computer is equipped with an FPGA microcontroller and a human-machine interface (HMI). Signals transmitted inside and outside the reactor's concrete walls via a millimeter-wave array communication system are ultimately input into the FPGA microcontroller for physically meaningful signal processing. The FPGA, through its signal acquisition port, acquires the SiC detector signals after communication at a fixed clock frequency into the FPGA board's storage space. A pre-written signal discrimination algorithm in the FPGA microcontroller processes the acquired SiC detector signals, removing environmental interference signals and noise signals from electronic sources, retaining only the valid neutron signals recorded by the SiC detectors as selected by the algorithm. The FPGA microcontroller further analyzes the signals after removing interference and noise, calculating the valid neutron pulse signals recorded by the SiC detectors per unit time. The statistically analyzed neutron count signals are displayed in real-time on the HMI, providing a certain degree of information about the reactor's operating status. In addition to displaying the neutron count rate directly recorded by the SiC detectors, the HMI also displays the real neutron fluence and neutron dose rate at the reactor's SiC detector deployment points in real time. The true neutron fluence rate is a multiple of the neutron count recorded by the SiC detector. This is achieved through a fixed coefficient conversion, obtained by convolving the reactor neutron energy spectrum with the standard response curve of the SiC detector. Multiplying the determined SiC detector neutron count rate by the count rate-flux conversion coefficient yields the true neutron fluence rate at the reactor SiC detector deployment point. The neutron dose rate, based on the fluence-dose conversion factors for different neutron energies given in national standards, combined with the proportions of neutrons at various energies indicated by the neutron energy spectrum, yields the average fluence-dose conversion factor for the reactor monitored by the SiC detector. Finally, multiplying the determined true neutron fluence rate by the average fluence-dose conversion factor yields the neutron dose rate at the reactor SiC detector deployment point. It should be noted that the data acquisition and processing functions of the FPGA microcontroller can be implemented using one or more of the following: ASIC chip, FPGA chip, PCB board, and ARM board.

[0043] The SiC-based radiation-resistant reactor core neutron detection system provided by this invention effectively solves the problems of conventional semiconductor radiation monitoring systems being unable to withstand high temperatures and radiation. The SiC used in this system, as a third-generation semiconductor material, possesses not only the common characteristics of conventional semiconductors such as high carrier mobility, high sensitivity, and fast response speed, but also wide bandgap and high displacement threshold energy. These characteristics determine the system's excellent high-temperature resistance and radiation resistance. Furthermore, this system utilizes SiC for wireless communication, enabling signal transmission through walls and allowing for real-time transmission and monitoring of reactor neutron signals. It has the following advantages:

[0044] (1) The main material of the detection system is SiC material with good radiation resistance. Compared with the commonly used plastic scintillators and other detectors, it has better radiation stability and can work stably for a long time in the reactor core environment with strong radiation and high temperature. Furthermore, due to the excellent properties of SiC material, the detection system has more accurate and efficient detection results for information such as neutron flux in the reactor than existing technologies.

[0045] (2) The wireless transmission system has the characteristics of reconfigurability, scalability and high integration through microwave communication technology; and both the transmitter module and the receiver module are made of SiC material to ensure that the wireless transmission system can operate stably for a long time under high irradiation field.

[0046] (3) By using microwave communication technology, reasonable internal connection relationship and signal discrimination processing method, the signal interference problem of wireless communication technology is basically overcome; and it can be combined with the detection system to realize the integrated construction of detection and communication, realize the miniaturization and lightweighting of the system, and meet the detection requirements of reactor core irradiation signal.

[0047] The above description is merely a preferred embodiment of the present invention and does not limit its patent scope. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, whether directly or indirectly applied to other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A SiC-based neutron detection system for a radiation-resistant reactor core, characterized in that, The system includes a detection device, a wireless communication device, and an industrial control computer. The detection device comprises a SiC detector, a preamplifier, a shaping circuit, a multi-stage amplification circuit, and a pulse extension circuit, which are connected in sequence. The detection device is used to convert the neutron signals detected in the reactor core into logic-level pulse train signals. The wireless communication device includes a transmitter module, an antenna module, and a receiver module. The transmitter communicates wirelessly with the receiver through the antenna module. The antenna module includes a millimeter-wave transmitting antenna array and a receiving antenna array. The millimeter-wave transmitting antenna array and the transmitter are disposed inside the reactor core, while the receiving antenna array and the receiver module are disposed outside the reactor core. The transmitting module converts the logic level pulse train signal into a microwave signal using DRO technology and drain modulation technology, and outputs the microwave signal to the millimeter-wave transmitting antenna array. The millimeter-wave transmitting antenna array outputs a millimeter-wave signal that passes through the core wall and reaches the receiving antenna array. The receiving module receives the through-wall signal through the receiving antenna array, and after amplification, filtering, detection and shaping, outputs it to the industrial control computer for processing and display.

2. The radiation-resistant reactor core neutron detection system according to claim 1, characterized in that, The transmitting module includes a frequency source, an SPDT microwave switch, a pulse drive circuit, a first isolator, and a second isolator. The frequency source, the first isolator, the SPDT microwave switch, the second isolator, and the millimeter-wave transmitting antenna array are connected in sequence. The frequency source adopts DRO technology. The pulse drive circuit is connected to the SPDT microwave switch. The pulse drive circuit drives the SPDT microwave switch to operate according to the received logic level pulse train signal.

3. The radiation-resistant reactor core neutron detection system according to claim 2, characterized in that, The transmitter module also includes an LDO unit, which is connected to the frequency source and the pulse drive circuit respectively.

4. The radiation-resistant reactor core neutron detection system according to claim 1, characterized in that, The detection device further includes a signal discrimination circuit, which is disposed between the preamplifier and the shaping circuit. The industrial control computer is equipped with an FPGA microcontroller. The signal discrimination algorithm is pre-written into the signal discrimination circuit through the FPGA microcontroller. The signal discrimination circuit is used to distinguish neutron signals in electrical signals from signals generated by other rays, and retains the valid neutron signals filtered by the signal discrimination algorithm. The FPGA microcontroller collects and stores the signals received from communication at a fixed clock frequency through the signal acquisition port to obtain the valid neutron pulse signals recorded per unit time, and then calculates the neutron count rate.

5. The radiation-resistant reactor core neutron detection system according to claim 4, characterized in that, The industrial control computer is equipped with a human-machine interface. The FPGA microcontroller calculates the true neutron fluence rate and neutron dose rate based on the neutron count rate. The human-machine interface can display the neutron count rate, true neutron fluence rate, and neutron dose rate at the SiC detector deployment point in real time. The true neutron fluence rate is a multiple of the neutron count rate, obtained through a fixed coefficient conversion. The neutron dose rate is calculated based on the fluence-dose conversion factor of neutrons with different energies, combined with the proportion between neutrons of different energies indicated by the neutron energy spectrum, to obtain the average fluence-dose conversion factor of the reactor monitored by the SiC detector. Finally, the determined true neutron fluence rate is multiplied by the average fluence-dose conversion factor to derive the neutron dose rate at the SiC detector deployment point.

6. The radiation-resistant reactor core neutron detection system according to claim 1, characterized in that, The millimeter-wave transmitting antenna array is a two-dimensional area array, which adopts a microstrip array antenna scheme and has a transmission power ≥20dBm.

7. The radiation-resistant reactor core neutron detection system according to claim 1, characterized in that, The SiC detector has a conversion layer in front of its built-in SiC material, and the material of the conversion layer is... 6 LiF or 10 B4C, the conversion layer is used to react with neutrons and produce alpha particles, the SiC detector detects the alpha particles produced by the reaction to obtain an electrical signal and transmit it to the preamplifier.

8. The radiation-resistant reactor core neutron detection system according to claim 1, characterized in that, The receiving module includes an amplifier circuit, a superheterodyne receiver, an active filter, and a radio frequency detector connected in sequence. The superheterodyne receiver is used to change the signal frequency to a predetermined frequency, and the active filter is used to filter out noise signals outside the frequency range of the signal.

9. The radiation-resistant reactor core neutron detection system according to claim 1, characterized in that, The millimeter-wave transmitting antenna array outputs millimeter-wave signals in the frequency band of 5–6 GHz.

10. The radiation-resistant reactor core neutron detection system according to claim 1, characterized in that, The reactor is one or more of the following: thermal neutron reactor, medium-energy neutron reactor, and fast neutron reactor.

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