Wide dose rate detection system and detection method

Abstract

The invention relates to the technical field of nuclear radiation detection, and particularly discloses a wide dose rate detection system and method, and the system comprises a scintillator detection module, a silicon detector detection module, a voltage conversion module, a signal processing module, and a power module. The scintillator detection module comprises a scintillator, a silicon photomultiplier and a first signal conditioning module, the silicon detector detection module comprises a silicon detector and a second signal conditioning module, the voltage conversion module comprises a high-voltage conversion module and a low-voltage conversion module, and the first signal conditioning module and the second signal conditioning module are both connected with the signal processing module. The signal processing module is respectively connected with the high-voltage conversion module and the low-voltage conversion module, and the high-voltage conversion module is connected with the silicon photomultiplier; and the low-voltage conversion module is connected with the silicon detector. The circuit structure is simple and effective, the working voltage needed by the whole detection system is low, and the power consumption and the structural size of an instrument are reduced while the requirement for the wide dose rate measurement range is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of nuclear radiation detection, and more specifically, relates to a wide dose rate detection system and a wide dose rate detection method. Background Art

[0002] In the field of nuclear radiation detection, portable nuclear radiation detectors are widely used in nuclear instruments because of their small size, lightness, ease of operation, ability to record radiation doses in real time, and ability to monitor the dose rate of radioactive rays in a specific area. In nuclear radiation detection instruments, the sensitivity directly affects the dose rate range of the instrument. Usually, the dose rate range required for radiation protection ranges from 10μSv / h-10mSv / h, and the energy range is 50keV-1.5MeV. For some radiation scenarios with a wide dose rate detection range, the range coverage can reach 7 to 8 orders of magnitude. At present, most of the domestic portable nuclear radiation monitoring instruments adopt a single detector design, and using only a single detector to achieve such a wide detection range will pose a great challenge to the detector design and the electronics system. Considering that each nuclear radiation probe has its own advantages and disadvantages, in order to meet the application requirements of wide dose rate detection, multiple nuclear radiation probes are often combined internationally. This multi-probe combination method fills the defects brought by a single detector and expands the detection range of the entire detection instrument. However, in the use of combined detectors, most of the combined nuclear radiation detectors used at home and abroad use a combination of GM counter tubes and scintillators, in which scintillators are mostly matched with photomultiplier tubes, but the use of photomultiplier tubes will increase the size of the detector and increase power consumption. At the same time, although the GM counter tube is cheap and simple in structure, its application is limited due to its limited life, high voltage required for operation, and relatively large size. Summary of the invention

[0003] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a wide dose rate detection system and a wide dose rate detection method. The circuit structure is simple and effective, the operating voltage required by the entire detection system is low and the detector size is small. While meeting the requirements of a wide dose rate measurement range, the power consumption and structural volume of the instrument are reduced.

[0004] As a first aspect of the present invention, a wide dose rate detection system is provided, including a scintillator detection module, a silicon detector detection module, a voltage conversion module, a signal processing module and a power supply module, wherein the scintillator detection module includes a scintillator, a silicon photomultiplier tube and a first signal conditioning module, the scintillator is connected to the silicon photomultiplier tube, the silicon photomultiplier tube is connected to the first signal conditioning module, the silicon detector detection module includes a silicon detector and a second signal conditioning module, the silicon detector is connected to the second signal conditioning module, the voltage conversion module includes a high voltage conversion module and a low voltage conversion module, the signal processing module includes a single chip microcomputer, the first signal conditioning module and the second signal conditioning module are connected to the first signal conditioning module, the voltage conversion module includes a high voltage conversion module and a low voltage conversion module, the signal processing module includes a single chip microcomputer, the first signal conditioning module and the second signal conditioning module are connected to the first signal conditioning module, the voltage conversion module includes a high voltage conversion module and a low voltage conversion module, the voltage conversion module includes a high voltage conversion module and a low voltage conversion module, the voltage conversion module includes a high voltage conversion module and a low voltage conversion module, the voltage conversion module includes a single chip microcomputer, the first signal conditioning module and the second signal conditioning module are connected to ... Both signal conditioning modules are connected to the single-chip microcomputer, and the single-chip microcomputer is connected to the high-voltage conversion module and the low-voltage conversion module respectively. The power supply module is used to supply power to the scintillator detection module, the silicon detector detection module, the voltage conversion module and the signal processing module; the high-voltage conversion module is connected to the silicon photomultiplier tube to provide the working voltage of the silicon photomultiplier tube; the low-voltage conversion module is connected to the silicon detector to provide the working voltage of the silicon detector; the scintillator detection module is used to detect radiation rays within the low dose rate range; the silicon detector detection module is used to detect radiation rays within the high dose rate range; the single-chip microcomputer is used to receive, process and output signals.

[0005] As a further improvement of the present invention, the scintillator is used to convert the radiation energy of X / γ rays into visible light; the silicon photomultiplier tube is used to receive the visible light output by the scintillator and convert the visible light into a first charge signal; the first signal conditioning module is used to process the first charge signal output by the silicon photomultiplier tube into a first voltage pulse signal; the single-chip computer obtains the counting rate of the first voltage pulse signal, determines the current dose rate value based on the counting rate of the first voltage pulse signal, and displays the current dose rate value.

[0006] As a further improvement of the present invention, the first signal conditioning module includes a signal amplification circuit and a first signal comparison circuit; the signal amplification circuit is used to amplify the first charge signal output by the silicon photomultiplier tube to output the amplified first charge signal; the first signal comparison circuit is used to identify the amplified first charge signal to output the first voltage pulse signal.

[0007] As a further improvement of the present invention, the signal amplification circuit includes an AC coupling capacitor C5, an amplifier chip A4, a resistor R9 and a resistor R10, and the first signal comparison circuit includes a comparator chip A5, a resistor R11, a resistor R12 and a resistor R13, one end of the AC coupling capacitor C5 is connected to the output end of the silicon photomultiplier tube, the other end of the AC coupling capacitor C5 is connected to the positive input end of the amplifier chip A4, the reverse input end of the amplifier chip A4 is respectively connected to one end of the resistor R9 and one end of the resistor R10, the other end of the resistor R9 is grounded, and the other end of the resistor R10 is connected to the output end of the amplifier chip A4; the positive input end of the comparator chip A5 is connected to the output end of the amplifier chip A4, the reverse input end of the comparator chip A5 is respectively connected to one end of the resistor R11 and one end of the resistor R12, and the output end of the comparator chip A5 is connected to one end of the resistor R13; the other end of the resistor R11 is grounded, and the other end of the resistor R12 and the other end of the resistor R13 are connected to the power supply Vcc.

[0008] As a further improvement of the present invention, the silicon detector is used to convert the radiation energy of X / γ rays into a second charge signal; the second signal conditioning module is used to process the second charge signal output by the silicon detector into a second voltage pulse signal; the single-chip computer obtains the counting rate of the second voltage pulse signal, determines the current dose rate value based on the counting rate of the second voltage pulse signal, and displays the current dose rate value.

[0009] As a further improvement of the present invention, the second signal conditioning module includes a charge-sensitive preamplifier circuit, a pole-zero cancellation circuit, a filtering circuit, a secondary amplifier circuit and a second signal comparison circuit; the charge-sensitive preamplifier circuit is used to preliminarily amplify the second charge signal output by the silicon detector to output the preliminarily amplified second charge signal; the pole-zero cancellation circuit is used to restore the baseline of the preliminarily amplified second charge signal to output the restored second charge signal; the filtering circuit is used to filter the restored second charge signal to output the filtered second charge signal; the secondary amplifier circuit is used to secondary amplify the filtered second charge signal to output the secondary amplified second charge signal; the second signal comparison circuit is used to identify the secondary amplified second charge signal to output the second voltage pulse signal.

[0010] As a further improvement of the present invention, the charge-sensitive preamplifier circuit includes an AC coupling capacitor C1, an amplifier chip A1, an integral capacitor C2 and a discharge resistor R1, the pole-zero cancellation circuit includes a resistor R2 and a capacitor C3, the filter circuit includes a resistor R3 and a capacitor C4, the secondary amplification circuit includes a resistor R4, a resistor R5 and an amplifier chip A2, and the second signal comparison circuit includes a resistor R6, a resistor R7, a resistor R8 and a comparator chip A3; one end of the AC coupling capacitor C1 is connected to the output end of the silicon detector, and the other end of the AC coupling capacitor C1 is respectively connected to one end of the integral capacitor C2, one end of the discharge resistor R1 and the reverse input end of the amplifier chip A1; the positive input end of the amplifier chip A1 is connected to the reference voltage Vref, and the output end of the amplifier chip A1 is respectively connected to the other end of the integral capacitor C2 and the other end of the discharge resistor R1, and is connected to the input end of the pole-zero cancellation circuit; one end of the resistor R2 is connected to one end of the capacitor C3 and intersects with the amplifier chip The output end of the chip A1; the other end of the resistor R2 is connected to the other end of the capacitor C3 and serves as the output end of the pole-zero cancellation circuit; one end of the capacitor C4 is connected to the output end of the pole-zero cancellation circuit, the other end of the capacitor C4 is connected to one end of the resistor R3 and serves as the output end of the filter circuit, and the other end of the resistor R3 is grounded; the positive input end of the amplifier chip A2 is connected to the output end of the filter circuit, the reverse input end of the amplifier chip A2 is respectively connected to one end of the resistor R4 and one end of the resistor R5; the other end of the resistor R4 is grounded; the other end of the resistor R5 is connected to the output end of the amplifier chip A2; the positive input end of the comparator chip A3 is connected to the output end of the amplifier chip A2, the reverse input end of the comparator chip A3 is respectively connected to one end of the resistor R6 and one end of the resistor R7, and the output end of the comparator chip A3 is connected to one end of the resistor R8; the other end of the resistor R6 is grounded, and the other end of the resistor R7 and the other end of the resistor R8 are connected to the power supply Vcc.

[0011] As a further improvement of the present invention, the signal processing module also includes a peripheral circuit connected to the single-chip microcomputer, and the peripheral circuit includes a reset circuit, a clock circuit, a communication circuit, a storage circuit, a key circuit, an sound and light alarm circuit and an LCD display circuit, which are used to provide support and expand functions for the single-chip microcomputer.

[0012] As a further improvement of the present invention, the power module includes a lithium battery, a lithium battery charging circuit, a power conversion circuit and a Type C interface device, the lithium battery charging circuit and the Type C interface device are used to charge the lithium battery; the power conversion circuit is used to convert the voltage of the lithium battery into the operating voltage of the scintillator detection module, the silicon detector detection module, the voltage conversion module and the signal processing module.

[0013] As a second aspect of the present invention, a wide dose rate detection method is provided, comprising the following steps: Starting the scintillator detection module to perform initial detection of radiation rays and initially obtaining a count rate of an output signal of the first signal conditioning module; Obtaining a dose rate value detected initially according to the count rate of the output signal of the first signal conditioning module obtained initially, and displaying the dose rate value detected initially; According to the dose rate value detected initially, determining whether the secondary detection is to switch the silicon detector detection module for detection or to keep the scintillator detection module for detection, and obtaining the dose rate value detected by the secondary detection; wherein, if the dose rate value detected initially is not within the detection dose rate range of the scintillator detection module, the secondary detection is switched to the silicon detector detection module for detection, otherwise the secondary detection keeps the scintillator detection module for detection, and simultaneously displays the dose rate value detected by the secondary detection; According to the secondary detected dose rate value, determine whether the next detection is to be performed using the silicon detector detection module or the scintillator detection module, and obtain the next detected dose rate value; wherein, if the secondary detected dose rate value is not within the detection dose rate range of the current detection module, switch to another detection module for detection, otherwise keep the current detection module to continue detection, and display the next detected dose rate value, and repeat this process.

[0014] Compared with the prior art, the beneficial effects of the present invention are: the combined system structure design of silicon detector and scintillator detector is adopted to expand the dose rate measurement range of the portable nuclear radiation detector. At the same time, in the scintillator detection module, the photomultiplier tube is replaced with a new silicon-based photon detection device SiPM, which reduces the volume and power consumption of the scintillator detection module. In addition, the amplifier circuits in the signal conditioning module of the present invention all adopt a dual-channel broadband low-noise amplifier chip design, which simplifies the circuit structure and facilitates miniaturization design. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a principle block diagram of the wide dose rate detection system provided by the present invention.

[0016] Figure 2 This is a circuit diagram of the first signal conditioning module provided by the present invention.

[0017] Figure 3 This is a circuit diagram of the second signal conditioning module provided by the present invention.

[0018] Figure 4 This is a working flow chart of the wide dose rate detection system provided by the present invention.

[0019] Figure 5 The present invention provides a flow chart of a wide dose rate detection method. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0021] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0022] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to describe the embodiments of the present invention described herein. In addition, similar terms such as "including" and "having" mean that in addition to those contents already listed in "including" and "having", other contents that have not been listed may also be "included" and "having"; for example, a process, method, system, product or device that may include a series of steps or units is not necessarily limited to those steps or units that have been clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0023] like Figure 1As shown, the present invention is a wide dose rate detection system, including a scintillator detection module, a silicon detector detection module, a voltage conversion module, a signal processing module and a power supply module, the scintillator detection module includes a scintillator, a silicon photomultiplier tube SiPM and a first signal conditioning module, the scintillator is connected to the silicon photomultiplier tube, the silicon photomultiplier tube is connected to the first signal conditioning module, the silicon detector detection module includes a silicon detector and a second signal conditioning module, the silicon detector is connected to the second signal conditioning module, the voltage conversion module includes a high voltage conversion module and a low voltage conversion module, the signal processing module includes a single chip microcomputer, the first signal conditioning module and the second The signal conditioning modules are all connected to the single-chip microcomputer, and the single-chip microcomputer is respectively connected to the high-voltage conversion module and the low-voltage conversion module. The power supply module is used to supply power to the scintillator detection module, the silicon detector detection module, the voltage conversion module and the signal processing module; the high-voltage conversion module is connected to the silicon photomultiplier tube to provide the working voltage of the silicon photomultiplier tube; the low-voltage conversion module is connected to the silicon detector to provide the working voltage of the silicon detector; the scintillator detection module is used to detect radiation rays within the low dose rate range; the silicon detector detection module is used to detect radiation rays within the high dose rate range; the single-chip microcomputer is used to receive, process and output signals.

[0024] Specifically, the voltage conversion module is used to control the working states of the scintillator detection module and the silicon detector detection module; the signal processing module is used to process the voltage signal obtained by the detection module and convert it into a dose rate; the power supply module is used to convert the lithium battery voltage into a stable working voltage for each module; and the conduction and shutdown of the high-voltage conversion module and the low-voltage conversion module are controlled by a single-chip microcomputer.

[0025] It should be noted that the high-voltage conversion module first boosts the +5V voltage to 30V through the voltage conversion chip LM2733, and then reduces the 30V voltage to 26V through the LDO voltage regulator chip TPS7A4901DGNT to provide the working bias voltage of the SiPM; the low-voltage conversion module uses the LDO voltage regulator chip AM1117-3.3 to reduce the 5V voltage to 3.3V to provide the working bias voltage of the silicon detector.

[0026] It should be noted that both the scintillator detection module and the silicon detector detection module are designed as independent circuit modules.

[0027] Preferably, the scintillator adopts a 10×10×10 mm³ CsI (Tl) scintillator, which is used to convert the radiation energy of X / γ rays into visible light; the silicon photomultiplier tube is a photoelectric detection device used in the field of light detection that has gradually emerged in recent years. Compared with the traditional PMT (photomultiplier tube), SiPM has the advantages of small size and can work under low bias voltage. The selected SIPM has a photosensitive area of ​​3 mm×3 mm, which is connected to the CsI (Tl) scintillator by bonding, and is used to receive the visible light output by the scintillator and convert the visible light into a first charge signal, which is 10 -7 ~10 -2 Gy / h dose rate range; the first signal conditioning module is used to process the first charge signal output by the silicon photomultiplier tube into a first voltage pulse signal; the single-chip computer obtains the count rate of the first voltage pulse signal, determines the current dose rate value according to the count rate of the first voltage pulse signal, and displays the current dose rate value.

[0028] Preferably, the first signal conditioning module includes a signal amplification circuit and a first signal comparison circuit; the signal amplification circuit is used to amplify the first charge signal output by the silicon photomultiplier tube to output the amplified first charge signal; the first signal comparison circuit is used to identify the amplified first charge signal to output the first voltage pulse signal.

[0029] Specifically, Figure 2 As shown, the signal amplification circuit includes an AC coupling capacitor C5, an amplifier chip A4, a resistor R9 and a resistor R10, and the first signal comparison circuit includes a comparator chip A5, a resistor R11, a resistor R12 and a resistor R13. One end of the AC coupling capacitor C5 is connected to the output end of the silicon photomultiplier tube, and the other end of the AC coupling capacitor C5 is connected to the positive input end of the amplifier chip A4. The reverse input end of the amplifier chip A4 is respectively connected to one end of the resistor R9 and one end of the resistor R10, the other end of the resistor R9 is grounded, and the other end of the resistor R10 is connected to the output end of the amplifier chip A4; the positive input end of the comparator chip A5 is connected to the output end of the amplifier chip A4, the reverse input end of the comparator chip A5 is respectively connected to one end of the resistor R11 and one end of the resistor R12, and the output end of the comparator chip A5 is connected to one end of the resistor R13; the other end of the resistor R11 is grounded, and the other end of the resistor R12 and the other end of the resistor R13 are connected to the power supply Vcc.

[0030] It should be noted that the amplifier chip A4 adopts the broadband low-noise amplifier chip OPA694, whose gain bandwidth reaches 675MHz; the comparator chip A5 adopts the low-power, high-speed comparator chip AD8042, whose output response time is 32ns and the conversion rate reaches 200V / us.

[0031] Preferably, the silicon detector has a depletion layer thickness of 300 μm and a sensitive area of ​​25 mm 2 The Si-PIN detector has the characteristics of small size, low operating voltage and high reliability, which is very beneficial to reducing the size and power consumption of the dose instrument. It is used to convert the radiation energy of X / γ rays into the second charge signal. -3 It has good measurement linearity within the dose rate range of 1000 to 2000 Gy / h; the second signal conditioning module is used to process the second charge signal output by the silicon detector into a second voltage pulse signal; the single-chip microcomputer obtains the count rate of the second voltage pulse signal, determines the current dose rate value according to the count rate of the second voltage pulse signal, and displays the current dose rate value.

[0032] Preferably, the second signal conditioning module includes a charge-sensitive preamplifier circuit, a pole-zero cancellation circuit, a filtering circuit, a secondary amplifier circuit and a second signal comparison circuit; the charge-sensitive preamplifier circuit is used to preliminarily amplify the second charge signal output by the silicon detector to output the preliminarily amplified second charge signal; the pole-zero cancellation circuit is used to restore the baseline of the preliminarily amplified second charge signal to output the restored second charge signal; the filtering circuit is used to filter the restored second charge signal (suppress signal noise and stabilize the waveform) to output the filtered second charge signal; the secondary amplifier circuit is used to secondary amplify the filtered second charge signal to output the secondary amplified second charge signal; the second signal comparison circuit is used to identify the secondary amplified second charge signal to output the second voltage pulse signal.

[0033] Specifically, Figure 3As shown, the charge sensitive preamplifier circuit includes an AC coupling capacitor C1, an amplifier chip A1, an integral capacitor C2 and a discharge resistor R1, the integral capacitor C2 is selected to be 0.5pF, and the discharge resistor R1 is selected to be 200MΩ; the pole-zero cancellation circuit includes a resistor R2 and a capacitor C3, the filter circuit includes a resistor R3 and a capacitor C4, the secondary amplification circuit includes a resistor R4, a resistor R5 and an amplifier chip A2, and the second signal comparison circuit includes a resistor R6, a resistor R7, a resistor R8 and a comparator chip A3; one end of the AC coupling capacitor C1 is connected to the output end of the silicon detector, and the other end of the AC coupling capacitor C1 is connected to the integral capacitor C3 and the comparator chip A3 respectively. One end of the capacitor C2, one end of the discharge resistor R1 and the reverse input end of the amplifier chip A1 are connected; the positive input end of the amplifier chip A1 is connected to the reference voltage Vref, wherein the reference voltage Vref is obtained by resistive voltage division of the power supply, and the amplifier chip A1 adopts one channel of the dual-channel high-gain bandwidth and low-noise operational amplifier chip AD8066, the input end of the chip adopts JFET, the input bias current is only 2pA, the input offset voltage is only 400μV, and the gain bandwidth is 145MHz; the amplifier chip A2 adopts another channel of the dual-channel high-gain bandwidth and low-noise operational amplifier chip AD8066; the comparator chip A3 adopts wide With low-noise amplifier chip OPA694; the output end of the amplifier chip A1 is respectively connected to the other end of the integrating capacitor C2 and the other end of the discharge resistor R1, and is connected to the input end of the pole-zero cancellation circuit; one end of the resistor R2 is connected to one end of the capacitor C3 and intersects at the output end of the amplifier chip A1; the other end of the resistor R2 is connected to the other end of the capacitor C3 and serves as the output end of the pole-zero cancellation circuit; one end of the capacitor C4 is connected to the output end of the pole-zero cancellation circuit, the other end of the capacitor C4 is connected to one end of the resistor R3 and serves as the output end of the filter circuit, and the other end of the resistor R3 is grounded; The positive input terminal is connected to the output terminal of the filter circuit, and the reverse input terminal of the amplifier chip A2 is respectively connected to one end of the resistor R4 and one end of the resistor R5; the other end of the resistor R4 is grounded; the other end of the resistor R5 is connected to the output terminal of the amplifier chip A2; the positive input terminal of the comparator chip A3 is connected to the output terminal of the amplifier chip A2, and the reverse input terminal of the comparator chip A3 is respectively connected to one end of the resistor R6 and one end of the resistor R7, and the output terminal of the comparator chip A3 is connected to one end of the resistor R8; the other end of the resistor R6 is grounded, and the other end of the resistor R7 and the other end of the resistor R8 are connected to the power supply Vcc.

[0034] Preferably, the signal processing module also includes a peripheral circuit connected to the single-chip microcomputer, and the peripheral circuit includes a reset circuit, a clock circuit, a communication circuit, a storage circuit, a key circuit, an audible and visual alarm circuit, and an LCD display circuit, which are used to provide necessary support and extended functions for the single-chip microcomputer. The single-chip microcomputer is a 32-bit microcontroller STM32F103C8T6 based on the Cortex-M3 core launched by STMicroelectronics (ST), which is mainly used to receive, process and output signals.

[0035] Preferably, the power module includes a lithium battery, a lithium battery charging circuit, a power conversion circuit and a Type C interface device, the lithium battery charging circuit and the Type C interface device are used to charge the lithium battery; the power conversion circuit is used to convert the voltage of the lithium battery into the operating voltage of the scintillator detection module, the silicon detector detection module, the voltage conversion module and the signal processing module.

[0036] It should be noted that the lithium battery is a 703048 type 3.7V-1000mAh polymer lithium battery, which is used as the power supply for the detection system; the lithium battery charging circuit uses the TP4056 chip, which is a linear charger for single-cell lithium batteries using constant current or constant voltage. The TP4056 chip has a SOP8 / MSOP8 package with a heat sink at the bottom, a small number of external components, and can be suitable for USB power supply, meeting the requirements of type-c charging line work and portable application requirements; the power conversion circuit uses the DC / DC direct current boost chip SX1308 to boost the output voltage of the lithium battery to 5V, and converts the output voltage of SX1308 into a stable 3.3V power supply voltage through the TLV1117LV33DCYR linear regulator.

[0037] The invention provides a wide dose rate detection system, which has a simple and effective circuit structure and adopts a combined design of a silicon detector and a scintillator detector, wherein the silicon detector uses a Si-PIN detector to measure a high dose rate range, and uses a scintillator with a smaller Si-PM to measure a low dose rate range. Considering that the photomultiplier tube and the GM counter tube require a high voltage of several hundred volts and are large in size, which is not conducive to the design concept of being portable, through the combined design of these two detectors, the operating voltage required for the entire detection system is lower and the detector size is smaller, which reduces the power consumption and structural volume of the instrument while meeting the requirements of a wide dose rate measurement range.

[0038] In this embodiment, a wide dose rate detection method is also provided. Figure 5 Please also refer to Figure 4 , the wide dose rate detection method comprises the following steps: Starting the scintillator detection module to perform initial detection of radiation rays and initially obtaining a count rate of an output signal of the first signal conditioning module; Obtaining a dose rate value detected initially according to the count rate of the output signal of the first signal conditioning module obtained initially, and displaying the dose rate value detected initially; According to the dose rate value detected initially, determining whether the secondary detection is to switch the silicon detector detection module for detection or to keep the scintillator detection module for detection, and obtaining the dose rate value detected by the secondary detection; wherein, if the dose rate value detected initially is not within the detection dose rate range of the scintillator detection module, the secondary detection is switched to the silicon detector detection module for detection, otherwise the secondary detection keeps the scintillator detection module for detection, and simultaneously displays the dose rate value detected by the secondary detection; It should be noted that, if the dose rate value detected for the first time is greater than the set dose rate threshold, it is determined that the secondary detection enters the high-range detection state, and the single-chip microcomputer turns off the scintillator detection module by turning off the high-voltage conversion module, and at the same time, the single-chip microcomputer turns on the silicon detector detection module for detection by turning on the low-voltage conversion module; if the dose rate value detected for the first time is less than or equal to the set dose rate threshold, it is determined that the secondary detection enters the low-range detection state, and the single-chip microcomputer controls the high-voltage conversion module to continue to be turned on to keep the scintillator detection module from continuing to detect; in the secondary detection process, the dose rate value detected by the current detection module is obtained by the single-chip microcomputer and displayed on the display screen, and the next detection is entered at the same time; According to the dose rate value detected by the secondary detection, it is determined whether the next detection is to be performed using the silicon detector detection module or the scintillator detection module, and the dose rate value detected next time is obtained through the single-chip microcomputer; wherein, if the dose rate value detected by the secondary detection is not within the detection dose rate range of the current detection module, another detection module is switched to perform detection, otherwise the current detection module is maintained to continue detection, and the dose rate value detected next time is displayed, and this is repeated.

[0039] Through the above process, the high-range detection module and the low-range detection module in the wide dose rate detection system can keep the measured dose rates within the measured range when performing radiation detection. At the same time, fast automatic switching between high and low range detection is achieved.

[0040] The present invention provides a wide dose rate detection method, which can switch to a silicon detector for detection through a voltage conversion module when the detection dose rate of a scintillator detector reaches an upper limit. The combination of these two detectors can detect X / γ rays in a larger dose rate range, solving the problem of insufficient detection upper limit of existing scintillator detectors.

[0041] In summary, the wide dose rate detection system and detection method provided by the present invention can expand the dose rate measurement range of portable nuclear radiation detectors while simplifying the device volume and power consumption. Combined detection of two detectors, silicon detector and scintillator detector, can achieve 10 -7 Detection of dose rates of nearly 8 orders of magnitude ~10Gy / h.

[0042] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A wide dose rate detection system, characterized in that: It comprises a scintillator detection module, a silicon detector detection module, a voltage conversion module, a signal processing module and a power supply module. The scintillator detection module comprises a scintillator, a silicon photomultiplier tube and a first signal conditioning module. The scintillator is connected to the silicon photomultiplier tube, and the silicon photomultiplier tube is connected to the first signal conditioning module. The silicon detector detection module comprises a silicon detector and a second signal conditioning module, and the silicon detector is connected to the second signal conditioning module. The voltage conversion module comprises a high-voltage conversion module and a low-voltage conversion module. The signal processing module comprises a single-chip microcomputer. The first signal conditioning module and the second signal conditioning module are both connected to the single-chip microcomputer, and the single-chip microcomputer is respectively connected to the high-voltage conversion module and the low-voltage conversion module. The power supply module is used to supply power to the scintillator detection module, the silicon detector detection module, the voltage conversion module and the signal processing module; the high-voltage conversion module is connected to the silicon photomultiplier tube to provide the working voltage of the silicon photomultiplier tube; the low-voltage conversion module is connected to the silicon detector to provide the working voltage of the silicon detector; the scintillator detection module is used to detect radiation rays within a low dose rate range; The silicon detector detection module is used to detect radiation rays within a high dose rate range; the single chip microcomputer is used to receive, process and output signals.

2. The wide dose rate detection system according to claim 1, characterized in that: The scintillator is used to convert the radiation energy of X / γ rays into visible light; the silicon photomultiplier tube is used to receive the visible light output by the scintillator and convert the visible light into a first charge signal; the first signal conditioning module is used to process the first charge signal output by the silicon photomultiplier tube into a first voltage pulse signal; the single-chip computer obtains the counting rate of the first voltage pulse signal, determines the current dose rate value according to the counting rate of the first voltage pulse signal, and displays the current dose rate value.

3. The wide dose rate detection system according to claim 2, characterized in that: The first signal conditioning module includes a signal amplification circuit and a first signal comparison circuit; the signal amplification circuit is used to amplify the first charge signal output by the silicon photomultiplier tube to output the amplified first charge signal; The first signal comparison circuit is used to identify the amplified first charge signal to output the first voltage pulse signal.

4. The wide dose rate detection system according to claim 3, characterized in that: The signal amplification circuit includes an AC coupling capacitor C5, an amplifier chip A4, a resistor R9 and a resistor R10. The first signal comparison circuit includes a comparator chip A5, a resistor R11, a resistor R12 and a resistor R13. One end of the AC coupling capacitor C5 is connected to the output end of the silicon photomultiplier tube, and the other end of the AC coupling capacitor C5 is connected to the positive input end of the amplifier chip A4. The reverse input end of the amplifier chip A4 is respectively connected to one end of the resistor R9 and one end of the resistor R10. The other end of the resistor R9 is grounded, and the other end of the resistor R10 is connected to the output end of the amplifier chip A4. The positive input end of the comparator chip A5 is connected to the output end of the amplifier chip A4. The reverse input end of the comparator chip A5 is respectively connected to one end of the resistor R11 and one end of the resistor R12. The output end of the comparator chip A5 is connected to one end of the resistor R13. The other end of the resistor R11 is grounded, and the other end of the resistor R12 and the other end of the resistor R13 are connected to the power supply Vcc.

5. The wide dose rate detection system according to claim 1, characterized in that: The silicon detector is used to convert the radiation energy of X / γ rays into a second charge signal; the second signal conditioning module is used to process the second charge signal output by the silicon detector into a second voltage pulse signal; the single-chip computer obtains the counting rate of the second voltage pulse signal, determines the current dose rate value according to the counting rate of the second voltage pulse signal, and displays the current dose rate value.

6. The wide dose rate detection system according to claim 5, characterized in that: The second signal conditioning module includes a charge-sensitive preamplifier circuit, a pole-zero phase cancellation circuit, a filter circuit, a secondary amplifier circuit, and a second signal comparison circuit; the charge-sensitive preamplifier circuit is used to preliminarily amplify the second charge signal output by the silicon detector to output the preliminarily amplified second charge signal; The pole-zero cancellation circuit is used to restore the baseline of the preliminarily amplified second charge signal to output a restored second charge signal; The filtering circuit is used to filter the restored second charge signal to output the filtered second charge signal; the secondary amplification circuit is used to secondary amplify the filtered second charge signal to output the secondary amplified second charge signal; The second signal comparison circuit is used to identify the second charge signal after the second amplification to output the second voltage pulse signal.

7. The wide dose rate detection system according to claim 6, characterized in that: The charge-sensitive preamplifier circuit includes an AC coupling capacitor C1, an amplifier chip A1, an integrating capacitor C2 and a discharge resistor R1, the pole-zero cancellation circuit includes a resistor R2 and a capacitor C3, the filter circuit includes a resistor R3 and a capacitor C4, the secondary amplification circuit includes a resistor R4, a resistor R5 and an amplifier chip A2, and the second signal comparison circuit includes a resistor R6, a resistor R7, a resistor R8 and a comparator chip A3; one end of the AC coupling capacitor C1 is connected to the output end of the silicon detector, and the other end of the AC coupling capacitor C1 is respectively connected to one end of the integrating capacitor C2, one end of the discharge resistor R1 and the reverse input end of the amplifier chip A1; the positive input end of the amplifier chip A1 is connected to the reference voltage Vref, and the output end of the amplifier chip A1 is respectively connected to the other end of the integrating capacitor C2 and the other end of the discharge resistor R1, and is connected to the input end of the pole-zero cancellation circuit; one end of the resistor R2 is connected to one end of the capacitor C3 and intersects with the output of the amplifier chip A1 end; the other end of the resistor R2 is connected to the other end of the capacitor C3 and serves as the output end of the pole-zero cancellation circuit; one end of the capacitor C4 is connected to the output end of the pole-zero cancellation circuit, the other end of the capacitor C4 is connected to one end of the resistor R3 and serves as the output end of the filter circuit, and the other end of the resistor R3 is grounded; the positive input end of the amplifier chip A2 is connected to the output end of the filter circuit, the reverse input end of the amplifier chip A2 is respectively connected to one end of the resistor R4 and one end of the resistor R5; the other end of the resistor R4 is grounded; the other end of the resistor R5 is connected to the output end of the amplifier chip A2; the positive input end of the comparator chip A3 is connected to the output end of the amplifier chip A2, the reverse input end of the comparator chip A3 is respectively connected to one end of the resistor R6 and one end of the resistor R7, and the output end of the comparator chip A3 is connected to one end of the resistor R8; the other end of the resistor R6 is grounded, and the other end of the resistor R7 and the other end of the resistor R8 are connected to the power supply Vcc.

8. The wide dose rate detection system according to claim 1, characterized in that: The signal processing module also includes a peripheral circuit connected to the single-chip microcomputer, and the peripheral circuit includes a reset circuit, a clock circuit, a communication circuit, a storage circuit, a key circuit, an audible and visual alarm circuit and an LCD display circuit, which are used to provide support and expansion functions for the single-chip microcomputer.

9. The wide dose rate detection system according to claim 1, wherein: The power module includes a lithium battery, a lithium battery charging circuit, a power conversion circuit and a Type C interface device. The lithium battery charging circuit and the Type C interface device are used to charge the lithium battery; the power conversion circuit is used to convert the voltage of the lithium battery into the operating voltage of the scintillator detection module, the silicon detector detection module, the voltage conversion module and the signal processing module.

10. A wide dose rate detection method, applied to the wide dose rate detection system according to any one of claims 1 to 9, characterized in that: The wide dose rate detection method comprises the following steps: Starting the scintillator detection module to perform initial detection of radiation rays and initially obtaining a count rate of an output signal of the first signal conditioning module; Obtaining a dose rate value detected initially according to the count rate of the output signal of the first signal conditioning module obtained initially, and displaying the dose rate value detected initially; According to the dose rate value detected initially, determining whether the secondary detection is to switch the silicon detector detection module for detection or to keep the scintillator detection module for detection, and obtaining the dose rate value detected by the secondary detection; wherein, if the dose rate value detected initially is not within the detection dose rate range of the scintillator detection module, the secondary detection is switched to the silicon detector detection module for detection, otherwise the secondary detection keeps the scintillator detection module for detection, and simultaneously displays the dose rate value detected by the secondary detection; According to the secondary detected dose rate value, determine whether the next detection is to be performed using the silicon detector detection module or the scintillator detection module, and obtain the next detected dose rate value; wherein, if the secondary detected dose rate value is not within the detection dose rate range of the current detection module, switch to another detection module for detection, otherwise keep the current detection module to continue detection, and display the next detected dose rate value, and repeat this process.

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