Low-cost desktop type scintillation detection system and multi-spectrum method
阅读说明：本技术 一种低成本桌面式闪烁探测系统及多谱方法 (Low-cost desktop type scintillation detection system and multi-spectrum method ) 是由 邓贞宙 唐庆 李永绣 王玉皞 于 2020-05-15 设计创作，主要内容包括：本发明涉及闪烁探测技术领域,提供一种低成本桌面式闪烁探测系统及多谱方法,其包括PC机、电压管理模块、闪烁探测装置、信号处理模块和微控制模块；所述PC机用于对闪烁探测系统进行测试操作、以太网连接和能谱显示；所述电源管理模块为闪烁探测系统的各个工作模块提供工作电压；所述探测器模块探测物质发生电离辐射时产生的闪光,将伽马射线转化为电信号,获取连续的脉冲信号；所述信号处理模块用于将探测器模块产生的微弱的不稳定的信号进行放大和滤波处理,输出稳定的连续脉冲信号到微控制模块；所述微控制模块将连续脉冲信号通过多谱方法对数据进行采样实现模数转换,再对转换后的数字信号进行处理,传输到PC机显示器显示能谱图。(The invention relates to the technical field of scintillation detection, and provides a low-cost desktop scintillation detection system and a multispectral method, wherein the desktop scintillation detection system comprises a PC (personal computer), a voltage management module, a scintillation detection device, a signal processing module and a micro control module; the PC is used for carrying out test operation, Ethernet connection and energy spectrum display on the scintillation detection system; the power supply management module provides working voltage for each working module of the scintillation detection system; the detector module detects flash light generated when ionizing radiation occurs to a substance, converts gamma rays into electric signals and acquires continuous pulse signals; the signal processing module is used for amplifying and filtering weak unstable signals generated by the detector module and outputting stable continuous pulse signals to the micro control module; the micro control module samples the continuous pulse signals to data through a multi-spectrum method to realize analog-to-digital conversion, processes the converted digital signals and transmits the digital signals to a PC display to display an energy spectrum.)
1. A low-cost desktop scintillation detection system, comprising: the device comprises a USB interface, a power management module, a flicker detection module, a signal processing module, a micro control module and a PC (personal computer);
wherein, the power management module includes: the charging circuit, the rechargeable lithium battery, the 3.3V voltage stabilizing circuit, the 5V voltage stabilizing circuit, the 30.6V booster circuit and the power switch circuit;
the scintillation detection module comprises a scintillation crystal, a light transmission device, a photomultiplier and a preamplifier circuit;
the signal processing module comprises an amplifying circuit and a filtering circuit;
the micro control module comprises: the device comprises a clock module, a key module, a data storage module, an ADC data acquisition module and a main control module;
the PC comprises a host and a display.
2. The low-cost desktop scintillation detection system of claim 1, wherein two USB interfaces are connectable simultaneously;
the USB interface for connecting the commercial power and the flicker detection system is a charging interface of the whole system, the charging plug converts 220V commercial power into 5V direct-current voltage, and the direct-current voltage is transmitted to the USB interface through the USB data line to charge the system; and the USB interface connected with the flicker detection system and the PC is used for transmitting the energy spectrum data detected by the system to the PC through a USB data line and displaying the energy spectrum on the display screen.
3. The low-cost desktop scintillation detection system of claim 1, wherein:
the charging circuit is used for providing working voltage for the whole flicker detection system, is connected with the USB interface and charges the lithium battery with 5V direct current voltage output by the USB interface;
the rechargeable lithium battery adopts a rechargeable lithium battery, and the output voltage is 3.6V to 4.2V;
the 3.3V voltage stabilizing circuit is used for converting the voltage of 3.6V-4.2V output by the battery into stable 3.3V voltage and providing stable working voltage for each module of the system;
the 5V voltage stabilizing circuit is used for stabilizing the voltage at 5V through the 5V voltage stabilizing circuit and providing input voltage for a subsequent booster circuit;
the starting voltage of the detector module is higher than 30V, and the 30.6V booster circuit provides input for the detector;
and the power switch circuit controls the on/off of the whole energy spectrometer system through the operation keys arranged on the shell.
4. The low-cost desktop scintillation detection system of claim 1, wherein: the scintillation detection module utilizes ionizing radiation to generate flashes in certain substances to realize photon detection, converts optical signals into electric signals and acquires continuous electric pulse signals; the scintillation crystal is used for receiving radioactive rays to cause ionization and excitation of scintillation atoms so as to emit scintillation light, and the scintillation crystal can be a single crystal or a scintillator array; the first end of the light transmission device is connected with the scintillation crystal and is used for receiving and transmitting scintillation light emitted from the inside of the scintillation crystal; a photomultiplier tube connected to the second end of the light transmission device for receiving the scintillation light transmitted from the light transmission device; the preamplifier is connected with the output end of the photomultiplier and amplifies the weak continuous electric pulse signal output by the photomultiplier to form a relatively stable continuous pulse signal.
5. The low-cost desktop scintillation detection system of claim 1, wherein: the amplifying circuit amplifies the continuous pulse signals output by the flicker detection module; the filter circuit filters the amplified pulse signals to obtain more stable pulse signals and outputs the more stable pulse signals to the micro-control module.
6. The low-cost desktop scintillation detection system of claim 1, wherein:
a clock module: the circuit comprises a 32.768KHz low-speed external clock circuit and an 8MHz high-speed external clock circuit, and provides a clock working source for the micro-control module;
a key module: the startup and shutdown operations are carried out through keys arranged on the shell;
a data storage module: storing data acquired by a scintillation type hand-held energy spectrometer based on an sql digitization method and a multispectral method into a memory card, and recording the data;
ADC data acquisition module: the system comprises a time sampling module and a voltage threshold module, wherein the time sampling module is used for sampling pulse signals amplified and filtered in a signal processing module to realize A/D conversion of data, processing the converted digital signals and transmitting the processed digital signals to an OLED display module;
a main control module: the monitoring to battery power can be realized, when the system is about to close, the power management module takes place a shutdown signal for microcontroller's main control module, and main control module receives can be after the shutdown signal with data storage before the shutdown, then takes place a shutdown signal for the power management module, and power module receives close the power behind the shutdown signal, the system stop work.
7. The system of claim 1, wherein the PC comprises a host and a display, and is connected to the scintillation detection system via a USB interface, so that the display can display an operation interface of the scintillation detection system and perform operations, and can also display an energy spectrometer generated by the scintillation detection system.
8. A low-cost desktop multi-spectral method, comprising the steps of:
s1: the USB interface is used for connecting a mains supply and a power supply management module of the flicker detection system, providing voltage for the detector system through a USB data line, and can also be used for connecting the detector system and a PC (personal computer) and transmitting an energy spectrum chart to a display;
s2: the power management module charges the system through the USB interface and provides different working voltages for each module of the flicker detection system;
s3: incident radiation is emitted into the scintillation crystal and loses energy in the scintillation crystal to cause ionization and excitation of scintillation atoms, excited electrons can excite visible light, weak unstable electric pulse signals formed by the photoelectrons through a multiplier tube are amplified by a preamplification circuit to form relatively stable pulse signals
S4: the signal processing module comprises an amplifying circuit and a filtering circuit, the continuous pulse signal obtained in the step S2 is amplified through the amplifying circuit, then the amplified signal is filtered through a filter, and then the filtered signal is transmitted to the micro control module;
s5: the microcontroller module samples the pulse signal amplified and filtered in the step S3 to realize A/D conversion of data, and transmits the processed digital signal to a PC display screen for energy spectrum display after processing the converted digital signal;
s6: the PC machine comprises a host machine and a display, wherein the host machine is used for carrying out test operation on the spectrometer, and the display is used for displaying an operation interface and a spectrum diagram output by the detection system.
9. The low-cost desktop multispectral method of claim 8, wherein the energy spectrum can be formed by a plurality of digitization methods during the process from scintillation pulse to energy spectrum formation.
10. The low-cost desktop multispectral method of claim 8, wherein the continuous pulse signal is obtained by: incident radiation is emitted into the scintillation crystal and loses energy in the scintillation crystal to cause ionization and excitation of scintillation atoms, and excited electrons can excite visible light; photons strike a photocathode of a photomultiplier through a light transmission process to generate a photoelectric effect to generate photoelectrons, the photoelectrons are multiplied in the photomultiplier, and finally the electrons enter a signal processing circuit through a positive electrode to form an electric pulse signal of which the pulse amplitude is in direct proportion to the energy of radiation rays.
Technical Field
The invention relates to the technical field of radiation detection, in particular to a low-cost desktop type scintillation detection system and a multispectral method.
Background
With the rapid development of nuclear technology, people are more and more likely to be exposed to radioactive substances in daily life, and particularly, in various aspects such as station security inspection, entry and exit inspection and quarantine, environmental detection, medical treatment and the like, the identification of radioactive nuclides is involved, so that the detection technology for enhancing nuclear radiation becomes particularly important. At present, a scintillation detector is mainly adopted for detection, but the currently adopted detector generally has the problems of high manufacturing cost, unstable energy spectrum technology and the like, the detector is difficult to be widely applied due to the high manufacturing cost, and the detection result is greatly uncertain due to the unstable energy spectrum technology.
Aiming at the problems of the current scintillation detector, the invention provides a low-cost desktop scintillation detection system and a multispectral method, so as to overcome the defects.
Disclosure of Invention
The invention aims to provide a multispectral method which is low in cost, convenient and fast to operate and adopts various digitalizations, namely a multispectral method.
In order to achieve the purpose, the technical scheme adopted by the low-cost desktop type scintillation detection system and the multispectral method provided by the invention is as follows:
including USB interface 110, power management module 200, scintillation detection module 300, signal processing module 400, little control module 500 and PC 600, wherein:
the USB interface 100 is used for connecting the scintillation detector with a mains supply and connecting the scintillation detector with a PC; the low-cost desktop type flicker detection system is provided with two USB interfaces, one USB interface is connected with a charging plug through a USB data line and is a charging interface of the whole system, the charging plug converts 220V alternating voltage of mains supply into 5V direct voltage, and then the direct voltage is transmitted to the USB interface through the USB data line to charge a lithium battery and provide working voltage for the system; and the other USB interface is used for connecting the flicker detection system with the PC, so that the flicker detection system can be operated through the PC, an operation interface and the energy spectrum diagram are displayed through a display of the PC, and data tested by the system can be transmitted to the PC.
The two USB interfaces are identical in structure, are not distinguished in the using process, and simultaneously need to be used simultaneously when the low-cost desktop type scintillation detection system works normally, and the USB interface connected with the
The power management module 200 comprises a battery charging circuit 210, a rechargeable lithium battery 220, a 3.3V voltage stabilizing circuit 230, a 5V voltage stabilizing circuit 240, a 30.6V boosting circuit 250 and a power switch circuit 260, wherein the power management module is used for providing working voltage for each module;
the battery charging circuit 210 is attached to the power management module 200, and is configured to charge the rechargeable lithium battery with the 5V dc voltage output by the USB interface 100, so as to provide a working voltage for the system;
the rechargeable lithium battery 220 belongs to the power management module 200, adopts a rechargeable lithium battery, and has an output voltage of 3.6V to 4.2V;
the 3.3V voltage stabilizing circuit 230 belongs to the power management module 200, converts the voltage of 3.6V-4.2V output by the rechargeable lithium battery into stable 3.3V voltage, and provides stable working voltage for each module of the system;
the 5V voltage stabilizing circuit 240 is attached to the
the 30.6V booster circuit 250 is attached to the power management module 200, the starting voltage of the flicker detection module is required to be higher than 30V, and the 30.6V booster circuit provides input for the flicker detection module;
the power switch circuit 260 is attached to the power management module 200, and controls the whole spectrometer system to be turned on or off through operation keys arranged on the shell.
The flash detection module 300 is used for detecting flash generated by ionizing radiation in certain substances and converting optical signals into electric pulse signals;
a scintillation detection module 300 comprising a scintillation crystal 310, a light transmission device 320, a photomultiplier tube 330, and a preamplification circuit 340; the flicker detection module 300 converts the optical signal into an electrical pulse signal, and outputs the electrical pulse signal to the signal processing module 400;
the scintillation crystal 310 is attached to the scintillation detection module 300, and the scintillation crystal adopted by the system can be a single crystal or a crystal array, and is used for generating energy loss in the scintillation crystal when incident radiation enters the scintillation crystal, so that ionization and excitation of scintillation atoms are caused, and excited electrons emit visible light, wherein the visible light generated in the scintillation crystal is output to the light transmission device 320;
the light transmission device 320 is attached to the scintillation detection module 300, and is configured to receive the visible light output by the scintillation crystal 310 and output the received visible light to the light detection device photomultiplier 330; the light transmission device is arranged between the scintillation crystal and the photomultiplier, is coupled with the photomultiplier, transmits visible light and protects the crystal;
a photomultiplier tube 330 attached to the scintillation detection module 300, connected to a second end of the light transmission device 320, for collecting the visible light output from the light transmission device;
photons are transmitted by a light transmission device and hit a photocathode of a photomultiplier to generate photoelectric effect to generate photoelectrons, the photoelectrons are multiplied in each multiplication stage of the photomultiplier, and finally are gathered at an anode of the photomultiplier to form an electric pulse signal with pulse amplitude in direct proportion to the energy of radiation rays, the number of output pulses is in direct proportion to the intensity of the incident radiation rays, and the electric pulse signal generated in the photomultiplier is output to a preamplifier circuit 340;
the pre-amplifier circuit 340, belonging to the scintillation detection module 300, is configured to amplify the weak unstable electrical pulse signal output from the photomultiplier tube, so as to obtain a relatively stable continuous pulse signal, and output the obtained continuous pulse signal to the signal processing module 400.
The signal processing module 400 is configured to amplify and filter the continuous pulse signal output by the flicker detection module 300;
the signal processing module 400 comprises an amplifying circuit 410 and a filtering circuit 420, and is used for amplifying and filtering signals and outputting the processed signals to the micro control module 500;
the amplifying circuit 410 is attached to the signal processing module 400 and amplifies a weak continuous pulse signal transmitted from the flicker detection module 300, the amplifying circuit adopts an AD8032ARZ chip, and the AD8032 can be formed by two integrated operational amplifiers, so that a first-stage output is used as a second-stage input in the circuit, meanwhile, the second-stage output is connected to a second-stage inverting input end to be used as feedback, the amplified signal is output at an IOUT2 port, and the amplified signal is output to the filter circuit 420;
the filter circuit 420, which is subordinate to the signal processing module 400, performs filtering processing on the amplified signal transmitted by the amplifying circuit, and filters out the interference signal that does not meet the requirement of the required signal, so that the signal is more stable and has stronger interference resistance, and the filter circuit outputs the signal to the micro control module 500.
The micro-control module 500 is used for performing system on-off operation on the spectrometer through keys arranged on the shell; simultaneously collecting detection data and storing the data; realizing A/D conversion of continuous pulse signals;
the micro control module 500 comprises a clock module 510, a key module 520, a data storage module 530, an ADC data acquisition module 540 and a main control module 550, and the micro control module transmits the converted digital signals and an operation interface to a PC for display and interface operation;
the clock module 510 is attached to the microcontroller module 500, and comprises a 32.768KHz low-speed external clock circuit and an 8MHz high-speed external clock circuit, and provides a clock working source for the microcontroller module;
the key module 520 is subordinate to the microcontroller module 500, and realizes the on-off operation of the system through keys arranged on the shell;
the data storage module 530 is subordinate to the microcontroller module 500, stores the data acquired by the scintillation detection system into a memory card, and records the detection data;
the ADC data acquisition module 540 is configured to sample the pulse signal amplified and filtered in the signal processing module, to implement a/D conversion of data, to process the converted digital signal, and to transmit the processed digital signal to the display;
the ADC data acquisition module 540 is subordinate to the micro-control module 500 and comprises a time acquisition module 541 and a voltage threshold module 542;
the time acquisition module 541 is configured to control a sampling interval of the voltage threshold module 542;
the voltage threshold module 542 performs voltage threshold on the analog signal to realize fitting;
the main control module 550 is subordinate to the microcontroller module 500, and the chip adopted by the main control module is STM32F103C8T6, and the chip meets the required interfaces and functions of the system; the monitoring to battery power can be realized, when the system is about to close, the power management module takes place a shutdown signal for microcontroller's main control module, and main control module receives can be after the shutdown signal with data storage before the shutdown, then takes place a shutdown signal for the power management module, and power module receives close the power behind the shutdown signal, the system stop work.
The PC 600 includes a host 610 and a display 620; the flash detection system is connected with a USB interface of the flash detection system through a USB data line, so that the flash detection system is connected with a PC; the PC can display the operation interface and the energy spectrum of the system and operate the system;
the host 610 is used for identifying the detection system, connecting with the system, and carrying out various digital generation energy spectrum operations, energy spectrum display operations and data transmission and storage operations on the detection system;
and the display 620 is used for displaying an operation interface and an energy spectrum diagram of the system.
According to the technical scheme, the desktop scintillation detection system and the multispectral method which are low in cost have simple operation methods, the detector can effectively and stably capture gamma photons, and a stable energy spectrogram can be obtained through the multispectral method.
In order to effectively improve technical stability and energy spectrum accuracy, the invention provides a low-cost desktop scintillation detection system and a multispectral method, which specifically comprise the following steps:
s1: the detection system is provided with two USB interfaces 100, one USB interface is used for connecting a mains supply and a power management module 200 of the flicker detection system and providing 5V voltage for the detection system through a USB data line, and the other USB interface is used for connecting the detection system and a PC 600 and transmitting an energy spectrum diagram to a display through the data line and also transmitting stored detection data to the PC;
s2: the power management module 200 charges the system through the USB interface 100, the USB interface provides a voltage of 5V, and the voltages of different magnitudes are obtained through the 3.3V voltage-stabilizing circuit 230, the 5V voltage-stabilizing circuit 240 and the 30.6V voltage-boosting circuit 250 in the power management module 200, so as to provide different working voltages for each module of the scintillation detection system;
s3: incident radiation is emitted into the scintillation crystal 310 and loses energy in the scintillation crystal, so that ionization and excitation of scintillation atoms are caused, and excited electrons can excite visible light; the photons are transmitted to the photocathode of the photomultiplier through the optical transmission device 320 to generate photoelectric effect to generate photoelectrons, the photoelectrons are multiplied in the photomultiplier, finally the electrons enter the signal processing circuit through the anode to form electric pulse signals with pulse amplitude in direct proportion to the energy of the radiation rays, and weak unstable electric pulse signals formed by the photoelectrons through the multiplier are subjected to signal amplification processing through the preamplification circuit 340 to form relatively stable pulse signals.
S4: the flicker detection module 300 outputs a stable pulse signal to the signal processing module 400, which includes an amplifying circuit 410 and a filter circuit 420, wherein the amplifying circuit amplifies the continuous pulse signal, and then transmits the amplified pulse signal to the filter circuit 420, so as to filter the pulse signal, and then transmits the filtered signal to the micro control module.
S5: the microcontroller module is mainly used for sampling the pulse signals amplified and filtered in the step S3 to realize A/D conversion of data, processing the converted digital signals and transmitting the processed digital signals to a display screen of a PC (personal computer) for energy spectrum display.
And S6, the PC comprises a host computer and a display, wherein the host computer is used for carrying out test operation on the spectrometer, and the display is used for displaying an operation interface and a spectrum diagram output by the detection system.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below.
FIG. 1 is a schematic diagram of a low-cost desktop scintillation detection system and a multispectral method according to an embodiment of the present invention;
FIG. 2 is a block diagram of the power management module of the low-cost desktop scintillation detection system and the multispectral approach of the present invention;
FIG. 3 is a block diagram of the structure of a flicker detection module in the low-cost desktop flicker detection system and multi-spectral method of the present invention;
FIG. 4 is a model diagram of a prototype of the low-cost desktop scintillation detection system and multispectral method of the present invention.
The photoelectric detector comprises a photoelectric detector 1, a
Detailed Description
The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.
As shown in figures 1 to 4 of the drawings,
the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, and the scope of the present invention will be more clearly and clearly defined.
As shown in fig. 1, a low-cost desktop scintillation detection system is comprised of six parts, wherein,
the first part is a USB interface 100, the system is provided with two identical USB interfaces 100, the two identical USB interfaces 100 are not distinguished when in use and are respectively used for connecting the detector with the mains supply and the detector with the PC, namely, the two identical USB interfaces are connected with the power management module 200 and the PC, the USB interface 100 is a charging interface of the whole system, a charging plug converts 220V alternating voltage of the mains supply into 5V direct voltage and is connected to the USB interface through a USB data line, and finally, the 5V direct voltage is provided for the system; the USB interface adopts a standard Micro USB interface, the Micro USB interface has small volume, and the occupied area on the circuit board is small; the system can only work normally after the two USB interfaces are connected correctly.
The second part is a power management module 200, the power management module 200 adjusts the required working voltage through different voltage adjusting circuits, and the power management module comprises a charging circuit 210, a rechargeable lithium battery 220, a 3.3V voltage stabilizing circuit 230, a 5V voltage stabilizing circuit 240, a 30.6V boosting circuit 250 and a power switch circuit 260;
as shown in fig. 2, the charging circuit 210 mainly provides a 5V dc voltage output by the USB interface for the safe charging management of the lithium battery, and a chip in the battery charging circuit in the detector system adopts CN3052A, CN3052A, which can perform constant current or constant voltage charging on a single lithium ion or lithium-polymer rechargeable battery, and output a 4.2V voltage, with a precision of 1%; the rechargeable lithium battery 220 is a lithium battery which can be repeatedly charged, and the output voltage is 3.6V to 4.2V; the 3.3V voltage stabilizing circuit 230 mainly functions to convert the voltage of 3.6V-4.2V output by the battery into stable 3.3V voltage and provide working voltage for each module of the system, the voltage stabilizing chip adopted by the 3.3V voltage stabilizing circuit 230 of the detection system is TPS62291, the TPS62291 is a high-efficiency synchronous voltage-reducing DC/DC converter with the efficiency of 96%, and the converter is optimized and applicable to a portable system powered by the battery; the 5V voltage stabilizing circuit 240 adopts a TPS61240 voltage boosting chip with the conversion efficiency higher than 90% and the conversion precision of +/-2%, the 5V voltage supplied by the USB interface is partially lost through the charging circuit, the voltage value is slightly low, and therefore the voltage with the wide voltage range of 2.3V-5.5V is boosted to 5V through the TPS61240 voltage boosting chip to provide input voltage for the subsequent 30.6V voltage boosting circuit 250; the 30.6V boosting circuit 250 adopts an LT8361 boosting chip as a main chip, the LT8361 is a DC-DC chip which has wide voltage input and can keep high-efficiency work under extremely low output current under the condition of a burst mode, can output stable direct current voltage under the condition of meeting the requirements of people, boosts the voltage of 5V to 30.6V and provides starting voltage for the flicker detection module 300; the power switch circuit 260 adopts a chip LTC2951, and the circuit controls the power management module through a key arranged outside the detector.
The third part is a scintillation detection module 300, which scintillation detection module 300 detects by using ionizing radiation to produce flashes of light in certain substances; incident radiation is emitted into the scintillation crystal and loses energy in the scintillation crystal to cause ionization and excitation of scintillation atoms, and excited electrons can excite visible light; the photons strike the photocathode of the photomultiplier through the light transmission process to generate the photoelectric effect and generate photoelectrons. The photoelectrons are multiplied in the photomultiplier, and finally the electrons enter a signal processing circuit through a positive electrode to form an electric pulse signal with pulse amplitude in direct proportion to the energy of the radiation rays, and the number of the output pulses is in direct proportion to the intensity of the incident radiation rays. The weak unstable electric pulse signal formed by the photoelectrons through the multiplier is amplified by the preamplifier to form a relatively stable pulse signal, and then the relatively stable pulse signal is input to the main amplifier for signal amplification.
The scintillation detection module 300 comprises a scintillation crystal 310, a light transmission device 320, a photomultiplier tube 330, and a preamplifier 340; wherein the content of the first and second substances,
the scintillation crystal 310 may be a single crystal or a 6 x 6 crystal array, wherein the size of the scintillation crystal is determined by the size of the photosensitive surface of the photomultiplier tube, and the scintillation crystal is configured to generate energy loss in the scintillation crystal when incident radiation is incident on the scintillation crystal, causing ionization and excitation of scintillation atoms, such that the excited electrons emit visible light; the light transmission device 320 is made of a glass material and is used for transmitting visible light to the photomultiplier tube 330; the photomultiplier tube 330 is a device that converts visible light into an analog pulse signal, and the photomultiplier tube used in the present scintillation detection system is a position-sensitive photomultiplier tube (PS-PMT); the preamplifier 340 is used for amplifying the analog pulse signal generated in the photomultiplier.
The fourth part is a signal processing module 400, which includes an amplifying circuit 410 and a filtering circuit 420, and is used for amplifying and filtering the pulse signal, so that the signal-to-noise ratio of the system can be improved, the relative influence of external interference can be reduced, the signal can be amplified to facilitate a/D sampling, impedance conversion and matching can be realized, and the signal processing module is designed to have high input impedance and low output impedance;
the chip of the amplifying circuit in the scintillation detection system adopts AD8032ARZ and AD8032ARZ single power supply, low-noise and low-distortion operational amplifier, and the series of operational amplifiers can operate in the power supply range of +2.7V (+ -1.35V) to +12V (+ -18V). This device employs a miniature package and provides low offset, drift and bandwidth while ensuring that the low quiescent current input range includes a negative power supply. The AD8032 amplifier circuit adopts an in-phase proportional amplification circuit, and the AD8032 can be seen to be composed of two integrated operational amplifiers, so that the first-stage output is used as the second-stage input in the circuit, meanwhile, the second-stage output is connected to the second-stage inverting input end to be used as feedback, and an amplified signal is output at an IOUT2 port.
The fifth part is a micro control module 500 which mainly samples the analog pulse signal to realize the A/D conversion of the data, then carries out a series of treatments on the converted digital signal, then transmits the treated data to a display through a USB interface to display, and simultaneously can store the data; the chip adopted by the micro-control module 500 is STM32F103C8T6, the chip meets the required interface and function of the system, the power supply management module provides working voltage for the STM32 chip, and the STM32 clock module consists of two crystal oscillator circuits 32.768KHz low-speed external clock circuits and an 8MHz high-speed external clock circuit and provides a clock working source for the STM32 main control module. Analog pulse signals of the detector are adjusted by the signal adjusting circuit and then transmitted to an ADC of an STM32 main control module for analog-to-digital conversion, then data are processed, and then the data are sent to a display for display.
The sixth part is a PC 600, which includes a host 610 and a display 620, the host 610 is used for testing, saving and other operations of the detection system, and the display 620 is used for displaying an operation interface and a power spectrum diagram.
FIG. 4 is a model diagram of a prototype of the low-cost desktop scintillation detection system and multispectral method of the present invention. The device comprises a display 1, a
After the power supply is connected, the PC is turned on, the two USB interfaces of the detector are connected, and after the line connection is checked to be correct, a switch key of the detector is pressed for detection; in the experiment, a 6 x 6 scintillation crystal array is adopted, scintillation pulses detected by a detector are transmitted to a display screen of a PC (personal computer) for scintillation pulse display, and finally, the stored scintillation pulses are synthesized into an energy spectrogram by a plurality of digital methods.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention. The present invention is not to be limited by the specific embodiments disclosed herein, and other embodiments that fall within the scope of the claims of the present application are intended to be within the scope of the present invention.
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