A fully automatic sample-changing measurement and analysis system and control method for gamma spectrum measurement

Abstract

The present invention relates to the field of radiation monitoring technology, and discloses a fully automatic sample exchange measurement and analysis system and control method for gamma spectrum measurement. The system includes: a low-background lead chamber, a gamma spectrometer, a six-axis manipulator, a PLC control component, an industrial computer, a sample waiting area, and a sample tested area. The method includes: presetting a sample exchange sequence and measurement parameters; the PLC drives the six-axis manipulator to grab the sample, opens and closes the lead cover after confirmation by a sensor, and completes automatic measurement using the gamma spectrometer; the measured spectrum is automatically analyzed by the industrial computer using a nuclide library, initially using a sub-classification library to identify the nuclide. If there is an unidentified energy peak, the nuclide library is switched for secondary analysis, and the activity concentration of the target characteristic radionuclide is calculated in combination with the efficiency curve and a report is generated. The present invention can achieve unattended fully automatic sample exchange, adaptive measurement, and intelligent analysis, significantly improving the efficiency of nuclear emergency monitoring.

Description

Technical Field

[0001] The present invention belongs to the technical field of radiation monitoring, and in particular relates to a gamma spectrum measurement and analysis system with fully automatic sample exchange and a control method. Background Art

[0002] Gamma spectroscopy is the most important detection method in the field of radiation monitoring because it does not destroy samples and can obtain the activity levels of all gamma-emitting radionuclides within a specific energy range (e.g., 50keV to 3000keV) in a single measurement. It is widely used in radiation environmental quality monitoring, nuclear facility supervisory monitoring, and nuclear accident emergency monitoring.

[0003] There are three main types of existing gamma spectroscopy sample changing technologies: the first is the traditional manual sample changing method, where samples are changed manually after a sample measurement is completed. This method requires personnel on duty, is inefficient, and cannot meet the needs of frequent sample changes at night or during nuclear accident emergency monitoring. The second is a sample changing system based on an X / Y-axis manipulator. This technology needs to be designed together with the lead chamber of the gamma spectrometer, can only serve one instrument, occupies a large area, has poor compatibility, and lacks a sample changing logic design that ensures long-term, safe and stable operation. The third is limited to sample changing components, such as sample transfer components, which are mechanical mechanisms and do not belong to a complete fully automatic sample changing system and have no analytical function.

[0004] There are two main types of existing gamma-ray spectrum measurement and analysis technologies: the first relies on technicians to manually strip and interpret the spectrum to obtain measurement information and calculate the measurement results. The entire process is time-consuming and labor-intensive, and is prone to human error. The second method uses the software's preset nuclide library and analysis program to output the results, and then the technicians screen and review them to determine the final analysis results. This method is not very targeted, especially when dealing with complex measurement spectra (such as nuclear accident emergency monitoring). It requires manual and repeated adjustment of the analysis program parameters to obtain accurate results, and it does not belong to fully automatic analysis.

[0005] Therefore, there is an urgent need to develop a fully automatic sample changing measurement and analysis system and control method for gamma energy spectrum measurement, which can realize unmanned fully automatic sample changing, adaptive measurement and intelligent analysis, and significantly improve the efficiency of nuclear emergency monitoring. Summary of the Invention

[0006] In order to solve the above technical problems, the present invention provides a gamma energy spectrum measurement fully automatic sample change measurement and analysis system and control method, which can realize unattended fully automatic sample change, adaptive measurement and intelligent analysis, and significantly improve the efficiency of nuclear emergency monitoring.

[0007] The present invention provides a fully automatic sample-changing measurement and analysis system for gamma spectrum measurement, the system comprising: a low-background lead chamber, a gamma spectrometer, a six-axis manipulator, a PLC control component, an industrial computer, a sample waiting area and a sample tested area;

[0008] The low-background lead chamber is used to hold samples and shield the external environment from ionizing radiation. The top is equipped with a lead cover that opens and closes automatically driven by a motor.

[0009] Gamma spectrometer, located below the low-background lead chamber, is used to automatically measure the gamma spectrum of the sample;

[0010] Sample testing area, used for placing samples to be tested;

[0011] The sample measured area is used to place the samples that have completed the measurement;

[0012] The six-axis manipulator is used to grab the samples to be tested placed in the sample waiting area and place them into the low-background lead chamber, and to grab the samples that have been measured from the low-background lead chamber and place them into the sample tested area;

[0013] PLC control component, used to send and receive signals to other modules in the system;

[0014] Industrial computer, used to run control software and store measurement data.

[0015] Furthermore, pressure sensors are provided at the bottom of the sample box in the sample to be tested area and the sample tested area, for sending a sample in place status signal to the PLC control component.

[0016] Furthermore, the lead cover is divided into two parts, each of which is equipped with a set of motors. A proximity sensor is provided at one end where the two parts of the lead cover are connected, and the opening and closing status signal is fed back to the PLC control component through the proximity sensor outside the lead cover.

[0017] Furthermore, the industrial computer has a built-in nuclide library module, which includes an environmental sample library, a nuclear accident emergency library, a radiation accident emergency library and their respective sub-category libraries; the industrial computer has a built-in efficiency curve library module, which stores detection efficiency data according to sample type.

[0018] The present invention also provides a control method for a gamma spectrum measurement and analysis system with a fully automatic sample exchange, which is used to execute the above-mentioned gamma spectrum measurement and analysis system with a fully automatic sample exchange, and the method comprises the following steps:

[0019] S1. Preset the sample changing sequence, measurement parameters and analysis parameters through the industrial computer;

[0020] S2, the PLC control component drives the six-axis manipulator to grab the samples in the sample area according to the sample replacement sequence;

[0021] S3, the PLC control component drives the six-axis manipulator to move above the low-background lead chamber after confirming that the sample is successfully grasped based on the sample in-position status signal sent by the pressure sensor in the sample test area;

[0022] S4. The PLC control component controls the motor in the lead cover of the low-background lead chamber to open the lead cover, and after confirming that the lead cover is fully opened through the opening and closing status signal sent by the proximity sensor, drives the six-axis manipulator to place the sample on the detection position of the gamma spectrometer in the low-background lead chamber;

[0023] S5. The PLC control component controls the motor in the lead cover of the low-background lead chamber to close the lead cover, and confirms that the lead cover is completely closed through the opening and closing status signal sent by the proximity sensor;

[0024] S6. The PLC control component sends a command to the gamma spectrometer to start automatic measurement of the sample according to the preset measurement parameters and analysis parameters. After the measurement is completed, the PLC control component automatically stores the measured spectrum to the industrial computer for automatic analysis;

[0025] S7. The PLC control unit controls the motor inside the lead cover of the low-background lead chamber to open the lead cover. After confirming that the lead cover is fully opened through the open / close status signal sent by the proximity sensor, the six-axis manipulator is driven to transfer the sample that has been measured to the sample measurement area. The sample placement is confirmed by the sample in-place status signal sent by the pressure sensor in the sample measurement area.

[0026] S8. The PLC control component repeatedly executes S2-S7 in the order of sample change until the measurement of all samples is completed.

[0027] Furthermore, in S1, the measurement parameters are preset by the industrial computer, including setting the measurement duration and / or setting the detection lower limit threshold of the target characteristic radioactive nuclide, and presetting the nuclide library category and its sub-category library category.

[0028] Furthermore, in S6, the PLC control component sends a command to the gamma spectrometer to start automatic measurement of the sample according to the preset measurement parameters. After the measurement is completed, the PLC control component automatically stores the measured spectrum to the industrial computer for automatic analysis, specifically including:

[0029] S61, the PLC control component calls preset measurement parameters and analysis parameters, controls the gamma spectrometer to automatically complete the measurement of the sample, and performs automatic analysis on the stored measurement spectrum;

[0030] S62, automatic analysis includes searching for energy peaks, calculating energy peak areas, background subtraction, nuclide identification based on pre-set sub-classification library categories, calculation of detection efficiency values ​​based on the efficiency curve library, calculation of activity concentration results of target characteristic radionuclides, and report generation;

[0031] S63, analyzing the report generated in S62. If there is no unidentified energy peak, the automatic analysis process is completed; if there is an unidentified energy peak, proceed to S64;

[0032] S64, switching to the preset nuclide library category for secondary nuclide identification;

[0033] S65. Recalculate the activity concentration of the target characteristic radioactive nuclide based on the result of the secondary nuclide identification and generate a report. The automatic analysis process is completed.

[0034] Furthermore, when the measurement parameters include a lower detection limit threshold of a target characteristic radionuclide, the industrial computer periodically calculates the real-time lower detection limit of the target characteristic radionuclide at preset time intervals during the measurement process;

[0035] When the real-time detection lower limit is lower than the detection lower limit threshold, the measurement is automatically terminated; otherwise, the measurement continues.

[0036] The embodiments of the present invention have the following technical effects:

[0037] The present invention controls the six-axis manipulator through a PLC control component, combines pressure sensors in the sample to be tested area and the sample tested area to provide real-time feedback on the sample in-place status, and a lead cover proximity sensor to monitor the open and closed status, forming a multiple redundant safety mechanism to ensure the safety and reliability of the manipulator's grasping and placement actions, avoid errors or accidents caused by human intervention, and realize continuous automatic sample replacement operations; the industrial computer presets the measurement time and / or detection lower limit threshold, regularly calculates the real-time detection lower limit during measurement and automatically terminates the measurement to achieve time optimization; a built-in multi-level nuclide library (environmental, nuclear accident, radiation accident library and subcategories) and efficiency curve library are used. During analysis, the sub-category library is first matched to identify the nuclides, and the unidentified energy peaks are automatically switched to the large category library for secondary analysis. The activity concentration is calculated in combination with the efficiency curve and the comprehensive correction factor. The multi-level nuclide library mechanism solves the problem of complex spectrum recognition without manual parameter adjustment, realizes automatic analysis, and reduces the number and time of analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 This is a schematic diagram of the overall structure of a fully automatic sample exchange measurement and analysis system for gamma ray spectrum measurement provided by an embodiment of the present invention;

[0040] Figure 2A schematic diagram of a pressure sensor in a fully automatic sample exchange measurement and analysis system for gamma ray spectrum measurement provided by an embodiment of the present invention;

[0041] Figure 3 A schematic diagram of a proximity sensor of a fully automatic sample exchange measurement and analysis system for gamma ray spectrum measurement provided by an embodiment of the present invention;

[0042] Figure 4 A flow chart of a method for controlling automatic sample change in a gamma ray spectrum measurement and analysis system provided by an embodiment of the present invention;

[0043] Figure 5 A logic diagram of a control method for automatic sample changing in a gamma energy spectrum measurement and analysis system provided by an embodiment of the present invention;

[0044] Figure 6 A schematic diagram of the control software interface of a fully automatic sample exchange measurement and analysis system for gamma ray spectrum measurement provided by an embodiment of the present invention;

[0045] Figure 7 A logic diagram of a control method for automatic analysis of a gamma spectrum measurement and analysis system with fully automatic sample exchange is provided in an embodiment of the present invention.

[0046] Description of reference numerals:

[0047] 1-Low-background lead chamber; 2-Gamma spectrometer; 3-Six-axis manipulator; 4-PLC control component; 5-Industrial computer; 6-Sample test area; 7-Sample test area; 8-Pressure sensor; 9-Proximity sensor. DETAILED DESCRIPTION

[0048] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0049] The embodiment of the present invention provides a fully automatic sample exchange measurement and analysis system for gamma ray spectrum measurement, Figure 1 1 is a schematic diagram of the overall structure of a fully automatic sample exchange measurement and analysis system for gamma ray spectrum measurement provided by an embodiment of the present invention. Figure 2 A schematic diagram of a pressure sensor in a gamma ray spectrum measurement and analysis system with fully automatic sample exchange is provided in an embodiment of the present invention. Figure 3 A schematic diagram of a proximity sensor of a fully automatic sample exchange measurement and analysis system for gamma ray spectrum measurement provided by an embodiment of the present invention, see Figure 1-Figure 3 , chest includes:

[0050] Low background lead chamber 1, gamma spectrometer 2, six-axis manipulator 3, PLC control unit 4, industrial computer 5, sample waiting area 6 and sample tested area 7;

[0051] The low-background lead chamber 1 is used to contain samples and shield the ionizing radiation from the external environment. The top is provided with a lead cover that is automatically opened and closed by a motor.

[0052] A gamma spectrometer 2 is provided below the low-background lead chamber 1 and is used to automatically measure the gamma spectrum of the sample;

[0053] The sample test area 6 is used to place the sample to be tested;

[0054] The sample measured area 7 is used to place the samples that have completed the measurement;

[0055] The six-axis manipulator 3 is used to grab the sample to be tested placed in the sample to be tested area 6 and place it into the low-background lead chamber 1, and to grab the sample that has been measured from the low-background lead chamber 1 and place it into the sample tested area 7;

[0056] PLC control component 4, used to send and receive signals to other modules in the system;

[0057] The industrial computer 5 is used to run the control software and store the measurement data.

[0058] In some embodiments, the gamma spectrometer 2 can select different detectors according to the needs of the analysis work, mainly including high purity germanium (HPGe) gamma spectrometer, sodium iodide (NaI) gamma spectrometer, lanthanum bromide (LaBr3) gamma spectrometer, cadmium zinc telluride (CTZ) gamma spectrometer, etc.

[0059] In some embodiments, pressure sensors 8 are provided at the bottom of the sample box in both the sample to be tested area 6 and the sample tested area 7 for sending a sample in place status signal to the PLC control component 4 .

[0060] In some embodiments, the lead cover is divided into two parts, each of which is equipped with a set of motors (not shown in the figure). A proximity sensor 9 is provided at the end where the two parts of the lead cover are connected, and the opening and closing status signal is fed back to the PLC control component through the proximity sensor 9 outside the lead cover.

[0061] Among them, the gamma spectrometer 2, the six-axis manipulator 3, the pressure sensor 8, the proximity sensor 9, and the motor inside the lead cover are electrically connected to the PLC control component 4 respectively, and the PLC control component 4 is electrically connected to the industrial computer 5.

[0062] In some embodiments, the industrial computer is installed with control software, allowing technicians to set parameters via a touch screen to automatically control and analyze the entire system. The system's operating parameters are displayed in real time on the touch screen. The industrial computer 5 also includes a built-in radionuclide library module, which contains an environmental sample library, a nuclear accident emergency library, and a radiation accident emergency library, as well as their respective sub-categorization libraries. The industrial computer 5 also includes a built-in efficiency curve library module, which stores detection efficiency data by sample type.

[0063] In some embodiments, a single six-axis manipulator 3 can also be used as a central execution unit, in conjunction with a PLC control component 4 that uniformly controls multiple low-background lead chambers 1 and multiple gamma spectrometers 2, and a shared industrial computer 5, to form a highly intensive operating system. Based on a preset sample replacement sequence, the six-axis manipulator 3 can simultaneously serve multiple sets of low-background lead chambers 1 and gamma spectrometers 2 within its working radius. When the system is expanded, it is only necessary to add low-background lead chambers 1 and corresponding gamma spectrometers 2 to the area accessible by the six-axis manipulator 3, without the need to add other modules. The newly added modules will automatically connect to the existing control system, and the same PLC control component 4 will coordinate the task queue in real time: for example, after controlling the six-axis manipulator 3 to grab the sample to be tested in the sample waiting area 6, it will be automatically assigned to different low-background lead chambers 1 according to the task requirements; at the same time, the running measurement tasks will synchronously transmit their spectra to the shared industrial computer 5 for parallel analysis. This design enables a single control system to synchronously drive the six-axis robot 3 to perform continuous grasping, precise delivery, and recovery operations for multiple samples, while supporting automatic measurement by multiple gamma spectrometers 2 and online analysis by the industrial computer 5, significantly improving task execution efficiency in high-throughput scenarios.

[0064] The embodiment of the present invention further provides a control method for a gamma spectrum measurement and analysis system with fully automatic sample exchange, which is used to execute the above-mentioned gamma spectrum measurement and analysis system with fully automatic sample exchange, Figure 4 A flow chart of a method for controlling automatic sample changing in a gamma ray spectrum measurement and analysis system provided by an embodiment of the present invention. Figure 5 A logic diagram of a control method for automatic sample change in a gamma spectrum measurement and analysis system provided by an embodiment of the present invention is shown in FIG. Figure 4 and Figure 5 , the method comprises the following steps:

[0065] Before executing the automatic sample exchange analysis process, the technician will put the processed samples into the sample box and place several samples in the sample waiting area in sequence. In this embodiment, the sample waiting area and the sample tested area can each hold 8 samples, and can also be expanded according to work needs.

[0066] S1. Preset the sample changing sequence, measurement parameters and analysis parameters through the industrial computer.

[0067] Specifically, Figure 6A schematic diagram of the control software interface of a gamma ray spectrum measurement and analysis system provided by an embodiment of the present invention, see Figure 6 , open the control software through the touch screen of the industrial computer, set the sample changing order, measurement parameters and analysis parameters; the sample changing order is the measurement order of the samples, and the preset measurement parameters include setting the measurement time and / or setting the detection lower limit threshold of the target characteristic radionuclide, and presetting the nuclide library category and its sub-category library category. Each sample can independently set the measurement start time, end measurement time, detection lower limit threshold of the target characteristic radionuclide and other parameters; the analysis parameters are the known parameters in the formula needed in the analysis process, such as the branching ratio (absolute intensity) of the characteristic gamma-ray full energy component, sample size, etc. The analysis parameters that need to be input are adaptively adjusted according to the selected calculation formula.

[0068] S2, the PLC control component drives the six-axis manipulator to grab the samples in the sample test area according to the sample replacement sequence.

[0069] S3. After the PLC control component confirms that the grasping is successful based on the sample in-place status signal sent by the pressure sensor in the sample test area, it drives the six-axis manipulator to move above the low-background lead chamber.

[0070] S4. The PLC control component controls the motor inside the lead cover of the low-background lead chamber to open the lead cover, and after confirming that the lead cover is fully opened through the opening and closing status signal sent by the proximity sensor, drives the six-axis manipulator to place the sample on the detection position of the gamma spectrometer in the low-background lead chamber, and then the six-axis manipulator returns to the position above the low-background lead chamber.

[0071] S5. When the PLC control component receives the homing signal from the six-axis manipulator, it controls the motor in the lead cover of the low-background lead chamber to close the lead cover, and confirms that the lead cover is completely closed through the opening and closing status signal sent by the proximity sensor.

[0072] S6. The PLC control component sends instructions to the gamma spectrometer to start automatic measurement of the sample according to the preset measurement parameters and analysis parameters. After the measurement is completed, the PLC control component automatically stores the measured spectrum to the industrial computer for automatic analysis.

[0073] In some embodiments, Figure 7 A logic diagram of a control method for automatic analysis of a gamma spectrum measurement and analysis system provided by an embodiment of the present invention is shown in FIG. Figure 7 , S6 includes the following sub-steps:

[0074] S61. The PLC control component calls preset measurement parameters and analysis parameters, controls the gamma spectrometer to automatically complete the measurement of the sample, and performs automatic analysis on the stored measurement spectrum.

[0075] In some embodiments, when the measurement parameter is measurement duration, the measurement duration can be set according to the sample activity level. The measurement duration can be achieved by presetting the measurement start time and end time, or by directly presetting the measurement duration.

[0076] In some embodiments, when the measurement parameters include a lower detection limit threshold for a target characteristic radionuclide, the industrial computer periodically calculates the real-time lower detection limit for the target characteristic radionuclide at a preset time interval during the measurement process. The preset time interval is set based on actual conditions, such as 5 minutes, 15 minutes, etc.

[0077] After presetting the measurement and analysis parameters, the system automatically completes the measurement and analysis. If you choose to preset the measurement start and end times, or the measurement duration, the system automatically completes the measurement based on these values ​​and stores the measured spectrum on the industrial computer. If you choose to preset the detection threshold, the measurement automatically terminates and the measured spectrum is automatically stored on the industrial computer when the real-time detection limit falls below the threshold; otherwise, the measurement continues.

[0078] Furthermore, in this embodiment, the real-time detection lower limit (Minimum Detectable Concentration, MDC) is calculated according to the following formula:

[0079] ;

[0080] Among them, n' b It represents the continuous background count rate of 2.54 times the full width at half maximum (FWHM) in the energy range of the characteristic gamma ray full energy peak of the nuclide, in cps; n b It indicates the net counting rate of natural background or interference peak in the energy region of the characteristic γ-ray full energy peak of the nuclide during background measurement, in cps; t s It represents the sample measurement live time, unit is s, where live time refers to the actual cumulative time that the detector effectively receives and processes gamma rays. In gamma energy spectrum measurement, when the gamma rays emitted by the sample hit the detector, the detector and subsequent electronic systems need time to process the signal (such as pulse shaping and analog-to-digital conversion). If the interval between two ray events is too short, the system may lose the subsequent signal because it is "too late to process". This invalid time is called dead time. The time when the system cannot respond is deducted from the total measurement time, and the remainder is the effective data acquisition time, that is, the "live time"; ε represents the detection efficiency of the characteristic gamma ray full-energy peak; η represents the branching ratio (absolute intensity) of the characteristic gamma ray full-energy component, and η is the nuclear physical parameter of the radionuclide, which is a fixed value; m represents the sample amount, such as weight, volume, etc., which is obtained by weighing, measuring, etc. before the start of the automatic measurement operation, and the unit is kg, L or m3 etc. n' b 、n b , t s The system acquires this information in real time as the measurement progresses. ε is automatically calculated using an efficiency curve library based on the characteristic gamma-ray full-energy peak. η is pre-stored in the nuclide library. m is entered into the system by the technician when presetting the measurement and analysis parameters and automatically retrieved during calculation. In some embodiments, the lower detection limit can also be calculated using other industry-recognized methods.

[0081] S62. Automatic analysis includes searching for energy peaks, calculating energy peak areas, background subtraction, identifying nuclides according to preset sub-classification library categories, calculating detection efficiency values ​​according to the efficiency curve library, calculating the activity concentration results of target characteristic radioactive nuclides, and generating reports.

[0082] Specifically, after each sample measurement is completed, the system automatically analyzes the measured spectrum according to a program. This analysis utilizes a built-in nuclide library, efficiency curve library, and analysis logic program. The nuclide library is divided into three categories: environmental sample library, nuclear accident emergency library, and radiation accident emergency library. Each category is further subdivided into subcategories such as air, biological, soil, and water based on sample type. The efficiency curve library is also subdivided by sample type.

[0083] Furthermore, in this embodiment, the activity concentration result of the target characteristic radionuclide can be calculated by referring to the following formula, or it can be adjusted according to the standard method:

[0084] ;

[0085] Where C represents the activity concentration of the target characteristic radionuclide, n s Indicates the full energy peak net count rate of characteristic gamma rays in the sample, unit: cps; n b It indicates the net count rate of natural background or interference peak in the energy region of the characteristic γ-ray full energy peak of the nuclide during background measurement, in cps; ε indicates the detection efficiency of the characteristic γ-ray full energy peak; η indicates the branching ratio (absolute intensity) of the characteristic γ-ray; m indicates the sample size, in kg, L or m 3 etc.; K represents a comprehensive correction factor, including decay correction, geometry correction, self-absorption correction, interference peak correction, cascade coincidence correction, filtration efficiency correction (applicable to aerosol sample analysis), etc. The above correction factors are all existing technologies. In this embodiment, automatic recognition and calculation can be set. s 、n b It is automatically calculated by the system software. ε is automatically calculated using the efficiency curve library based on the characteristic gamma-ray full energy peak. η is pre-built into the nuclide library. K and m are entered into the system by technicians when presetting the measurement and analysis parameters.

[0086] S63, analyzing the report generated by S62. If there is no unidentified energy peak, the automatic analysis process is completed; if there is an unidentified energy peak, proceed to S64.

[0087] S64. Switch to the preset nuclide library category for secondary nuclide identification.

[0088] Exemplarily, the nuclide identification technology process includes:

[0089] Energy peak positioning and feature extraction: The system performs an automatic peak-finding algorithm on the collected gamma energy spectrum to accurately locate the energy position of the full-energy peak (unit: keV) and calculate the peak area as the key input parameter for nuclide identification.

[0090] Hierarchical nuclide library matching mechanism:

[0091] Initial nuclide identification (i.e., nuclide identification based on the preset sub-category library category in step S62): The sub-category nuclide library preset in the industrial computer (i.e., the sub-category library category, such as "Nuclear Accident Emergency Library - Air Sample") is called to automatically compare the energy peak with the theoretical energy value of the characteristic gamma rays of the nuclides in the library.

[0092] Secondary nuclide identification (i.e., switching to the preset nuclide library category for secondary nuclide identification in step S64): If there are unmatched energy peaks (such as new nuclides or interfering peaks), the system automatically switches to the large nuclide library (i.e., the preset nuclide library category, such as the complete "Nuclear Accident Emergency Library") for global search to solve the problem of complex energy spectrum identification.

[0093] Branching Ratio Verification and Multi-peak Correlation: For successfully matched nuclides, the system further verifies their characteristic gamma-ray branching ratios to eliminate false positives. For nuclides with multiple characteristic gamma rays (such as the 661.6keV peak of cesium-137), the system automatically correlates the multi-peak signals, improving accuracy through dual-factor energy-intensity matching.

[0094] Real-time output and report generation: Identification results (nuclide name and energy peak data) are directly used for subsequent activity concentration calculations, and analysis reports are automatically generated and uploaded to the cloud.

[0095] In this embodiment, accurate analysis of the sample can be completed through at most two automatic analyses.

[0096] S65. Recalculate the activity concentration of the target characteristic radioactive nuclide based on the result of the secondary nuclide identification and generate a report. The automatic analysis process is completed.

[0097] In some embodiments, the generated result report may include key information such as sample identification number, sample type, sample sampling time, sample measurement time, sample geometric dimensions, sample quantity, measurement time, instrument energy scale and efficiency scale information, peak search information, background subtraction information, nuclide identification information, nuclide qualitative and quantitative analysis results, nuclide detection lower limit, and analysis result uncertainty.

[0098] S7, the PLC control component controls the motor inside the lead cover of the low-background lead chamber to open the lead cover, and after confirming that the lead cover is fully opened through the opening and closing status signal sent by the proximity sensor, drives the six-axis robot to transfer the measured sample to the sample measured area, and confirms that the sample placement is completed through the sample in-place status signal sent by the pressure sensor in the sample measured area.

[0099] S8. The PLC control component repeatedly executes S2-S7 in the order of sample change until the measurement of all samples is completed.

[0100] Furthermore, in this embodiment, the generated result report and original spectrum file can be automatically uploaded to the cloud platform, or can be sent to a designated network address in real time for storage and viewing according to user needs.

[0101] The present invention controls the six-axis manipulator through a PLC control component, combines pressure sensors in the sample to be tested area and the sample tested area to provide real-time feedback on the sample in-place status, and a lead cover proximity sensor to monitor the open and closed status, forming a multiple redundant safety mechanism to ensure the safety and reliability of the manipulator's grasping and placement actions, avoid errors or accidents caused by human intervention, and realize continuous automatic sample replacement operations; the industrial computer presets the measurement time and / or detection lower limit threshold, regularly calculates the real-time detection lower limit during measurement and automatically terminates the measurement to achieve time optimization; a built-in multi-level nuclide library (environmental, nuclear accident, radiation accident library and subcategories) and efficiency curve library are used. During analysis, the sub-category library is first matched to identify the nuclides, and the unidentified energy peaks are automatically switched to the large category library for secondary analysis. The activity concentration is calculated in combination with the efficiency curve and the comprehensive correction factor. The multi-level nuclide library mechanism solves the problem of complex spectrum recognition without manual parameter adjustment, realizes automatic analysis, and reduces the number and time of analysis.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. A control method for a fully automatic sample exchange measurement and analysis system for gamma ray spectrum measurement, characterized in that: The method comprises the following steps: S1. Presetting the sample changing sequence, measurement parameters, and analysis parameters through the industrial computer; Presetting the measurement parameters through the industrial computer includes setting the measurement time and / or setting the detection lower limit threshold of the target characteristic radioactive nuclide, and presetting the nuclide library category and its sub-category library category; S2, the PLC control component drives the six-axis manipulator to grab the sample in the sample area to be tested according to the sample changing sequence; S3, the PLC control component drives the six-axis manipulator to move above the low-background lead chamber after confirming that the sample is successfully grasped based on the sample in-position status signal sent by the pressure sensor in the sample test area; S4, the PLC control component controls the motor in the lead cover of the low-background lead chamber to open the lead cover, and after confirming that the lead cover is fully opened through the opening and closing state signal sent by the proximity sensor, drives the six-axis manipulator to place the sample on the detection position of the gamma spectrometer in the low-background lead chamber; S5, the PLC control component controls the motor in the lead cover of the low-background lead chamber to close the lead cover, and confirms that the lead cover is completely closed through the opening and closing status signal sent by the proximity sensor; S6. The PLC control component sends a command to the gamma spectrometer to start automatic measurement of the sample according to the preset measurement parameters and analysis parameters. After the measurement is completed, the PLC control component automatically stores the measured spectrum to the industrial computer for automatic analysis; Specifically include: S61, the PLC control component calls preset measurement parameters and analysis parameters, controls the gamma spectrometer to automatically complete the measurement of the sample, and performs automatic analysis on the stored measurement spectrum; S62, automatic analysis includes searching for energy peaks, calculating energy peak areas, background subtraction, nuclide identification based on pre-set sub-classification library categories, calculation of detection efficiency values ​​based on the efficiency curve library, calculation of activity concentration results of target characteristic radionuclides, and report generation; S63, analyzing the report generated in S62. If there is no unidentified energy peak, the automatic analysis process is completed; if there is an unidentified energy peak, proceed to S64; S64, switching to the preset nuclide library category for secondary nuclide identification; S65. Recalculate the activity concentration of the target characteristic radionuclide based on the result of the secondary nuclide identification and generate a report. The automatic analysis process is completed. S7, the PLC control component controls the motor in the lead cover of the low-background lead chamber to open the lead cover, and after confirming that the lead cover is fully opened through the opening and closing status signal sent by the proximity sensor, drives the six-axis manipulator to transfer the sample that has completed measurement to the sample measurement area, and confirms that the sample placement is complete through the sample in-place status signal sent by the pressure sensor in the sample measurement area; S8. The PLC control component repeatedly executes S2-S7 according to the sample changing sequence until the measurement of all samples is completed.

2. The control method of a gamma spectrum measurement and analysis system with fully automatic sample exchange according to claim 1, characterized in that: When the measurement parameter includes a lower detection limit threshold of a target characteristic radionuclide, the industrial computer periodically calculates the real-time lower detection limit of the target characteristic radionuclide at preset time intervals during the measurement process; When the real-time detection lower limit is lower than the detection lower limit threshold, the measurement is automatically terminated; otherwise, the measurement continues.

3. A gamma spectrum measurement and analysis system with fully automatic sample exchange, used to implement the control method of the gamma spectrum measurement and analysis system with fully automatic sample exchange, characterized in that: The system includes: a low-background lead chamber, a gamma spectrometer, a six-axis manipulator, a PLC control component, an industrial computer, a sample waiting area and a sample tested area; The low-background lead chamber is used to accommodate samples and shield ionizing radiation from the external environment. A lead cover is provided on the top that is automatically opened and closed by a motor. The lead cover is divided into two parts, each of which is equipped with a set of motors. A proximity sensor is provided at one end where the two parts of the lead cover meet. The proximity sensor on the outside of the lead cover feeds back an opening and closing status signal to the PLC control component. The gamma spectrometer is arranged below the low-background lead chamber and is used to automatically measure the gamma spectrum of the sample; The sample testing area is used to place the sample to be tested; The sample measured area is used to place samples that have completed measurement; The bottom of the sample box in the sample to be tested area and the sample tested area are both provided with pressure sensors for sending a sample in place status signal to the PLC control component; The six-axis manipulator is used to grab the sample to be tested placed in the sample to be tested area and put it into the low-background lead chamber, and to grab the sample that has been measured from the low-background lead chamber and put it into the sample tested area; The PLC control component is used to send and receive signals to other modules in the system respectively; The industrial computer is used to run control software and store measurement data.

4. The fully automatic sample exchange measurement and analysis system for gamma spectrum measurement according to claim 3, characterized in that: The industrial computer has a built-in nuclide library module, which includes an environmental sample library, a nuclear accident emergency library, a radiation accident emergency library and their respective sub-classification libraries; the industrial computer has a built-in efficiency curve library module, which stores detection efficiency data according to sample type.

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