A real-time energy response correction method, system, and terminal for dose rate meters

Abstract

This invention discloses a real-time energy response correction method, system, and terminal for a dose rate meter. The method involves acquiring the pulse amplitude spectrum of the detector under several different monoenergetic X / γ-ray conditions to obtain the detector's amplitude-energy response function and energy spectrum broadening function. The method also simulates the energy deposition spectra of the detector under several other monoenergetic X / γ-ray conditions and performs energy spectrum broadening to obtain their corresponding simulated energy spectra. The energy range is divided into a certain number of energy intervals, and a linear programming optimization algorithm is used to obtain the correction coefficients for each energy interval. In experiments at different dose rates, the measured pulse amplitude spectrum per unit time is converted into an energy spectrum using the amplitude-energy response function. The count rates of each energy interval are weighted and summed using the correction coefficients to obtain the weighted total count rate as the detector's response value. Finally, a conversion function from count rate to dose rate is fitted, and a program is written to realize the real-time calculation and conversion from pulse amplitude spectrum to dose rate.

Description

Technical Field

[0001] This invention relates to the field of nuclear radiation monitoring technology and applications, specifically to a real-time energy response correction method, system, and terminal for dose rate meters. Background Technology

[0002] In the field of radiation protection, scintillation detectors, semiconductor detectors, and gas ionization detectors are generally used as sensing probes for dose rate meters. The average current of the signal or the count rate of the detector can represent the energy deposited in the material. Since there is a linear relationship between the amount of energy deposited per unit time and the dose rate, the dose rate can be calibrated by the magnitude of the current response or the count rate. Because detectors have different detection efficiencies for X / γ rays of different energies, all detectors exhibit inconsistent photon energy responses, especially near low energies (below 200 keV), where the response value is excessively large, differing by several times relative to higher energy photon radiation such as 137Cs or 60Co. This results in significant errors in the dose rate meter's measurement results, severely affecting its accuracy. Therefore, energy response correction is required for dose rate meters to meet the national standard GB / T 12162-2004, which stipulates that the relative response error of the detector under different energy X / γ rays relative to a 137Cs radiation source should be within ±30%, thus achieving accurate dose rate measurement.

[0003] To address this issue, researchers both domestically and internationally have undertaken extensive work. The most common method is physical layer shielding compensation. While this approach generally meets the ±30% error requirement of national standards, it is limited by several factors from a physical structure perspective. These limitations include reduced detector efficiency, increased instrument weight, and negative impacts on qualitative and quantitative analysis. Furthermore, it is difficult to obtain more accurate dose rate measurements over a wide energy range. Particularly when measuring different quantities (e.g., personal dose equivalent rate versus ambient dose equivalent rate), timely response coefficient conversion is impossible, leading to significant energy response correction errors.

[0004] Besides physical compensation, the measured energy spectrum can also be directly converted into dose without the need for spectrum decomposition through the energy spectrum-dose conversion method. Many similar energy response correction methods have emerged both domestically and internationally, such as the total count rate method and the Beck formula method. The classic method is to achieve energy response correction by solving the energy spectrum-dose conversion G(E) function. However, the above methods separate the instrumentation and processing methods. The absorbed dose rate cannot be displayed in real time while measuring the energy spectrum. Moreover, this method has high requirements for energy spectrum data processing, requiring a multichannel analyzer and a high-speed computing chip. The system is complex and costly, especially under strong radiation fields, which places higher demands on the hardware of the dose rate measurement instrument. Summary of the Invention

[0005] In order to overcome the defects of the prior art, the present invention aims to provide a real-time energy response correction method, system and terminal for a dose rate meter, so as to solve the technical problems of large energy response correction error and inability to simultaneously display the absorbed dose rate in real time when measuring the energy spectrum in the prior art.

[0006] This invention is achieved through the following technical solution:

[0007] A real-time energy response correction method for a dose rate meter includes the following steps:

[0008] Step 1: Obtain the pulse amplitude spectrum of the detector under p types of monoenergetic X / γ-ray radiation sources, and obtain the "amplitude-energy" response function of the detector by the peak position of the full-energy peak of the obtained p pulse amplitude spectra, and convert the pulse amplitude spectrum into an energy spectrum.

[0009] Step 2: Obtain the full width at half maximum (FWHM) of the full-energy peaks under p types of monoenergetic X / γ-ray radiation sources, and obtain the energy spectrum broadening formula for the detector by fitting a function formula.

[0010] Step 3: Establish a simulation model of the detector described in Step 1, and obtain the energy deposition spectrum of the detector under q different energies of monoenergetic X / γ rays; use the energy spectrum broadening formula in Step 2 to broaden the energy deposition spectrum, and obtain the simulated energy spectrum of the detector under q different energies of monoenergetic X / γ rays.

[0011] Step 4: Divide the maximum energy range of the simulated energy spectrum under q different energies of monoenergetic X / γ rays into m energy intervals. Assign an energy response correction coefficient to each interval. Use the correction coefficient to compensate for the counts of each energy interval and sum them up to obtain the weighted total count as the response value of the detector.

[0012] Step 5, with energy of Under the condition of single-energy X / γ-ray incident radiation, the pulse amplitude spectrum per unit time of the detector obtained in the actual experiment is converted into an energy spectrum using the response function obtained in step 1. The count rate of each energy range is denoted as... And using the correction coefficient described in step 4 to adjust the count rate in different energy ranges. Compensation and weighted summation are performed, and the result is divided by the reference dose rate to obtain the corrected detector response value under the incident energy. Based on the corrected count rate of the detector under different reference dose rates in the standard radiation field measured in the experiment, the conversion function from detector count rate to dose rate is obtained by fitting.

[0013] Step 6: Write a real-time energy response correction program and apply the response function, correction coefficient, and conversion function to the actual dose rate meter to realize the calculation from the measured pulse amplitude spectrum per unit time to the count rate and then to the dose rate, thus completing the real-time energy response correction work.

[0014] Preferably, in step 1, the peak positions of the full-energy peaks of the acquired p pulse amplitude spectra are calibrated with energy to determine the detector's amplitude-energy response function. A linear fit is then used to establish the correspondence between the multichannel analyzer channel address and the incident X / γ-ray energy, and the pulse amplitude spectrum is converted into a gamma spectrum. The formula for the amplitude-energy linear response function fitting is:

[0015]

[0016] in, K 1 represents the slope fitted by the "energy-amplitude" linear response function. B 1 represents the intercept obtained by fitting the "energy-amplitude" linear response function.

[0017] Preferably, in step 2, the full width at half maximum (FWHM) of the full-energy peak under p types of monoenergetic X / γ-ray radiation sources is obtained using Gaussian fitting, and a functional formula relating the FWHM of the full-energy peak of the detector system to the incident gamma-ray energy is obtained. The energy spectrum broadening formula for the detector is then obtained by fitting this functional formula. The energy spectrum broadening formula is as follows:

[0018] ;

[0019] in, The broadening factor is the ratio between the energy corresponding to the full-energy peak of the gamma spectrum of the detector system and the full width at half maximum (FWHM). The broadening factor and its formula are used to broaden the unbroadened energy deposition spectrum to obtain the simulated energy spectrum. E The energy of the incident X / γ rays.

[0020] Preferably, in step 3, the establishment of the detector's simulation model includes setting the detector's geometry and materials, setting the type and location of the radiation source, setting the physical process, and setting the material's optical parameters.

[0021] Preferably, in step 4, for q The maximum energy range of each simulated energy spectrum is divided into: The system uses an energy range with appropriate thresholds to filter out system noise via a pulse discriminator. When a photon enters the detector, it generates a pulse signal after photoelectric conversion. The amplitude of the pulse signal is extracted. If the pulse amplitude exceeds the threshold, the signal is considered valid; otherwise, it is considered noise and discarded. The minimum value of the energy range should be above the discrimination threshold, and the same pulse amplitude spectrum data acquisition time should be set.

[0022] Preferably, in step 5, the number of particle events detected by the detector in each energy range is obtained, the total detection time is recorded, and the count rate for each energy range is obtained by dividing the total detection time by the total detection time. and energy range Count rate within Perform correction and weighting, partitioning The correction factor is The formula for the corrected detector response at each energy point is:

[0023]

[0024] when , The value is the detector response value before correction, i.e., without energy range correction weighting;

[0025] in The number of energy intervals, For energy is The corresponding corrected detector energy response value under X / γ rays. For interval The corresponding energy response correction factor, For interval The count rate within, For energy The air kerma rate of X / γ rays.

[0026] Furthermore, each interval has a corresponding energy response correction coefficient. Actual count rate in different energy ranges under X / γ rays of different energies The total count rate after correction is obtained by multiplying by the correction coefficients for each interval and then weighting the results. The calculation formula is as follows:

[0027]

[0028] in, , E The energy of the incident X / γ rays, For interval The corresponding energy response correction factor, For interval The count rate within, The number of energy intervals, Indicates in Parameters within the interval.

[0029] Energy is The detector response value under X / γ rays is obtained by the following formula:

[0030]

[0031] in, , E The energy of the incident X / γ rays, For interval The corresponding energy response correction factor, For interval The count rate within, The number of energy intervals, Indicates in Parameters in the interval for Air kerma rate.

[0032] Preferably, in step 5, the count rate to dose rate conversion function is obtained by fitting experimental data. For the count rate to dose rate conversion, the count rate of the detector can represent the energy deposited in the material per unit time, and there is a linear relationship between the amount of deposited energy and the dose rate. The formula for the conversion function between count rate and dose rate obtained by linearly fitting the dose rate response curve is as follows:

[0033]

[0034] Among them, among them, The slope is the result of fitting the linear transformation function of "dose rate - count rate". The intercept is fitted to the linear transformation function of dose rate-count rate.

[0035] A real-time energy response correction system for a dose rate meter, comprising:

[0036] The first digital waveform data acquisition module is used to acquire the pulse amplitude spectrum of the detector under p kinds of monoenergetic X / γ-ray radiation sources, and obtain the "amplitude-energy" response function of the detector by the peak position of the full-energy peak of the acquired p pulse amplitude spectrum, and convert the pulse amplitude spectrum into an energy spectrum.

[0037] The second digital waveform data acquisition module is used to obtain the full width at half maximum (FWHM) of the full-energy peak under p types of monoenergetic X / γ-ray radiation sources, and obtain the energy spectrum broadening formula of the detector by fitting a function formula.

[0038] The data simulation module is used to establish a simulation model of the detector and obtain the energy deposition spectrum of the detector under q different energies of monoenergetic X / γ rays; the energy deposition spectrum is broadened using the energy spectrum broadening formula to obtain the simulated energy spectrum of the detector under q different energies of monoenergetic X / γ rays;

[0039] The first data stitching module is used to divide the maximum energy range of the simulated energy spectrum under q different energies of monoenergetic X / γ rays into m energy intervals. Each interval is assigned an energy response correction coefficient. The counts of each energy interval are compensated and summed using the correction coefficients to obtain the weighted total count as the response value of the detector.

[0040] The second data stitching module is used to stitch together data at an energy level of [missing information]. Under the condition of single-energy X / γ-ray incident radiation, the pulse amplitude spectrum per unit time of the detector obtained in the actual experiment is converted into an energy spectrum using the response function obtained in step 1. The count rate of each energy range is denoted as... And the count rate in different energy ranges was adjusted using correction coefficients. Compensation and weighted summation are performed, and the result is divided by the reference dose rate to obtain the corrected detector response value under the incident energy. Based on the corrected count rate of the detector under different reference dose rates in the standard radiation field measured in the experiment, the conversion function from detector count rate to dose rate is obtained by fitting.

[0041] The real-time energy response correction module is used to write real-time energy response correction programs and apply response functions, correction coefficients, and conversion functions to actual dose rate meters to realize the calculation from the measured pulse amplitude spectrum per unit time to the count rate and then to the dose rate, thus completing the real-time energy response correction work.

[0042] A mobile terminal includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the real-time energy response correction method for a dose rate meter as described above.

[0043] Compared with the prior art, the present invention has the following beneficial technical effects:

[0044] This invention provides a real-time energy response correction method for dose rate meters. It obtains the detector's amplitude-energy response function and energy spectrum broadening function by acquiring pulse amplitude spectra of the detector under several different monoenergetic X / γ rays. Then, it simulates the energy deposition spectra of the detector under several other different monoenergetic X / γ rays and performs energy spectrum broadening to obtain their corresponding simulated energy spectra. The energy range is divided into a certain number of energy intervals, and a linear programming optimization algorithm is used to obtain the correction coefficients for each energy interval. Then, in experiments at different dose rates, the measured pulse amplitude spectrum per unit time is converted into an energy spectrum using the amplitude-energy response function. The count rates of each energy interval are weighted and summed using the correction coefficients to obtain the weighted total count rate as the detector's response value. Finally, a conversion function from count rate to dose rate is fitted, and a program is written to realize the real-time calculation and conversion from pulse amplitude spectrum to dose rate. This method differs from the energy spectrum-dose conversion function method in that it does not require prior acquisition of energy spectrum data for conversion, has low requirements for the instrument's data processing capabilities, and only requires writing the corresponding correction coefficients once for a specific detector. Attached Figure Description

[0045] Figure 1 This is a flowchart of the real-time energy response correction method for a dose rate meter in this invention;

[0046] Figure 2 In the embodiments of the present invention, the Cs3Cu2I5:Tl detectors are respectively in 137 Cs、 60 Co、 241 Am、 152 Pulse amplitude spectrum under Eu gamma-ray excitation source;

[0047] Figure 3 The above is the amplitude-energy response curve of the Cs3Cu2I5:Tl detector in an embodiment of the present invention.

[0048] Figure 4 The figures show the relative response curves of the detector before and after energy response correction in this embodiment of the invention.

[0049] Figure 5 This is a graph showing the relative deviation between the dose rate measurements and the standard values ​​of the radiation field before and after energy response correction according to the present invention. Detailed Implementation

[0050] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0051] The present invention will now be described in further detail with reference to the accompanying drawings:

[0052] The purpose of this invention is to provide a real-time energy response correction method, system, and terminal for a dose rate meter, so as to solve the technical problems of large energy response correction error and inability to simultaneously display the absorbed dose rate in real time when measuring the energy spectrum in the prior art.

[0053] Specifically, according to Figure 1 As shown, the real-time energy response correction method for a dose rate meter includes the following steps:

[0054] Step 1: Obtain the pulse amplitude spectrum of the detector under p types of monoenergetic X / γ-ray radiation sources, and obtain the "amplitude-energy" response function of the detector by the peak position of the full-energy peak of the obtained p pulse amplitude spectra, and convert the pulse amplitude spectrum into an energy spectrum.

[0055] Specifically, at least two or more measurements must be taken (i.e. p≥2 The pulse amplitude spectrum under incident single-energy X / γ-ray radiation source, using 137 Cs、 60 Co、 152 Eu、 241 Four types of gamma-ray radiation sources (Am) are used to ensure an accurate amplitude-energy response function. During pulse amplitude spectrum measurement, the characteristic parameters (triggering mode, trigger threshold, poles, etc.) of the energy spectrum acquisition system should be kept consistent.

[0056] Specifically, to subsequently divide the energy range and avoid the influence of spectral drift, the peak positions of the full-energy peaks in the pulse amplitude spectrum need to be energy-calibrated to determine the detector's amplitude-energy response function. Preferably, a linear fit is used to establish the correspondence between the multichannel analyzer channel address and the incident X / γ-ray energy, and the resulting pulse amplitude spectrum is converted into a gamma energy spectrum. For the Cs3Cu2I5:Tl detector, the fitting formula for the amplitude-energy linear response function is:

[0057]

[0058] in, K 1 is, B 1 is

[0059] Step 2: Obtain the full width at half maximum (FWHM) of the full-energy peaks under p types of monoenergetic X / γ-ray radiation sources, and obtain the energy spectrum broadening formula for the detector by fitting a function formula.

[0060] Specifically, Gaussian fitting is used to obtain the half-width at half maximum (FWHM) of the full-energy peak in the detector gamma spectrum in step three, and the functional formula between the FWHM of the full-energy peak of the detector system in step three and the incident gamma ray energy is obtained. Preferably, for the Cs3Cu2I5:Tl detector, the broadening fitting formula is:

[0061]

[0062] in, The broadening factor is the ratio between the energy corresponding to the full-energy peak of the gamma spectrum of the detector system and the full width at half maximum (FWHM). The broadening factor and its formula are used to broaden the unbroadened energy deposition spectrum to obtain the simulated energy spectrum. E The energy of the incident X / γ rays.

[0063] Specifically, in the experiment of fitting the energy-full width at half maximum (FWHM) scale to the single-energy full-energy peak in the detector pulse amplitude spectrum, the details are as follows:

[0064] First, the detector used in the calibration experiment is a scintillation detector, which consists of a scintillation crystal and a SiPM (SiM). The cubic scintillator is polished on all six sides and wrapped with a polytetrafluoroethylene (PTFE) optical reflective film on five sides. The light-emitting surface is coupled to the sensitive area of ​​the SiPM through optical silicone grease. The input end of the front-end detection unit is connected to the digital multichannel analyzer through a data transmission line. The PC communicates with the digital multichannel analyzer through a high-speed USB interface to complete the transmission and processing of pulse amplitude spectrum data.

[0065] Second, obtain the pulse voltage signal values ​​generated by the energy deposition of X / γ rays in the scintillation detector at different energies, and calibrate the linear relationship between incident photon energy and pulse amplitude.

[0066] Third, after X / γ rays of different energies deposit energy in the scintillator to generate light pulse signals, they are converted into voltage pulse signals by the SiPM readout circuit. The voltage pulse signals are then converted into corresponding digital waveform signals by a digital multichannel analyzer. The amplitude of the digital waveform signals is extracted, and the relationship between the detector's pulse amplitude and output voltage value at different energies is measured. The linear relationship between the incident photon energy and the pulse amplitude is obtained through the energy-pulse amplitude scale information.

[0067] Fourth, the pulse voltage signal value based on the scintillation detector is converted into a corresponding digital waveform signal, and the amplitude of the corresponding digital waveform signal is extracted and converted into a count rate value. In the dose rate meter based on the scintillation detector, the dose rate and the count rate value are positively correlated, that is, the size of the detector count rate characterizes the size of the dose rate to a certain extent.

[0068] Step 3: Establish a simulation model of the detector described in Step 1, and obtain the energy deposition spectrum of the detector under q different energies of monoenergetic X / γ rays; use the energy spectrum broadening formula in Step 2 to broaden the energy deposition spectrum, and obtain the simulated energy spectrum of the detector under q different energies of monoenergetic X / γ rays.

[0069] Specifically, establishing the detector's simulation model includes setting the detector's geometry and materials, setting the type and location of the radiation source, setting the physical processes, and setting the material's optical parameters. When establishing the model, the environmental factors of the measurement system should be fully considered, and the geometric conditions and measurement environment in the model should be consistent with the actual conditions in step one.

[0070] Step 4: Divide the maximum energy range of the simulated energy spectrum under q different energies of monoenergetic X / γ rays into m energy intervals. Assign an energy response correction coefficient to each interval. Use the correction coefficient to compensate for the counts of each energy interval and sum them up to obtain the weighted total count as the response value of the detector.

[0071] Specifically, when obtaining the energy deposition spectrum of the detector under q different energies of monoenergetic X / γ rays, the parameter settings of the simulation source and the number of simulation events must be kept completely consistent.

[0072] Specifically, for q The maximum energy range of each simulated energy spectrum is divided into: The system uses an energy range with appropriate thresholds to filter out system noise via a pulse discriminator. When a photon enters the detector, it generates a pulse signal after photoelectric conversion. The amplitude of the pulse signal is extracted. If the pulse amplitude exceeds the threshold, the signal is considered valid; otherwise, it is considered noise and discarded. The minimum value of the energy range should be above the discrimination threshold, and the same pulse amplitude spectrum data acquisition time should be set.

[0073] Step 5, with energy of Under the condition of single-energy X / γ-ray incident radiation, the pulse amplitude spectrum per unit time of the detector obtained in the actual experiment is converted into an energy spectrum using the response function obtained in step 1. The count rate of each energy range is denoted as... And using the correction coefficient described in step 4 to adjust the count rate in different energy ranges. Compensation and weighted summation are performed, and the result is divided by the reference dose rate to obtain the corrected detector response value under the incident energy. Based on the corrected count rate of the detector under different reference dose rates in the standard radiation field measured in the experiment, the conversion function from detector count rate to dose rate is obtained by fitting.

[0074] Specifically, the number of particle events detected by the detector in each energy range is obtained, the total detection time is recorded, and the count rate for each energy range is obtained by dividing the total detection time by the total detection time. and energy range Count rate within Perform correction and weighting, partitioning The correction factor is The formula for the corrected detector response at each energy point is:

[0075]

[0076] when , The value is the detector response value before correction, i.e., without energy range correction weighting;

[0077] in The number of energy intervals, For energy is The corresponding corrected detector energy response value under X / γ rays. For interval The corresponding energy response correction factor, For interval The count rate within, For energy The air kerma rate of X / γ rays.

[0078] For the Cs3Cu2I5:Tl detector, inconsistencies in energy response within the energy range of 50keV to 1250keV can severely affect the accuracy of measurement results. Therefore, preferably, the experiment uses ten energy points: narrow-spectrum X-rays at 33keV, 48keV, 65keV, 83keV, 100keV, 118keV, 164keV, and 208keV, and gamma rays at 662keV and 1250keV.

[0079] It should be noted that in the method described in this invention, the detector is considered to be in a state of charged particle equilibrium, and therefore the bremsstrahlung effect of the particles is ignored. At this time, the value of the air kerma rate is equal to the value of the air absorbed dose rate. The air absorbed dose rate is obtained by testing in a spherical ionization chamber in the experiment. Therefore, in the method described in this patent, the air kerma rate and the air absorbed dose rate are regarded as the same value.

[0080] Specifically, each interval has a corresponding energy response correction coefficient. Actual count rate in different energy ranges under X / γ rays of different energies The total count rate after correction is obtained by multiplying by the correction coefficients for each interval and then weighting the results. The calculation formula is as follows:

[0081]

[0082] in, , E The energy of the incident X / γ rays, For interval The corresponding energy response correction factor, For interval The count rate within, The number of energy intervals, Indicates in Parameters within the interval.

[0083] Energy is The detector response value under X / γ rays is obtained by the following formula:

[0084]

[0085] in, , E The energy of the incident X / γ rays, For interval The corresponding energy response correction factor, For interval The count rate within, The number of energy intervals, Indicates in Parameters in the interval for Air kerma rate.

[0086] in, variance This indicates that the detector is in q The magnitude of fluctuations in the detector response at different X / γ energies, when When the minimum value is taken, the detector's energy response consistency is the best, that is, the detector at... q The relative response error is minimized under different energies. Based on this constraint, the energy response correction coefficient can be obtained, i.e. The energy response correction coefficient for each energy range is calculated using the following formula:

[0087]

[0088]

[0089] in, , for .

[0090] First, determine the detector's position in the aforementioned... q The average response value at different X / γ ray energies, when When taking the minimum value, the solution can be obtained based on this constraint. The value of, i.e. The specific values ​​of the correction coefficients for each energy range.

[0091] Specifically, when dividing the maximum energy range of the simulated energy spectrum into intervals, the correction principle should be followed: the number of intervals should be as small as possible while meeting the relative deviation requirements of energy response in national standards, facilitating the subsequent development and debugging of dose rate instruments. Detector overresponse problems mostly occur in the low-energy region; therefore, interval division is primarily focused on the low-energy region.

[0092] Specifically, the count rate to dose rate conversion function is obtained by fitting experimental data. For count rate-based dose rate conversion, the detector's count rate represents the energy deposited in the material per unit time, and there is a linear relationship between the amount of deposited energy and the dose rate. Preferably, the detector is placed at a standard point within a radiation field with a known dose rate, and the detector is adjusted relative to the target area. 137 The distance to the Cs radiation source is used to change the dose rate at the detector's location, thus obtaining the dose rate and count rate response functions of the detector at 662 keV. More preferably, a conversion function between the count rate and dose rate is obtained by linearly fitting the detector's dose rate response curve. The conversion function and the corresponding corrected total count rate are then used to determine the conversion function. The dose rate before and after dose rate meter calibration was calculated. For the Cs3Cu2I5:Tl detector, the dose rate response curve was linearly fitted to obtain the conversion function between count rate and dose rate.

[0093]

[0094] Among them, among them, The slope is the result of fitting the linear transformation function of "dose rate - count rate". The intercept is fitted to the linear transformation function of dose rate-count rate.

[0095] Step 6: Write a real-time energy response correction program and apply the response function, correction coefficient, and conversion function to the actual dose rate meter to realize the calculation from the measured pulse amplitude spectrum per unit time to the count rate and then to the dose rate, thus completing the real-time energy response correction work.

[0096] Example

[0097] First, it is necessary to obtain the actual pulse amplitude spectrum of the detector under different monoenergetic gamma rays. To improve the accuracy of the energy calibration and the energy-half-width at half maximum (HWHM) calibration, the following method is adopted: 137 Cs、 60 Co、 152 Eu、 241 Am four types of monoenergetic gamma-ray radiation sources. In this embodiment, a scintillator + SiPM is used to form the front-end probe unit of the scintillator detector. The scintillator is a thallium-doped copper cesium iodide (Cs3Cu2I5:Tl) scintillator crystal with a size of 6×6×5mm. The Cs3Cu2I5:Tl crystal has excellent energy discrimination ability and can well identify energy spectrum information in the energy range of 30keV~1250keV. This crystal has high light yield, good energy resolution and high sensitivity, and has good overall scintillator performance. All six sides of the scintillator crystal are polished, five of which are wrapped with polytetrafluoroethylene optical reflective film, and the remaining side is coupled to the light receiving area of ​​the SiPM through optical silicone grease as the light emitting surface. The SiPM selected for scintillator energy spectrum measurement is the MiscroFJ-60035-TSV series produced by SenSL. It has low dark count, high photon detection efficiency, and various packaging methods, making it very suitable for dose rate meter applications. The photosensitive area of ​​the SiPM is 6.07×6.07mm. 2 It has high photon detection efficiency for scintillation light with wavelengths in the range of 320nm to 550nm. The SiPM operating voltage is set to 30V. The multichannel analyzer in the energy spectrum data acquisition system is an ORTEC EASY-MCA-8K.

[0098] X / γ rays emitted from a radiation source enter the scintillator, depositing energy within it and causing ground-state electrons to transition to excited states. These excited electrons de-excite and emit fluorescent photons, which are received by the SiPM (Silicon Magnetic Processing Unit). The optical signal is proportionally converted into electrons and amplified. The amplified electrical signal is further amplified by subsequent analog circuitry. The SiPM operates on a driver board powered by a low-voltage power supply. The SiPM and driver board are placed in a sealed aluminum box to protect against light and reduce noise. Before and after energy spectrum measurements, the scintillator needs to be placed in a dark chamber to avoid the influence of scintillator afterglow on the test results. In this embodiment, the radiation signal detection unit system consists of a detector, signal amplification circuit, a 60MB / s pipelined high-speed analog-to-digital converter (FADC, Fast-ADC), a field-programmable gate array (FPGA), and host computer software. The energy spectrum acquisition system consists of a detector, a multichannel analyzer, an oscilloscope, and a PC. During energy spectrum measurements, the data acquisition threshold needs to be adjusted to filter out most of the detector's noise and background. 137 Cs、 60 Co、 241Am、 152 Energy spectrum data were obtained using Eu as the excitation source. In this example, the detectors respectively... 137 Cs、 152 Eu、 60 Co、 241 The pulse amplitude spectrum under the Am excitation source is as follows: Figure 2 As shown, Gaussian fitting is performed on the full-energy peak of monoenergetic gamma rays with known energies in the energy spectrum, and the peak width is calibrated using the measured spectrum to obtain the functional relationship between FWHM and energy, as well as the broadening coefficient. Preferably, for the Cs3Cu2I5:Tl detector, the formula is:

[0099]

[0100] in, This refers to the energy and full width at half maximum (FWHM) broadening factor of this detector system.

[0101] A simulation model of the experimental measurement platform was established using MCNP5 software based on the Monte Carlo method, according to the actual measurement environment. This included setting the detector geometry and materials, setting the type and location of the radiation source, setting the physical processes, and setting the material optical parameters. When establishing the model, the environmental factors of the measurement system should be fully considered, and the geometric conditions and measurement environment in the model should be consistent with the actual conditions in step one. The energy of the point source was set, and energy deposition spectra at photon energies of 33keV, 48keV, 65keV, 83keV, 100keV, 118keV, 164keV, 208keV, 662keV, and 1250keV were obtained sequentially. Using the FWHM and energy calibration information obtained in the above steps, as well as the broadening formula, Gaussian broadening was performed on the simulated energy deposition spectra to obtain the simulated energy spectra at the ten broadened energies.

[0102] The above steps are necessary because the types of standard sources available in practice are limited, and their energies are not uniformly distributed within the energy range (30keV-2MeV) specified in the national standard GB / T12162-2004. Furthermore, actual measurements are subject to problems such as energy spectrum drift and correction errors in experimental instruments. Using simulated energy spectra to obtain energy response correction coefficients can effectively solve these problems. In the process of energy response correction of detectors in actual radiation fields, the energy response correction coefficient values ​​obtained from simulated energy spectrum data serve as excellent reference values, and have a greater likelihood of meeting the requirements of the national standard GB / T 12162-2004 regarding the detector's performance relative to X / γ rays at different energies. 137 The requirement is that the response error of Cs is within ±30%.

[0103] The analog energy spectrum data is processed offline by converting it from high-speed analog-to-digital converter (ADC) to digital waveform data, and then from high-speed digital amplifier (DA) to analog signal. This process realizes the conversion from spectral data to digital waveform data and then to analog signal. The conversion process can be configured with sampling weights to output analog pulse signals with different fluence rates and analog pulse signals with different white noise levels.

[0104] The amplitudes of the generated pulse waveforms are fixed, and the peak values ​​of the Gaussian peaks generated in the multichannel analyzer are recorded. The relationship between the pulse amplitude and the output voltage value of the detector at different energies is measured. The linear relationship between the incident photon energy and the pulse amplitude is obtained through the energy-pulse amplitude scale information. In this embodiment, the generated pulse amplitudes are set to 50mV, 100mV, 150mV, 200mV, 250mV, and 300mV, respectively. As a result, the peak positions of the Gaussian peaks generated in the multichannel analyzer are in channels 382, ​​743, 1105, 1466, 1828, and 2189, respectively. From the correspondence between the pulse amplitude and the peak position, the function curve of the waveform signal pulse amplitude (i.e., signal voltage value) and the channel address in the multichannel analyzer can be calibrated.

[0105] With the pulse amplitude spectrum measurement parameters fixed in the multichannel analyzer, the detector in this embodiment, as described in the above steps, is... 137 Cs、 60 Co、 241 Am、 152 By analyzing the pulse amplitude spectrum under Eu excitation, and finding the peak value of the monoenergetic full-energy peak with known energy, a function curve relating energy to channel address can be obtained. This allows for energy calibration and the conversion of the pulse amplitude spectrum into a gamma spectrum. Figure 3 The figure shows the energy response curve of the Cs3Cu2I5:Tl detector in this invention. Using the pulse amplitude-channel address function and energy-channel address scaling information, the photon energy and detector amplitude-energy response function for the Cs3Cu2I5:Tl detector can be obtained as follows:

[0106]

[0107] The simulated energy spectrum data at ten energies—33keV, 48keV, 65keV, 83keV, 100keV, 118keV, 164keV, 208keV, 662keV, and 1250keV—are divided into several intervals based on energy. In this embodiment, the intervals are divided into ten ranges: 20-40keV, 40-60keV, 60-80keV, 80-100keV, 100-120keV, 120-150keV, 150-200keV, 200-500keV, 500-800keV, and 800-1500keV. In this embodiment, the number of energy intervals should be minimized while ensuring the energy response correction effect. Since detector overresponse mostly occurs in the low-energy region, most intervals are divided in the low-energy range (20-200keV) where overresponse is more severe.

[0108] In this invention, the linear relationship between photon energy and the amplitude of the light pulse generated by the detector can be obtained from the above steps. Therefore, the corresponding pulse amplitude value can be obtained for each energy interval, as shown in Table 1.

[0109] Table 1 Energy and Pulse Amplitude Scale

[0110]

[0111] As can be seen from the above steps, the method of the present invention divides the energy value into intervals, that is, divides the waveform pulse amplitude value in the radiation field into intervals. When used in the dose rate meter to correct the energy response in the radiation field, the pulse signal amplitude can be directly divided without distinguishing the energy of photons in the radiation field. Furthermore, the energy response correction coefficient for the same detector can be obtained at once without identifying the energy in the radiation field each time. Therefore, in the actual measurement of dose rate value in the radiation field, it is not necessary to obtain energy spectrum data using a multichannel analyzer.

[0112] In the method of this invention, each energy interval has a corresponding energy response correction coefficient. By multiplying the count rate within each energy interval by the corresponding energy response correction coefficient and dividing by the air absorbed dose rate in the standard radiation field, the corrected energy response value for each pulse amplitude interval at that energy can be obtained. The sum of the corrected energy response values ​​for each interval at the same energy is the detector response value at that energy. Corrected energy response values ​​for ten photon energies—33keV, 48keV, 65keV, 83keV, 100keV, 118keV, 164keV, 208keV, 662keV, and 1250keV—can be obtained. The detector response calculation formula is as follows:

[0113]

[0114] In this embodiment, the maximum range of energy response is divided into ten intervals, therefore m The value is 10. For the average energy is The corrected detector response value corresponding to the X / γ rays. These are the energy response correction coefficients for each interval. For partitioning The count rate within, For energy The air kerma rate under X / γ rays is determined by the standard reference dose rate value in the experimental radiation field.

[0115] when , Energy range weighting is not performed at this time; that is, the original detector response values ​​for different energies are used.

[0116] Based on the principle of minimizing the relative deviation between the corrected response values ​​of the detector under different incident energies, the average value of the corrected response value corresponding to the count rates of ten energy points (33keV, 48keV, 65keV, 83keV, 100keV, 118keV, 164keV, 208keV) and gamma rays (662keV, 1250keV) is obtained through a linear programming extremum algorithm. The calculation formula is as follows:

[0117]

[0118] variance This indicates the magnitude of fluctuation in the detector's response at different X / γ energies. When the minimum value is taken, the detector's energy response consistency is best, and the result is obtained at... Under the constraint of taking the minimum value The value of, i.e. The energy response correction coefficients are divided into ten intervals in this embodiment, with the maximum energy response range divided into ten intervals. m The value is 10, and the calculation formula is:

[0119]

[0120] Under experimental conditions, this correction coefficient will be used as the base value, and fine-tuning can be performed according to the actual energy response correction coefficient during the experiment. In this actual experiment, the maximum range of energy of interest is divided into ten pulse amplitude intervals, from which ten energy response correction coefficients can be calculated. The coefficients corresponding to each interval are shown in Table 2.

[0121] Table 2 Correction intervals and correction coefficients

[0122]

[0123] Substituting the correction coefficients into the above formula yields the relative response values ​​of the detector at different energies. The relative response curves of the detector before and after energy response correction are shown in the figure below. Figure 4 As shown in the figure, the maximum permissible error range (±30%) in the national standard is marked. For the Cs3Cu2I5:Tl scintillation detector, the detection efficiency for low-energy rays and high-energy rays differs by several times, with the relative response difference reaching as high as 800%~900%. After energy response, the detector's maximum positive relative error is 8.26%, the maximum negative error is 4.36%, and the overall maximum error is 8.26%, which is far better than the national standard requirement of ±30% for the detector's relative energy response error.

[0124] For dose rate conversion using a count rate method, the detector's count rate represents the energy deposited in the material per unit time. The amount of deposited energy has a linear relationship with the dose rate. By placing the detector at a standard point within a radiation field with a known dose rate, and adjusting the detector... 137 The distance from the Cs radiation source is used to change the dose rate at the detector's location, resulting in a linear response curve of dose rate versus count rate at 662 keV. A conversion function between count rate and dose rate is obtained by linearly fitting the detector's dose rate response curve. This conversion function, along with energy... Corresponding corrected total count rate Calculate the dose rate before and after the dose rate meter is calibrated.

[0125] Place the detector at a reference point within the radiation field, and adjust the detector relative to... 137 The distance to the Cs radiation source is used to change the dose rate at the detector's location, resulting in a linear response curve of dose rate versus count rate for the Cs3Cu2I5:Tl detector at 662 keV. The count rate-dose rate conversion function is obtained by fitting the linear response curve. This function is then used to convert the count rate value after energy response correction to dose rate, and this conversion is written into the real-time energy response correction program. In this invention patent, the formula for the conversion function obtained by linearly fitting the linear response curve of the Cs3Cu2I5:Tl detector dose rate is as follows:

[0126]

[0127] In this embodiment, the relative deviation between the dose rate measurement values ​​and the standard value of the radiation field before and after energy response correction is shown in the figure below. Figure 5 As shown, the relative deviation of the dose rate was calculated to be -3.3% to 8.6%, verifying the feasibility of this method.

[0128] The energy response correction coefficients are pre-set in the real-time energy response correction software. The real-time energy response correction system in this invention is software developed based on LabVIEW. The main program includes three modules: a digital waveform data acquisition module, a gigabit Ethernet data splicing module, and a real-time energy response correction module. The input of the digital waveform data acquisition module is connected to the SiPM readout circuit, used to convert the pulse voltage signal output by the detector into digital waveform data, extract the waveform amplitude value, and transmit it to the PC. The data splicing module is used to transmit data between the real-time energy response correction program and the digital waveform data acquisition module, realizing real-time energy response correction. The real-time energy response correction module processes the pulse waveform amplitude information extracted by the digital waveform data acquisition module, performs energy response correction, and displays the count, virtual count, real-time count rate, corrected real-time count rate, and radiation field dose rate in real time.

[0129] In summary, this invention provides a real-time energy response correction method for dose rate meters. This method is based on the correction concept of pulse amplitude weighting (PAW). First, pulse amplitude spectra of the detector under several different monoenergetic X / γ rays are acquired. The amplitude-energy response function and energy spectrum broadening function of the detector are obtained through their corresponding full-energy peaks and their full width at half maximum (FWHM). Then, the energy deposition spectra of the detector under several other monoenergetic X / γ rays are simulated and the energy spectrum is broadened to obtain their corresponding simulated energy spectra for determining the correction coefficients. The energy spectrum range is divided into a certain number of energy intervals, and the correction coefficients for each energy interval are obtained using a linear programming optimization algorithm. Then, in experiments at different dose rates, the measured pulse amplitude spectrum per unit time is converted into an energy spectrum using the amplitude-energy response function. The count rates of each energy interval are weighted and summed using the correction coefficients to obtain the weighted total count rate as the detector's response value. Finally, a conversion function from count rate to dose rate is obtained through fitting. The aforementioned response function, correction coefficients, and conversion function are applied to a practical dose rate meter for calculating the dose rate from the measured unit-time pulse amplitude spectrum. This method, applied to a Cs3Cu2I5:Tl detector, shows a maximum relative error of 8.26% in energy response to narrow-spectrum X / γ gamma rays (10 energy points) and a maximum dose rate error of 8.6%, compared to the energy response to 137Cs gamma rays. This invention solves the problem of excessively large detector response to low-energy X / γ rays in dose rate meters, improves measurement accuracy, reduces instrument development costs, and has significant engineering application value.

[0130] The present invention also provides a real-time energy response correction system for a dose rate meter, comprising:

[0131] The first digital waveform data acquisition module is used to acquire the pulse amplitude spectrum of the detector under p kinds of monoenergetic X / γ-ray radiation sources, and obtain the "amplitude-energy" response function of the detector by the peak position of the full-energy peak of the acquired p pulse amplitude spectrum, and convert the pulse amplitude spectrum into an energy spectrum.

[0132] The second digital waveform data acquisition module is used to obtain the full width at half maximum (FWHM) of the full-energy peak under p types of monoenergetic X / γ-ray radiation sources, and obtain the energy spectrum broadening formula of the detector by fitting a function formula.

[0133] The data simulation module is used to establish a simulation model of the detector and obtain the energy deposition spectrum of the detector under q different energies of monoenergetic X / γ rays; the energy deposition spectrum is broadened using the energy spectrum broadening formula to obtain the simulated energy spectrum of the detector under q different energies of monoenergetic X / γ rays;

[0134] The first data stitching module is used to divide the maximum energy range of the simulated energy spectrum under q different energies of monoenergetic X / γ rays into m energy intervals. Each interval is assigned an energy response correction coefficient. The counts of each energy interval are compensated and summed using the correction coefficients to obtain the weighted total count as the response value of the detector.

[0135] The second data stitching module is used to stitch together data at an energy level of [missing information]. Under the condition of single-energy X / γ-ray incident radiation, the pulse amplitude spectrum per unit time of the detector obtained in the actual experiment is converted into an energy spectrum using the response function obtained in step 1. The count rate of each energy range is denoted as... And the count rate in different energy ranges was adjusted using correction coefficients. Compensation and weighted summation are performed, and the result is divided by the reference dose rate to obtain the corrected detector response value under the incident energy. Based on the corrected count rate of the detector under different reference dose rates in the standard radiation field measured in the experiment, the conversion function from detector count rate to dose rate is obtained by fitting.

[0136] The real-time energy response correction module is used to write real-time energy response correction programs and apply response functions, correction coefficients, and conversion functions to actual dose rate meters to realize the calculation from the measured pulse amplitude spectrum per unit time to the count rate and then to the dose rate, thus completing the real-time energy response correction work.

[0137] The input terminal of the digital waveform data acquisition module is connected to the SiPM readout circuit, which is used to convert the pulse voltage signal output by the detector into digital waveform data, extract the pulse amplitude value and transmit it to the PC.

[0138] The gigabit Ethernet data splicing module is used to transmit data between the real-time energy response correction program and the digital waveform data acquisition module to achieve real-time correction of the energy response.

[0139] The real-time energy response correction module is used to process the pulse waveform amplitude information extracted by the digital waveform data acquisition module, perform energy response correction, and display the count, virtual count, real-time count rate, corrected real-time count rate, and radiation field dose rate in real time.

[0140] The present invention also provides a mobile terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor, such as a real-time energy response correction program for a dose rate meter.

[0141] For example, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the mobile terminal.

[0142] The mobile terminal can be a computing device such as a desktop computer, laptop, handheld computer, or cloud server. The mobile terminal may include, but is not limited to, a processor and a memory.

[0143] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. This processor is the control center of the mobile terminal, connecting various parts of the mobile terminal via various interfaces and lines.

[0144] The memory can be used to store the computer program and / or module. The processor implements various functions of the mobile terminal by running or executing the computer program and / or module stored in the memory and calling the data stored in the memory.

[0145] The memory may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a function (such as sound playback, image playback, etc.); the data storage area may store data created based on the use of the mobile phone (such as audio data, phonebook, etc.). Furthermore, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disks, RAM, plug-in hard disks, SmartMediaCards (SMC), Secure Digital (SD) cards, FlashCards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not 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 modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A real-time energy response correction method for a dose rate meter, characterized in that, Includes the following steps: Step 1: Obtain the pulse amplitude spectrum of the detector under p types of monoenergetic X / γ-ray radiation sources, and obtain the "amplitude-energy" response function of the detector by the peak position of the full-energy peak of the obtained p pulse amplitude spectra, and convert the pulse amplitude spectrum into an energy spectrum. Step 2: Obtain the full width at half maximum (FWHM) of the full-energy peaks under p types of monoenergetic X / γ-ray radiation sources, and obtain the energy spectrum broadening formula for the detector by fitting a function formula. Step 3: Establish a simulation model of the detector described in Step 1, and obtain the energy deposition spectrum of the detector under q different energies of monoenergetic X / γ rays; use the energy spectrum broadening formula in Step 2 to broaden the energy deposition spectrum, and obtain the simulated energy spectrum of the detector under q different energies of monoenergetic X / γ rays. Step 4: Divide the maximum energy range of the simulated energy spectrum under q different energies of monoenergetic X / γ rays into m energy intervals. Assign an energy response correction coefficient to each interval. Use the correction coefficient to compensate for the counts of each energy interval and sum them up to obtain the weighted total count as the response value of the detector. Step 5, with energy of Under the condition of single-energy X / γ-ray incident radiation, the pulse amplitude spectrum per unit time of the detector obtained in the actual experiment is converted into an energy spectrum using the response function obtained in step 1. The count rate of each energy range is denoted as... ; And the correction coefficient described in step 4 is used to adjust the count rate in different energy ranges. Compensation and weighted summation are performed, and the result is divided by the reference dose rate to obtain the corrected detector response value under the incident energy. Based on the corrected count rate of the detector under different reference dose rates in the standard radiation field measured in the experiment, the conversion function from detector count rate to dose rate is obtained by fitting. Step 6: Write a real-time energy response correction program and apply the response function, correction coefficient, and conversion function to the actual dose rate meter to realize the calculation from the measured pulse amplitude spectrum per unit time to the count rate and then to the dose rate, thus completing the real-time energy response correction work.

2. The real-time energy response correction method for a dose rate meter according to claim 1, characterized in that, In step 1, the peak positions of the full-energy peaks of the acquired p pulse amplitude spectra are calibrated using energy scaling to determine the detector's amplitude-energy response function. A linear fit is then used to establish the correspondence between the multichannel analyzer channel address and the incident X / γ-ray energy. The pulse amplitude spectrum is then converted into a gamma spectrum. The formula for the amplitude-energy linear response function fitting is as follows: in, K 1 represents the slope fitted by the "energy-amplitude" linear response function. B 1 represents the intercept of the "energy-amplitude" linear response function; energy is in keV; channel address is in channels.

3. The real-time energy response correction method for a dose rate meter according to claim 1, characterized in that, In step 2, the full width at half maximum (FWHM) of the full-energy peaks under p single-energy X / γ-ray radiation sources is obtained using Gaussian fitting. A functional formula relating the FWHM of the full-energy peaks of the detector system to the incident gamma-ray energy is then derived. This functional formula is used to fit the detector's spectral broadening formula, which is: ； in, The broadening factor is the ratio between the energy corresponding to the full-energy peak of the gamma spectrum of the detector system and the full width at half maximum (FWHM). The broadening factor and its formula are used to broaden the unbroadened energy deposition spectrum to obtain the simulated energy spectrum. E The energy of the incident X / γ rays.

4. The real-time energy response correction method for a dose rate meter according to claim 1, characterized in that, In step 3, the establishment of the detector's simulation model includes setting the detector's geometry and materials, setting the type and location of the radiation source, setting the physical processes, and setting the material's optical parameters.

5. The real-time energy response correction method for a dose rate meter according to claim 1, characterized in that, In step 4, for q The maximum energy range of each simulated energy spectrum is divided into: The system uses an energy range with appropriate thresholds to filter out system noise via a pulse discriminator. When a photon enters the detector, it generates a pulse signal after photoelectric conversion. The amplitude of the pulse signal is extracted. If the pulse amplitude exceeds the threshold, the signal is considered valid; otherwise, it is considered noise and discarded. The minimum value of the energy range should be above the discrimination threshold, and the same pulse amplitude spectrum data acquisition time should be set.

6. The real-time energy response correction method for a dose rate meter according to claim 1, characterized in that, In step 5, the number of particle events detected by the detector in each energy range is obtained, the total detection time is recorded, and the count rate for each energy range is obtained by dividing the total detection time by the total detection time. and energy range Count rate within Perform correction and weighting, partitioning The correction factor is The formula for the corrected detector response at each energy point is: when , The value is the detector response value before correction, i.e., without energy range correction weighting; in The number of energy intervals. For energy is The corresponding corrected detector energy response value under X / γ rays. For interval The corresponding energy response correction factor, For interval The count rate within, For energy The air kerma rate of X / γ rays.

7. A real-time energy response correction method for a dose rate meter according to claim 6, characterized in that, Each interval has a corresponding energy response correction coefficient. Actual count rate in different energy ranges under X / γ rays of different energies The total count rate after correction is obtained by multiplying by the correction coefficients for each interval and then weighting the results. The calculation formula is as follows: in, , E The energy of the incident X / γ rays, For interval The corresponding energy response correction factor, For interval The count rate within, The number of energy intervals. Indicates in Parameters within the interval; Energy is The detector response value under X / γ rays is obtained by the following formula: in, , E The energy of the incident X / γ rays, For interval The corresponding energy response correction factor, For interval The count rate within, The number of energy intervals. Indicates in Parameters in the interval for Air kerma rate.

8. A real-time energy response correction method for a dose rate meter according to claim 1, characterized in that, In step 5, the count rate to dose rate conversion function is obtained by fitting experimental data. For the count rate to dose rate conversion, the detector's count rate represents the energy deposited in the material per unit time, and there is a linear relationship between the amount of deposited energy and the dose rate. The formula for the conversion function between count rate and dose rate obtained by linearly fitting the dose rate response curve is as follows: Among them, among them, The slope is the result of fitting the linear transformation function of "dose rate - count rate". Find the intercept for the linear transformation function of "dose rate - count rate"; The unit is Count rate, in units of .

9. A real-time energy response correction system for a dose rate meter, characterized in that, include The first digital waveform data acquisition module is used to acquire the pulse amplitude spectrum of the detector under p kinds of monoenergetic X / γ-ray radiation sources, and obtain the "amplitude-energy" response function of the detector by the peak position of the full-energy peak of the acquired p pulse amplitude spectrum, and convert the pulse amplitude spectrum into an energy spectrum. The second digital waveform data acquisition module is used to obtain the full width at half maximum (FWHM) of the full-energy peak under p types of monoenergetic X / γ-ray radiation sources, and obtain the energy spectrum broadening formula of the detector by fitting a function formula. The data simulation module is used to establish a simulation model of the detector and obtain the energy deposition spectrum of the detector under q different energies of monoenergetic X / γ rays; the energy deposition spectrum is broadened using the energy spectrum broadening formula to obtain the simulated energy spectrum of the detector under q different energies of monoenergetic X / γ rays; The first data stitching module is used to divide the maximum energy range of the simulated energy spectrum under q different energies of monoenergetic X / γ rays into m energy intervals. Each interval is assigned an energy response correction coefficient. The counts of each energy interval are compensated and summed using the correction coefficients to obtain the weighted total count as the response value of the detector. The second data stitching module is used to stitch together data at an energy level of [missing information]. Under the condition of single-energy X / γ-ray incident radiation, the pulse amplitude spectrum per unit time of the detector obtained in the actual experiment is converted into an energy spectrum using the response function obtained in step 1. The count rate of each energy range is denoted as... ; And the count rate in different energy ranges was adjusted using correction coefficients. Compensation and weighted summation are performed, and the result is divided by the reference dose rate to obtain the corrected detector response value under the incident energy. Based on the corrected count rate of the detector under different reference dose rates in the standard radiation field measured in the experiment, the conversion function from detector count rate to dose rate is obtained by fitting. The real-time energy response correction module is used to write real-time energy response correction programs and apply response functions, correction coefficients, and conversion functions to actual dose rate meters to realize the calculation from the measured pulse amplitude spectrum per unit time to the count rate and then to the dose rate, thus completing the real-time energy response correction work.

10. A mobile terminal, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of a real-time energy response correction method for a dose rate meter as described in any one of claims 1 to 8.

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