A method and system for rapid determination of the concentration of radioactive radon in air based on scintillation

Abstract

The application discloses a method and system for rapidly measuring the concentration of radioactive radon in air based on a flow type of scintillation. The method is based on the scintillation method for measuring the net count rate of alpha particles, and needs to obtain the net count rate of alpha particles in a corresponding time period in the measurement. In combination with the decay law of radon and daughter and the air exchange condition of a chamber, the relationship between the net count of alpha particles generated by the decay of radon and daughter in newly pumped air in a corresponding measurement time period in the measurement chamber and the volume of the measurement chamber, the pump speed and the radioactive concentration of air in the original chamber is established, so that the sensitivity coefficient of the corresponding measurement of the radioactive radon concentration of the to-be-measured air is obtained, and the radioactive radon concentration in the to-be-measured air is obtained in real time. The method can rapidly and real-timely measure the radioactive radon concentration in air under the condition of a dynamic flow type, can greatly save the measurement time and timely reflect the change of the radon concentration in air, is helpful to protect workers and the public from the harm of radon radiation, is favorable to promoting the safety production of the nuclear industry, and has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of environmental radioactivity monitoring technology, specifically relating to a method and system for rapid determination of radioactive radon concentration in air based on scintillation-based airflow. Background Technology

[0002] Radon is the only naturally occurring radioactive gas in nature, primarily produced through the decay of radioactive elements such as uranium and thorium in soil and rocks. The main radioactive particles produced by radon and its decay products are alpha particles, which are generally negligible in external radiation exposure; the primary source of internal radiation is inhalation. Radon radiation not only affects the health of the general public in natural environments, but it is also a major source of radiation requiring control in nuclear industry settings such as the nuclear fuel cycle and uranium mining. To protect workers and the public from the hazards of radon radiation, rapid measurement of radon concentration is necessary. This not only allows for timely assessment of the concentration and changes of radioactive radon in the environment to help adjust radiation protection measures promptly, but also facilitates the rapid identification of sources of radon changes to ensure safe production.

[0003] The concentration of radioactive radon in the air is used to describe the level of radioactivity of radon gas in the environment (unit: Bq / m³). 3 Radon is generally measured by measuring alpha particles produced by radon and its decay products. When measuring ambient radon concentration, a radon meter needs to first evacuate the air to be measured into the measurement chamber. This involves completely replacing the existing air in the chamber, requiring a sufficient amount of air to be drawn in. Furthermore, the decay of radon and its decay products in the newly drawn-in air takes time to reach equilibrium, and the number of alpha particles released at different times is a function of time. Some radon meters can only measure alpha particles emitted by specific radon decay products (such as Po-218 and Po-216). Both of these issues make it difficult to accurately measure the concentration of radioactive radon in the air in real time.

[0004] Currently, the methods for rapid radon measurement in the literature are as follows: (1) Rapid radon measurement by ZnS(Ag) scintillation method involves pumping the air to be measured only once and then sealing the measurement chamber. During the static process, the net count rate of radioactive particles is measured, and the radioactive radon concentration is calculated by combining the theoretical sensitivity coefficient correction factor obtained by the decay law of radon and its progeny. This method is simple, but since it only pumps the air once, it cannot guarantee the complete replacement of the air in the measurement chamber. If replacement is required, a long pumping time is needed, which results in an insufficient response speed; (2) Rapid radon measurement by semiconductor method also involves pumping the air pumping process. In addition, since this method can only measure specific radon progeny (such as Po-218, Po-216) by electrostatic adsorption and measure the α particles they emit, this will cause the following major problems: [1] This method can only measure and requires the adsorption and accumulation of a sufficient number of specific radon progeny, which will result in a slow response and a large measurement error in the same measurement time. [2] The adsorption efficiency of this method is very sensitive to humidity, so it is easy to fail in a high humidity environment. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a method and system for rapid determination of radioactive radon concentration in the air based on scintillation flow, thereby solving the technical problems of slow response speed, high error and sensitivity to humidity in the measurement of radioactive radon concentration in the air in the prior art, and realizing accurate, rapid and real-time monitoring of radioactive radon concentration in the air.

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

[0007] A method for rapid determination of radioactive radon concentration in air based on scintillation flow includes the following steps:

[0008] P1: Obtain the net alpha particle count rate within the corresponding time period during the measurement;

[0009] P2: Obtain the radon concentration value in the air to be tested by using the obtained net alpha particle count rate and the preset radon concentration solution model;

[0010] The radon concentration calculation model considers the relationship between the net count rate of radon and its decay products in the air entering the measurement chamber during the measurement period, the volume of the measurement chamber, the sampling pump speed, and the initial concentration of radon and its decay products in the measurement chamber. It obtains the sensitivity conversion coefficient of the radioactive radon concentration in the air and uses the sensitivity conversion coefficient to convert the net count rate of radon and its decay products in the air entering the measurement chamber during the measurement period into the radon concentration value in the environment.

[0011] Preferably, the construction of the radon concentration solution model is specifically as follows:

[0012] P21: Establish the relationship between the net count rate of radon and its decay products generated by alpha particles in the air entering the measurement chamber during the measurement period and the volume of the measurement chamber, the sampling pump speed, and the initial concentration of radon and its decay products in the measurement chamber, and obtain the number of radon and its decay products in the air entering the measurement chamber.

[0013] P22: The radioactivity of radon and its progeny is obtained by the number of radon and its progeny in the air entering the measuring chamber, and the sensitivity conversion coefficient is obtained by the radioactivity of radon and its progeny.

[0014] P23: Establish the radon concentration solution model using the sensitivity conversion coefficient and the sensitivity of the tester itself.

[0015] Preferably, in step P21, the establishment of the relationship between the net count rate of alpha particles generated by the decay of radon and its progeny in the air entering the measurement chamber during the measurement time period and the volume of the measurement chamber, the sampling pump speed, and the initial concentration of radon and its progeny in the measurement chamber, to obtain the number of radon and its progeny in the air entering the measurement chamber, specifically involves:

[0016]

[0017] In the formula, N0(t), N1(t), N2(t), N3(t), and N4(t) are respectively 222 Rn、 218 Po、 214 Pb, 214 Bi、 214 The number of Pos varies with time t; k0 is a constant; Q is the sampling pump speed, m 3 / s; V is the volume of the measuring cavity, m 3 N 0,env λ is a constant; o λ1, λ2, λ3, and λ4 are respectively 222 Rn、 218 Po、 214 Pb, 214 Bi、 214 The decay constant of Po, s -1 .

[0018] Preferably, in step P22, the radioactivity of radon and its progeny is obtained by counting the number of radon and its progeny in the air entering the measuring chamber, and the sensitivity conversion coefficient is obtained by using the radioactivity of radon and its progeny; specifically:

[0019] A o (t)=λ0N0(t)

[0020] A1(t)=λ1N1(t)

[0021] A2(t)=λ2N2(t)

[0022] A3(t)=λ3N3(t)

[0023] A4(t)=λ4N4(t)

[0024]

[0025] In the formula, A o A1(t), A2(t), A3(t), and A4(t) represent the radioactivity of radon and its progeny; b is the sensitivity conversion factor; T S To completely replace the air inside the measurement chamber with radon and its decay products, and to measure any time point after the replaced radon and its decay products have reached decay equilibrium; T x This is to measure any point in time before the air inside the cavity is completely replaced by radon and its decay products, and before the replaced radon and its decay products reach decay equilibrium.

[0026] Preferably, in step P23, the step of establishing the radon concentration solution model using the sensitivity conversion coefficient and the instrument's own sensitivity specifically involves:

[0027]

[0028] In the formula, C m The measured value of radioactive radon concentration in the air to be tested is Bq / m³. 3 ;n x (ΔT) is the real-time value of the net alpha particle count rate during the time period ΔT, in cpm; S x To predict sensitivity, cpm / (Bq / m 3 S represents the sensitivity of the tester itself, cpm / (Bq / m). 3 b is the sensitivity conversion coefficient.

[0029] Preferably, after step P2, the method further includes obtaining the error value of the radon concentration in the air to be measured within the corresponding measurement time period.

[0030] A system for rapid determination of radioactive radon concentration in air based on scintillation flow, comprising:

[0031] The data acquisition module is used to acquire the net alpha particle count rate within the corresponding time period during the measurement.

[0032] The data processing module is used to obtain the radon concentration value in the air to be tested by using the acquired net alpha particle count rate and a preset radon concentration solution model.

[0033] The radon concentration calculation model considers the relationship between the net count rate of radon and its decay products in the air entering the measurement chamber during the measurement period, the volume of the measurement chamber, the sampling pump speed, and the initial concentration of radon and its decay products in the measurement chamber. It obtains the sensitivity conversion coefficient of the radioactive radon concentration in the air and uses the sensitivity conversion coefficient to convert the net count rate of radon and its decay products in the air entering the measurement chamber during the measurement period into the radon concentration value in the environment.

[0034] Preferably, the data acquisition module includes a measurement mode setting module and a data transmission module that communicate with each other;

[0035] The measurement method setting module is used to set the method for obtaining the net alpha particle count rate according to experimental requirements and system design; the data transmission module is used to transmit the obtained net alpha particle count rate to the data processing module.

[0036] The data processing module includes a sensitivity conversion coefficient acquisition module, a predicted sensitivity acquisition module, and a radon concentration acquisition module, which are configured to communicate sequentially.

[0037] The sensitivity conversion coefficient acquisition module is used to acquire the sensitivity conversion coefficient based on the ratio between the theoretical net alpha particle count rates for different measurement time periods; the predicted sensitivity acquisition module is used to acquire the predicted sensitivity based on the sensitivity conversion coefficient and the sensitivity of the tester itself; the radon concentration acquisition module is used to acquire the radon concentration value in the air to be tested based on the predicted sensitivity and the net alpha particle count rate within the corresponding time period acquired by the data acquisition module.

[0038] Preferably, the system further includes an accuracy and error analysis module, which communicates with the radon concentration acquisition module to evaluate the accuracy of the acquired radon concentration value.

[0039] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described method.

[0040] Compared with the prior art, the present invention has the following beneficial technical effects:

[0041] This invention discloses a method for determining the concentration of radioactive radon in air based on scintillation-based airflow. In this method, the net alpha particle count rate within a corresponding time period during the measurement is obtained. This net alpha particle count rate represents the alpha particle count rate within the time period before the air in the measurement chamber is completely replaced by radon and its progeny, and before the replaced radon and its progeny reach decay equilibrium. The radon concentration in the air to be measured is obtained by acquiring this net alpha particle count rate and using a pre-defined radon concentration calculation model. The pre-defined radon concentration calculation model considers the relationship between the detector measurement chamber volume, the detector sampling flow rate, and the initial radon and its progeny concentration in the measurement chamber, effectively ensuring the accuracy of the algorithm. Furthermore, during the solution process, the model uses a sensitivity conversion coefficient to convert the instrument sensitivity into a predicted sensitivity for different time periods in the early stage of the measurement, avoiding the need to wait for the existing air in the measurement chamber to be completely replaced and for the existing radon and its progeny in the chamber to reach decay equilibrium. Combined with the real-time acquired net alpha particle count rate, this model can quickly obtain the radon concentration of the air to be measured. Therefore, in actual measurement, this method effectively shortens the measurement time, avoids the time-consuming process of waiting for complete replacement and decay, and, through model construction and solution, can collect the net alpha particle count rate within any time period before measurement to obtain the radon concentration value of the air to be measured, effectively realizing dynamic monitoring of environmental radon concentration. In summary, this method is simple to operate, can achieve real-time measurement and quickly obtain the radon concentration value of the air to be measured under dynamic airflow conditions, avoids the time-consuming process required in the early stage of measurement, and uses the scintillation chamber method for measurement. The design is reasonable and effectively avoids the influence of environmental humidity, resulting in high reliability. This provides more scientific and reliable data for radiation assessment and has broad application prospects.

[0042] Furthermore, in the radon concentration calculation model of this invention, the sensitivity conversion coefficient of the model is determined by theoretically deriving the net count rate of alpha particles in different time periods. The determination of the sensitivity conversion coefficient here enables the model to effectively obtain the predicted sensitivity before the existing air in the measurement chamber is completely replaced and before the existing radon and its progeny in the chamber reach decay equilibrium, thereby quickly obtaining the radon concentration of the air to be measured and shortening the measurement time.

[0043] Furthermore, after step P2, the method also includes obtaining the error value of the radon concentration in the air to be measured within the corresponding measurement time period, so that the measurer can control the accuracy of the measurement results in real time. When the accuracy and error are large, the instrument settings can be adjusted to make corrections, thus ensuring the accuracy of the measurement results.

[0044] In addition, this invention also discloses a system for rapid determination of radioactive radon concentration in the air based on scintillation flow. The system adopts a modular design to ensure that each module operates independently and is easy to manage, as well as easy to calibrate during use. It achieves high efficiency, flexibility and accuracy in radon measurement. The system can be widely used in complex environments to accurately assess radon concentration and protect public health and environmental safety. It has important application value, especially in underground engineering, nuclear facility operation and maintenance and accident rescue.

[0045] Furthermore, the data acquisition module includes a measurement mode setting module and a data transmission module that communicate with each other. The measurement mode setting module is used to set the acquisition method of the alpha particle net count rate according to experimental requirements and system design. The data transmission module is used to transmit the acquired alpha particle net count rate to the data processing module. The data processing module includes a sensitivity conversion coefficient acquisition module, a predicted sensitivity acquisition module, and a radon concentration acquisition module that are configured in sequence. First, the measurement mode setting module ensures the air intake mode and pumping speed in multi-cycle dynamic measurement. The setting of the sensitivity conversion coefficient acquisition module lays the foundation for the calculation of predicted sensitivity. The setting of the predicted sensitivity acquisition module lays the foundation for the calculation of radon concentration. The radon concentration acquisition module effectively realizes the conversion of the alpha particle net count rate of the air in the measurement chamber that has not been completely replaced, and the replaced radon and its progeny before reaching decay equilibrium, into the radon concentration value of the air to be measured, realizing the real-time and rapid acquisition of radon concentration. The modular structure of this system brings independence, which allows each functional part to be developed, measured, and maintained independently, reducing mutual interference, improving the system's response speed and accuracy, and facilitating expansion and upgrades, thus improving the overall reliability and adaptability of the measurement system.

[0046] Furthermore, the system also includes an accuracy and error analysis module, which communicates with the radon concentration acquisition module and is used to evaluate the accuracy of the acquired radon concentration value. This module can provide feedback and optimize system performance by comparing the error between the radon concentration of the air to be tested measured by a standard instrument and the radon concentration acquired by the present invention. Attached Figure Description

[0047] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1This is a schematic diagram of a method and system for rapid determination of radioactive radon concentration in air based on scintillation in this invention (S1: Determine the measurement method; S2: Construct a rapid radon concentration solution model and obtain the general solution; S3: Set experimental conditions and solve for the predicted sensitivity; S4: Calculate the radon concentration value; S5: Experimental verification and error analysis of the algorithm; M1: Measurement method setting module; M2: Sensitivity conversion coefficient acquisition module; M3: Predicted sensitivity acquisition module; M4: Radon concentration acquisition module; M5: Accuracy and error analysis module).

[0049] Figure 2 for 222 decay framework diagram of Rn and its daughters;

[0050] Figure 3 b is the sensitivity conversion coefficient for different pumping time intervals under airflow circulation;

[0051] Figure 4 The experimental verification results of the algorithm with a single cycle time of 5 minutes under airflow circulation are shown in the figure (in the figure: the radon concentration of the test environment is C, and the error bar is the absolute error of C; the RAD7-5830 is used as the standard instrument for monitoring the radon concentration of the test environment, and its radon concentration curve reflects the real-time radon concentration C during the measurement process). rt The radon concentration value under the algorithm is C. m Its error bar is C m The absolute error ε and the relative error between C and C are δ. Furthermore, the measurement time 0 in the figure is the moment the pump starts working. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0053] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0054] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0055] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0056] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0057] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0058] The present invention will now be described in further detail with reference to the accompanying drawings:

[0059] Example 1

[0060] This invention discloses a method for rapid determination of radioactive radon concentration in air based on scintillation flow, comprising the following steps:

[0061] P1: Obtain the net alpha particle count rate within the corresponding time period during the measurement;

[0062] The real-time value of the alpha particle net count rate is acquired here through a flow-gas sampling method, in which a constant airflow velocity is maintained; and the real-time value of the alpha particle net count rate is obtained through a continuous measurement mode.

[0063] P2: Obtain the radon concentration value in the air to be tested by using the obtained net alpha particle count rate and the preset radon concentration solution model;

[0064] The radon concentration calculation model considers the relationship between the net count rate of radon and its decay products in the air entering the measurement chamber during the measurement period, the volume of the measurement chamber, the sampling pump speed, and the initial concentration of radon and its decay products in the measurement chamber. It obtains the sensitivity conversion coefficient of the radioactive radon concentration in the air and uses the sensitivity conversion coefficient to convert the net count rate of radon and its decay products in the air entering the measurement chamber during the measurement period into the radon concentration value in the environment.

[0065] In a preferred embodiment, the construction of the radon concentration solution model is specifically as follows:

[0066] P21: Establish the relationship between the net count rate of radon and its decay products generated by alpha particles in the air entering the measurement chamber during the measurement period and the volume of the measurement chamber, the sampling pump speed, and the initial concentration of radon and its decay products in the measurement chamber, and obtain the number of radon and its decay products in the air entering the measurement chamber.

[0067] P22: The radioactivity of radon and its progeny is obtained by the number of radon and its progeny in the air entering the measuring chamber, and the sensitivity conversion coefficient is obtained by the radioactivity of radon and its progeny.

[0068] P23: Establish the radon concentration solution model using the sensitivity conversion coefficient and the sensitivity of the tester itself.

[0069] More specifically, in step P21, establishing the relationship between the net count rate of alpha particles generated by the decay of radon and its progeny in the air entering the measurement chamber during the measurement time period and the volume of the measurement chamber, the sampling pump speed, and the initial concentration of radon and its progeny in the measurement chamber, and obtaining the number of radon and its progeny particles in the air entering the measurement chamber, specifically involves:

[0070]

[0071]

[0072] In the formula, N0(t), N1(t), N2(t), N3(t), and N4(t) are respectively 222 Rn、 218 Po、 214 Pb, 214 Bi、 214 The number of Pos varies with time t; k0 is a constant; Q is the sampling pump speed, m 3 / s; V is the volume of the measuring cavity, m 3 N 0,env λ is a constant; o λ1, λ2, λ3, and λ4 are respectively 222 Rn、 218 Po、 214 Pb, 214 Bi、214 The decay constant of Po, s -1 .

[0073] In step P22, the radioactivity of radon and its progeny is obtained by counting the number of radon and its progeny particles in the air entering the measuring chamber, and the sensitivity conversion coefficient is obtained by using the radioactivity of radon and its progeny particles; specifically:

[0074] A o (t)=λ0N0(t)

[0075] A1(t)=λ1N1(t)

[0076] A2(t)=λ2N2(t)

[0077] A3(t)=λ3N3(t)

[0078] A4(t)=λ4N4(t)

[0079]

[0080] In the formula, A(ΔT) is the net alpha particle count rate (unit: cpm) theoretically derived during the time interval ΔT after the air in the measurement chamber has been completely replaced by radon and its progeny, and the replaced radon and its progeny have reached decay equilibrium. x (ΔT) is the net alpha particle count rate (unit: cpm) theoretically derived during the time period ΔT before the air in the measurement chamber is completely replaced by radon and its progeny, and before the replaced radon and its progeny reach decay equilibrium.

[0081] The above A(ΔT) and A x The theoretical derivation of (ΔT) is as follows:

[0082]

[0083] In the formula, A o A1(t), A2(t), A3(t), and A4(t) represent the radioactivity of radon and its progeny; b is the sensitivity conversion factor; T S To completely replace the air inside the measurement chamber with radon and its decay products, and to measure any time point after the replaced radon and its decay products have reached decay equilibrium; T x This is to measure any point in time before the air inside the cavity is completely replaced by radon and its decay products, and before the replaced radon and its decay products reach decay equilibrium.

[0084] Based on the decay patterns of radon and its decay products, it is known that the initial time after radon completes its replacement and reaches decay equilibrium is approximately 260 minutes. Therefore, in a preferred embodiment, T S260 minutes is preferred, but it is not limited to a fixed 260 minutes, as long as sufficient replacement and decay are ensured.

[0085] When T S When the optimal time is 260 min, the theoretical derivation process of the above sensitivity conversion coefficient b is as follows:

[0086]

[0087] In step P23, the establishment of the radon concentration solution model using the sensitivity conversion coefficient and the instrument's own sensitivity specifically involves:

[0088]

[0089] In the formula, C m The measured value of radioactive radon concentration in the air to be tested is Bq / m³. 3 ;n x (ΔT) is the real-time value of the net α-particle count rate during the time period ΔT, in cpm; s x To predict sensitivity, cpm / (Bq / m 3 S represents the sensitivity of the tester itself, cpm / (Bq / m). 3 b is the sensitivity conversion coefficient.

[0090] Of course, to ensure the accuracy of the measurement, step P2 also includes obtaining the error value of the radon concentration value in the air to be measured within the corresponding measurement time period, that is, analyzing the accuracy of the obtained radon concentration value to ensure the accuracy and reliability of the measurement results.

[0091] Additionally, it should be noted that this invention relates to a method for rapid determination of radioactive radon concentration in air based on a scintillation-based gas flow method. The term "scintillation" refers to the method of continuously measuring radon concentration in air using the phenomenon of scintillation emission. This scintillation emission phenomenon refers to the emission produced by the interaction of alpha particles generated from the decay of radon and its progeny with a scintillator. The principle of scintillation radon measurement is that the interaction of alpha particles generated from the decay of radon and its progeny with a scintillator produces a fluorescence effect. A photomultiplier tube converts this fluorescence signal into an electrical pulse signal, which is amplified by electronic circuitry and finally recorded. The number of pulses per unit time (pulse count rate) is proportional to the radon concentration, thus determining the radon concentration in the corresponding environment. "Gas flow method" refers to a measurement or operation method whose core feature is to perform detection or processing by continuously flowing gas. Specifically, in radon measurement, flow-through radon measurement refers to continuously flowing radon-containing air into the measurement chamber using an air pump or other driving device, and using the flowing gas to complete the real-time detection of radon concentration; "radioactive radon concentration" refers to the radioactive level of radon gas in the environment (unit: Bq / m³). 3 ).

[0092] Example 2

[0093] To further illustrate the rapid method for determining radioactive radon concentration of the present invention in more detail, this embodiment is provided:

[0094] This invention discloses a method and system for rapid determination of radioactive radon concentration in air based on scintillation-based airflow. The method determines the measurement mode, constructs a theoretical model for rapid radon concentration calculation, considers parameters such as pump speed and measurement time, obtains sensitivity conversion coefficients for different time periods to arrive at a predicted sensitivity, and then combines this with the real-time acquired detector net count rate to obtain the radon concentration value. This value is then compared with the radon concentration obtained from a standard instrument to calculate the error. This method transforms differential equations into a system of linear equations, solves them using matrix methods, and considers the effects of pump speed and radon decay, simplifying the calculation process while improving accuracy, ensuring efficient and accurate radon concentration determination. Furthermore, the system adopts a modular design, specifically including a measurement mode setting module, a sensitivity conversion coefficient acquisition module, a predicted sensitivity acquisition module, a radon concentration acquisition module, and an accuracy and error analysis module, ensuring that each module operates independently and is easy to manage. This technology can be widely applied in complex environments to accurately assess radon concentration, ensuring public health and environmental safety, and has significant application value, particularly in underground engineering, nuclear facility operation and maintenance, and accident rescue.

[0095] The specific steps of the above-mentioned method for rapid determination of radioactive radon concentration in air based on scintillation are as follows:

[0096] Step S1: Determine the measurement method. The determination of the measurement method is mainly based on the selection of the gas sampling method and measurement mode for the purpose of rapid radon measurement. First, regarding the gas sampling method, to ensure the radon gas to be measured quickly fills the measurement chamber, flowing gas sampling is considered the most suitable method. This is because during the simultaneous sampling and counting process, the net count rate data of alpha particles generated by the decay of radon and its progeny in the test environment can be quickly obtained, shortening the experimental time. Second, a continuous measurement mode is selected, which helps to record the real-time value of the net count rate of alpha particles at the current stage, rapidly reflecting the radon concentration.

[0097] Preferably, a flowing gas sampling method with a maintained constant airflow velocity is employed. This reduces the risk of contamination from radon entering the measurement chamber while minimizing its residence time in the pipe. Furthermore, continuous sampling ensures the stability of the rapidly acquired count rate. To ensure the accuracy and efficiency of the count rate, the instrument should possess a high-efficiency data acquisition system to track changes in radon concentration in real time. Additionally, theoretical estimations can be performed in the early stages of the experiment, and the effectiveness of the gas sampling method and measurement mode can be verified and optimized to ensure the reliability and accuracy of the final data. In summary, by selecting flowing gas sampling and continuous measurement modes, the radon concentration measurement system can significantly improve data acquisition speed and experimental efficiency.

[0098] Step S2: Construct a rapid solution model for radon concentration and find the general solution. The theoretical model needs to comprehensively consider the dynamic process of radon gas being drawn into and expelled from the measurement chamber via a pump, as well as the decay process of radon and its progeny within the measurement chamber. These two processes can be described by defining corresponding differential equations, where the measurement chamber volume, pump speed, and decay constant are key parameters. Using these parameters, combined with the initial number of radon and its progeny particles in the measurement chamber and the pumping ratio, a coupled dynamic model of the number of radon and its progeny particles is further constructed to solve for the change in the number of radon and its progeny particles decaying during the simultaneous pumping and measurement process. It is worth noting that the number of radon and its progeny particles decaying here is a change over time.

[0099] Specifically, a mathematical model can be used to substitute the volume of the measuring chamber, pump speed, and decay constant to establish relevant differential equations. These equations are then simplified using numerical methods and matrix transformations to solve for the quantitative changes in the decay process of radon and its progeny, obtaining a general solution. Finally, by setting initial and boundary conditions, the sensitivity conversion coefficient is calculated before the existing air in the measuring chamber is completely replaced and before the existing radon and its progeny reach decay equilibrium. Furthermore, this coefficient is used to solve for the predicted sensitivity under the combined effects of kinetic effects and decay, achieving rapid measurement of radon concentration.

[0100] Preferably, the differential equations of the quantity change N(t) of radon and its progeny during the decay process in the coupled model of gas flow and radon decay concentration change are shown in equations (1) to (5).

[0101]

[0102] Where N0(t), N1(t), N2(t), N3(t), and N4(t) are respectively 222 Rn、 218 Po、 214 Pb, 214 Bi、 214 The number of nuclides such as Po changes with time t; in the decay chain of radon and its progeny, only 222 Rn is in a gaseous state. 218 Po、 214 Pb, 214 Bi、 214 Po is all solid, therefore it is believed that only 222 The proportion of Rn drawn into the measuring chamber is then k0 = 1; Q is the sampling pump speed, in meters per second (m). 3 / s; V is the volume of the measuring cavity, in m³. 3 N 0,env To represent the number of radon nuclides in the environment to be tested, considering normalization, the initial value can be set to 1, with the unit being the number of nuclides; λ oλ1, λ2, λ3, and λ4 are respectively 222 Rn、 218 Po、 214 Pb, 214 Bi、 214 The decay constants of nuclides such as Po, expressed in s. -1 .

[0103] Specifically, the obtained differential equation system (1) to (5) is converted into matrix form, as shown in formula (6).

[0104]

[0105] Where N is a vector representing the number of radon and its progeny: [N0(t),N1(t),N2(t),N3(t),N4(t)] T ;

[0106] A is a coefficient matrix, including decay constant, pump speed and measurement chamber volume, etc., and its form is shown in formula (7);

[0107]

[0108] b is the source term, which describes the input from the external environment, and its form is shown in formula (8);

[0109]

[0110] For a system of linear differential equations with constant coefficients, the analytical solution is shown in equation (9):

[0111]

[0112] Among them, e At N(A) is the matrix exponent, which can be obtained by eigenvalue decomposition of matrix A or by directly calculating the matrix exponent; N(0) is the initial condition vector. At the initial time, there is no radon or its progeny in the measurement cavity, therefore N(0) = [0,0,0,0,0]. T τ is a time variable, representing the parameter of the integral. The integral term represents the integral of the variable τ over the time interval [0, t].

[0113] According to formulas (1) to (9), the general solution for the change of the number of radon and its progeny nuclides with time t can be obtained, as shown in formulas (10) to (14):

[0114]

[0115] N3(t)=… (13)

[0116] N4(t)=… (14)

[0117] Where σ1 = 2.5e + 37Q + 5.2e + 31V; σ2 = 5.0e + 33Q - 1.9e + 31V;

[0118] σ3=5.0e+34Q-2.1e+31V; σ4=3.1e+27Q-1.3e+31V; σ5=2.5e+35Q-1.5e+32V…; ω1=e -3.7e-3t ;ω2=e -4.3e-4t …;

[0119] The above equations are further solved to obtain the radioactivity A(t) of radon and its progeny, where the unit is cps, as shown in formulas (15) to (19):

[0120] A o (t)=λ0N0(t) (15)

[0121] A1(t)=λ1N1(t) (16)

[0122] A2(t)=λ2N2(t) (17)

[0123] A3(t)=λ3N3(t) (18)

[0124] A4(t)=λ4N4(t) (19)

[0125] Therefore, the sensitivity conversion coefficient b can be solved according to formulas (20) to (22).

[0126]

[0127] Where C represents the radon concentration in the air being measured, in Bq / m³. 3 A(ΔT) is the net alpha particle count rate during the time interval ΔT after the air inside the measurement chamber has been completely replaced by radon and its progeny, and the replaced radon and its progeny have reached decay equilibrium; the unit is cps. x (ΔT) is the net alpha particle count rate during the time interval ΔT before the air in the measurement chamber is completely replaced by radon and its progeny, and before the replaced radon and its progeny reach decay equilibrium. The unit is cps. Here, A(ΔT) and A x (ΔT) are all derived theoretically; S is the detector sensitivity. It is worth noting that S is an inherent property of the instrument and is therefore known. The unit here is cps / (Bq / m). 3 );S x To measure the predictive sensitivity during the time interval ΔT before the replaced radon and its decay products reach decay equilibrium, where the air inside the cavity is not completely replaced by radon and its decay products, the unit here is cps / (Bq / m³). 3 ); ΔT is the measurement time for a single cycle, and the unit here is seconds; Tx The measurement is performed at a certain initial moment before the air inside the cavity is completely replaced by radon and its decay products, and before the replaced radon and its decay products reach decay equilibrium. The unit here is seconds (s); b is the sensitivity conversion coefficient, which has no unit or dimension.

[0128] It is worth noting that in formula (22), the starting time for the complete replacement of the air in the measuring chamber with radon and its decay products, and for the replaced radon and its decay products to reach decay equilibrium, is selected as 260 min. This is based on the theoretical derivation of the decay law of radon and its decay products, which shows that the time required to achieve full replacement and decay equilibrium is approximately 260 min. In addition, considering the speed, T is set here. x The zero point is the moment when the pump starts working.

[0129] Step S3: Set experimental conditions and solve for the predicted sensitivity. The experimental conditions are mainly set around the flow-type pumping design to ensure that the system operates under specific parameters to meet the requirements of response speed and measurement accuracy. Parameters such as the volume of the measurement chamber, pump speed, and single-cycle measurement time determine the dynamic change rate of radon and its progeny in the measurement chamber. Based on this, the corresponding predicted sensitivity S under different conditions can be obtained by combining formula (22). x Furthermore, setting these parameters appropriately helps to quickly obtain the magnitude and rate of change in radon concentration during the experiment, making the measurement data more accurate and repeatable.

[0130] Preferably, in specific operation, the rate at which radon gas fills the measurement chamber can be adjusted by setting specific measurement chamber volume V, pump speed Q, and single-cycle measurement time ΔT, so that the measurement system accurately reflects the radon concentration of the environment under test under the optimal parameters of the radon concentration algorithm that is solved quickly. It is worth noting that for a detector, its measurement chamber volume is fixed, so the main parameters to be adjusted are the pump speed and the single-cycle measurement time.

[0131] Step S4: Calculate the radon concentration value. Data acquisition and processing are crucial steps in the rapid determination of radon concentration during the calculation process. By acquiring real-time measurement data during the experiment and combining it with predicted sensitivity, the radon concentration value can be quickly derived, thus achieving efficient measurement. This process requires the use of the sensitivity conversion coefficient b calculation method in Step S2 and the specific experimental conditions in Step S3 (generally pump speed Q and single-cycle measurement time ΔT) to predict the detector sensitivity S. x Dynamic calculations were performed to ensure accurate tracking of radon concentration and to meet the experimentally set response speed and accuracy requirements. Finally, based on the real-time acquired net alpha particle count rate n... x (ΔT), the radon concentration C is calculated according to formula (23). m ,

[0132]

[0133] Preferably, firstly, based on experimental conditions and set parameters, the sensitivity conversion coefficient *b* at different times is calculated, and the corresponding radon concentration data is recorded. Data acquisition is achieved by setting up a fast-response detection system to ensure that the data sampling frequency meets experimental requirements. Next, the acquired concentration data is filtered and denoised (generally designed in the data acquisition circuit) to reduce the impact of environmental interference on data accuracy. Finally, the radon concentration value is calculated based on the theoretical model, and the data results are dynamically monitored in real time according to changes over time to ensure the accuracy and reliability of rapid radon measurement.

[0134] Step S5: Experimental Validation and Error Analysis of the Algorithm. After the algorithm is applied, experimental validation is performed to ensure its effectiveness in rapidly calculating radon concentration. The accuracy of the algorithm is evaluated by comparing the radon concentration obtained by the algorithm with the standard concentration in the measurement system. This process helps to identify potential biases in the model and further optimize the algorithm parameters to improve its accuracy and response speed.

[0135] Preferably, the standard radon concentration of the measurement system is first obtained using a standard instrument as a reference value. Then, under different experimental conditions, the radon concentration C of the environment to be measured is compared with the algorithm measurement result C. m By comparing the results, the absolute error ε and relative error δ of the obtained radon concentration are calculated. Analysis of these error values ​​evaluates the algorithm's measurement accuracy and distribution, identifying its applicability and error control under specific conditions. Based on the comparison results, adjustments may be needed to the fixed constants or other parameters in the model to ensure a high degree of agreement between experimental data and theoretical results, achieving a more stable and rapid radon measurement effect.

[0136] Specifically, the absolute error ε and relative error δ of the radon concentration results obtained by the algorithm are calculated according to formulas (24) to (26).

[0137]

[0138] Where, Δn x,error (ΔT) represents the net count error of signal particles within the time interval ΔT, measured in cps; n s The sample count rate is measured and can be directly obtained experimentally, with units of cps; t s n is the sample measurement time, in seconds (s). b The background count rate is directly obtained from experiments and is measured in cps; t b ε represents the background measurement time in seconds; ε is the absolute error of the radon concentration result obtained by the algorithm in Bq / m³. 3 δ represents the relative error between the radon concentration obtained by the algorithm and the radon concentration in the standard radon chamber, and is dimensionless.

[0139] Specifically, the measurement time interval ΔT is generally the same as the experimental data acquisition time and the background data acquisition time, i.e., ΔT = t s =t b .

[0140] Example 3

[0141] This invention proposes a rapid method for determining the concentration of radioactive radon in air based on scintillation-based airflow, the flowchart of which is shown below. Figure 1 As shown:

[0142] Step 1: In the design of the sampling method, for the gas sampling method, regardless of the sampling requirements, in order to quickly obtain the radon concentration of the ambient air to be tested, it should be set to flow gas sampling. This is because the process of sampling and counting simultaneously is the fastest way to obtain the net count of the experiment. For the measurement mode, in order to obtain the net count rate of alpha particles in real time, a continuous measurement mode should be adopted. For the design of the gas extraction device, the flow meter is used in conjunction with a frequency-controlled pump. This is to take into account factors such as flow monitoring, pump speed adjustment, and the airtightness of the gas extraction system.

[0143] By employing a flow-through sampling and continuous measurement mode, the radon concentration measurement system achieves real-time counting during the sampling process, significantly improving the speed and efficiency of signal data acquisition. The combined design of the flow meter and frequency-controlled pump enables precise flow control and ensures system airtightness, reducing errors caused by unstable airflow or leaks. This systematic design not only ensures rapid response but also improves data accuracy, laying a solid technical foundation for rapid radon concentration determination.

[0144] Step 2: In the process of constructing a rapid solution model for radon concentration and finding the general solution, in order to quickly measure radon concentration, it is necessary to analyze the entire system and establish a mathematical model by combining gas flow, the decay process of radon and its progeny, and the instrument's operating mode. Based on Figure 2 The decay chain of radon and its decay products is detailed below:

[0145] The differential equations of radon and the number of progeny particles N(t) with respect to time t in the coupled model of gas flow and radon decay process are shown in equations (1) to (5).

[0146]

[0147] Where N0(t), N1(t), N2(t), N3(t), and N4(t) are respectively 222 Rn、 218 Po、 214 Pb, 214 Bi、 214 The number of nuclides such as Po changes with time t; in the decay chain of radon and its progeny, only 222 Rn is in a gaseous state.218 Po、 214 Pb, 214 Bi、 214 Po is all solid, therefore it is believed that only 222 The proportion of Rn drawn into the measuring chamber is then k0 = 1; Q is the pump speed, in meters per second (m). 3 / s; V is the volume of the measuring cavity, in m³. 3 N 0,env To represent the number of radon nuclides in the environment to be tested, considering normalization, the initial value can be set to 1, with the unit being the number of nuclides; λ o λ1, λ2, λ3, and λ4 are respectively 222 Rn、 218 Po、 214 Pb, 214 Bi、 214 The decay constants of nuclides such as Po, expressed in s. -1 .

[0148] Specifically, the obtained differential equation system (1) to (5) is converted into matrix form, as shown in formula (6).

[0149]

[0150] Where N is a vector representing the number of radon and its progeny: [N0(t),N1(t),N2(t),N3(t),N4(t)] T ;

[0151] A is a coefficient matrix, including ventilation coefficients such as decay constant, pump speed and measurement chamber volume, and its form is shown in formula (7);

[0152]

[0153] b is the source term, which describes the input from the external environment, and its form is shown in formula (8);

[0154]

[0155] For a system of linear differential equations with constant coefficients, the analytical solution is shown in equation (9):

[0156]

[0157] Among them, e At N(A) is the matrix exponent, which can be obtained by eigenvalue decomposition of matrix A or by directly calculating the matrix exponent; N(0) is the initial condition vector. At the initial time, there is no radon or its progeny in the measurement cavity, therefore N(0) = [0,0,0,0,0]. T τ is a time variable, representing the parameter of the integral. The integral term represents the integral of the variable τ over the time interval [0, t].

[0158] Based on formulas (1) to (9) and substituting λ o =3.82d, λ1=3.1min, λ2=27.06min, λ3=19.71min, λ4=163.6μs, and the general solution for the change of the number of radon and its progeny nuclides with time t can be obtained, as shown in formulas (10) to (14):

[0159]

[0160] N3(t)=… (13)

[0161] N4(t)=… (14)

[0162] Where σ1 = 2.5e + 37Q + 5.2e + 31V; σ2 = 5.0e + 33Q - 1.9e + 31V;

[0163] σ3=5.0e+34Q-2.1e+31V; σ4=3.1e+27Q-1.3e+31V; σ5=2.5e+35Q-1.5e+32V…; ω1=e -3.7e-3t ;ω2=e -4.3e-4t …;

[0164] The above equations are further solved to obtain the radioactivity A(t) of radon and its progeny, in cps, as shown in formulas (15) to (19):

[0165] A o (t)=λ0N0(t) (15)

[0166] A1(t)=λ1N1(t) (16)

[0167] A2(t)=λ2N2(t) (17)

[0168] A3(t)=λ3N3(t) (18)

[0169] A4(t)=λ4N4(t) (19)

[0170] Therefore, the sensitivity conversion coefficient b can be solved according to formulas (20) to (22).

[0171]

[0172] Where C represents the concentration of radon in the air to be measured, in Bq / m³. 3 A(ΔT) is the net alpha particle count rate during the time interval ΔT after the air inside the measurement chamber has been completely replaced by radon and its progeny, and the replaced radon and its progeny have reached decay equilibrium; the unit is cps.x (ΔR) is the net alpha particle count rate during the time interval ΔR before the replaced radon and its progeny reach decay equilibrium, measured in cps. Here, A(ΔT) and A... x (ΔT) are all derived theoretically; S is the detector sensitivity. It is worth noting that S is an inherent property of the instrument, therefore the sensitivity of the radon meter is known, and S is 0.29 cpm / (Bq / m³). 3 );S x The prediction sensitivity is measured in cps / (Bq / m³) during the time interval ΔT before the replaced radon and its decay products reach decay equilibrium, when the air inside the cavity is not completely replaced by radon and its decay products. 3 ); ΔT is the measurement time for a single cycle, in seconds; T x The measurement is taken at a certain initial moment before the air inside the cavity is not completely replaced by radon and its decay products, and before the replaced radon and its decay products reach decay equilibrium. The unit is seconds. b is the sensitivity conversion coefficient, which has no unit or dimension.

[0173] It is worth noting that in formula (22), the starting time for the complete replacement of air in the measurement chamber and the decay equilibrium of radon and its progeny is set at 260 min. This is based on the theoretical derivation of the decay law of radon and its progeny, which shows that the time required for complete replacement and decay is approximately 260 min. In addition, considering the speed, T is set here. x The zero point is the moment when the pump starts working.

[0174] Step 3: The experimental conditions are set primarily around the design of the gas flow pumping system to ensure the system operates under specific parameters to meet the requirements of response speed and measurement accuracy. Parameters such as the measurement chamber volume and pump speed determine the dynamic rate of change of radon and its progeny quantities within the measurement chamber. Setting these parameters appropriately helps control the amplitude and rate of change in radon concentration during the experiment, making the measurement data more accurate and repeatable, and ensuring stable experimental operation. In the specific implementation, Q is the pump speed, taken as 1.3 L / min; V is the measurement chamber volume, taken as 5 L; ΔT of 3, 5, 8, 10, 15, 20, and 30 min yields the sensitivity conversion coefficient b for different pumping time intervals under the gas flow circulation, as shown below. Figure 3 As shown. In addition, when verifying the algorithm effect by example, ΔT = 5min is taken, and the specific expressions (23) to (27) of formulas (10) to (14) can be obtained.

[0175] N0(t) = 1.0 - 1.0 * e -4.3e-3t (twenty three)

[0176] N1(t) = 3.5e-3e -4.3e-3t -4.0e-3e -3.7e-3t +5.6e-4 (24)

[0177] N2(t)=4.5e-3e -3.7e-3t -6.2e-3e -4.3e-4t -3.3e-3e -4.3e-3t +4.9e-3 (25)

[0178] N3(t) = 3.8e-4e -4.3e-3t +0.013e -5.9e-4t -0.017e -4.3e-4t -6.2e-4e -3.7e-3t +3.6e-3 (26)N4(t)=5.2e-11e -4.3e-3t -6.2e-36e -4.2e+3t +1.8e-9e -5.9e-4t -2.3e-9e -4.3e-4t -8.5e-11e -3.7e-3t +5.0e-10 (27)

[0179] Therefore, based on the obtained b values ​​(5.20 for 0-5 min, 2.17 for 5-10 min, 1.69 for 10-15 min, 1.54 for 15-20 min, 1.47 for 20-25 min, 1.42 for 25-30 min, 1.38 for 30-35 min, 1.35 for 35-40 min, etc.) and the known detector sensitivity S = 0.29 cpm / (Bq / m²), 3 The detector's predicted sensitivity S can be calculated for different time periods. x (0-5min is 0.06cpm / (Bq / m)) 3 ), 5-10 min is 0.13 cpm / (Bq / m 3 ), 10-15 min is 0.17 cpm / (Bq / m 3 ), 15-20 min is 0.19 cpm / (Bq / m 3 ), 20-25 min is 0.20 cpm / (Bq / m 3 ), 25-30 min is 0.20 cpm / (Bq / m 3 ), 30-35 min is 0.21 cpm / (Bq / m 3 ), 35-40 min is 0.21 cpm / (Bq / m 3 ...).

[0180] Step 4: Calculate the radon concentration value. Based on the obtained b value and the sensitivity S at different times... x Combined with the real-time net alpha particle count rate n x (ΔT), the radon concentration value C under the rapid radon measurement algorithm is calculated according to formula (28).m ,

[0181]

[0182] Here, n x (ΔT) represents the real-time net count rate of alpha particles within a certain time period measured experimentally, in cpm. Therefore, based on S obtained in step 3... x and the n obtained from the experiment x (ΔT), C was calculated m (0-5min is 7407.50±178.57Bq / m) 3 The concentration of oxygen was 7369.16 ± 109.66 Bq / m³ for 5-10 minutes. 3 The concentration at 10-15 min was 7286.38 ± 95.57 Bq / m. 3 The concentration of oxygen was 7527.17 ± 92.26 Bq / m³ after 15-20 minutes. 3 The concentration of 7402.61 ± 89.30 Bq / m³ was observed at 20-25 min. 3 The concentration of oxygen at 25-30 min was 7609.96 ± 89.01 Bq / m³. 3 The concentration at 30-35 min is 7548.07 ± 87.45 Bq / m. 3 The concentration of oxygen at 35-40 min was 7443.19 ± 85.74 Bq / m³. 3 ...)

[0183] Step 5: Experimental verification and error analysis of the algorithm. A standard radon chamber was selected (its concentration was measured using a calibrated standard instrument RAD7-05830, C = 7371.89 Bq / m³). 3 Experimental verification was conducted, and the absolute error ε and relative error δ of the radon concentration results were obtained by solving the algorithm according to formulas (29) to (31).

[0184]

[0185] Where, Δn x,error (ΔT) represents the net count error of signal particles within the time interval ΔT, measured in cps; n s The sample count rate is measured and can be directly obtained experimentally, with units of cps; t s n is the sample measurement time, in seconds (s). b The background count rate is directly obtained from experiments and is measured in cps; t b ε represents the baseline measurement time in seconds; ε is the absolute error of the concentration result obtained by the algorithm in Bq / m³. 3 δ represents the relative error between the concentration result obtained by the algorithm and the standard radon chamber concentration, and is dimensionless.

[0186] The measurement time interval is the same as the experimental data collection time, and it is the same as the baseline measurement time, i.e., ΔT = t. s =t b =300s.

[0187] The final experimental verification results are shown below. Figure 4 As shown in the figure, when the probe used in a single cycle of air extraction (i.e., measurement) is 5 minutes, C m The average value is 7460.99 Bq / m 3 The mean absolute error ε is 80.26 Bq / m. 3 The mean absolute value of the relative error δ was 1.21%, and the maximum absolute value of the relative error was 3.86%. It is worth noting that within the first cycle [0, 5 min] of the measurement, C... m 7407.50 Bq / m 3 The absolute error is 178.57 Bq / m. 3 The absolute value of the relative error is 0.48%. This indicates that the algorithm can provide measurement results that are close to the true value within the initial measurement cycle, and the error gradually stabilizes within a small range as the number of cycles increases. Especially after multiple cycles, both the relative and absolute errors of the algorithm remain in a low range, demonstrating its adaptability and accuracy in complex dynamic environments. Furthermore, the algorithm's rapid radon measurement characteristic allows for immediate concentration estimation after each cycle, facilitating rapid response and real-time monitoring. This algorithm not only shortens the measurement time but also avoids the delay caused by waiting for the time-consuming process of complete replacement and decay, significantly improving the efficiency of radon measurement. This advantage of high precision and high efficiency makes it of significant practical value in environmental safety monitoring and suitable for diverse dynamic monitoring scenarios.

[0188] Example 4

[0189] In addition, this invention also discloses a system for rapid determination of radioactive radon concentration in air based on scintillation flow, comprising:

[0190] The data acquisition module is used to acquire the net alpha particle count rate within a corresponding time period during the measurement. The data acquisition module includes a measurement mode setting module and a data transmission module that communicate with each other. The measurement mode setting module is used to set the acquisition method of the net alpha particle count rate according to experimental requirements and system design. The data transmission module is used to transmit the acquired net alpha particle count rate to the data processing module.

[0191] The data processing module is used to obtain the radon concentration value in the air to be tested by using the acquired net alpha particle count rate and a preset radon concentration solution model.

[0192] The data processing module includes a sensitivity conversion coefficient acquisition module, a predicted sensitivity acquisition module, and a radon concentration acquisition module, which are configured to communicate sequentially. The sensitivity conversion coefficient acquisition module is used to acquire a sensitivity conversion coefficient based on the ratio between the theoretical net alpha particle count rates for different measurement time periods. The predicted sensitivity acquisition module is used to acquire a predicted sensitivity based on the sensitivity conversion coefficient and the instrument's own sensitivity. The radon concentration acquisition module is used to acquire the radon concentration value in the air to be measured based on the predicted sensitivity and the net alpha particle count rate within the corresponding time period acquired by the data acquisition module.

[0193] The radon concentration calculation model considers the relationship between the net count rate of radon and its decay products in the air entering the measurement chamber during the measurement period, the volume of the measurement chamber, the sampling pump speed, and the initial concentration of radon and its decay products in the measurement chamber. It obtains the sensitivity conversion coefficient of the radioactive radon concentration in the air and uses the sensitivity conversion coefficient to convert the net count rate of radon and its decay products in the air entering the measurement chamber during the measurement period into the radon concentration value in the environment.

[0194] In a further preferred embodiment, the system also includes an accuracy and error analysis module, which communicates with the radon concentration acquisition module to evaluate the accuracy of the acquired radon concentration value.

[0195] Example 5

[0196] To further explain in detail the scintillation-based rapid airflow determination system for radioactive radon concentration in the air described in Example 4 above, this example will be used for illustration:

[0197] This invention provides a rapid method for determining the concentration of radioactive radon in air based on scintillation-based airflow. The method is simple in principle and offers significant advantages for radon concentration measurement through the introduction of a rapid radon measurement approach. Compared to traditional methods, this method enables real-time measurement and rapid acquisition of effective results under dynamic airflow conditions, avoiding the time required for complete replacement of the existing air in the measurement chamber and for the existing radon and its decay products to reach decay equilibrium, thus significantly shortening the measurement time. Simultaneously, while maintaining measurement accuracy, this method improves the system response speed by rationally setting the pumping rate and single measurement time, providing technical support for rapid dynamic monitoring. Furthermore, this rapid radon measurement method can continuously monitor under multiple pumping cycles, ensuring accurate reflection of radon concentration in complex environments and providing effective protection for environmental safety monitoring and rapid response.

[0198] In addition, this invention also proposes a system for rapid determination of radioactive radon concentration in air based on scintillation flow, mainly a multi-cycle dynamic rapid radon measurement device based on the scintillation chamber method. Its five main modules are described below, designed to achieve rapid measurement of environmental radon concentration through the synergistic effect of multiple modules. Specific module descriptions are as follows:

[0199] Module M1 Measurement Mode Setting Module: This module is the foundation of the system. Its core function is to rationally set the gas sampling method and measurement mode according to the requirements of rapid radon measurement, providing accurate and reliable input data for the algorithm. Flow-through sampling is prioritized to quickly fill the measurement chamber with the radon gas to be measured, rapidly acquiring environmental radon concentration information during simultaneous sampling and counting, effectively shortening experimental time. Continuous measurement mode is selected to help record the real-time value of the net alpha particle count rate at the current stage, quickly reflecting the radon concentration. By optimizing the gas sampling method and measurement mode, this module provides efficient basic data support for the algorithm, while ensuring the stability of response speed and accuracy in multi-cycle dynamic measurements. It is a key link in achieving accurate calculation and rapid radon measurement by the algorithm. Therefore, setting the measurement mode in Module M1 is one of the key steps to ensure stable system operation and reliable experimental data.

[0200] Module M2, the sensitivity conversion coefficient acquisition module, is the core of the rapid radon measurement algorithm. It constructs and solves a theoretical model to describe the changes in radon and its decay products over time during the measurement process. Based on radon decay characteristics and initial conditions, this module establishes a mathematical model including key parameters such as pump speed and extraction rate, ensuring the model accurately reflects the actual dynamic measurement process. By obtaining the general solution through analytical or numerical methods, this module can quickly obtain the conversion relationship between the predicted sensitivity and the instrument's own sensitivity. The design and implementation of Module M2 not only improves the efficiency of rapid radon measurement but also ensures the accuracy of theoretical calculations, providing a solid theoretical foundation for the reliability of experimental data. It is an important component of the entire measurement system.

[0201] Module M3, the Predicted Sensitivity Acquisition Module, comprises two parts: experimental condition setting and predicted sensitivity calculation. These two parts are responsible for the reasonable setting of experimental conditions and the calculation of predicted sensitivity. In dynamic measurements, the optimization of experimental conditions directly affects the efficiency and accuracy of the measurement. This module stabilizes the system between rapid response and accurate measurement by reasonably setting key parameters such as the measurement chamber volume, pump speed, and pumping time. Simultaneously, the module calculates the predicted sensitivity of the measurement system based on a theoretical model, quantifies the system's response to changes in radon concentration, and rapidly calculates the radon concentration of the measurement system under different experimental conditions. It can also guide the optimization of experimental parameters to improve the overall performance of the system. Therefore, Module M3 plays a crucial role in the entire system. Through comprehensive analysis of experimental conditions and sensitivity, it not only affects the effectiveness of the rapid radon measurement algorithm but also provides important support for subsequent data processing, making it a key link in achieving the goal of rapid radon measurement.

[0202] It is worth noting that this module relies on the sensitivity conversion coefficient obtained in M2. The sensitivity conversion coefficient, combined with the detector's own sensitivity, is used to obtain the predicted sensitivity, thereby quickly and accurately converting the collected real-time net alpha particle count data into radon concentration, ensuring it accurately reflects the radon concentration of the environment under test. Since the rapid radon measurement process is affected by pump speed, measurement chamber volume, and the decay characteristics of radon and its progeny, this module needs to comprehensively consider various factors in the gas flow sampling mode to calculate a conversion coefficient suitable for the dynamic measurement process. This module not only determines the system's dynamic sensitivity but also directly affects the accuracy of subsequent radon concentration measurements. Furthermore, this scintillation chamber method for radon measurement requires gas flow cyclic measurement, and the duration of a single measurement directly affects the accuracy of the measurement data. By reasonably setting the measurement duration, the system can achieve stability between response speed and measurement accuracy. Especially in the multi-cycle dynamic measurement mode, setting the pumping time for each cycle can effectively improve measurement efficiency and ensure the representativeness of the measurement results at each stage. A reasonable time setting also ensures the sensitivity conversion and subsequent radon concentration calculation, avoiding data deviation due to insufficient or excessive measurement time.

[0203] Module M4 Radon Concentration Acquisition Module: This module combines predicted sensitivity with the currently measured net alpha particle count data to further calculate and acquire the radon concentration, providing a quantitative basis for rapid radon measurement. By analyzing current data and combining it with predicted sensitivity, it quickly obtains the radon concentration value under current conditions. This module achieves real-time calculation under dynamic conditions and can provide reliable measurement values ​​through sensitivity analysis during multiple measurement cycles. This method not only improves the system's response speed to radon concentration but also allows for feedback adjustments through algorithms to optimize the rapid measurement process. This module can significantly shorten experimental time and accelerate the system's response speed while ensuring measurement accuracy, making it a crucial step in achieving rapid radon measurement.

[0204] Module M5 Accuracy and Error Analysis: This module is primarily used for verifying and evaluating the errors in the algorithm's results. By comparing the radon concentration value measured by a standard instrument with the radon concentration value obtained by the algorithm, the absolute and relative errors are calculated to assess the algorithm's accuracy. Errors may arise from discrepancies between model assumptions and experimental conditions. Analyzing and summarizing these errors allows for the optimization of model parameters, enhancing measurement accuracy and robustness. In multi-cycle measurement mode, this module not only verifies radon concentration but also allows for parameter adjustment via feedback, such as pump speed and evacuation time, ensuring high accuracy under different experimental conditions. The results of error analysis provide guidance for subsequent experiments, guaranteeing the overall system's measurement reliability and are crucial for verifying the algorithm's effectiveness and ensuring the accuracy of rapid radon measurement.

[0205] This invention provides a system for rapid determination of radioactive radon concentration in air based on scintillation-based airflow. This system achieves high efficiency, flexibility, and accuracy in radon measurement through a modular design. Firstly, the measurement mode setting module ensures rapid response during multi-cycle dynamic measurements. The rapid radon concentration calculation theoretical model construction and solution in the sensitivity conversion coefficient acquisition module lays a solid theoretical foundation for the accuracy of theoretical calculations and the reliability of experimental data. The experimental condition setting and predicted sensitivity solution in the predicted sensitivity acquisition module ensure that the system can flexibly adjust the measurement duration and pump speed to meet the needs of different experimental time conditions. The radon concentration acquisition module obtains the radon concentration of the test environment based on the current real-time alpha particle net count rate data, supporting rapid radon measurement. The accuracy and error analysis module compares the radon concentration in the standard radon chamber with the acquired radon concentration to provide feedback and optimize system performance. The modular structure allows for the independent development, measurement, and maintenance of each functional part, reducing mutual interference, improving the system's response speed and accuracy, and facilitating expansion and upgrades, thus enhancing the overall reliability and adaptability of the measurement system.

[0206] Example 6

[0207] To further explain the radon measurement system in this invention, this embodiment will be used as an example:

[0208] This invention proposes a scintillation-based system for rapid determination of radioactive radon concentration in air. The system is designed to obtain a sensitivity conversion coefficient based on a coupled model of gas flow and radon decay concentration changes, and to construct a multi-cycle dynamic rapid radon measurement device based on the scintillation chamber method. Figure 1 As shown:

[0209] Module 1: Measurement Mode Setting Module. This module is the foundation of the system. Its core function is to rationally set the gas sampling method and measurement mode according to the requirements of rapid radon measurement, providing accurate and reliable input data for the algorithm. Here, it is set to a continuous sampling and counting mode using flowing gas.

[0210] Module 2: Sensitivity Conversion Coefficient Acquisition Module. This module is the core of the rapid radon concentration calculation algorithm. It is responsible for constructing and solving the theoretical model to describe the variation of radon concentration during the measurement process. Here, the differential equations for radon and the number of progeny particles with respect to time are constructed in the coupled model of gas flow and radon decay, and then the general solution is obtained, laying the foundation for the calculation of the sensitivity conversion coefficient.

[0211] Module 3: Predicted Sensitivity Acquisition Module. This module is responsible for setting appropriate experimental conditions and calculating the predicted sensitivity.

[0212] Module 4: Radon Concentration Acquisition Module. This module combines the predicted sensitivity with the currently collected real-time net count rate of alpha particles to further calculate the radon concentration, providing a quantitative basis for rapid radon measurement. By analyzing the current data and combining it with the predicted sensitivity, the radon concentration value to be measured is obtained.

[0213] Module 5: Accuracy and Error Analysis Module. This module is primarily used to verify the algorithm's results and assess errors. By comparing the radon concentration values ​​in the standard radon chamber with the acquired radon concentration values, the absolute and relative errors are calculated to evaluate the algorithm's accuracy.

[0214] The device for rapid determination of radioactive radon concentration in air based on scintillation utilizes a modular design to achieve an efficient, flexible, and accurate radon measurement process.

[0215] The measurement time setting and sensitivity conversion coefficient acquisition module supports flexible adjustment of measurement duration and predicted sensitivity to adapt to different experimental conditions. The predicted sensitivity acquisition module converts the current net alpha particle count rate to radon concentration in real time, ensuring the validity of radon concentration data. The radon concentration acquisition module quickly calculates the radon concentration, while the error analysis module optimizes system performance by comparing measurement and calculation results. The measurement mode setting module ensures response speed in multi-cycle dynamic measurements. The construction and solution process of the rapid radon concentration calculation theoretical model lays the foundation for the accuracy of theoretical calculations, providing a solid theoretical basis for the reliability of experimental data. The experimental condition setting and predicted sensitivity solution ensure that the system can flexibly adjust the measurement duration and pump speed to meet the needs of different experimental time conditions. The radon concentration value calculation module obtains the radon concentration of the air to be measured based on the current data, supporting rapid radon measurement. The algorithm experimental verification and error analysis module provides feedback and optimizes system performance by comparing the radon concentration in the standard radon chamber with the error of the acquired results. Through modular and independent device design, high efficiency, flexibility, and accuracy in radon measurement are achieved. First, the independence brought by the modular structure allows each functional part to be developed, expanded, measured and maintained independently, reducing mutual interference, improving the system's response speed and accuracy, and facilitating expansion and upgrades, thus improving the overall reliability and adaptability of the measurement system.

[0216] This invention not only proposes an innovative method and system for rapid determination of radioactive radon concentration in air based on scintillation flow, but also elaborates on the design of the terminal equipment necessary to implement this method. This terminal equipment, as the carrier of the method, ensures the efficient and accurate execution of the entire measurement process and transforms the measurement data into readable and usable information, providing strong technical support for environmental radon monitoring.

[0217] The terminal device in this embodiment serves as a crucial bridge connecting the measurement method with practical applications. It integrates a processor, memory, and a computer program stored in the memory and capable of running on the processor, collectively forming the hardware and software foundation for implementing a rapid radon measurement method. The processor, as the core of the terminal device, is responsible for executing instructions in the computer program, completing the entire process from data acquisition and processing to result output. The memory stores the computer program, modules, and data generated during the measurement process, ensuring the integrity and traceability of the information.

[0218] The processor is the "brain" of the terminal device, and its performance directly affects the measurement speed and accuracy. The processor in this invention can be a central processing unit (CPU), or a high-performance computing unit such as a digital signal processor (DSP), application-specific integrated circuit (ASIC), or off-the-shelf programmable gate array (FPGA), to meet the computing needs of different application scenarios. These processor types each have their own characteristics; for example, CPUs excel at general-purpose computing, DSPs are suitable for signal processing, while ASICs and FPGAs provide high parallel processing capabilities and customized functions, ensuring the flexibility and efficiency of the measurement method.

[0219] As a data storage medium, the capacity and access speed of the memory are equally crucial. The memory in this invention includes, but is not limited to, read-only memory (ROM), random access memory (RAM), and various external storage media such as USB flash drives, portable hard drives, magnetic disks, and optical disks. ROM stores fixed program instructions and constants, ensuring basic functions during system startup; RAM serves as a temporary data storage area, supporting fast data access and processing by the processor. External storage media provide larger storage space, facilitating long-term preservation of measurement data and program updates.

[0220] The computer program is the core software for implementing the measurement method, containing all the instructions required to execute measurement steps, process data, and display results. To improve the maintainability and scalability of the program, this invention adopts a modular design, dividing the computer program into one or more modules / units. Each module / unit is responsible for implementing a specific function; for example, the data acquisition module is responsible for acquiring net count rate data from the detector, the data processing module is responsible for calculating radon concentration based on a theoretical model, and the result display module is responsible for presenting the measurement results to the user in an intuitive way.

[0221] These modules / units are stored in memory and executed by the processor on demand. This modular design allows for easy addition or modification of functions, as well as separate measurement and debugging without affecting other modules, significantly improving development efficiency and program stability.

[0222] The computer program in this invention can not only run inside a terminal device, but also be stored on a computer-readable storage medium for sale or use as a standalone product. These storage media include, but are not limited to, physical media such as USB flash drives, external hard drives, and optical discs, as well as software distribution media transmitted over a network. The computer program exists in these media in the form of source code, object code, executable files, or certain intermediate forms, and users can choose the appropriate media and program format for installation and use as needed.

[0223] It is worth noting that the scope of computer-readable storage media may vary depending on the legislation and patent practices of different jurisdictions. In some regions, electrical carrier signals and telecommunication signals may not be considered part of computer-readable storage media. Therefore, appropriate adjustments must be made in accordance with local laws and regulations in specific applications.

[0224] This invention provides a comprehensive and reliable solution for the rapid determination of radioactive radon concentration in air based on scintillation flow, through a carefully designed terminal device, efficient processor and memory configuration, modular computer program, and flexible selection of computer-readable storage media. This solution not only improves measurement efficiency and accuracy but also lays a solid foundation for the intelligent and automated development of environmental radon monitoring.

[0225] This invention discloses a method and system for rapid determination of radioactive radon concentration in air based on scintillation-based airflow. The method determines the measurement mode, constructs a theoretical model for rapid radon concentration calculation, considers parameters such as pump speed and measurement time, obtains sensitivity conversion coefficients, and combines this with the real-time acquired detector net count rate to measure the radon concentration in the target environment. The measurement is then compared with the radon concentration measured by a standard instrument to calculate the error. This method transforms differential equations into a system of linear equations and solves them using matrix methods, balancing computational accuracy and efficiency. It accurately couples the dynamic effects of pump speed with the decay characteristics of radon, making the measurement more efficient and accurate. Furthermore, the system adopts a modular design, including a measurement mode setting module, a sensitivity conversion coefficient acquisition module, a predicted sensitivity acquisition module, a radon concentration acquisition module, and an accuracy and error analysis module. This ensures that each module operates independently and is easy to manage, and that each module can be flexibly configured, ensuring the system is suitable for different environments and operates stably. Through continuous gas flow measurement, the system monitors environmental radon concentration in real time and provides high-precision data. Its accurate monitoring capabilities can promptly identify radiation risks, ensuring public health and environmental safety. It has broad application value in complex environments such as underground engineering, nuclear facility operation and maintenance, and accident rescue.

[0226] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for rapid determination of radioactive radon concentration in air based on scintillation flow, characterized in that, Includes the following steps: P1: Obtain the net alpha particle count rate within the corresponding time period during the measurement; P2: Obtain the radon concentration value in the air to be tested by using the obtained net alpha particle count rate and the preset radon concentration solution model; The radon concentration solution model considers the relationship between the net count rate of radon and its decay products in the air entering the measurement chamber during the measurement period and the volume of the measurement chamber, the sampling pump speed, and the initial concentration of radon and its decay products in the measurement chamber during the construction process. The sensitivity conversion coefficient of the radioactive radon concentration in the air is obtained, and the net count rate of radon and its decay products in the air entering the measurement chamber during the measurement period is converted into the radon concentration value in the environment through the sensitivity conversion coefficient. The radon concentration calculation model is constructed as follows: P21: Establish the relationship between the net count rate of radon and its decay products generated by alpha particles in the air entering the measurement chamber during the measurement period and the volume of the measurement chamber, the sampling pump speed, and the initial concentration of radon and its decay products in the measurement chamber, and obtain the number of radon and its decay products in the air entering the measurement chamber. P22: The radioactivity of radon and its progeny is obtained by the number of radon and its progeny in the air entering the measuring chamber, and the sensitivity conversion coefficient is obtained by the radioactivity of radon and its progeny. P23: Establish the radon concentration solution model using the sensitivity conversion coefficient and the sensitivity of the tester itself; In P21, the relationship between the net count rate of alpha particles generated by the decay of radon and its progeny in the air entering the measurement chamber during the measurement period and the volume of the measurement chamber, the sampling pump speed, and the initial concentration of radon and its progeny in the measurement chamber, and the acquisition of the number of radon and its progeny particles in the air entering the measurement chamber, is specifically as follows: In the formula, , , , , They are respectively 222 Rn、 218 Po、 214 Pb, 214 Bi、 214 The number of Po changes with time t; It is a constant; For sampling pump speed, m 3 / s; To measure the cavity volume, m 3 ; It is a constant; , , , , For respectively 222 Rn、 218 Po、 214 Pb, 214 Bi、 214 The decay constant of Po, s -1 .

2. The method for rapid determination of radioactive radon concentration in air based on scintillation flow according to claim 1, characterized in that, In step P22, the radioactivity of radon and its progeny is obtained by counting the number of radon and its progeny particles in the air entering the measuring chamber, and the sensitivity conversion coefficient is obtained by using the radioactivity of radon and its progeny particles; specifically: In the formula, , , , as well as The radioactivity of radon and its decay products; This is the sensitivity conversion coefficient; To completely replace the air in the measurement chamber with radon and its decay products, and to any time point after the replaced radon and its decay products have reached decay equilibrium; This is to measure any point in time before the air inside the cavity is completely replaced by radon and its decay products, and before the replaced radon and its decay products reach decay equilibrium.

3. The method for rapid determination of radioactive radon concentration in air based on scintillation according to claim 1, characterized in that, In step P23, the establishment of the radon concentration solution model using the sensitivity conversion coefficient and the instrument's own sensitivity specifically involves: = In the formula, The measured value of radioactive radon concentration in the air to be tested is Bq / m³. for Real-time value of the net alpha particle count rate over the time period, in cpm; For predicting sensitivity, cpm / (Bq / m³); The sensitivity of the instrument itself is measured in cpm / (Bq / m³). This is the sensitivity conversion coefficient.

4. The method for rapid determination of radioactive radon concentration in air based on scintillation flow according to claim 1, characterized in that, Step P2 is followed by obtaining the error value of the radon concentration in the air to be measured within the corresponding measurement time period.

5. A system for rapid determination of radioactive radon concentration in air based on scintillation flow, characterized in that, The steps for implementing the method for rapid determination of radioactive radon concentration in air based on scintillation as described in any one of claims 1 to 4 include: The data acquisition module is used to acquire the net alpha particle count rate within the corresponding time period during the measurement. The data processing module is used to obtain the radon concentration value in the air to be tested by using the acquired net alpha particle count rate and a preset radon concentration solution model. The radon concentration calculation model considers the relationship between the net count rate of radon and its decay products in the air entering the measurement chamber during the measurement period, the volume of the measurement chamber, the sampling pump speed, and the initial concentration of radon and its decay products in the measurement chamber. It obtains the sensitivity conversion coefficient of the radioactive radon concentration in the air and uses the sensitivity conversion coefficient to convert the net count rate of radon and its decay products in the air entering the measurement chamber during the measurement period into the radon concentration value in the environment.

6. The system for rapid determination of radioactive radon concentration in air based on scintillation according to claim 5, characterized in that, The data acquisition module includes a measurement mode setting module and a data transmission module that communicate with each other; The measurement method setting module is used to set the method for obtaining the net alpha particle count rate according to experimental requirements and system design; the data transmission module is used to transmit the obtained net alpha particle count rate to the data processing module. The data processing module includes a sensitivity conversion coefficient acquisition module, a predicted sensitivity acquisition module, and a radon concentration acquisition module, which are configured to communicate sequentially. The sensitivity conversion coefficient acquisition module is used to acquire the sensitivity conversion coefficient based on the ratio between the theoretical net alpha particle count rates for different measurement time periods; the predicted sensitivity acquisition module is used to acquire the predicted sensitivity based on the sensitivity conversion coefficient and the sensitivity of the tester itself; the radon concentration acquisition module is used to acquire the radon concentration value in the air to be tested based on the predicted sensitivity and the net alpha particle count rate within the corresponding time period acquired by the data acquisition module.

7. The system for rapid determination of radioactive radon concentration in air based on scintillation according to claim 5, characterized in that, The system also includes an accuracy and error analysis module, which communicates with the data processing module to evaluate the accuracy of the acquired radon concentration values.

8. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 4.

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