Human neutron dose assessment method and system

Abstract

The present invention relates to the field of nuclear emergency technology and provides a method and system for evaluating human neutron dose. The method measures the radioactive nuclides generated by the reaction between neutrons and sodium in the human body. 24 The characteristic gamma ray intensity of Na determines the neutron dose received by the human body; the human body neutron dose assessment method and system of the present invention achieve the technical effects of lowering the detection limit, simplifying the calculation process, increasing the neutron dose assessment speed and improving the neutron dose assessment accuracy.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear emergency response, and in particular to a method and system for evaluating human neutron dose. Background Art

[0002] In nuclear explosions and nuclear accidents, neutron external exposure is an important source of human radiation. Therefore, when people are exposed to nuclear radiation, timely and accurate assessment of neutron external exposure dose is of great value for medical treatment of the injured and assessment of the degree of harm of the accident.

[0003] The dose assessment method for measuring the induced radioactivity generated by neutron irradiation in the human body is called neutron activation method, which is a neutron-specific external dose assessment method. Specifically, when a person is irradiated by neutron rays, the neutrons will react with the body's internal organs. 23 The Na element undergoes a radiation capture reaction to produce radionuclides 24 Na, 24 Na β - The decay releases characteristic gamma rays with energies of 1.369 MeV or 2.754 MeV. By measuring the intensity of these two characteristic gamma rays, the amount of radiation in the body of the irradiated person can be calculated. 24 The activity of Na can be used to estimate the neutron dose.

[0004] However, in the process of external radiation dose assessment, there are the following disadvantages: first, sodium accounts for only 0.15% of the mass of the human body, and the sodium produced by neutron irradiation is 24 The yield of Na is even smaller, and it is difficult to accurately measure the intensity of its characteristic gamma rays; when the irradiated personnel are exposed to a neutron dose of ≤100 mGy, it is difficult to accurately assess the neutron dose; second, neutrons and 23 The reaction probability (i.e., reaction cross section) of Na undergoing radiation capture reaction is related to the neutron energy. The reaction cross section of low-energy neutrons is higher than that of high-energy neutrons, and the neutron dose is positively correlated with the neutron energy. This leads to 24 Na activity is not linearly related to neutron dose. The energy distribution of neutrons irradiated to the human body must also be considered, which affects the accuracy of dose assessment. Third, in existing neutron dose assessment methods, the radiation detectors used to measure characteristic gamma rays are not uniformly positioned on the human body surface. Common measurement methods include chest, abdomen, top of the head, and full-body scans. 24 The Na characteristic gamma ray intensity is converted into human body through calculation 24 Na specific activity per unit body mass 24 Na radioactivity, finally used 24The external irradiation neutron dose is calculated using the conversion coefficient of Na specific activity to neutron dose. In other words, the inconsistency of the measurement position means that 24 The Na characteristic ray intensity is converted to 24 The neutron dose can only be calculated based on the Na specific activity. The calculation process is cumbersome and not conducive to the rapid assessment of neutron dose.

[0005] Therefore, a human neutron dose assessment method with high measurement efficiency is urgently needed. Summary of the invention

[0006] The present invention provides a method and system for evaluating human neutron dose, so as to solve at least one technical problem existing in the prior art.

[0007] To achieve the above-mentioned purpose, the present invention provides a method for evaluating human neutron dose, the method comprising:

[0008] Obtaining the type of neutron source, the time when neutron irradiation occurs, and the irradiation geometry of the irradiated person when the neutron irradiation occurs; and determining the neutron energy distribution reaching the body of the irradiated person based on the type of neutron source and the irradiation geometry of the irradiated person when the neutron irradiation occurs;

[0009] At set times, radiation detectors are used to detect radionuclides at set locations on the body of the exposed person. 24 The characteristic gamma ray intensity of Na is measured to obtain 24 The full energy peak count of characteristic gamma rays of Na at a set energy and the time when the measurement starts;

[0010] According to the time of neutron irradiation, the energy distribution of neutrons reaching the body of the irradiated person, the geometric conditions of the irradiated person when the neutron irradiation occurs, and the radiation detector measured 24 The full energy peak count of characteristic gamma rays of set energy of Na and the time when measurement starts; the neutron dose of the irradiated personnel is determined by formula;

[0011] The formula is:

[0012]

[0013] Among them, D T is the neutron dose of the irradiated personnel, N c Measured for radiation detectors 24 The total energy peak count of characteristic gamma rays of set energy of Na, p(E) is the neutron energy distribution reaching the body of the irradiated person, n m (E) is the radiation detector measured after a monoenergetic neutron with energy E irradiates the human body under the same irradiation geometry as the irradiated person. 24 The full energy peak count of characteristic gamma rays of Na at a set energy, dT (E) is the neutron dose caused by a monoenergetic neutron with energy E irradiating the human body under the same irradiation geometry as the irradiated person, Emax is the maximum energy of the neutron irradiating the human body, and λ is 24 The decay constant of Na is 1.2836×10 -5 , t1 is the time when neutron irradiation occurs, t2 is the time when the measurement starts, for 24 Decay coefficient of Na;

[0014] Among them, n m (E) and d T (E) The pre-acquired total energy peak count value set and neutron dose value set are respectively obtained according to the irradiation geometric conditions of the irradiated person.

[0015] Further, preferably, the set position of the body of the irradiated person is the position from the 12th thoracic vertebra to the 1st lumbar vertebra on the back of the irradiated person.

[0016] Further, preferably, according to the set time, the radiation detector is used to detect the radioactive nuclide at the set position of the irradiated person's body. 24 The characteristic gamma ray intensity of Na is measured, including,

[0017] The exposed person lies on his back on the bed, and the radiation detector is set under the bed. The radiation detector is close to the set position of the exposed person's body and detects radioactive nuclides for a set time. 24 Measurement of the intensity of characteristic gamma rays of Na;

[0018] The bed surface is a canvas piece, and the thickness of the bed surface is less than 2mm.

[0019] Further, preferably, the geometric conditions of radiation irradiation include front irradiation, back irradiation, left irradiation, right irradiation, rotational irradiation and isotropic irradiation.

[0020] Further, preferably, the measurement setting time of the radiation detector is 10-30 minutes.

[0021] Further, preferably, 24 The set energy of the characteristic gamma ray of Na is 1.369 MeV and / or 2.754 MeV.

[0022] Further, preferably, the method for pre-acquiring the total energy peak count value set includes using a Monte Carlo program to obtain the unit monoenergetic neutron radiation measured by the radiation detector at a set position on the body of the irradiated person after irradiating the human body with various irradiation geometric conditions. 24 A data set of full energy peak counts of characteristic gamma rays of set energy of Na;

[0023] The method for pre-acquiring a neutron dose value set includes using a Monte Carlo program to obtain a data set of neutron doses generated by unit monoenergetic neutrons within an energy range of 0-20 MeV irradiating a human body under various irradiation geometric conditions.

[0024] The present invention also protects a human neutron dose assessment system, the system comprising:

[0025] A neutron irradiation data acquisition unit is used to acquire the type of neutron source, the time when neutron irradiation occurs, and the irradiation geometric conditions of the irradiated person when the neutron irradiation occurs; and determine the neutron energy distribution reaching the body of the irradiated person according to the type of neutron source and the irradiation geometric conditions of the irradiated person when the neutron irradiation occurs;

[0026] The measuring unit is used to measure the radionuclides at the set position of the body of the irradiated person using the radiation detector according to the set time. 24 The characteristic gamma ray intensity of Na is measured to obtain 24 The full energy peak count of characteristic gamma rays of Na at a set energy and the time when the measurement starts;

[0027] The neutron dose determination unit is used to determine the neutron dose according to the time when the neutron irradiation occurs, the neutron energy distribution reaching the body of the irradiated person, the irradiation geometric conditions of the irradiated person when the neutron irradiation occurs, and the radiation measured by the radiation detector. 24 The full energy peak count of characteristic gamma rays of set energy of Na and the time when measurement starts; the neutron dose of the irradiated personnel is determined by formula;

[0028] The formula is:

[0029]

[0030] Among them, D T is the neutron dose of the irradiated personnel, N c Measured for radiation detectors 24 The total energy peak count of characteristic gamma rays of set energy of Na, p(E) is the neutron energy distribution reaching the body of the irradiated person, n m (E) is the radiation detector measured after a monoenergetic neutron with energy E irradiates the human body under the same irradiation geometry as the irradiated person. 24 The full energy peak count of characteristic gamma rays of Na at a set energy, d T (E) is the neutron dose caused by a monoenergetic neutron with energy E irradiating the human body under the same irradiation geometry as the irradiated person, Emax is the maximum energy of the neutron irradiating the human body, and λ is 24 The decay constant of Na is 1.2836×10 -5, t1 is the time when neutron irradiation occurs, t2 is the time when the measurement starts, for 24 Decay coefficient of Na;

[0031] Among them, n m (E) and d T (E) The pre-acquired total energy peak count value set and neutron dose value set are respectively obtained according to the irradiation geometric conditions of the irradiated person.

[0032] The present invention also protects an electronic device, the electronic device comprising:

[0033] at least one processor; and,

[0034] a memory communicatively connected to the at least one processor; wherein,

[0035] The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can perform the steps in the human body neutron dose assessment method as described above.

[0036] The present invention also protects a computer-readable storage medium storing a computer program, characterized in that when the computer program is executed by a processor, the human body neutron dose assessment method as described above is implemented.

[0037] The present invention establishes a method and system for evaluating human neutron dose, which has the following beneficial effects:

[0038] 1) The position with the highest gamma-ray flux on the body surface of the irradiated person is used as the measurement position of the radiation detector. The position from the 12th thoracic vertebra to the 1st lumbar vertebra on the back is compared with the position on the front chest. 24 The Na characteristic γ-ray fluence is increased by 15-35%, thereby improving 24 The detection efficiency of Na characteristic gamma rays and the technical effect of reducing the detection limit;

[0039] 2) Take the position with the highest gamma-ray flux on the body surface of the exposed person as the standard measurement position, and establish 24 The method of converting Na characteristic gamma ray intensity directly to neutron dose simplifies the neutron dose assessment process and improves the speed of neutron dose assessment;

[0040] 3) By simulating the irradiation of human body with neutrons of different energies 24The Na characteristic gamma-ray intensity and neutron dose are used to obtain the total energy peak count value set and the neutron dose value set; and the neutron dose caused by a monoenergetic neutron with an energy of E irradiating the human body under the same irradiation geometry conditions as the irradiated person can be quickly obtained through the total energy peak count value set and the neutron dose value set; and the radiation detector measured by a monoenergetic neutron with an energy of E irradiating the human body under the same irradiation geometry conditions as the irradiated person can be quickly obtained. 24 The full-energy peak counts of the characteristic gamma rays of the set energy of Na; thus, the neutron dose can be obtained by simply calculating the acquired neutron irradiation scene data and the radiation detector measurement data, thereby achieving the technical effect of improving the accuracy of neutron dose assessment. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic diagram of an implementation scenario of a method for assessing human neutron dose provided by an embodiment of the present invention;

[0042] Among them, 101, exposed personnel; 102, measurement bed; 103, radiation detector;

[0043] Figure 2 A schematic diagram of a flow chart of a method for assessing human neutron dose provided by an embodiment of the present invention;

[0044] Figure 3 The continuous distribution and segmented results of neutron energy of the californium-252 neutron source;

[0045] Figure 4 This is a diagram of neutron dose caused by monoenergetic neutrons irradiating the human body.

[0046] Figure 5 It is a full energy peak count diagram of characteristic gamma rays with an energy of 1.369 MeV measured by the radiation detector at the position from the 12th thoracic vertebra to the 1st lumbar vertebra on the back of the irradiated person after 100 mGy neutron irradiation;

[0047] Figure 6 A schematic diagram of the principle of a human neutron dose assessment system provided by an embodiment of the present invention;

[0048] Figure 7 A schematic diagram of the internal structure of an electronic device for implementing human neutron dose assessment provided by an embodiment of the present invention;

[0049] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION

[0050] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0051] Figure 1 and Figure 2 The human neutron dose assessment method of the present invention is generally described. Figure 1 A schematic diagram of an implementation scenario of a method for assessing human neutron dose provided by an embodiment of the present invention. Figure 2 A schematic flow chart of a method for assessing human neutron dose according to an embodiment of the present invention.

[0052] like Figure 2 As shown, the human neutron dose assessment method includes steps S210 to S230.

[0053] S210. Obtain the type of neutron source, the time when neutron irradiation occurs, and the irradiation geometric conditions of the irradiated person when the neutron irradiation occurs; and determine the neutron energy distribution reaching the body of the irradiated person based on the type of neutron source and the irradiation geometric conditions of the irradiated person when the neutron irradiation occurs.

[0054] Specifically, the geometric conditions of radiation irradiation include anterior irradiation (AP), posterior irradiation (PA), left lateral irradiation (LLAT), right lateral irradiation (RLAT), rotational irradiation (ROT) and isotropic irradiation (ISO).

[0055] In the specific implementation process, it is necessary to obtain specific data in the irradiated scene by questioning the irradiated personnel. For example, the irradiated personnel are asked about their distance, position, shielding conditions from the neutron source when neutron irradiation occurs, and the irradiation geometry conditions of the irradiated personnel when neutron irradiation occurs. Then, based on the type of neutron source, the irradiation geometry conditions of the irradiated personnel when neutron irradiation occurs, and the distance, position and shielding conditions of the irradiated personnel from the neutron source when neutron irradiation occurs, the Monte Carlo program is used to calculate the neutron energy distribution (expressed as p(E)) reaching the irradiated personnel's body.

[0056] In a specific embodiment, in order to improve the accuracy of neutron dose assessment, the continuous neutron energy distribution is segmented according to energy, so that the continuous energy distribution is converted into a discrete energy distribution. The segment interval can be 0.5-1.5 MeV. The specific segment interval value can be specifically set according to the actual application scenario.

[0057] S220. Use radiation detectors to detect radionuclides at set locations on the body of the exposed person at set times. 24 The characteristic gamma ray intensity of Na is measured to obtain 24 The total energy peak count of characteristic gamma rays of Na at a set energy and the time when the measurement started.

[0058] Figure 1 A schematic diagram of an implementation scenario of a method for assessing human neutron dose provided by an embodiment of the present invention; Figure 1As shown, the exposed person 101 lies on his back on the bed surface of the measurement bed 102, and the radiation detector 103 is correspondingly arranged under the bed surface, and the radiation detector 103 is close to the set position of the body of the exposed person 101 to measure the radioactive nuclides for a set time. 24 The characteristic gamma ray intensity of Na is measured; in order to further ensure that the radiation detector obtains 24 The efficiency of the characteristic gamma ray intensity of Na is set as a canvas bed with a thickness of <2 mm.

[0059] That is, the irradiated person 101 lies on his back on the cot, and the radiation detector 104 is placed close to the position between the 12th thoracic vertebra and the 1st lumbar vertebra on the back of the irradiated person. Because the cot is lighter and thinner than wooden or metal beds, it can reduce the attenuation loss of gamma rays from the body of the irradiated person 101 to the radiation detector 103. In the specific implementation process, the radiation detector is a scintillation detector, which can be, but is not limited to, a high purity germanium HPGe detector, a NaI (Tl) detector, or a LaBr3 (Ce) detector.

[0060] Monte Carlo simulation is used to calculate the 24 Na distribution and simulation 24 The distribution of Na characteristic gamma rays on the human body surface, with the position with the highest gamma ray flux on the body surface as the radiation detector measurement position.

[0061] In the specific implementation process, because the liver is located from the 12th thoracic vertebra to the 1st lumbar vertebra, the sodium content in the liver is 0.2%, which is higher than other major organs, and the mass and density are high. The sodium content of the liver is stable, the sodium metabolism is slow, and it is less affected by food intake and body size differences, so it is suitable for 24 That is to say, under all neutron irradiation geometric conditions, the position from the 12th thoracic vertebra to the 1st lumbar vertebra on the back of the irradiated person is the surface 24 The radiation detector has the highest detection efficiency at the location where the Na characteristic gamma ray flux is the highest. Therefore, the lowest setting position of the neutron dose measurement lower limit is the position from the 12th thoracic vertebra to the 1st lumbar vertebra on the back of the irradiated person. In summary, the 12th thoracic vertebra to the 1st lumbar vertebra is where the liver is located, and this position is the surface of the body. 24 The position with the highest Na characteristic gamma-ray fluence is 15-35% higher than the front chest gamma-ray fluence. The radiation detector has the highest detection efficiency at this position and the lowest measurement limit for neutron dose.

[0062] It should be noted that the use of radiation detectors to obtain radionuclides produced by the reaction of neutrons with sodium in the human body 24 The intensity of Na's characteristic gamma rays, and the radiation detector can obtain various energies24 In order to improve the accuracy of neutron dose assessment, the radiation detector acquires 24 The set energy of the characteristic gamma ray of Na is 1.369 MeV and / or 2.754 MeV.

[0063] In the specific implementation process, the measurement setting time of the radiation detector is 10-30 minutes. The radiation detector measures the irradiated person for 10 minutes and records the full energy peak count of the characteristic gamma ray with an energy of 1.369MeV or 2.754MeV. That is to say, using the human neutron dose assessment method of the present invention, it is only necessary to use the radiation detector to measure the human body of the irradiated person for a minimum of 10 minutes, and then use the measurement results to obtain the neutron dose assessment value of the irradiated person. The technical effect of greatly simplifying the assessment process is achieved.

[0064] In addition, in the specific implementation process, the radiation detector can be used to measure the full energy peak count of the characteristic gamma ray with an energy of 1.369 MeV, and then the neutron dose assessment value can be obtained; the radiation detector can also be used to measure the full energy peak count of the characteristic gamma ray with an energy of 2.754 MeV, and then the neutron dose assessment value can be obtained; the radiation detector can also be used to measure the full energy peak count of the characteristic gamma ray with an energy of 1.369 MeV, and then the neutron dose assessment value one can be obtained, and then the radiation detector can be used to measure the full energy peak count of the characteristic gamma ray with an energy of 2.754 MeV, and then the neutron dose assessment value two can be obtained, and the average of the neutron dose assessment value one and the neutron dose assessment value two can be taken as the final neutron dose assessment value.

[0065] In short, by fixing the measurement position of the exposed personnel and selecting the measurement bed in the measurement scene, the measurement time can be shortened and the exposed personnel can be treated accurately. 24 Efficient measurement of the characteristic gamma-ray intensity of Na.

[0066] In the specific implementation process, it is also necessary to pre-acquire the total energy peak count value set and the neutron dose value set. The pre-acquisition method of the total energy peak count value set includes using a Monte Carlo program to obtain the unit monoenergetic neutron irradiation under various irradiation geometric conditions, and the radiation detector measured at the set position of the irradiated person's body. 24 A data set of full-energy peak counts of characteristic gamma rays of set energy of Na; a method for pre-acquiring a set of neutron dose values, comprising using a Monte Carlo program to obtain a data set of neutron doses generated by unit monoenergetic neutrons in an energy range of 0-20MeV after irradiating the human body under various irradiation geometric conditions.

[0067] In a specific embodiment, in order to improve the accuracy of neutron dose assessment, the continuous neutron energy distribution is divided into energy segments, so that the continuous energy distribution is converted into a discrete energy distribution. Then, according to the energy segmentation, the pre-established full energy peak count value set and neutron dose value set are compared, and the corresponding values ​​measured by the radiation detector after the monoenergetic neutron irradiates the human body under the same irradiation geometry as the irradiated person are obtained. 24 The full energy peak count of characteristic gamma rays of set energy of Na and the neutron dose caused by monoenergetic neutrons irradiating the human body under the same irradiation geometry as the irradiated personnel. Each point value is converted into a stage average value, and then weighted summed, so as to achieve the technical effect of improving the accuracy of the assessment.

[0068] That is to say, through the pre-established total energy peak count value set and neutron dose value set, in the actual human neutron dose assessment scenario, after determining the irradiation geometry of the irradiated person, by traversing the set according to the irradiation geometry of the irradiated person, the radiation detector measured by a monoenergetic neutron with energy E after irradiating the human body under the same irradiation geometry as the irradiated person can be obtained. 24 The full-energy peak count of the characteristic gamma rays of the set energy of Na and the neutron dose caused by a monoenergetic neutron with energy E irradiating the human body under the same irradiation geometry conditions as the irradiated person.

[0069] S230, based on the time of neutron irradiation, the neutron energy distribution reaching the body of the irradiated person, the irradiation geometric conditions of the irradiated person when the neutron irradiation occurs, and the radiation detector measured 24 The full energy peak count of characteristic gamma rays of set energy of Na and the time when measurement starts; the neutron dose of the irradiated personnel is determined by the formula;

[0070] The formula is:

[0071]

[0072] Among them, D T is the neutron dose of the irradiated personnel, N c Measured for radiation detectors 24 The total energy peak count of characteristic gamma rays of set energy of Na, p(E) is the neutron energy distribution reaching the body of the irradiated person, n m (E) is the radiation detector measured after a monoenergetic neutron with energy E irradiates the human body under the same irradiation geometry as the irradiated person. 24 The full energy peak count of characteristic gamma rays of Na at a set energy, d T (E) is the neutron dose caused by a monoenergetic neutron with energy E irradiating the human body under the same irradiation geometry as the irradiated person, Emax is the maximum energy of the neutron irradiating the human body, and λ is24 The decay constant of Na is 1.2836×10 -5 , t1 is the time when neutron irradiation occurs, t2 is the time when the measurement starts, for 24 Decay coefficient of Na.

[0073] It should be noted that n m (E) and d T (E) is obtained by pre-acquired full energy peak count value set and neutron dose value set according to the irradiation geometry conditions of the irradiated personnel. That is, d T (E) and n m (E) is a data calculated in advance. Therefore, in the assessment of human neutron dose, it is only necessary to obtain the time t1 of neutron irradiation, the time t2 of measurement start, the neutron energy distribution p(E) reaching the body of the irradiated person, the irradiation geometry of the irradiated person, and the full energy peak count N of the characteristic gamma rays with an energy of 1.369 MeV or 2.754 MeV measured by the radiation detector at the back of the irradiated person. c The neutron dose D of the irradiated personnel can be calculated T .

[0074] The human body neutron dose assessment method of the present invention improves the human body neutron dose assessment method by determining the measurement position of the radiation detector for measuring characteristic gamma rays on the human body surface. 24 The detection efficiency of Na characteristic γ-rays is improved, and the detection limit is reduced; and this position is used as the measurement standard position to establish 24 The direct conversion method of Na characteristic gamma ray intensity and neutron dose simplifies the calculation process and improves the evaluation speed of neutron dose. The accuracy and efficiency of dose evaluation are improved by obtaining the total energy peak count value set and neutron dose value set.

[0075] Example 1

[0076] Take the case where the exposed person 101 is irradiated by a californium-252 neutron source as an example.

[0077] 1) Ask the irradiated person about the distance, position, shielding situation from the neutron source when neutron irradiation occurs, and the irradiation geometry of the irradiated person when neutron irradiation occurs. Then, according to the type of neutron source, the irradiation geometry of the irradiated person when neutron irradiation occurs, the distance, position and shielding situation from the neutron source when neutron irradiation occurs, calculate the neutron energy distribution (expressed as p(E)) reaching the irradiated person's body through the Monte Carlo program.

[0078] Figure 3 The continuous distribution and segmented results of neutron energy of the californium-252 neutron source are shown in FIG. Figure 3The continuous energy spectrum with an average energy of 2.35 MeV is shown. The continuous energy distribution of neutrons from the californium-252 neutron source is divided into energy segments, so that the continuous energy distribution is converted into a discrete energy distribution.

[0079] Figure 4 and Figure 5 The pre-acquired total energy peak count value set and neutron dose value set are generally described; among them, Figure 4 It is the neutron dose diagram caused by monoenergetic neutrons irradiating the human body, that is, a collection of neutron dose values. Figure 5 It is a full energy peak count diagram of characteristic gamma rays with an energy of 1.369 MeV measured by the radiation detector at the position from the 12th thoracic vertebra to the 1st lumbar vertebra on the back of the irradiated person after 100 mGy neutron irradiation, that is, a set of full energy peak count values.

[0080] 2) The exposed person 101 lies on his back on a measurement bed 102 with a canvas surface of 1.5 mm thickness. The NaI (Tl) detector is placed close to the position between the 12th thoracic vertebra and the 1st lumbar vertebra on the back of the exposed person. 24 The characteristic gamma ray intensity of Na was measured for 10 minutes, and the full energy peak counts N of the characteristic gamma ray with an energy of 1.369 MeV were recorded. c , and record the measurement start time t2.

[0081] Select the most suitable irradiation geometry to Figure 3 and Figure 4 The data in is used as the initial data to calculate the neutron dose d caused by monoenergetic neutron irradiation of the human body under the same irradiation geometry as that of the irradiated person 101. T (E) and the full energy peak counts n of characteristic gamma rays with an energy of 1.369 MeV measured by the radiation detector after irradiation of the human body with monoenergetic neutrons m (E).

[0082] The neutron dose D of the irradiated person 101 can be calculated according to the following formula: T :

[0083]

[0084] Among them, D T is the neutron dose of the irradiated personnel, N c Measured for radiation detectors 24 The energy of Na is the full energy peak count of the characteristic gamma ray of 1.369 MeV, p(E) is the neutron energy distribution reaching the body of the irradiated person, n m (E) is the radiation detector measured after a monoenergetic neutron with energy E irradiates the human body under the same irradiation geometry as the irradiated person. 24The energy of Na is 1.369 MeV, which is the full energy peak count of characteristic gamma rays. T (E) is the neutron dose caused by a monoenergetic neutron with energy E irradiating the human body under the same irradiation geometry as the irradiated person, Emax is the maximum energy of the neutron irradiating the human body, and λ is 24 The decay constant of Na is 1.2836×10 -5 , t1 is the time when neutron irradiation occurs, t2 is the time when the measurement starts, for 24 Decay coefficient of Na.

[0085] The above formula is used to calculate the dose of 100mGy. 252 The total energy peak count of the characteristic gamma ray with energy of 1.369 MeV that should be measured by the radiation detector after the Cf neutron exposure personnel 101 is compared with the experimental measurement result N c For comparison, see Table 1.

[0086] Table 1 100mGy 252 The energy of Cf neutrons after irradiation of the human body is 1.369 MeV. 24 Comparison of the counting results of Na characteristic gamma rays and the calculation results of the human neutron dose assessment method of the present invention

[0087]

[0088]

[0089] It can be seen from Table 1 that the deviation between the human neutron dose assessment method of the present invention and the experimental value is ≤3.24%. The lower limit of neutron dose measurement is reduced from 100mGy to 1mGy, and the measurement time is only 10 minutes. Rapid, accurate, and low detection limit human neutron dose assessment is achieved.

[0090] The human neutron dose assessment method of the present invention realizes the 24 The characteristic gamma-ray intensity of Na is then used to obtain the neutron dose assessment value, which not only simplifies the calculation process but also improves the speed of neutron dose assessment. 24 The detection efficiency of Na's characteristic gamma rays reduces the detection limit, and the accuracy of neutron dose assessment is improved by segmenting the neutron energy distribution.

[0091] like Figure 5As shown, the present invention provides a human neutron dose assessment system 600, which can be installed in an electronic device. According to the functions to be implemented, the human neutron dose assessment system 600 can include a neutron irradiation data acquisition unit 610, a measurement unit 620, and a neutron dose determination unit 6300. The module described in the present invention can also be referred to as a unit, which refers to a series of computer program segments that can be executed by an electronic device processor and can complete fixed functions, which are stored in the memory of the electronic device.

[0092] In this embodiment, the functions of each module / unit are as follows:

[0093] The neutron irradiation data acquisition unit 610 is used to acquire the type of neutron source, the time when neutron irradiation occurs, and the irradiation geometric conditions of the irradiated person when the neutron irradiation occurs; and determine the neutron energy distribution reaching the body of the irradiated person according to the type of neutron source and the irradiation geometric conditions of the irradiated person when the neutron irradiation occurs;

[0094] The measuring unit 620 is used to measure the radioactive nuclides at the set position of the body of the irradiated person using the radiation detector according to the set time. 24 The characteristic gamma ray intensity of Na is measured to obtain 24 The full energy peak count of characteristic gamma rays of Na at a set energy and the time when the measurement starts;

[0095] The neutron dose determination unit 630 is used to determine the neutron dose according to the time when the neutron irradiation occurs, the neutron energy distribution reaching the body of the irradiated person, the irradiation geometry of the irradiated person when the neutron irradiation occurs, and the radiation measured by the radiation detector. 24 The full energy peak count of characteristic gamma rays of set energy of Na and the time when measurement starts; the neutron dose of the irradiated personnel is determined by formula;

[0096] The formula is:

[0097]

[0098] Among them, D T is the neutron dose of the irradiated personnel, N c Measured for radiation detectors 24 The total energy peak count of characteristic gamma rays of set energy of Na, p(E) is the neutron energy distribution reaching the body of the irradiated person, n m (E) is the radiation detector measured after a monoenergetic neutron with energy E irradiates the human body under the same irradiation geometry as the irradiated person. 24 The full energy peak count of characteristic gamma rays of Na at a set energy, d T(E) is the neutron dose caused by a monoenergetic neutron with energy E irradiating the human body under the same irradiation geometry as the irradiated person, Emax is the maximum energy of the neutron irradiating the human body, and λ is 24 The decay constant of Na is 1.2836×10 -5 , t1 is the time when neutron irradiation occurs, t2 is the time when the measurement starts, for 24 Decay coefficient of Na;

[0099] Among them, n m (E) and d T (E) The pre-acquired total energy peak count value set and neutron dose value set are respectively obtained according to the irradiation geometric conditions of the irradiated person.

[0100] The human neutron dose assessment system of the present invention uses the position with the highest gamma-ray flux on the body surface of the irradiated person as the measurement position of the radiation detector, and compares the position from the 12th thoracic vertebra to the 1st lumbar vertebra on the back with the position on the front chest. 24 The Na characteristic γ-ray fluence is increased by 15-35%, thereby improving 24 The detection efficiency of Na characteristic gamma rays is improved, and the technical effect of reducing the detection limit is achieved; the position with the highest gamma ray flux on the body surface of the irradiated person is used as the measurement standard position, and a measurement method is established from the irradiated person 24 The method of converting Na characteristic gamma ray intensity directly to neutron dose simplifies the neutron dose evaluation process and improves the speed of neutron dose evaluation.

[0101] like Figure 7 As shown, the present invention provides an electronic device 7 for a method for evaluating human neutron dose.

[0102] The electronic device 7 may include a processor 70 , a memory 71 and a bus, and may also include a computer program stored in the memory 71 and executable on the processor 70 , such as a human neutron dose assessment program 72 .

[0103] The memory 71 includes at least one type of readable storage medium, and the readable storage medium includes flash memory, mobile hard disk, multimedia card, card-type memory (for example: SD or DX memory, etc.), magnetic memory, disk, optical disk, etc. The memory 71 may be an internal storage unit of the electronic device 7 in some embodiments, such as a mobile hard disk of the electronic device 7. The memory 71 may also be an external storage device of the electronic device 7 in other embodiments, such as a plug-in mobile hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the electronic device 7. Further, the memory 71 may also include both an internal storage unit of the electronic device 7 and an external storage device. The memory 71 may not only be used to store application software and various types of data installed in the electronic device 7, such as the code of the human neutron dose assessment program, etc., but also be used to temporarily store data that has been output or is to be output.

[0104] The processor 70 may be composed of an integrated circuit in some embodiments, for example, a single packaged integrated circuit, or a plurality of packaged integrated circuits with the same or different functions, including one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and combinations of various control chips, etc. The processor 30 is the control core (Control Unit) of the electronic device, and uses various interfaces and lines to connect various components of the entire electronic device, and executes or executes programs or modules (such as human neutron dose assessment programs, etc.) stored in the memory 71, and calls data stored in the memory 71 to execute various functions of the electronic device 7 and process data.

[0105] The bus may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. The bus is configured to realize connection and communication between the memory 71 and at least one processor 70, etc.

[0106] Figure 7 Only an electronic device with components is shown, and those skilled in the art will understand that Figure 7The structure shown does not constitute a limitation on the electronic device 7, and may include fewer or more components than shown in the figure, or combine certain components, or arrange the components differently.

[0107] For example, although not shown, the electronic device 7 may also include a power source (such as a battery) for supplying power to each component. Preferably, the power source may be logically connected to the at least one processor 70 through a power management device, so that the power management device can realize functions such as charging management, discharging management, and power consumption management. The power source may also include any components such as one or more DC or AC power sources, recharging devices, power failure detection circuits, power converters or inverters, and power status indicators. The electronic device 7 may also include a variety of sensors, Bluetooth modules, Wi-Fi modules, etc., which will not be repeated here.

[0108] Furthermore, the electronic device 7 may also include a network interface. Optionally, the network interface may include a wired interface and / or a wireless interface (such as a WI-FI interface, a Bluetooth interface, etc.), which is generally used to establish a communication connection between the electronic device 7 and other electronic devices.

[0109] Optionally, the electronic device 7 may further include a user interface, which may be a display, an input unit (such as a keyboard), or a standard wired interface or a wireless interface. Optionally, in some embodiments, the display may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, and an OLED (Organic Light-Emitting Diode) touch device. The display may also be appropriately referred to as a display screen or a display unit, which is used to display information processed in the electronic device 7 and to display a visual user interface.

[0110] It should be understood that the embodiment is for illustration only and the scope of the patent application is not limited to this structure.

[0111] The human neutron dose assessment program 72 stored in the memory 71 in the electronic device 7 is a combination of multiple instructions. When running in the processor 70, it can achieve: obtaining the type of neutron source, the time when neutron irradiation occurs, and the irradiation geometry of the irradiated person when the neutron irradiation occurs; and determining the neutron energy distribution reaching the body of the irradiated person according to the type of neutron source and the irradiation geometry of the irradiated person when the neutron irradiation occurs; according to the set time, using the radiation detector to detect the radioactive nuclide at the set position of the body of the irradiated person. 24 The characteristic gamma ray intensity of Na is measured to obtain 24The total energy peak count of the characteristic gamma ray of the set energy of Na and the time when the measurement starts; according to the time when neutron irradiation occurs, the energy distribution of neutrons reaching the body of the irradiated person, the irradiation geometry of the irradiated person when neutron irradiation occurs, and the radiation detector measured 24 The total energy peak count of characteristic gamma rays of set energy of Na and the time when measurement starts; the neutron dose of the irradiated personnel is determined by the formula; wherein the formula is:

[0112]

[0113] Among them, D T is the neutron dose of the irradiated personnel, N c Measured for radiation detectors 24 The total energy peak count of characteristic gamma rays of set energy of Na, p(E) is the neutron energy distribution reaching the body of the irradiated person, n m (E) is the radiation detector measured after a monoenergetic neutron with energy E irradiates the human body under the same irradiation geometry as the irradiated person. 24 The full energy peak count of characteristic gamma rays of Na at a set energy, d T (E) is the neutron dose caused by a monoenergetic neutron with energy E irradiating the human body under the same irradiation geometry as the irradiated person, Emax is the maximum energy of the neutron irradiating the human body, and λ is 24 The decay constant of Na is 1.2836×10 -5 , t1 is the time when neutron irradiation occurs, t2 is the time when the measurement starts, for 24 The decay coefficient of Na; where n m (E) and d T (E) The pre-acquired total energy peak count value set and neutron dose value set are respectively obtained according to the irradiation geometric conditions of the irradiated person.

[0114] Specifically, the specific implementation method of the processor 70 for the above instructions can refer to Figure 1 The description of the relevant steps in the corresponding embodiment is not repeated here. It should be emphasized that in order to further ensure the privacy and security of the above-mentioned human neutron dose assessment program, the above-mentioned database can store the processed data in the node of the blockchain where the server cluster is located.

[0115] Furthermore, if the module / unit integrated in the electronic device 7 is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. The computer-readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, and a read-only memory (ROM).

[0116] The embodiment of the present invention further provides a computer-readable storage medium, which may be non-volatile or volatile, and stores a computer program. When the computer program is executed by a processor, the following are achieved: obtaining the type of neutron source, the time when neutron irradiation occurs, and the irradiation geometry of the irradiated person when the neutron irradiation occurs; and determining the neutron energy distribution reaching the body of the irradiated person according to the type of neutron source and the irradiation geometry of the irradiated person when the neutron irradiation occurs; and detecting the radioactive nuclides at the set position of the body of the irradiated person using a radiation detector according to the set time. 24 The characteristic gamma ray intensity of Na is measured to obtain 24 The total energy peak count of the characteristic gamma ray of the set energy of Na and the time when the measurement starts; according to the time when neutron irradiation occurs, the energy distribution of neutrons reaching the body of the irradiated person, the irradiation geometry of the irradiated person when neutron irradiation occurs, and the radiation detector measured 24 The total energy peak count of characteristic gamma rays of set energy of Na and the time when measurement starts; the neutron dose of the irradiated personnel is determined by the formula; wherein the formula is:

[0117]

[0118] Among them, D T is the neutron dose of the irradiated personnel, N c Measured for radiation detectors 24 The total energy peak count of characteristic gamma rays of set energy of Na, p(E) is the neutron energy distribution reaching the body of the irradiated person, n m (E) is the radiation detector measured after a monoenergetic neutron with energy E irradiates the human body under the same irradiation geometry as the irradiated person. 24 The full energy peak count of characteristic gamma rays of Na at a set energy, d T (E) is the neutron dose caused by a monoenergetic neutron with energy E irradiating the human body under the same irradiation geometry as the irradiated person, Emax is the maximum energy of the neutron irradiating the human body, and λ is 24 The decay constant of Na is 1.2836×10 -5 , t1 is the time when neutron irradiation occurs, t2 is the time when the measurement starts, for 24 The decay coefficient of Na; where n m (E) and d T (E) The pre-acquired total energy peak count value set and neutron dose value set are respectively obtained according to the irradiation geometric conditions of the irradiated person.

[0119] Specifically, the specific implementation method when the computer program is executed by the processor can refer to the description of the relevant steps in the human neutron dose assessment method in the embodiment, which will not be repeated here.

[0120] In the several embodiments provided by the present invention, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of the modules is only a logical function division, and there may be other division methods in actual implementation.

[0121] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0122] In addition, each functional module in each embodiment of the present invention may be integrated into one processing unit, each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of hardware plus software functional modules.

[0123] It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0124] Therefore, no matter from which point of view, the embodiments should be regarded as illustrative and non-restrictive, and the scope of the present invention is limited by the appended claims rather than the above description, so it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any attached figure mark in the claims should not be regarded as limiting the claims involved.

[0125] The blockchain referred to in this invention is a new application mode of computer technologies such as distributed data storage, peer-to-peer transmission, consensus mechanism, encryption algorithm, etc. Blockchain is essentially a decentralized database, a string of data blocks generated by cryptographic methods. Each data block contains a batch of network transaction information, which is used to verify the validity of its information (anti-counterfeiting) and generate the next block. Blockchain can include the underlying blockchain platform, platform product service layer, and application service layer.

[0126] In addition, it is clear that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units or devices stated in the system claim can also be implemented by one unit or device through software or hardware. The second and other words are used to indicate names, but not to indicate any particular order.

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for assessing human neutron dose, characterized in that: Methods include, Obtaining the type of neutron source, the time when neutron irradiation occurs, and the irradiation geometric conditions of the irradiated person when the neutron irradiation occurs; and determining the neutron energy distribution reaching the body of the irradiated person according to the type of neutron source and the irradiation geometric conditions of the irradiated person when the neutron irradiation occurs; At set times, radiation detectors are used to detect radionuclides at set locations on the body of the exposed person. 24 The characteristic gamma ray intensity of Na is measured to obtain 24 The full energy peak count of characteristic gamma rays of Na at a set energy and the time when the measurement starts; According to the time when the neutron irradiation occurs, the distribution of neutron energy reaching the body of the irradiated person, the irradiation geometric conditions of the irradiated person when the neutron irradiation occurs, and the radiation detector measured 24 The full energy peak count of characteristic gamma rays of set energy of Na and the time when measurement starts; the neutron dose of the irradiated personnel is determined by formula; Wherein, the formula is: Among them, D T is the neutron dose of the irradiated personnel, N c Measured for radiation detectors 24 The total energy peak count of characteristic gamma rays of set energy of Na, p(E) is the neutron energy distribution reaching the body of the irradiated person, n m (E) is the radiation detector measured after a monoenergetic neutron with energy E irradiates the human body under the same irradiation geometry as the irradiated person. 24 The full energy peak count of characteristic gamma rays of Na at a set energy, d T (E) is the neutron dose caused by a monoenergetic neutron with energy E irradiating the human body under the same irradiation geometry as the irradiated person, Emax is the maximum energy of the neutron irradiating the human body, and λ is 24 The decay constant of Na is 1.2836×10 -5 , t1 is the time when neutron irradiation occurs, t2 is the time when the measurement starts, for 24 Decay coefficient of Na; Among them, the n m (E) and d T (E) The pre-acquired total energy peak count value set and neutron dose value set are respectively obtained according to the irradiation geometric conditions of the irradiated person.

2. The method for assessing human neutron dose according to claim 1, characterized in that: The set position of the body of the irradiated person is the position from the 12th thoracic vertebra to the 1st lumbar vertebra on the back of the irradiated person.

3. The method for assessing human neutron dose according to claim 1 or 2, characterized in that: According to the set time, the radiation detector is used to detect the radioactive nuclides at the set position of the exposed person's body. 24 The characteristic gamma ray intensity of Na is measured. include, The exposed person lies on his back on the bed, and the radiation detector is correspondingly arranged under the bed, and the radiation detector is close to the set position of the exposed person's body to detect the radioactive nuclides for a set time. 24 Measurement of the intensity of characteristic gamma rays of Na; Wherein, the bed surface is a canvas piece, and the thickness of the bed surface is less than 2mm.

4. The method for assessing human neutron dose according to claim 1, characterized in that: The geometric conditions of the ray irradiation include front irradiation, back irradiation, left irradiation, right irradiation, rotational irradiation and isotropic irradiation.

5. The method for assessing human neutron dose according to claim 3, characterized in that: The set time for the measurement of the radiation detector is 10-30 minutes.

6. The method for assessing human neutron dose according to claim 1, characterized in that: Said 24 The set energy of the characteristic gamma ray of Na is 1.369 MeV and / or 2.754 MeV.

7. The method for assessing human neutron dose according to claim 1, characterized in that: The method for pre-acquiring the total energy peak count value set comprises using a Monte Carlo program to obtain the unit monoenergetic neutron radiation measured by the radiation detector at a set position of the irradiated person's body after irradiating the human body with various irradiation geometric conditions. 24 A data set of full energy peak counts of characteristic gamma rays of set energy of Na; The method for pre-acquiring a set of neutron dose values ​​comprises using a Monte Carlo program to acquire a data set of neutron doses generated when unit monoenergetic neutrons within an energy range of 0-20 MeV are irradiated to a human body under various irradiation geometric conditions.

8. A human neutron dose assessment system, characterized in that: The system includes, a neutron irradiation data acquisition unit, for acquiring the type of neutron source, the time when neutron irradiation occurs, and the irradiation geometric conditions of the irradiated person when the neutron irradiation occurs; and determining the neutron energy distribution reaching the body of the irradiated person according to the type of neutron source and the irradiation geometric conditions of the irradiated person when the neutron irradiation occurs; The measuring unit is used to measure the radionuclides at the set position of the irradiated person's body using the radiation detector according to the set time. 24 The characteristic gamma ray intensity of Na is measured to obtain 24 The full energy peak count of characteristic gamma rays of Na at a set energy and the time when the measurement starts; The neutron dose determination unit is used to determine the neutron dose according to the time when the neutron irradiation occurs, the neutron energy distribution reaching the body of the irradiated person, the irradiation geometric conditions of the irradiated person when the neutron irradiation occurs, and the radiation detector measured. 24 The full energy peak count of characteristic gamma rays of set energy of Na and the time when measurement starts; the neutron dose of the irradiated personnel is determined by formula; Wherein, the formula is: Among them, D T is the neutron dose of the irradiated personnel, N c Measured for radiation detectors 24 The total energy peak count of characteristic gamma rays of set energy of Na, p(E) is the neutron energy distribution reaching the body of the irradiated person, n m (E) is the radiation detector measured after a monoenergetic neutron with energy E irradiates the human body under the same irradiation geometry as the irradiated person. 24 The full energy peak count of characteristic gamma rays of Na at a set energy, d T (E) is the neutron dose caused by a monoenergetic neutron with energy E irradiating the human body under the same irradiation geometry as the irradiated person, Emax is the maximum energy of the neutron irradiating the human body, and λ is 24 The decay constant of Na is 1.2836×10 -5 , t1 is the time when neutron irradiation occurs, t2 is the time when the measurement starts, for 24 Decay coefficient of Na; Among them, the n m (E) and d T (E) The pre-acquired total energy peak count value set and neutron dose value set are respectively obtained according to the irradiation geometric conditions of the irradiated person.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the steps in the human body neutron dose assessment method as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for assessing human neutron dose according to any one of claims 1 to 7 is implemented.

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