Source item calculation method for proton and heavy ion irradiation sample
By establishing a three-dimensional particle transport model and calculating nuclear reaction cross-section data, the problem of lag in the assessment of radioactive source terms in proton and heavy ion irradiated samples was solved, enabling rapid and accurate prediction of radioactive source terms and supporting safe design and waste management.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA INST FOR RADIATION PROTECTION
- Filing Date
- 2025-12-30
- Publication Date
- 2026-05-12
AI Technical Summary
In existing technologies, the determination of the radioactive source term of samples after proton and heavy ion irradiation relies on experimental measurements, which results in assessment lag and the inability to predict in advance, leading to difficulties in safety design and waste management.
A three-dimensional particle transport model was established using the Monte Carlo particle transport procedure. Combined with nuclear reaction cross-section data, the amount of each radionuclide generated in the sample was calculated. The radioactive source term parameters, including total activity and radiation energy distribution, were calculated through decay characteristics.
This enables rapid prediction of radioactive source terms before sample irradiation, reducing experimental measurement errors and ensuring the accuracy of safety design and waste management.
Smart Images
Figure CN122017924A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of radiation detection technology, and in particular to a method for calculating the source term of proton and heavy ion irradiated samples. Background Technology
[0002] Proton and heavy ion beams, as important particle irradiation sources, play an irreplaceable role in fundamental nuclear physics research, ground-based simulation of space radiation effects, radioactive isotope preparation, and advanced particle therapy. In these applications, samples (such as structural materials, biological specimens, or therapeutic targets) irradiated with high-energy protons or heavy ions undergo a series of complex nuclear reactions, including spallation, capture, and fragmentation, leading to the activation of the sample itself and the production of various radionuclides with different half-lives and decay characteristics. Accurately determining the types, activities, and energy spectra of these induced radionuclides—the "radioactive source term"—is a scientific prerequisite for subsequent radiation safety protection, radioactive waste classification and management, irradiation facility operation optimization, and in-depth analysis of experimental data.
[0003] Currently, the industry generally relies on experimental measurement methods to determine the radioactive source terms of samples irradiated with protons and heavy ions, with high-purity germanium (HPGe) gamma-ray spectroscopy being the most common. This method identifies nuclides and calculates their activity by directly measuring the irradiated sample and analyzing its characteristic gamma-ray peaks. However, this traditional experimental method suffers from significant assessment delays and cannot predict the radioactive source terms of the sample in advance. Summary of the Invention
[0004] To address the shortcomings of existing technologies, the purpose of this application is to provide a method for calculating the source terms of proton and heavy ion irradiated samples, which can quickly predict and calculate the radioactive source terms of the samples in advance, providing reliable data support for safety design, waste management, and experimental analysis.
[0005] To achieve the above objectives, this application provides a method for calculating the source term of proton and heavy ion irradiated samples, comprising: The irradiation condition parameters and sample parameters are obtained; the irradiation condition parameters include incident particle type, energy distribution, beam intensity, beam spot size, incident angle, and total fluence; the sample parameters include the geometric structure model of the sample, material composition, and nuclide composition of each component. Based on the irradiation condition parameters and sample parameters, a three-dimensional particle transport model of the sample was established using the Monte Carlo particle transport program to simulate the transport process of incident particles in the sample. Using the aforementioned three-dimensional particle transport model, combined with the nuclear reaction cross-section data of the incident particles and each target nucleus in the sample, coupled transport calculations are performed to obtain the number of each radionuclide generated in the sample. Based on the amount of each radionuclide generated, establish a list of activation products containing the types of nuclides and their generation information; Based on the list of activated products and the decay characteristics of each radionuclide, the radioactive source term parameters of the sample are calculated, including total activity and / or radiation energy distribution.
[0006] Furthermore, the specific steps for obtaining the quantity of each radionuclide generated in the sample by using the three-dimensional particle transport model, combined with the nuclear reaction cross-sectional data of the incident particle and each target nucleus in the sample, to perform coupled transport calculations are as follows: ; in, For the first i The number of radioactive nuclides The reaction cross section of nuclide i The decay constant of nuclide i (s -1 ), The beam intensity (A) represents the incident particle beam. Irradiation time (s).
[0007] Furthermore, the total activity is calculated using the following formula: ; in, This represents the total activity of radionuclides. For the first i The activity (Bq) of a radionuclide.
[0008] Furthermore, the Monte Carlo particle transport procedure is built on the Geant4, MCNP, or FLUKA software platform.
[0009] Furthermore, the sample includes any one of stainless steel, tungsten, copper, and graphite.
[0010] Furthermore, the radiation energy distribution is calculated based on the production quantity of radionuclides and the radiation emission information of various nuclides in the standard database according to the nuclide generation ratio.
[0011] To achieve the above objectives, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the source term calculation method as described above.
[0012] To achieve the above objectives, this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the source item calculation method as described above.
[0013] The source term calculation method for proton and heavy ion irradiated samples in this application can be calculated based on preset irradiation parameters before the sample is actually irradiated, thereby predicting its radioactivity level in advance, which can guide shielding design, formulate waste management strategies and optimize irradiation processes.
[0014] The source term calculation method for proton and heavy ion irradiated samples in this application can calculate all possible radionuclides that may be generated, without being limited by experimental measurement methods. In particular, it can also calculate and evaluate difficult-to-detect nuclides (pure β emitters, low-energy photon emitters), ensuring the integrity of source term information. The calculation also reduces systematic and statistical errors in experimental measurements.
[0015] The source term calculation method for proton and heavy ion irradiated samples in this application can complete the evaluation of complex scenarios in a short time, which is much faster than the experimental process that requires sample preparation, cooling and long-term measurement.
[0016] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing this application. Attached Figure Description
[0017] The accompanying drawings are provided to further illustrate the present application and form part of the specification. Together with the embodiments of the present application, they serve to explain the present application but do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart illustrating the method for calculating the source terms of proton and heavy ion irradiated samples in Example 1 of this application. Figure 2 A schematic diagram of the list of activated products; Figure 3 A schematic diagram illustrating the changes in radioactivity; Figure 4 This is a schematic diagram of the gamma spectrum of a proton-irradiated sample. Detailed Implementation
[0018] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While some embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this application. It should be understood that the drawings and embodiments of this application are for illustrative purposes only and are not intended to limit the scope of protection of this application.
[0019] It should be understood that the steps described in the method embodiments of this application may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this application is not limited in this respect.
[0020] The term "comprising" and its variations as used herein are open-ended inclusions, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below.
[0021] It should be noted that the terms "one" and "multiple" used in this application are illustrative rather than restrictive, and those skilled in the art should understand that, unless explicitly stated otherwise in the context, they should be understood as "one or more". "Multiple" should be understood as two or more.
[0022] The embodiments of this application will now be described in detail with reference to the accompanying drawings.
[0023] Example 1 One embodiment of this application provides a method for calculating the source term of a proton and heavy ion irradiated sample, which will be described below. Figure 1-4 The method for calculating the source terms of the proton and heavy ion irradiated samples in this application is described as follows: Step S101: Obtain irradiation condition parameters and sample parameters; the irradiation condition parameters include incident particle type, energy distribution, beam intensity, beam spot size, incident angle, and total fluence; the sample parameters include the geometric structure model of the sample, material composition, and nuclide composition of each component; It is understandable that the irradiation condition parameters and sample parameters were known before the calculation.
[0024] In this application embodiment, S30408 stainless steel is used as the sample. S30408 stainless steel is a common structural material in proton accelerators and heavy ion accelerators. S30408 stainless steel materials that have been in service inside the accelerator for a long time are prone to transmutation and spallation reactions after being irradiated by protons, and thus become radioactive and become radioactive waste. In order to transport and store these radioactive wastes, it is necessary to first identify their radioactive source terms. Therefore, simulating and calculating their radioactive source terms is an important guarantee for ensuring safe transportation and disposal.
[0025] In other embodiments, the sample may also be any one of stainless steel, tungsten, copper, and graphite.
[0026] It should be noted that the main components of S30408 stainless steel include: Fe, Cr, Ni, Si, C, etc. 56 Taking Fe as an example, it will undergo a dispersion reaction with the incident protons to generate 50 Mn (half-life of 283 ms) 49Short-lived nuclides such as Cr (half-life of 42.3 min) and 52 Medium-lived nuclides such as Mn (half-life of 5.60 days) are also produced. 22 Long-lived nuclides such as Na (half-life of 2.61a) and others, while 22 Na and other substances will release energy through processes such as β decay to reach a stable state.
[0027] Step S102: Based on the irradiation condition parameters and sample parameters, a three-dimensional particle transport model of the sample is established using the Monte Carlo particle transport program to simulate the transport process of incident particles in the sample. In this embodiment of the application, the Monte Carlo particle transport procedure is built on the Geant4, MCNP, or FLUKA software platform.
[0028] Step S103: Using the three-dimensional particle transport model, combined with the nuclear reaction cross-section data of the incident particles and each target nucleus in the sample, perform coupled transport calculations to obtain the number of each radionuclide generated in the sample. In this embodiment of the application, the three-dimensional particle transport model is used, combined with the reaction cross section or response function of protons or each nuclide in the S30408 stainless steel sample, to calculate the number of each radionuclide generated in the sample after irradiating S30408 stainless steel with a proton energy of 600MeV and a flux of 1.0×10¹⁰ p / cm².
[0029] The amount of each radionuclide generated is calculated using the following formula: ; in, For the first i The number of radioactive nuclides The reaction cross section of nuclide i The decay constant of nuclide i (s -1 ), The beam intensity (A) represents the incident particle beam. Irradiation time (s).
[0030] Step S104: Based on the amount of each radionuclide generated, establish a list of activation products containing the types of nuclides and their generation information.
[0031] Once the amount of each radionuclide generated is calculated, a list of activation products can be established.
[0032] like Figure 2 As shown, Figure 2 The sample contains various nuclides and their quantities.
[0033] Step S105: Calculate the radioactive source term parameters of the sample based on the list of activated products and the decay characteristics of each radionuclide. The radioactive source term parameters include total activity and / or radiation energy distribution. In this embodiment, the total activity is calculated using the following formula: ; in, This represents the total activity of radionuclides. For the first i The activity (Bq) of a radionuclide.
[0034] Figure 3 This is a schematic diagram illustrating the changes in radioactivity, such as... Figure 3 As shown, the total radioactivity of the proton-irradiated S30408 sample decreased rapidly with increasing time. In the embodiments of this application, the radiation energy distribution is calculated based on the production quantity of radionuclides and the radiation emission information of various nuclides in the standard database according to the nuclide generation ratio.
[0035] For example, such as Figure 4 As shown, Figure 4 This is a schematic diagram of the gamma spectrum of a proton-irradiated sample. In summary, by calculating the total activity and radiation energy distribution, it is possible to comprehensively assess the radioactivity level of irradiated samples.
[0036] Example 2 One embodiment of this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the source item calculation method as described above.
[0037] Example 3 One embodiment of this application provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the source term calculation method as described above.
[0038] The above description is merely a partial embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of disclosure in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.
[0039] Furthermore, while the operations are described in a specific order, this should not be construed as requiring these operations to be performed in the specific order shown or in sequential order. Multitasking and parallel processing may be advantageous in certain environments. Similarly, while several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of this application. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.
[0040] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.
Claims
1. A method for calculating the source term of a proton and heavy ion irradiated sample, characterized in that, include: Obtain irradiation condition parameters and sample parameters; the irradiation condition parameters include incident particle type, energy distribution, beam intensity, beam spot size, incident angle, and total fluence. The sample parameters include the sample's geometric structure model, material composition, and the nuclide composition of each component; Based on the irradiation condition parameters and sample parameters, a three-dimensional particle transport model of the sample was established using the Monte Carlo particle transport program to simulate the transport process of incident particles in the sample. Using the aforementioned three-dimensional particle transport model, combined with the nuclear reaction cross-section data of the incident particles and each target nucleus in the sample, coupled transport calculations are performed to obtain the number of each radionuclide generated in the sample. Based on the amount of each radionuclide generated, establish a list of activation products containing the types of nuclides and their generation information; Based on the list of activated products and the decay characteristics of each radionuclide, the radioactive source term parameters of the sample are calculated, including total activity and / or radiation energy distribution.
2. The method for calculating the source term of proton and heavy ion irradiated samples according to claim 1, characterized in that, The specific steps for obtaining the quantity of each radionuclide generated in the sample by using the three-dimensional particle transport model, combined with the nuclear reaction cross-section data of the incident particle and each target nucleus in the sample, to perform coupled transport calculations are as follows: ； in, For the first i The number of radioactive nuclides The reaction cross section of nuclide i The decay constant of nuclide i (s -1 ), The beam intensity (A) represents the incident particle beam. Irradiation time (s).
3. The method for calculating the source term of proton and heavy ion irradiated samples according to claim 2, characterized in that, The total activity is calculated using the following formula: ； in, This represents the total activity of radionuclides. For the first i The activity (Bq) of a radionuclide.
4. The method for calculating the source term of proton and heavy ion irradiated samples according to claim 1, characterized in that, The Monte Carlo particle transport program is built on the Geant4, MCNP, or FLUKA software platform.
5. The method for calculating the source term of proton and heavy ion irradiated samples according to claim 1, characterized in that, The samples include any one of stainless steel, tungsten, copper, and graphite.
6. The method for calculating the source term of a proton and heavy ion irradiated sample according to claim 1, characterized in that, The radiation energy distribution is calculated based on the production quantity of radionuclides and the radiation emission information of various nuclides in the standard database, according to the nuclide generation ratio.
7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the source term calculation method as described in any one of claims 1 to 6.
8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the source term calculation method as described in any one of claims 1 to 6.