CN-122017924-A - Source term calculation method for proton and heavy ion irradiation sample

Abstract

The application relates to the technical field of detection, in particular to a source item calculation method for a proton and heavy ion irradiation sample. The method comprises the steps of obtaining irradiation condition parameters and sample parameters, establishing a three-dimensional particle transport model of a sample by adopting a Monte Carlo particle transport program based on the irradiation condition parameters and the sample parameters so as to simulate the transport process of incident particles in the sample, carrying out coupling transport calculation by combining nuclear reaction section data of the incident particles and target targets in the sample by utilizing the three-dimensional particle transport model to obtain the generation quantity of each radionuclide in the sample, establishing an activated product list containing nuclide types and generation information thereof, and calculating radioactive source item parameters of the sample, wherein the radioactive source item parameters comprise total activity and/or radiation energy distribution. The source item calculation method can predict and calculate the radioactive source item of the sample in advance and quickly before the sample is actually irradiated.

Inventors

• GAO XUDONG
• JIAO LIMIN
• HAO JIAXIN
• ZHANG PEIDONG
• CHEN LEI
• WANG PENGYI
• SUN SHUTANG
• ZHUANG DAJIE
• LI GUOQIANG

Assignees

• 中国辐射防护研究院

Dates

Publication Date

20260512

Application Date

20251230

Claims (8)

1. 1. A method for calculating a source term for a proton and heavy ion irradiated sample, comprising: Obtaining irradiation condition parameters and sample parameters, wherein the irradiation condition parameters comprise incident particle types, energy distribution, beam intensity, beam spot size, incident angles and total fluence, and the sample parameters comprise a geometric structure model of a sample, material components and nuclide compositions of the components; Based on the irradiation condition parameters and the sample parameters, a Monte Carlo particle transport program is adopted to establish a three-dimensional particle transport model of the sample so as to simulate the transport process of incident particles in the sample; carrying out coupling transport calculation by utilizing the three-dimensional particle transport model and combining nuclear reaction section data of incident particles and target targets in a sample to obtain the generation quantity of each radionuclide in the sample; according to the generation quantity of each radionuclide, an activated product list containing the nuclide types and generation information of the nuclide types is established; A radioactive source term parameter of the sample is calculated from the activation product inventory and decay characteristics of each radionuclide, the radioactive source term parameter comprising a total activity and/or a radiation energy distribution.
2. 2. The method for calculating the source term of the proton and heavy ion irradiation sample according to claim 1, wherein the specific steps of using the three-dimensional particle transport model and combining the nuclear reaction section data of the incident particles and each target nuclear reaction in the sample to perform coupled transport calculation to obtain the generation quantity of each radionuclide in the sample adopts the following formula: ; Wherein, the For the number of i-th radionuclides, For the reaction cross section of the nuclide i, Is the decay constant (s -1 ) of nuclide i, For the beam intensity (a) of the incident particles, The irradiation time(s).
3. 3. The method of claim 2, wherein the total activity is calculated using the formula: ; Wherein, the For the total activity of the radionuclide, Is the activity (Bq) of the ith radionuclide.
4. 4. The method of claim 1, wherein the monte carlo particle transport program is constructed based on Geant4, MCNP or FLUKA software platform.
5. 5. The method for calculating the source term of a proton and heavy ion irradiation sample according to claim 1, wherein the sample comprises any one of stainless steel, tungsten, copper and graphite.
6. 6. The method according to claim 1, wherein the radiation energy distribution is calculated according to the number of radionuclides produced and the radiation information released from each type of nuclides in the standard database according to the nuclide generation ratio.
7. 7. A computer readable storage medium having stored thereon a computer program, which when executed by a processor implements the source item calculation method according to any one of claims 1 to 6.
8. 8. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the source item calculation method of any one of claims 1 to 6 when the computer program is executed by the processor.

Description

Source term calculation method for proton and heavy ion irradiation sample Technical Field The application relates to the technical field of radiation detection, in particular to a source item calculation method for a proton and heavy ion irradiation sample. Background Proton and heavy ion beams are used as important particle irradiation sources, and play an irreplaceable role in the fields of nuclear physical basic research, space radiation effect ground simulation, radioisotope preparation, advanced particle treatment and the like. During these applications, the sample (e.g., a structural material, biological specimen, or therapeutic target) may undergo a complex series of nuclear reactions, including spallation, trapping, fragmentation, etc., upon exposure to energetic protons or heavy ions, resulting in activation of the sample itself, resulting in a variety of radionuclides with different half-lives and decay characteristics. The type, activity and the released radiation energy spectrum of the induced radionuclides, namely 'radioactive source item', are accurately known, and are scientific preconditions for developing subsequent radiation safety protection, radioactive waste classification management, radiation facility operation optimization and experimental data deep analysis. Currently, the industry generally relies on experimental measurement means for radioactive source item determination of samples after proton, heavy ion irradiation, with high purity germanium (HPGe) gamma spectroscopy being most common. The method is characterized in that the nuclide is identified and the activity of the nuclide is calculated by directly measuring the irradiated sample and analyzing the characteristic gamma ray peak of the sample. However, this conventional experimental method has a problem in that the evaluation is seriously delayed and the sample radioactive source item cannot be predicted in advance. Disclosure of Invention In order to solve the defects in the prior art, the application aims to provide a source item calculation method for a proton and heavy ion irradiation sample, which is used for predicting and calculating the radioactive source item of the sample in advance and providing reliable data support for safety design, waste management and experimental analysis. To achieve the above object, the present application provides a source term calculation method of a proton and heavy ion irradiation sample, comprising: Obtaining irradiation condition parameters and sample parameters, wherein the irradiation condition parameters comprise incident particle types, energy distribution, beam intensity, beam spot size, incident angles and total fluence, and the sample parameters comprise a geometric structure model of a sample, material components and nuclide compositions of the components; Based on the irradiation condition parameters and the sample parameters, a Monte Carlo particle transport program is adopted to establish a three-dimensional particle transport model of the sample so as to simulate the transport process of incident particles in the sample; carrying out coupling transport calculation by utilizing the three-dimensional particle transport model and combining nuclear reaction section data of incident particles and target targets in a sample to obtain the generation quantity of each radionuclide in the sample; according to the generation quantity of each radionuclide, an activated product list containing the nuclide types and generation information of the nuclide types is established; A radioactive source term parameter of the sample is calculated from the activation product inventory and decay characteristics of each radionuclide, the radioactive source term parameter comprising a total activity and/or a radiation energy distribution. Further, the specific steps of using the three-dimensional particle transport model to combine the nuclear reaction section data of the incident particles and each target nucleic acid in the sample to perform coupling transport calculation and obtain the generation quantity of each radionuclide in the sample adopt the following formula: ; Wherein, the For the number of i-th radionuclides,For the reaction cross section of the nuclide i,Is the decay constant (s -1) of nuclide i,For the beam intensity (a) of the incident particles,The irradiation time(s). Further, the total activity is calculated using the following formula: ; Wherein, the For the total activity of the radionuclide,Is the activity (Bq) of the ith radionuclide. Further, the Monte Carlo particle transport program is built based on Geant4, MCNP or FLUKA software platforms. Further, the sample includes any one of stainless steel, tungsten, copper and graphite. Furthermore, the radiation energy distribution is calculated according to the production quantity of the radioactive nuclides and the radiation information released by various nuclides in a standard database according to the nuclide generation p