Method for simulating defects of metal tungsten

Abstract

The embodiment of the invention relates to the field of computer material science, in particular to a method for simulating defects of metal tungsten, and the defects are generated when the metal tungsten is irradiated by He ions and W ions. The simulation method comprises the following steps: S1, simulating He ions and W ions to irradiate metal tungsten; s2, determining an off-location damage peak position of the metal tungsten irradiated by the metal tungsten in the step S1; s3, determining a source item of a defect cluster in the metal tungsten at the off-location damage peak position; s4, simplifying the configuration space of the defect cluster; s5, determining reaction coefficients of different types of defect clusters; s6, determining the concentration of the defect cluster in the irradiation time according to the source item, the configuration space and the reaction coefficient; and S7, determining the simulation of the defect of the metal tungsten according to the concentration. According to the simulation method provided by the embodiment of the invention, the accuracy of simulating the defects of the metal tungsten can be improved, and the efficiency of simulating the defects of the metal tungsten can be improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of computer material science, and specifically to a method for simulating defects in metal tungsten. Background Art

[0002] The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] Metal tungsten is an alternative material for the divertor and the first wall of a nuclear fusion reactor. The fusion reaction will generate high-energy neutrons and helium ions. The high-energy neutrons and helium ions will irradiate the metal tungsten, causing a large number of defects in the metal tungsten. These defects will cause the metal tungsten to harden and become brittle, thus affecting its service life.

[0004] In order to design metallic tungsten for nuclear fusion reactors, it is necessary to study the defects produced by irradiating metallic tungsten with high-energy neutrons and helium ions. However, due to the lack of high-energy neutron generation equipment for fusion reactions, it is difficult to accurately study the defects produced in metallic tungsten. Summary of the invention

[0005] A brief overview of the present application is provided below in order to provide a basic understanding of certain aspects of the present application. It should be understood that this overview is not an exhaustive overview of the present application. It is not intended to identify the key or important parts of the present application, nor is it intended to limit the scope of the present application. Its purpose is merely to present certain concepts in a simplified form as a prelude to a more detailed description discussed later.

[0006] The embodiment of the present application provides a method for simulating defects in metal tungsten, and the defects are caused by the metal tungsten being irradiated by He ions and W ions. The simulation method provided by the embodiment of the present application includes the following steps: S1: simulating the irradiation of metal tungsten by He ions and W ions; S2: determining the off-site damage peak position of the metal tungsten after the metal tungsten irradiation in step S1; S3: determining the source term of the defect cluster in the metal tungsten at the off-site damage peak position; S4: simplifying the configuration space of the defect cluster; S5: determining the reaction coefficient of different types of defect clusters; S6: determining the concentration of the defect cluster within the irradiation time according to the source term, the configuration space and the reaction coefficient; S7: determining the simulation of the defect of metal tungsten according to the concentration.

[0007] The simulation method provided in the embodiments of the present application can improve the accuracy of the concentration of determined defect clusters within the irradiation time by determining the off-situ damage peak position, source terms, reaction coefficients of different types of defect clusters, and simplifying the configuration space of defect clusters, which is beneficial to improving the accuracy of the simulation of defects in metal tungsten, and further to improving the accuracy of defect research on metal tungsten; at the same time, by simplifying the configuration space of defect clusters, the configuration space of defect clusters can be effectively simplified, reducing the number of defect clusters that need to be determined, which is beneficial to improving the efficiency of the simulation of defects in metal tungsten. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Other objects and advantages of the present application will become apparent from the following description of the embodiments of the present application with reference to the accompanying drawings, and will help to provide a comprehensive understanding of the present application.

[0009] Figure 1 It is a flowchart of the simulation method provided in the embodiment of the present application.

[0010] Figure 2 is based on Figure 1 The simulation method shown is a schematic flow chart of determining the off-situ damage peak position of metal tungsten after irradiation of metal tungsten in step S1.

[0011] Figure 3 is based on Figure 1 The simulation method shown is a schematic diagram of the flow of determining the source term of the defect cluster at the peak position of the ex-situ damage after He ion irradiation of metal tungsten.

[0012] Figure 4 is based on Figure 1 The simulation method shown is a schematic diagram of the flow of determining the source term of the defect cluster at the peak position of the ex-situ damage after W ion irradiation of metal tungsten.

[0013] Figure 5 is based on Figure 1 Schematic diagram of the simulation method flow for simplifying the configuration space of defect clusters.

[0014] Figure 6 is to use Figure 5 The process shown is a schematic diagram of the configuration space obtained after simplifying the configuration space.

[0015] Description of reference numerals:

[0016] 51. Upper limit of configuration space; 52. Lower limit of configuration space; 53. Configuration space.

[0017] It should be noted that the drawings are not necessarily drawn to scale, but are merely shown in a schematic manner that does not affect the reader's understanding. DETAILED DESCRIPTION

[0018] Exemplary embodiments of the present application will be described below in conjunction with the accompanying drawings. For the sake of clarity and conciseness, not all features of the actual implementation are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the process of developing any such actual implementation in order to achieve the developer's specific goals, such as meeting those constraints related to the system and business, and these constraints may vary from implementation to implementation. In addition, it should be understood that although the development work may be very complex and time-consuming, it is only a routine task for those skilled in the art who benefit from the content of this application.

[0019] It is also necessary to explain here that, in order to avoid obscuring the present application due to unnecessary details, only the device structure and / or processing steps closely related to the scheme according to the present application are shown in the accompanying drawings, while other details that are not very relevant to the present application are omitted.

[0020] The inventors of the present application have discovered that due to the lack of high-energy neutron generation equipment for fusion reactions, it is difficult to conduct a comprehensive study on the defects produced in metal tungsten. Therefore, in order to conduct a comprehensive study on the defects produced in metal tungsten, He ions and W ions are usually used to irradiate metal tungsten and the defects produced by the irradiation are simulated to study the defects in metal tungsten.

[0021] In order to study the defects of metal tungsten in the related art, it is necessary to simulate each defect in the defect configuration space, resulting in a huge number of defects that need to be simulated. The simulation of the defects of metal tungsten is time-consuming and inefficient.

[0022] In order to solve the above problems, an embodiment of the present application provides a method for simulating defects in metal tungsten, where the defects are caused by irradiation of metal tungsten with He ions and W ions. Figure 1 The simulation method provided in the embodiment of the present application may include the following steps: S1: simulating He ion and W ion irradiation of metal tungsten; S2: determining the off-situ damage peak position of the metal tungsten after the metal tungsten irradiation in step S1; S3: determining the source term of the defect clusters in the metal tungsten at the off-situ damage peak position; S4: simplifying the configuration space of the defect clusters; S5: determining the reaction coefficients of different types of defect clusters; S6: determining the concentration of the defect clusters within the irradiation time based on the source term, the configuration space and the reaction coefficient; S7: determining the simulation of the defects of the metal tungsten based on the concentration.

[0023] The simulation method provided in the embodiments of the present application can improve the accuracy of the concentration of determined defect clusters within the irradiation time by determining the off-situ damage peak position, source terms, reaction coefficients of different types of defect clusters, and simplifying the configuration space of defect clusters, which is beneficial to improving the accuracy of the simulation of defects in metal tungsten, and further to improving the accuracy of defect research on metal tungsten; at the same time, by simplifying the configuration space of defect clusters, the configuration space of defect clusters can be effectively simplified, reducing the number of defect clusters that need to be determined, which is beneficial to improving the efficiency of the simulation of defects in metal tungsten.

[0024] In some embodiments, the defects generated by the irradiation of metal tungsten with He ions and W ions may be defect clusters, such as vacancy-helium clusters V x He y , vacancy cluster V x 、Interstitial Cluster I x , monomer defects, etc., wherein x and y are positive integers greater than or equal to 1, and monomer defects may include He1, V1, and I1.

[0025] In some embodiments, in step S1, the order of He ion and W ion irradiation can be first irradiating with He ions and then irradiating with W ions.

[0026] In some embodiments, in step S6, the source term, the configuration space, the reaction coefficient, and the concentration of the defect clusters during the irradiation time satisfy the following expressions:

[0027]

[0028] Among them C i is the concentration of the i-th defect cluster, t is the irradiation time, G i is the source term, L i is the total absorption rate of dislocation, grain boundary and surface to the i-th defect cluster, is the reaction coefficient of defect cluster j combining with defect cluster k to form defect cluster i, is the reaction coefficient of defect cluster i combining with defect cluster j to form defect cluster k, and N is the total number of this type of defect clusters in the configuration space.

[0029] In the related art, the size of defects generated by irradiating metal tungsten with He ions and W ions is small and difficult to observe, for example, a few nanometers to tens of nanometers. When the defect is below 1 nanometer, it is difficult to observe the defect with a transmission electron microscope. In the embodiment of the present application, the concentration of any defect cluster at the irradiation time can be determined through the above expression, which is convenient for studying defects of smaller size, and further helps to improve the accuracy of the simulation of defects of metal tungsten.

[0030] In some embodiments, the simulation of defects in metal tungsten using the simulation method provided in the embodiments of the present application is an ion irradiation simulation performed at room temperature, ignoring all decomposition reactions. In such an embodiment, in the ion irradiation simulation performed at room temperature, the decomposition reaction hardly occurs, so all decomposition reactions can be ignored, which is beneficial to improve the accuracy of the total number of defect clusters in the configuration space.

[0031] See also Figure 2 In some embodiments, the step S2 may further include: S21, determining the irradiation energy of He ions and W ions; S22, determining the off-site damage distribution of the metal tungsten after irradiation by He ions and W ions according to the irradiation energy; S23, determining the off-site damage peak according to the off-site damage distribution; S24, determining the off-site damage peak position in step S23. In such an embodiment, the off-site damage peak position of the irradiated metal tungsten can be determined through the above steps.

[0032] In some embodiments, since the off-site damage of the metal tungsten after ion irradiation is very shallow (the off-site damage is close to the surface of the metal tungsten, and the depth is usually in the micrometer range), the off-site damage is difficult to observe. Therefore, in step S22, the SRIM software can be used to calculate and determine the off-site damage distribution of the metal tungsten after the He ions and W ions are irradiated to the metal tungsten according to the irradiation energy. In some embodiments, the damage depth distribution curve of the metal tungsten after the He ions and W ions are irradiated to the metal tungsten is obtained by calculation, and the off-site damage distribution of the metal tungsten after the He ions and W ions are irradiated to the metal tungsten is determined according to the damage depth distribution curve. Since the off-site damage at different depths is different, in order to facilitate the simulation of the defects of the metal tungsten, the off-site damage peak, that is, the maximum value point on the damage depth distribution curve, can be selected to simulate the defects of the metal tungsten.

[0033] In some embodiments, in order to approach the spatial uniformity of defects produced by high-energy neutron irradiation, the irradiation sequence and irradiation time of He ions and W ions can be designed so that the ex-situ damage peak values ​​of metal tungsten after irradiation by He ions and W ions are almost the same.

[0034] See also Figure 3In some embodiments, in step S3, it may also include: S31, determining the probability distribution of off-situ damage energy of metal tungsten after irradiation by He ions based on the irradiation energy of step S21; S32, determining the off-situ damage energy based on the probability distribution of off-situ damage energy of step S31; S33, determining the off-situ damage position of the off-situ damage energy of step S32; S34, determining the size distribution of cascade defect clusters at the off-situ damage position of step S33; S35: determining the irradiation dose and irradiation time of He ions; S36: determining the He ion concentration at the off-situ damage peak position of metal tungsten after irradiation by He ions; S37: determining the source term of the defect cluster at the off-situ damage peak position after irradiation by He ions based on the off-situ damage energy probability distribution of step S31, the cascade defect cluster size distribution of step S34, the irradiation dose and irradiation time of He ions in step S35 and the He ion concentration in step S36. In such an embodiment, the above steps can determine the source term of the defect cluster at the peak position of the ex-situ damage of the metal tungsten after He ion irradiation based on the peak position of the ex-situ damage of the metal tungsten after He ion irradiation.

[0035] In some embodiments, in step S31, SRIM software can also be used to determine the probability distribution of off-situ damage energy of metal tungsten after He ion irradiation based on the irradiation energy.

[0036] In some embodiments, in step S32, the off-situ damage energy may be 10 typical damage energies randomly selected from the off-situ damage energy probability distribution in step S31.

[0037] In some embodiments, in step S34, 10 off-site damage positions with typical damage energies may be used to perform room temperature cascade collision simulations using molecular dynamics to determine the size distribution of cascade defect clusters at the off-site damage positions.

[0038] In some embodiments, in step S36, SRIM software can also be used to determine the He ion depth distribution after He ion irradiation of metal tungsten by calculation based on the irradiation energy; and determine the He ion concentration at the ex-situ damage peak position based on the He ion depth distribution and the ex-situ damage peak position.

[0039] In some embodiments, in step S37, the cascade defect cluster size distribution of step S34 can be weighted by the off-situ damage energy probability distribution of step S31, and then combined with the He ion irradiation dose and irradiation time of step S35 and the He ion concentration of step S36 to determine the source term of the defect cluster in the metal tungsten at the off-situ damage peak position after He ion irradiation of the metal tungsten.

[0040] In some embodiments, in step S37, the source item may include vacancy clusters V in metal tungsten after He ion irradiation. x 、Interstitial Cluster I x and the source term of He1.

[0041] See also Figure 4 In some embodiments, in step S3, the following may be included: S31: Determine the probability distribution of off-site damage energy of metal tungsten after irradiation by W ions according to the irradiation energy of step S21; S32: Determine the off-site damage energy according to the probability distribution of off-site damage energy of step S31; S33: Determine the off-site damage position of the off-site damage energy of step S32; S34: Determine the size distribution of cascade defect clusters at the off-site damage position of step S33; S35: Determine the irradiation dose and irradiation time of W ions; S36: Determine the source term of the defect cluster at the off-site damage peak position after irradiation by W ions according to the probability distribution of off-site damage energy of step S31, the size distribution of cascade defect clusters of step S33, and the irradiation dose and irradiation time of W ions of step S35. In such an embodiment, the above steps can determine the source term of the defect cluster at the off-site damage peak position of metal tungsten after irradiation by W ions according to the off-site damage peak position of metal tungsten after irradiation by W ions.

[0042] In some embodiments, in step S31, SRIM software may be used to determine the probability distribution of off-situ damage energy of metal tungsten after irradiation of metal tungsten by W ions according to the irradiation energy.

[0043] In some embodiments, in step S32, the off-situ damage energy may be 10 typical damage energies randomly selected from the off-situ damage energy probability distribution in step S31.

[0044] In some embodiments, in step S34, 10 off-site damage positions with typical damage energies may be used to perform room temperature cascade collision simulations using molecular dynamics to determine the size distribution of cascade defect clusters at the off-site damage positions.

[0045] In some embodiments, in step S36, the cascade defect cluster size distribution of step S34 can be weighted by the off-situ damage energy probability distribution of step S31, and then combined with the irradiation dose and irradiation time of W ions in step S35 to determine the source term of the defect cluster in the metal tungsten at the off-situ damage peak position after the W ion irradiation of the metal tungsten.

[0046] In some embodiments, in step S36, the source item may include vacancy clusters V in the metal tungsten after W ion irradiation. x and interstitial cluster I x The source term.

[0047] In some embodiments, the configuration space of the defect cluster may be a two-dimensional space. In some embodiments, an xoy coordinate system may be established in the configuration space of the defect cluster to characterize the position of the defect cluster in the configuration space by the two-dimensional coordinates (x, y) of the defect space.

[0048] See also Figure 5 In some embodiments, the step S4 may further include: S41: Ignore I x He y and I x He y V z Cluster; S42: Determine V x He y The upper limit of the cluster configuration space; S43: Determine V x He y The lower limit of the configuration space of the cluster.

[0049] In order to simulate the defects of metal tungsten, it is necessary to determine the concentration of each defect cluster in the configuration space. x He y Clusters, the number of defect clusters to be determined is x*y. Assume that the largest vacancy-helium cluster is V 272 He 816 , the number of defect clusters that need to be determined is 221952, which makes the simulation efficiency of defects in metal tungsten low.

[0050] In such an embodiment, the configuration space of defect clusters can be effectively simplified through the above steps, and it is also possible to simulate higher He ion and W ion irradiation energies in a shorter time through the simulation method provided in the embodiment of the present application.

[0051] In some embodiments, the vacancy-helium cluster V x He y A capture mutation reaction will occur in the configuration space. When the capture mutation reaction occurs, the vacancy-helium cluster V x He y It absorbs helium clusters He y Then the interstitial atoms are squeezed out, making the vacancy-helium cluster V x He y The volume of the vacancy-helium cluster V x He y The capture mutation reaction will occur continuously, making the vacancy-helium cluster V x He y The volume continues to increase.

[0052] Specifically, the reaction process of the captured mutation reaction can be reflected by the following reaction formula:

[0053] He z +V x He y →V x He z+y →V x+1 He z+y +I1,

[0054] Wherein, x, y and z are all positive integers greater than or equal to 1.

[0055] The continuous occurrence of the capture mutation reaction is due to the vacancy-helium cluster V x He y The gas pressure in the air is too high, and the vacancy-helium cluster V can be enlarged by squeezing out the interstitial atoms. x He y The volume of the vacancy-helium cluster V x He y The gas pressure in the vacancy-helium cluster V x He y It can continue to absorb helium clusters and continuously undergo capture mutation reactions.

[0056] In some embodiments, at room temperature, the vacancy clusters in the metallic tungsten hardly diffuse, and the vacancy-helium clusters V x He y The vacancy clusters in the lattice are almost all obtained through capture mutation reactions. Therefore, when simplifying the configuration space of defect clusters, it is necessary to consider the vacancy-helium cluster V x He y The captured mutation reaction.

[0057] In some embodiments, in step S41, molecular dynamics simulation can be used to capture the mutation reaction and establish V x He y The relationship between the x-coordinate and the y-coordinate of the cluster, V x He y The upper limit of the configuration space of the cluster. In the xoy coordinate system, clusters above the upper limit of the configuration space are unstable due to capture mutation reactions and can be regarded as non-existent.

[0058] In some embodiments, the diffusion of vacancy clusters can be neglected and V is established based on the capture mutation reaction. x He y The relationship between the x-coordinate and the y-coordinate of the cluster, V x He y The lower limit of the configuration space of the cluster. In the xoy coordinate system, clusters below the lower limit of the configuration space cannot be formed by capture mutation reactions.

[0059] In some embodiments, step S4 may further include determining the total number of each defect cluster in the simplified configuration space.

[0060] In some embodiments, in step S5, the following may be further included: S51: determining that the type of defect cluster is one of helium cluster and interstitial cluster; S52: determining the capture radius and diffusion coefficient of the defect cluster in step S51; S53: determining the capture radius and diffusion coefficient of the reactant that reacts with the defect cluster in step S51. In such an embodiment, the type of defect cluster can be determined through the above steps, which is conducive to determining the reaction coefficients of different types of defect clusters.

[0061] At room temperature, different types of defect clusters in tungsten metal diffuse differently. For example, interstitial cluster I x It will diffuse in one dimension along the close-packed direction of the lattice

[111] . The helium cluster He in the metal tungsten y Three-dimensional diffusion will occur. Since the collision free paths of three-dimensional diffusion and one-dimensional diffusion are different, the reaction coefficients of different types of defect clusters are determined differently. Therefore, when determining the reaction coefficient of a defect cluster, it is necessary to first determine the type of defect cluster.

[0062] In some embodiments, in step S53, the reactants reacting with the helium clusters or interstitial clusters may be helium clusters, vacancy clusters, and vacancy-helium clusters.

[0063] In one embodiment, when the type of the defect cluster in step S51 is a helium cluster, step S5 may further include: S54: determining the reaction coefficient of the defect cluster according to the capture radius and diffusion coefficient of the defect cluster in step S52 and the capture radius and diffusion coefficient of the reactant in step S53. In such an embodiment, the reaction coefficient of the helium cluster can be determined through the above steps.

[0064] In some embodiments, in step S54, the determined reaction coefficients may include: reaction coefficients between helium clusters and helium clusters, reaction coefficients between helium clusters and vacancy clusters, and reaction coefficients between helium clusters and vacancy-helium clusters.

[0065] In some embodiments, the reaction coefficient K of the helium cluster and the reactant may satisfy the following expression:

[0066] K = 4π(R1+R2)(D1+D2),

[0067] Where R1 is the capture radius of the helium cluster, R2 is the capture radius of the reactant, D1 is the diffusion coefficient of the helium cluster, and D2 is the diffusion coefficient of the reactant.

[0068] In some embodiments, when the type of defect cluster in step S51 is an interstitial cluster, in step S5, the following may be further included: S54: determining the type of reactant in step S53; S55: determining the reaction coefficient of the defect cluster according to the capture radius and diffusion coefficient of the defect cluster in step S52, the capture radius and diffusion coefficient of the reactant in step S53, and the type of the reactant in step S53. In such an embodiment, the reaction coefficient of the interstitial cluster can be determined through the above steps.

[0069] In some embodiments, in step S54, the determined reaction coefficients may include: reaction coefficients between interstitial clusters and interstitial clusters, reaction coefficients between interstitial clusters and vacancy clusters, and reaction coefficients between interstitial clusters and vacancy-helium clusters.

[0070] In some embodiments, the reaction coefficient K between interstitial clusters may satisfy the following expression:

[0071]

[0072] Where R1 and R2 are the capture radii of interstitial clusters, D1 and D2 are the diffusion coefficients of interstitial clusters, and C1 and C2 are the concentrations of interstitial clusters.

[0073] When using the above expression to determine the reaction coefficient K between interstitial clusters, it is necessary to satisfy D1≥D2. If not, the rightmost term of the above expression is

[0074] In some embodiments, the reaction coefficients of interstitial clusters with vacancy clusters and the reaction coefficients K of interstitial clusters with vacancy-helium clusters may satisfy the following expressions:

[0075] K=6π 2 D(R1+R2) 2 ∑ s C s (R1+R s ) 2 ,

[0076] Where D represents the diffusion coefficient of the interstitial cluster, C s is the concentration of all defect clusters that react with interstitial clusters, including the concentration of vacancy clusters, the concentration of vacancy-helium clusters, and the concentration of interstitial clusters, R sis the capture radius of the defect cluster that reacts with the interstitial cluster, R1 is the capture radius of the interstitial cluster, and R2 is the capture radius of the reactant that reacts with the interstitial cluster. Among them, the reaction coefficient between the interstitial cluster and the reactant depends not only on the characteristics of the interstitial cluster and the reactant, but also on the characteristics of other reactants that can react with the interstitial cluster. To ensure the accuracy of the reaction coefficient K, it is necessary to traverse all defect clusters that can react with the interstitial cluster.

[0077] In some embodiments, step S5 may further include: ignoring the absorption of He clusters by dislocations, grain boundaries and surfaces; and determining reaction coefficients of interstitial clusters reacting with dislocations, grain boundaries and surfaces.

[0078] In some embodiments, the reaction coefficient of the interstitial clusters reacting with the dislocations may satisfy the following expression:

[0079]

[0080] Where D is the diffusion coefficient of the interstitial cluster, ρ is the dislocation density, and r d represents the dislocation core radius.

[0081] In some embodiments, the reaction coefficient of the interstitial clusters reacting with the grain boundaries may satisfy the following expression:

[0082]

[0083] Where D represents the diffusion coefficient of the interstitial cluster, R gb Represents the grain radius.

[0084] In some embodiments, the reaction coefficient of the interstitial clusters reacting with the surface may satisfy the following expression:

[0085]

[0086] Where D represents the diffusion coefficient of the interstitial clusters and l represents the thickness of the metal tungsten.

[0087] In some embodiments, the reaction coefficients between interstitial clusters and interstitial clusters, the reaction coefficients between interstitial clusters and vacancy clusters, and the reaction coefficients between interstitial clusters and vacancy-helium clusters can change with the change of irradiation time. Substituting the above reaction coefficients into the relationship between the source term, configuration space, reaction coefficient and the concentration of defect clusters during the irradiation time, a series of ordinary differential equations with different coefficients can be obtained. These equations can constitute a set of variable coefficient ordinary differential equations.

[0088] In some embodiments, the total absorption rate L of dislocations, grain boundaries, and surfaces for the i-th defect cluster is iIt can be determined based on the reaction coefficient associated with defect cluster i and the diffusion coefficient of defect cluster i.

[0089] In some embodiments, the ion irradiation time, the concentration corresponding to each defect cluster, the source term, the total number in the configuration space, and the reaction coefficient can be substituted into the relationship between the source term, the configuration space, the reaction coefficient, and the concentration of the defect clusters during the irradiation time to obtain a differential equation related to the concentration of each defect cluster during the irradiation time, and then a group of differential equations related to the concentration of each defect cluster during the irradiation time can be obtained. By solving the above group of differential equations, the defects of metal tungsten can be simulated.

[0090] In some embodiments, the initial state value of the differential equation group can be set to 0, and the final state value of the differential equation group is obtained by solving the differential equation group, thereby realizing the simulation of the defects of metal tungsten in the He ion irradiation stage; the final state value of the equation group obtained by the above solution is set to the initial state value of the equation group when solving it again, and the differential equation group is solved again to obtain the final state value of the differential equation group under this initial state value, thereby realizing the simulation of the defects of metal tungsten in the W ion irradiation stage; the above two simulation processes are combined to complete the entire simulation of the defects of metal tungsten, wherein the differential equation group can be solved by calling the open source differential equation solver LSODA or SUNDIALS.

[0091] The process of simulating defects in metal tungsten is described in detail below.

[0092] The irradiation of metal tungsten by He ions with an irradiation energy of 200keV and W ions with an irradiation energy of 4MeV was simulated, and the off-situ damage distribution, off-situ damage energy probability distribution and He ion concentration at the off-situ damage peak position of metal tungsten after He ion irradiation were calculated by SRIM software, and then the source term after He ion irradiation and the source term after W ion irradiation were determined. Taking He ion irradiation as an example, under 200keV He ion irradiation, the off-situ damage peak is about 10keV. Molecular dynamics is used to simulate cascade collisions at 1-10keV energy to obtain the size distribution of cascade defect clusters, and then weighted by the damage energy probability distribution to obtain the source term after He ion irradiation.

[0093] Afterwards, the configuration space of defect clusters is simplified, see Figure 6 , with y = 5x 0.86 As the upper limit of the configuration space, y = 5(x-1) 0.86 +1 is used as the lower limit 52 of the configuration space, and the configuration space 53 is simplified to obtain the simplified configuration space 53.

[0094] Then, the reaction coefficient of each defect cluster is calculated according to the expression satisfied by the reaction coefficients of different types of defect clusters.

[0095] Afterwards, the concentration of each defect cluster is determined, expressed as V n He m For example, due to the lower limit of the configuration space, interstitial clusters cannot be absorbed, otherwise a capture mutation reaction will occur immediately after absorption to release interstitial atoms; and since vacancy clusters do not diffuse at room temperature, only V n He m The reaction between clusters and helium clusters, combined with the above, is related to V n He m The differential equation for the concentration of clusters during the irradiation time is:

[0096]

[0097] Afterwards, the open source differential equation solver LSODA or SUNDIALS is used to simulate the He and W ion irradiation stages, respectively, to obtain the simulation of the defects of metal tungsten.

[0098] Regarding the embodiments of the present application, it should also be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other to obtain new embodiments.

[0099] The above are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. The protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for simulating defects in metal tungsten, wherein the defects are caused by irradiation of the metal tungsten with He ions and W ions, characterized in that: It includes the following steps: S1: simulating the He ions and the W ions irradiating the metal tungsten; S2: determining the off-site damage peak position of the metal tungsten after the metal tungsten is irradiated in step S1; S3: determining the source term of the defect cluster in the metal tungsten at the off-situ damage peak position; S4: simplifying the configuration space of the defect clusters; S5: determining the reaction coefficients of different types of defect clusters; S6: determining the concentration of the defect clusters within the irradiation time according to the source term, the configuration space and the reaction coefficient; S7: Determine a simulation of defects of the metal tungsten according to the concentration.

2. The method according to claim 1, characterized in that In step S6, the source term, the configuration space, the reaction coefficient, and the concentration of the defect clusters during the irradiation time satisfy the following expressions: Among them C i is the concentration of the i-th defect cluster, t is the irradiation time, G i is the source term, L i is the total absorption rate of dislocation, grain boundary and surface to the i-th defect cluster, is the reaction coefficient of defect cluster j combining with defect cluster k to form defect cluster i, is the reaction coefficient of defect cluster i combining with defect cluster j to form defect cluster k, and N is the total number of defect clusters in the configuration space.

3. The method according to claim 2, characterized in that The simulations are ion irradiation simulations performed at room temperature, ignoring all decomposition reactions.

4. The method according to claim 1, characterized in that: In step S2, it also includes: S21, determining the irradiation energy of the He ions and the W ions; S22, determining, according to the irradiation energy, the off-situ damage distribution of the metal tungsten after the metal tungsten is irradiated by the He ions and the W ions; S23, determining an off-site damage peak value according to the off-site damage distribution; S24, determining the off-site damage peak position in step S23.

5. The method according to claim 4, characterized in that In the S3 step, it also includes: S31, determining the probability distribution of off-situ damage energy of the metal tungsten after the metal tungsten is irradiated by the He ions according to the irradiation energy of step S21; S32, determining the off-site damage energy according to the off-site damage energy probability distribution in step S31; S33, determining the off-site damage position of the off-site damage energy in step S32; S34, determining the size distribution of the cascade defect clusters at the off-site damage position of step S33; S35: Determine the irradiation dose and irradiation time of the He ions; S36: determining the He ion concentration at the peak position of the off-situ damage to the metal tungsten after the metal tungsten is irradiated by the He ions; S37: According to the off-situ damage energy probability distribution of step S31, the cascade defect cluster size distribution of step S34, the He ion irradiation dose and irradiation time of step S35 and the He ion concentration of step S36, determine the source term of the defect cluster at the off-situ damage peak position after the He ions irradiate the metal tungsten.

6. The method according to claim 4, characterized in that In the S3 step, it also includes: S31, determining the probability distribution of off-situ damage energy of the metal tungsten after the metal tungsten is irradiated by the W ions according to the irradiation energy of step S21; S32, determining the off-site damage energy according to the off-site damage energy probability distribution in step S31; S33, determining the off-site damage position of the off-site damage energy in step S32; S34, determining the size distribution of the cascade defect clusters at the off-site damage position of step S33; S35: Determine the irradiation dose and irradiation time of the W ions; S36: According to the off-situ damage energy probability distribution of step S31, the cascade defect cluster size distribution of step S33, and the irradiation dose and irradiation time of the W ions in step S35, determine the source term of the defect cluster at the off-situ damage peak position after the W ions irradiate the metal tungsten.

7. The method according to claim 1, characterized in that The configuration space of the defect cluster is a two-dimensional space; In step S4, it also includes: S41: Ignore I x He y and I x He y V z Clusters; S42: Determine V x He y The upper limit of the cluster's configuration space; S43: Determine V x He y The lower limit of the configuration space of the cluster.

8. The method according to claim 1, characterized in that In step S5, it also includes: S51: Determine that the type of the defect cluster is one of a helium cluster and an interstitial cluster; S52: Determine the capture radius and diffusion coefficient of the defect cluster in step S51; S53: Determine the capture radius and diffusion coefficient of the reactants that react with the defect clusters in step S51.

9. The method according to claim 8, characterized in that When the type of the defect cluster in step S51 is a helium cluster, step S5 further includes: S54: Determine the reaction coefficient of the defect cluster according to the capture radius and diffusion coefficient of the defect cluster in step S52 and the capture radius and diffusion coefficient of the reactant in step S53.

10. The method according to claim 8, characterized in that When the type of the defect cluster in step S51 is a gap cluster, step S5 further includes: S54: Determine the type of the reactant in step S53; S55: Determine the reaction coefficient of the defect cluster according to the capture radius and diffusion coefficient of the defect cluster in step S52, the capture radius and diffusion coefficient of the reactant in step S53, and the type of the reactant in step S53.

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