Sputtering corrosion integrated simulation calculation method and system for ion engine grid electrode assembly

Abstract

The invention discloses an ion engine grid electrode assembly sputtering corrosion integrated simulation calculation method and system, and the method comprises the steps: building an ion-atom collision physical model through employing a molecular dynamics method, and obtaining a scattering angle parameter of incident particles in a target material; calculating the differential sputtering yield of the gate material, and obtaining the angular distribution characteristics of sputtering target atoms in the space under different incident angles; performing spatial integration on the differential sputtering yield of the gate material to obtain the total sputtering yield of the gate material; and establishing a PIC-MCC numerical calculation simulation model based on a PIC-MCC method, substituting the calculated gate material sputtering atom spatial distribution and total sputtering yield formula into the PIC-MCC numerical calculation simulation model as boundary conditions, establishing a gate assembly sputtering corrosion integrated simulation model, and calculating the corrosion morphology of the gate. According to the method, rapid, accurate and integrated pre-estimation calculation of the sputtering and corrosion processes of the grid electrode assembly is realized.

Description

Technical Field

[0001] The present invention belongs to the field of sputtering corrosion of ion engine grid components, and in particular relates to an integrated simulation calculation method and system for sputtering corrosion of ion engine grid components. Background Art

[0002] Ion engines are widely used in deep space exploration due to their high specific impulse, long life, and ability to be repeatedly started. The grid system is a key component for accelerating ions and generating thrust. As the thruster runs, the acceleration grid will corrode and degrade, leading to corrosion failure of the grid component, which seriously restricts the performance and service life of the ion thruster.

[0003] In order to explore deeper into the universe, the grid system needs to have a longer working life. At present, the working life of the grid is generally extended by replacing the metal molybdenum with carbon-carbon material, but this also makes the full life estimation test of the grid component time-consuming, inefficient and costly. In order to speed up the design optimization and model iteration of the ion engine grid component, it is urgent to analyze and estimate the working performance and working life of the ion grid component in a shorter time.

[0004] At present, the research on carbon-carbon gate sputtering at home and abroad is mainly focused on the component level and material level. In the research on the gate component corrosion level, the redeposition effect of sputtered atoms is not taken into account, resulting in the low accuracy of the gate component corrosion morphology predicted by the current simulation model. In the research on the sputtering damage level of gate materials, the current research is mainly focused on experiments, and the experiments are mainly based on the measurement of total sputtering yield, lacking the study of the spatial distribution law of sputtering atoms under different ion incident states. In order to accurately evaluate the sputtering corrosion morphology of gate components, it is necessary to start from the gate material level and calculate the spatial distribution law of sputtering target atoms under different ion incident energies and angles, so as to establish an integrated simulation calculation method from gate material sputtering damage to gate component sputtering corrosion, and realize high-precision prediction of gate component corrosion morphology and service life. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention proposes an integrated simulation calculation method and system for the sputtering corrosion of the gate assembly of an ion engine. This method can not only improve the simulation accuracy of the gate assembly life, but also study the evolution law of sputtering corrosion of the gate assembly surface morphology under different gate structures and operating parameters, obtain the core influencing factors affecting the corrosion of the gate assembly, and provide effective methods to inhibit sputtering corrosion, thereby realizing fast, accurate and integrated estimation and calculation of the sputtering and corrosion process of the gate assembly.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] An integrated simulation calculation method for sputtering corrosion of an ion engine grid assembly comprises the following steps:

[0008] S1: Taking the carbon-carbon gate of the ion engine as the research object, starting from the carbon-carbon gate material, by using the molecular dynamics method, the ion-atom collision physical model is established to solve the cascade collision process of the incident ions inside the gate material, and obtain the scattering angle parameters of the incident particles inside the target material;

[0009] S2: Calculate the differential sputtering yield of the gate material based on the scattering angle parameters of the incident particles inside the target material, and obtain the angular distribution characteristics of the sputtering target atoms in space under different incident angles;

[0010] S3: According to the angular distribution characteristics of the sputtering target atoms in space at different incident angles, the differential sputtering yield of the gate material is spatially integrated to obtain the total sputtering yield of the gate material;

[0011] S4: A PIC-MCC numerical calculation simulation model is established based on the PIC-MCC method. The calculated spatial distribution of sputtered atoms of the gate material and the total sputtering yield formula are substituted into the PIC-MCC numerical calculation simulation model as boundary conditions to establish an integrated simulation model of sputtering corrosion of the gate component. Based on the integrated simulation model of sputtering corrosion of the gate component, the corrosion morphology of the gate is calculated.

[0012] Preferably, in S1, the method for obtaining the scattering angle parameters of the incident particles inside the target material comprises:

[0013]

[0014] In the formula, θ CM is the scattering angle in the center-of-mass system, p is the collision parameter, r0 is the closest distance between the two nuclei, V(r) is the shielding interatomic potential, and E C is the kinetic energy of the incident ion in the center-of-mass system, and r is the distance between atoms.

[0015] Preferably, in S2, the method for obtaining the angular distribution characteristics of the sputtering target atoms in space at different incident angles includes:

[0016]

[0017] Where N a is the total number of sputtered atoms collected, N is the total number of sputtered atoms leaving the target, θ is the angle between the da area and the target surface normal, It is the angle between the projection of area da in the xy plane and the y-axis. a is the subscript of N, which is the abbreviation of the word area.

[0018] Preferably, in S3, the method for obtaining the total sputtering yield of the gate material comprises:

[0019] Y(E,θ)=Y(E,0)·Y′,

[0020] Among them, Y(E,0) is the relationship between the total sputtering yield Y and the ion incident energy, In the formula, S n is the nuclear stopping cross section, which is based on the krypton-carbon KC potential, Q is the empirical proportional parameter, and E th is the threshold energy, μ is the empirical index, λ is used to trigger the start of the decrease, ∈ is the reduced energy, and w is an intermediate parameter with no meaning;

[0021] Y′ is the relationship between the total sputtering yield and angle, Where a is the expected energy range, α and β are the scattering range of ions along the incident direction and the scattering range of ions perpendicular to the incident direction, respectively, and A is an intermediate parameter with no meaning.

[0022] Preferably, in S4, the method for realizing integrated simulation calculation from gate material sputtering damage to gate component corrosion morphology prediction includes:

[0023] S41: throwing ions from the left boundary of the computational domain;

[0024] S42: Solve the electric potential of each grid point in the calculation domain to obtain the grid electric field distribution;

[0025] S43: Drive the particle motion in the calculation domain according to Newton's laws of motion to obtain the current velocity and position information;

[0026] S44: performing charge exchange collision to generate charge exchange ions;

[0027] S45: Count the total number of particles in the calculation domain, and proceed to the next step when the number change is less than 1‰, otherwise repeat S41 to S44;

[0028] S46: compare the current beam current with the beam current setting value, and proceed to the next step if the difference is within 1%, otherwise repeat S41 to S45;

[0029] S47: Count the amount of corrosion caused by the charge exchange ions on the gate, and calculate the deposition rate of the sputtered atoms on the gate to obtain the time required to corrode a single grid;

[0030] S48: Repeating the processes S41 to S47 under the new gate morphology;

[0031] S49: The calculation ends when the gate corrosion setting time is reached.

[0032] The present invention also provides an integrated simulation and calculation system for sputtering corrosion of an ion engine grid assembly, comprising: a scattering angle parameter acquisition module, an angular distribution characteristic acquisition module, a total sputtering yield acquisition module, and an integrated simulation and calculation module;

[0033] The scattering angle parameter acquisition module is used to take the carbon-carbon gate of the ion engine as the research object, starting from the carbon-carbon gate material, by adopting the molecular dynamics method, establish an ion-atom collision physical model, solve the cascade collision process of the incident ions inside the gate material, and obtain the scattering angle parameters of the incident particles inside the target material;

[0034] The angular distribution characteristic acquisition module is used to calculate the differential sputtering yield of the gate material according to the scattering angle parameters of the incident particles inside the target material, and obtain the angular distribution characteristics of the sputtering target atoms in space under different incident angles;

[0035] The total sputtering yield acquisition module is used to spatially integrate the differential sputtering yield of the gate material according to the angular distribution characteristics of the sputtering target atoms in space at different incident angles to obtain the total sputtering yield of the gate material;

[0036] The integrated simulation calculation module is used to establish a PIC-MCC numerical calculation simulation model based on the PIC-MCC method, and the calculated spatial distribution of sputtering atoms of the gate material and the total sputtering yield formula are substituted into the PIC-MCC numerical calculation simulation model as boundary conditions to establish an integrated simulation model of sputtering corrosion of the gate component. Based on the integrated simulation model of sputtering corrosion of the gate component, the corrosion morphology of the gate is calculated.

[0037] Preferably, in the scattering angle parameter acquisition module, the process of obtaining the scattering angle parameters of incident particles inside the target material includes:

[0038]

[0039] In the formula, θ CM is the scattering angle in the center-of-mass system, p is the collision parameter, r0 is the closest distance between the two nuclei, V(r) is the shielding interatomic potential, and E C is the kinetic energy of the incident ion in the center-of-mass system, and r is the distance between atoms.

[0040] Preferably, in the angular distribution characteristic acquisition module, the process of obtaining the angular distribution characteristics of the sputtering target atoms in space at different incident angles includes:

[0041]

[0042] Where N a is the total number of sputtered atoms collected, N is the total number of sputtered atoms leaving the target, θ is the angle between the da area and the target surface normal, It is the angle between the projection of area da in the xy plane and the y-axis. a is the subscript of N, which is the abbreviation of the word area.

[0043] Preferably, in the total sputtering yield obtaining module, the process of obtaining the total sputtering yield of the gate material includes:

[0044] Y(E,θ)=Y(E,0)·Y′,

[0045] Among them, Y(E,0) is the relationship between the total sputtering yield Y and the ion incident energy, In the formula, S n is the nuclear stopping cross section, which is based on the krypton-carbon KC potential, Q is the empirical proportional parameter, and E th is the threshold energy, μ is the empirical index, λ is used to trigger the start of the decrease, ∈ is the reduced energy, and w is an intermediate parameter with no meaning;

[0046] Y′ is the relationship between the total sputtering yield and angle, Where a is the expected energy range, α and β are the scattering range of ions along the incident direction and the scattering range of ions perpendicular to the incident direction, respectively, and A is an intermediate parameter with no meaning.

[0047] Preferably, in the integrated simulation calculation module, the process of implementing the integrated simulation calculation from the sputtering damage of the gate material to the prediction of the corrosion morphology of the gate component includes:

[0048] S41: throwing ions from the left boundary of the computational domain;

[0049] S42: Solve the electric potential of each grid point in the calculation domain to obtain the grid electric field distribution;

[0050] S43: Drive the particle motion in the calculation domain according to Newton's laws of motion to obtain the current velocity and position information;

[0051] S44: performing charge exchange collision to generate charge exchange ions;

[0052] S45: Count the total number of particles in the calculation domain, and proceed to the next step when the number change is less than 1‰, otherwise repeat S41 to S44;

[0053] S46: compare the current beam current with the beam current setting value, and proceed to the next step if the difference is within 1%, otherwise repeat S41 to S45;

[0054] S47: Count the amount of corrosion caused by the charge exchange ions on the gate, and calculate the deposition rate of the sputtered atoms on the gate to obtain the time required to corrode a single grid;

[0055] S48: Repeating the processes S41 to S47 under the new gate morphology;

[0056] S49: The calculation ends when the gate corrosion setting time is reached.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] The present invention discloses an integrated simulation calculation method and system for sputtering corrosion of an ion engine grid assembly. By simulating the probability distribution of sputtering atoms of carbon-carbon materials under different ion incident energies and azimuths, an integrated simulation model is built in combination with the PIC-MCC method, and the dynamic evolution of the grid morphology and the re-deposition process of the sputtered atoms are considered, thereby improving the simulation accuracy of the life of the grid assembly. Based on the study of the sputtering corrosion evolution law of the grid assembly surface morphology under different grid structures (screen grid aperture and thickness, acceleration grid aperture and thickness, grid spacing) and operating parameters (screen grid and acceleration grid voltage, upstream plasma density, background gas pressure), the core influencing factors affecting the corrosion of the grid assembly are obtained, and an effective method for inhibiting sputtering corrosion is given. For the first time, the simulation integration from the gate material to the grid assembly is realized, which greatly reduces the cost of the grid assembly life assessment and provides guidance for the design of long-life ion engine grid assemblies. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0060] Figure 1 A schematic diagram of a flow chart of an integrated simulation calculation method for sputtering corrosion of an ion engine grid assembly according to an embodiment of the present invention;

[0061] Figure 2 Schematic diagram of a differential sputtering yield evaluation model according to an embodiment of the present invention;

[0062] Figure 3 It is a schematic diagram of a two-dimensional axisymmetric grid center hole plasma simulation calculation domain according to an embodiment of the present invention;

[0063] Figure 4 This is a flow chart of an integrated calculation method for sputtering corrosion of an ion engine grid assembly according to an embodiment of the present invention. DETAILED DESCRIPTION

[0064] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0065] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0066] Embodiment 1

[0067] like Figure 1 As shown, the present invention provides an integrated simulation calculation method for sputtering corrosion of an ion engine grid assembly, comprising the following steps:

[0068] S1: Taking the carbon-carbon gate of the ion engine as the research object, starting from the carbon-carbon gate material, by using the molecular dynamics method, the ion-atom collision physical model is established to solve the cascade collision process of the incident ions inside the gate material, and obtain the scattering angle parameters of the incident particles inside the target material;

[0069] S2: Calculate the differential sputtering yield of the gate material based on the scattering angle parameters of the incident particles inside the target material, and obtain the angular distribution characteristics of the sputtering target atoms in space under different incident angles;

[0070] S3: According to the angular distribution characteristics of the sputtering target atoms in space at different incident angles, the differential sputtering yield of the gate material is spatially integrated to obtain the total sputtering yield of the gate material;

[0071] S4: A PIC-MCC numerical calculation simulation model is established based on the PIC-MCC method. The calculated spatial distribution of sputtered atoms of the gate material and the total sputtering yield formula are substituted into the PIC-MCC numerical calculation simulation model as boundary conditions to establish an integrated simulation model of sputtering corrosion of the gate component. Based on the integrated simulation model of sputtering corrosion of the gate component, the corrosion morphology of the gate is calculated.

[0072] In this embodiment, S1: taking the carbon-carbon gate of the ion engine as the research object, starting from the carbon-carbon gate material, by adopting the molecular dynamics method, a physical model of ion-atom collision is established, the cascade collision process of the incident ions inside the gate material is solved, and the scattering angle parameters of the incident particles inside the target material are obtained.

[0073] The collision physics model of the calculation program adopts random phase approximation, two-body approximation collision and central potential approximation methods. The code calculates the random motion process of ions and obtains valid results through a large amount of statistical data. Each trajectory corresponds to a particle (ion or collision target atom) with a specified starting position, a given direction and an incident energy. Each particle moves freely along a random straight line. The step length of each movement is selected as the average distance between atoms, and the probability of scattering at each step length is determined. The energy loss depends on the density of the target atoms and the nuclear stopping energy and electronic stopping energy. Due to the interaction between the nuclei and extranuclear electrons of the two particles, the direction of particle movement will change. The scattering angle of the incident particle can be obtained by formula (1):

[0074]

[0075] θ CM is the scattering angle in the center-of-mass system, where p is the collision parameter, r0 is the closest distance between the two nuclei, V(r) is the screening interatomic potential, and E C is the kinetic energy of the incident ion in the mass center system, and r is the distance between atoms. The energy of the particle after the collision is obtained through the momentum conservation and energy conservation equations. Finally, after a series of collisions, if the recoil particle energy E recoil Reduce to the minimum setting value E min Below, or when the particle leaves the target area, the program will no longer record the trajectory. When the target atoms leave the target surface, the program will count the number of atoms that leave.

[0076] In this embodiment, S2: according to S1, the differential sputtering yield of the gate material is calculated to obtain the angular distribution characteristic parameters of the sputtered atoms in space.

[0077] After the sputtered atoms recoil from the surface of the gate material, in order to evaluate their spatial distribution, the output data of the calculation program needs to be processed. A hemispherical surface is used to collect the sputtered atoms leaving the target surface. The mathematical model for evaluating the angular distribution of sputtered atoms is as follows: Figure 2 shown.

[0078] Take the polar angle interval [θ1,θ2] and the azimuth angle interval like Figure 2 In the present invention, the polar angle interval is Δθ=1°, and the azimuth angle interval is Therefore, within the azimuth angle interval, the distribution of sputtered atoms is considered to be identical. The distribution probability of sputtered atoms in the shaded area is obtained as:

[0079]

[0080] Where N ais the total number of sputtered atoms collected in the shaded area, N is the total number of sputtered atoms leaving the target, θ is the angle between the da area and the target surface normal, It is the angle between the projection of area da in the xy plane and the y-axis. a is the subscript of N, which is the abbreviation of the word area.

[0081] In this embodiment, S3: according to S2, spatially integrate the differential sputtering yield of the gate material to obtain the total sputtering yield of the gate material.

[0082] The gate corrosion program first collects the ion energy E, velocity direction, and ion incident angle (polar angle) θ bombarding the acceleration gate in 2000 time steps, and then obtains the sputtering corrosion rate at different positions on the gate surface according to the sputtering yield empirical formula (11)-(13). The sputtering corrosion of the carbon material of the present invention is calculated based on the sputtering yield formula of Eckstein and Wei, and first obtains the relationship between the total sputtering yield Y and the ion incident energy:

[0083]

[0084] In the formula, S n is the nuclear stopping cross section, which is based on the krypton-carbon KC potential, Q is the empirical proportional parameter, and E th is the threshold energy, μ is the empirical index, λ is used to trigger the start of the decrease, ∈ is the reduced energy, and w is an intermediate parameter with no meaning.

[0085] The relationship between the total sputtering yield and the angle is obtained by equation (12):

[0086]

[0087] Where a is the expected energy range, α and β are the scattering range of ions along the incident direction and the scattering range of ions perpendicular to the incident direction, respectively, and A is an intermediate parameter with no meaning.

[0088] The final sputtering yield is:

[0089] Y(E,θ)=Y(E,0)·Y′ (5)

[0090] In this embodiment, S4: According to S2 and S3, a PIC-MCC numerical calculation simulation model is established based on the PIC-MCC method, and the calculated spatial distribution of sputtering atoms of the gate material and the total sputtering yield formula are substituted into the PIC-MCC numerical calculation simulation model as boundary conditions to establish an integrated simulation model of sputtering corrosion of the gate component, and the corrosion morphology of the gate is calculated based on the integrated simulation model of sputtering corrosion of the gate component.

[0091] in, Figure 1The left side of the figure is the PIC-MCC numerical simulation model, which can calculate the plasma parameters in the discharge chamber. The right side is the sputtering model, which can calculate the sputtering yield and sputtering atom distribution.

[0092] The PIC-MCC method is used to simulate the process of the ion engine grid extracting beam ions from the discharge chamber and the CEX ions hitting the acceleration grid hole wall. The calculation area established is as follows Figure 3 As shown in the figure, the ions in the discharge chamber enter from the left boundary and are accelerated by the screen grid and the acceleration grid before being drawn out from the right boundary of the computational domain. The PIC-MCC simulation method is divided into four parts:

[0093] (1) Ion ejection at the left boundary, electric field solution, ion motion and CEX collision.

[0094] The ion scattering at the left boundary is mainly done by assigning the radial initial position r to the ion through the random number rand, and setting the axial initial position z to 0. The ion axial velocity v z Set to Bohm velocity, radial velocity follows Maxwell distribution v r . Use equations (3) and (4) to assign values ​​to them respectively.

[0095]

[0096] Where k is the Boltzmann constant, T e is the electron temperature, m i is the ion mass, v is the particle velocity, T n is the macroscopic temperature of the particle.

[0097] (2) Electric field solution: Poisson's equation (Equation (5)) is used to obtain the electric potential at the grid points, and the electric field at the grid points is solved by finite difference of the electric potential (Equation (6)).

[0098]

[0099] in, is the vector differential operator, φ is the electric potential, e is the elementary charge, ε0 is the vacuum dielectric constant, n i is the ion number density, n e is the electron number density.

[0100] (3) The leapfrog method is used to solve the motion equations of ions. The electric field at the grid point is interpolated to the location of the ions and then substituted into the ion motion equations (Equations (7) and (8)) to solve the ion motion velocity and displacement.

[0101]

[0102] Among them, q is the charge of the particle and x is the displacement of the particle.

[0103] (4) CEX collision uses the empty collision method. The frequency and probability of a collision between any ion and a neutral atom in space within Δt are shown in equations (9) and (10), respectively.

[0104] ν i =σ T (v i ) n (x i )v i (12)

[0105] P i =1-exp[-σ T (v i ) n (x i )v i Δt] (13)

[0106] Among them, v i is the ion velocity, n n is the neutral gas density, x i is the current position of the ion, P i is the probability of ion collision, and Δt is the time step.

[0107] According to S1 to S4, the construction of the integrated model of sputtering corrosion of the gate component can be realized. The overall simulation calculation method of the integrated model of sputtering corrosion of the gate component proposed in the present invention is as follows: Figure 4 As shown:

[0108] S41: throwing ions from the left boundary of the computational domain;

[0109] S42: Solve the electric potential of each grid point in the calculation domain to obtain the grid electric field distribution;

[0110] S43: Drive the particle motion in the calculation domain according to Newton's laws of motion to obtain the current velocity and position information;

[0111] S44: performing charge exchange collision to generate charge exchange ions;

[0112] S45: Count the total number of ions in the calculation domain, and proceed to the next step when the number change is less than 1‰, otherwise repeat S41 to S44;

[0113] S46: compare the current beam current with the beam current setting value, and proceed to the next step if the difference is within 1%, otherwise repeat S41 to S45;

[0114] S47: Count the amount of corrosion caused by the charge exchange ions on the gate, and calculate the deposition rate of the sputtered atoms on the gate to obtain the time required to corrode a single grid;

[0115] S48: Repeating the processes S41 to S47 under the new gate morphology;

[0116] S49: The calculation ends when the gate corrosion setting time is reached.

[0117] Embodiment 2

[0118] The present invention also provides an integrated simulation and calculation system for sputtering corrosion of an ion engine grid assembly, comprising: a scattering angle parameter acquisition module, an angular distribution characteristic acquisition module, a total sputtering yield acquisition module, and an integrated simulation and calculation module;

[0119] The scattering angle parameter acquisition module is used to take the carbon-carbon gate of the ion engine as the research object, starting from the carbon-carbon gate material, and using the molecular dynamics method to establish an ion-atom collision physics model, solve the cascade collision process of the incident ions inside the gate material, and obtain the scattering angle parameters of the incident particles inside the target material;

[0120] The angular distribution characteristic acquisition module is used to calculate the differential sputtering yield of the gate material according to the scattering angle parameters of the incident particles inside the target material, and obtain the angular distribution characteristics of the sputtering target atoms in space under different incident angles;

[0121] The total sputtering yield acquisition module is used to spatially integrate the differential sputtering yield of the gate material according to the angular distribution characteristics of the sputtering target atoms in space at different incident angles to obtain the total sputtering yield of the gate material;

[0122] The integrated simulation calculation module is used to establish an integrated simulation model of sputtering corrosion of gate components based on the PIC-MCC method. The calculated spatial distribution of sputtering atoms of gate materials and the total sputtering yield formula are used as boundary conditions and substituted into the PIC-MCC numerical calculation simulation model, ultimately realizing the integrated simulation calculation from sputtering damage of gate materials to prediction of corrosion morphology of gate components.

[0123] In this embodiment, in the scattering angle parameter acquisition module, the process of obtaining the scattering angle parameters of the incident particles inside the target material includes:

[0124]

[0125] In the formula, θ CM is the scattering angle in the center-of-mass system, p is the collision parameter, r0 is the closest distance between the two nuclei, V(r) is the shielding interatomic potential, and E C is the kinetic energy of the incident ion in the center-of-mass system, and r is the distance between atoms.

[0126] In this embodiment, in the angular distribution characteristic obtaining module, the process of obtaining the angular distribution characteristics of the sputtering target atoms in space at different incident angles includes:

[0127]

[0128] Where N a is the total number of sputtered atoms collected, and N is the total number of sputtered atoms leaving the target.

[0129] In this embodiment, in the total sputtering yield obtaining module, the process of obtaining the total sputtering yield of the gate material includes:

[0130] Y(E,θ)=Y(E,0)·Y′,

[0131] Among them, Y(E,0) is the relationship between the total sputtering yield Y and the ion incident energy, In the formula, S n is the nuclear stopping cross section, which is based on the krypton-carbon KC potential, Q is the empirical proportional parameter, and E th is the threshold energy, μ is the empirical index, λ is used to trigger the start of the decrease, ∈ is the reduced energy, and w is an intermediate parameter with no meaning;

[0132] Y′ is the relationship between the total sputtering yield and angle, Where a is the expected energy range, α and β are the scattering range of ions along the incident direction and the scattering range of ions perpendicular to the incident direction, respectively, and A is an intermediate parameter with no meaning.

[0133] In this embodiment, in the integrated simulation calculation module, the process of implementing the integrated simulation calculation from the sputtering damage of the gate material to the prediction of the corrosion morphology of the gate component includes:

[0134] S41: throwing ions from the left boundary of the computational domain;

[0135] S42: Solve the electric potential of each grid point in the calculation domain to obtain the grid electric field distribution;

[0136] S43: Drive the particle motion in the calculation domain according to Newton's laws of motion to obtain the current velocity and position information;

[0137] S44: performing charge exchange collision to generate charge exchange ions;

[0138] S45: Count the total number of particles in the calculation domain, and proceed to the next step when the number change is less than 1‰, otherwise repeat S41 to S44;

[0139] S46: compare the current beam current with the beam current setting value, and proceed to the next step if the difference is within 1%, otherwise repeat S41 to S45;

[0140] S47: Count the amount of corrosion caused by the charge exchange ions on the gate, and calculate the deposition rate of the sputtered atoms on the gate to obtain the time required to corrode a single grid;

[0141] S48: Repeating the processes S41 to S47 under the new gate morphology;

[0142] S49: The calculation ends when the gate corrosion setting time is reached.

[0143] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. An integrated simulation calculation method for sputtering corrosion of an ion engine grid assembly, characterized in that: The following steps are involved: S1: Taking the carbon-carbon gate of the ion engine as the research object, starting from the carbon-carbon gate material, by using the molecular dynamics method, the ion-atom collision physical model is established to solve the cascade collision process of the incident ions inside the gate material, and obtain the scattering angle parameters of the incident particles inside the target material; S2: Calculate the differential sputtering yield of the gate material based on the scattering angle parameters of the incident particles inside the target material, and obtain the angular distribution characteristics of the sputtering target atoms in space under different incident angles; S3: According to the angular distribution characteristics of the sputtering target atoms in space at different incident angles, the differential sputtering yield of the gate material is spatially integrated to obtain the total sputtering yield of the gate material; S4: A PIC-MCC numerical calculation simulation model is established based on the PIC-MCC method. The calculated spatial distribution of sputtered atoms of the gate material and the total sputtering yield formula are substituted into the PIC-MCC numerical calculation simulation model as boundary conditions to establish an integrated simulation model of sputtering corrosion of the gate component. Based on the integrated simulation model of sputtering corrosion of the gate component, the corrosion morphology of the gate is calculated.

2. The ion engine grid assembly sputtering corrosion integrated simulation calculation method according to claim 1 is characterized in that: In S1, the method for obtaining the scattering angle parameters of the incident particles inside the target material includes: In the formula, θ CM is the scattering angle in the center-of-mass system, p is the collision parameter, r0 is the closest distance between the two nuclei, V(r) is the shielding interatomic potential, and E C is the kinetic energy of the incident ion in the center-of-mass system, and r is the distance between atoms.

3. The ion engine grid assembly sputtering corrosion integrated simulation calculation method according to claim 1, characterized in that: In S2, the method for obtaining the angular distribution characteristics of sputtering target atoms in space at different incident angles includes: Where N a is the total number of sputtered atoms collected, N is the total number of sputtered atoms leaving the target, θ is the angle between the da area and the target surface normal, It is the angle between the projection of area da in the xy plane and the y-axis. a is the subscript of N, which is the abbreviation of the word area.

4. The integrated simulation calculation method for sputtering corrosion of ion engine grid components according to claim 1 is characterized in that: In S3, the method for obtaining the total sputtering yield of the gate material includes: Y(E,θ)=Y(E,0)·Y′, Among them, Y(E,0) is the relationship between the total sputtering yield Y and the ion incident energy, In the formula, S n is the nuclear stopping cross section, which is based on the krypton-carbon KC potential, Q is the empirical proportional parameter, and E th is the threshold energy, μ is the empirical index, λ is used to trigger the start of the decrease, ∈ is the reduced energy, and w is an intermediate parameter with no meaning; Y′ is the relationship between the total sputtering yield and angle, Where a is the expected energy range, α and β are the scattering range of ions along the incident direction and the scattering range of ions perpendicular to the incident direction, respectively, and A is an intermediate parameter with no meaning.

5. The ion engine grid assembly sputtering corrosion integrated simulation calculation method according to claim 1, characterized in that: In S4, the method for realizing integrated simulation calculation from gate material sputtering damage to gate component corrosion morphology prediction includes: S41: throwing ions from the left boundary of the computational domain; S42: Solve the electric potential of each grid point in the calculation domain to obtain the grid electric field distribution; S43: Drive the particle motion in the calculation domain according to Newton's laws of motion to obtain the current velocity and position information; S44: performing charge exchange collision to generate charge exchange ions; S45: Count the total number of particles in the calculation domain, and proceed to the next step when the number change is less than 1‰, otherwise repeat S41 to S44; S46: compare the current beam current with the beam current setting value, and proceed to the next step if the difference is within 1%, otherwise repeat S41 to S45; S47: Count the amount of corrosion caused by the charge exchange ions on the gate, and calculate the deposition rate of the sputtered atoms on the gate to obtain the time required to corrode a single grid; S48: Repeating the processes S41 to S47 under the new gate morphology; S49: The calculation ends when the gate corrosion setting time is reached.

6. An integrated simulation and calculation system for sputtering corrosion of ion engine grid components, characterized in that: include: Scattering angle parameter acquisition module, angular distribution characteristics acquisition module, total sputtering yield acquisition module, integrated simulation calculation module; The scattering angle parameter acquisition module is used to take the carbon-carbon gate of the ion engine as the research object, starting from the carbon-carbon gate material, by adopting the molecular dynamics method, establish an ion-atom collision physical model, solve the cascade collision process of the incident ions inside the gate material, and obtain the scattering angle parameters of the incident particles inside the target material; The angular distribution characteristic acquisition module is used to calculate the differential sputtering yield of the gate material according to the scattering angle parameters of the incident particles inside the target material, and obtain the angular distribution characteristics of the sputtering target atoms in space under different incident angles; The total sputtering yield acquisition module is used to spatially integrate the differential sputtering yield of the gate material according to the angular distribution characteristics of the sputtering target atoms in space at different incident angles to obtain the total sputtering yield of the gate material; The integrated simulation calculation module is used to establish a PIC-MCC numerical calculation simulation model based on the PIC-MCC method, and the calculated spatial distribution of sputtering atoms of the gate material and the total sputtering yield formula are substituted into the PIC-MCC numerical calculation simulation model as boundary conditions to establish an integrated simulation model of sputtering corrosion of the gate component. Based on the integrated simulation model of sputtering corrosion of the gate component, the corrosion morphology of the gate is calculated.

7. The ion engine grid assembly sputtering corrosion integrated simulation and calculation system according to claim 6, characterized in that: In the scattering angle parameter acquisition module, the process of obtaining the scattering angle parameters of the incident particles inside the target material includes: In the formula, θ CM is the scattering angle in the center-of-mass system, p is the collision parameter, r0 is the closest distance between the two nuclei, V(r) is the shielding interatomic potential, and E C is the kinetic energy of the incident ion in the center-of-mass system, and r is the distance between atoms.

8. The ion engine grid assembly sputtering corrosion integrated simulation and calculation system according to claim 6, characterized in that: In the angular distribution characteristic acquisition module, the process of obtaining the angular distribution characteristics of the sputtering target atoms in space at different incident angles includes: Where N a is the total number of sputtered atoms collected, N is the total number of sputtered atoms leaving the target, θ is the angle between the da area and the target surface normal, It is the angle between the projection of area da in the xy plane and the y-axis. a is the subscript of N, which is the abbreviation of the word area.

9. The ion engine grid assembly sputtering corrosion integrated simulation and calculation system according to claim 6, characterized in that: In the total sputtering yield obtaining module, the process of obtaining the total sputtering yield of the gate material includes: Y(E,θ)=Y(E,0)·Y′, Among them, Y(E,0) is the relationship between the total sputtering yield Y and the ion incident energy, In the formula, S n is the nuclear stopping cross section, which is based on the krypton-carbon KC potential, Q is the empirical proportional parameter, and E th is the threshold energy, μ is the empirical index, λ is used to trigger the start of the decrease, ∈ is the reduced energy, and w is an intermediate parameter with no meaning; Y′ is the relationship between the total sputtering yield and angle, Where a is the expected energy range, α and β are the scattering range of ions along the incident direction and the scattering range of ions perpendicular to the incident direction, respectively, and A is an intermediate parameter with no meaning.

10. The ion engine grid assembly sputtering corrosion integrated simulation and calculation system according to claim 6, characterized in that: In the integrated simulation calculation module, the process of implementing the integrated simulation calculation from the sputtering damage of the gate material to the prediction of the corrosion morphology of the gate component includes: S41: throwing ions from the left boundary of the computational domain; S42: Solve the electric potential of each grid point in the calculation domain to obtain the grid electric field distribution; S43: Drive the particle motion in the calculation domain according to Newton's laws of motion to obtain the current velocity and position information; S44: performing charge exchange collision to generate charge exchange ions; S45: Count the total number of particles in the calculation domain, and proceed to the next step when the number change is less than 1‰, otherwise repeat S41 to S44; S46: compare the current beam current with the beam current setting value, and proceed to the next step if the difference is within 1%, otherwise repeat S41 to S45; S47: Count the amount of corrosion caused by the charge exchange ions on the gate, and calculate the deposition rate of the sputtered atoms on the gate to obtain the time required to corrode a single grid; S48: Repeating the processes S41 to S47 under the new gate morphology; S49: The calculation ends when the gate corrosion setting time is reached.

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