A method, system, device and terminal for calculating and evaluating the risk of charge in a medium

Abstract

The present invention belongs to the technical field of charged protection in dielectrics, and discloses a method, system, device and terminal for calculating and evaluating the risk of charged in dielectrics. By constructing a specimen model and a shielding layer model, constructing an electron radiation source model and calculating relevant radiation parameters and radiation data, the simulation of the radiation process of the dielectric under a monoenergetic electron radiation environment and the simulation of the radiation process of the dielectric under a real-space electron radiation environment are respectively realized and exported; four voltage application conditions are analyzed, the working voltage range is set to 100 - 1000V, and three levels of voltages 100V, 500V and 1000V are selected for calculation; by constructing a simulation scheme for the grounding method, the influence of the grounding method on the electric field distribution in the dielectric is analyzed; a charge transport model is constructed and solved to realize the risk assessment of electrostatic discharge in the dielectric. The present invention can fully consider the influence of factors such as electron radiation, working voltage, and the grounding method of the dielectric on the charged in the dielectric, and is more in line with the actual working conditions of the spacecraft dielectric.

Description

Technical Field

[0001] The present invention belongs to the technical field of in-dielectric charging protection, and particularly relates to a method, a system, a device and a terminal for calculating and evaluating the risk of in-dielectric charging. Background Art

[0002] At present, the interaction between high-energy electrons and spacecraft dielectrics easily triggers in-dielectric charging phenomena. In-dielectric charging seriously affects the service life of insulating dielectrics and the operating stability of sensitive electronic devices on spacecraft, threatening the operation safety of spacecraft. With the development of high-power and high-voltage spacecraft, the required thickness of insulating dielectrics is increasing continuously. The release of deposited charges in thick insulating dielectrics is more difficult, and it is more likely to trigger in-dielectric charging, resulting in dielectric electrostatic discharge. Moreover, with the increase of the operating voltage of spacecraft, the in-dielectric charging characteristics of dielectrics under the combined action of the operating voltage and electron radiation are still unknown. It is also necessary to comprehensively consider the grounding method and grounding position under the actual working conditions of dielectrics to comprehensively analyze the transport characteristics of internal charges in dielectrics under electron radiation, which are all lacking in current research.

[0003] The current risk assessment of in-dielectric charging mainly adopts the method of simulation calculation, and judges whether there is a risk of electrostatic discharge by comparing the electric field intensity inside the dielectric under the corresponding electron radiation conditions with the breakdown field strength of the dielectric. With the development of high-voltage and high-power spacecraft, the current risk assessment scheme of in-dielectric charging is no longer applicable. The operating voltage, grounding method, etc. of spacecraft will all affect the transport and distribution of charges in dielectrics, which is an indispensable part. Therefore, when conducting discharge risk assessment, it is necessary to comprehensively consider the in-dielectric charging characteristics under the coupling of multiple factors such as electron radiation, operating voltage and grounding method of dielectrics. This is the content lacking in current research.

[0004] With the development of high-voltage and high-power spacecraft, the existing risk assessment methods of in-dielectric charging are no longer applicable, because the operating voltage, grounding method, etc. of spacecraft will all affect the transport and distribution of charges in dielectrics, which is an indispensable part. However, the current methods mainly consider a single factor of electron radiation and fail to comprehensively consider the influence of operating voltage and grounding method on the in-dielectric charging characteristics.

[0005] Through the above analysis, the problems and defects of the existing technology are as follows:

[0006] (1) Since the operating voltage, voltage application position, grounding method, etc. of spacecraft will all affect the transport and distribution of charges in dielectrics, the existing risk assessment method of in-dielectric charging considering only the electron radiation factor is no longer applicable.

[0007] (2) There is a lack of a comprehensive analysis scheme for in-dielectric charging characteristics and in-dielectric charging risk assessment that combines electron radiation factors, operating voltage, grounding method, and shielding factors. Summary of the invention

[0008] In response to the problems existing in the prior art, the present invention provides a method, system, device and terminal for calculating and evaluating the risk of internal electrification in a medium, and in particular, relates to a method, system, medium, device and terminal for calculating and evaluating the risk of internal electrification in a medium under the coupling of multiple factors such as electronic radiation, shielding, operating voltage, and grounding method.

[0009] The present invention is implemented as follows: a method for calculating and evaluating the risk of electrification in a medium, the method comprising: constructing a sample model and a shielding layer model, constructing an electronic radiation source model and calculating relevant radiation parameters, and calculating and exporting radiation data to respectively realize the simulation of the medium radiation process under a monoenergetic electron radiation environment and the medium radiation process under a real space electron radiation environment; analyzing four voltage application conditions, setting the working voltage range to 100-1000V, and selecting three voltage levels of 100V, 500V and 1000V for calculation; analyzing the influence of the grounding method on the electric field distribution in the medium by constructing a grounding method simulation scheme; constructing a charge transport model and solving it to realize the risk assessment of electrostatic discharge in the medium.

[0010] Furthermore, the method for calculating and assessing the risk of electrical discharge in a medium includes the following steps:

[0011] Step 1: Determine the electron radiation simulation scheme by simulating the medium radiation process in a monoenergetic electron radiation environment and in a real space electron radiation environment, combined with shielding factors;

[0012] Step 2: Analyze the four voltage application conditions and determine the working voltage simulation scheme.

[0013] Step 3: Determine the simulation scheme of the grounding method and analyze the influence of the grounding method on the electric field distribution in the medium;

[0014] Step 4: After constructing the charge transport model, solve the charge transport model to achieve a comprehensive evaluation and calculation of the electrostatic discharge risk in the medium.

[0015] Furthermore, the determination of the electron radiation simulation scheme in step 1 includes:

[0016] (1) Simulation of dielectric radiation process in monoenergetic electron radiation environment

[0017] The Monte Carlo method was used to simulate the interaction between the medium and the incident electrons, and the open source software Geant4 was used to write the corresponding electron radiation program for simulation.

[0018] 1) Construct the sample model and shielding layer model;

[0019] Program in Geant4 to construct the three-dimensional models of the corresponding sample, shielding layer and vacuum environment according to the medium sample material, size, shielding layer material and thickness; set the medium model as the detector and divide it into 100*100*10 volume micro-elements to detect and record the charge deposition and energy deposition at each position inside the medium.

[0020] Construct a disc sample model with a diameter of 10 cm and a thickness of 1 mm according to the actual size of the polyimide sample, and place the whole in a vacuum environment; construct an aluminum shielding layer 10 cm to the left of the sample, with a size of 15 cm×15 cm and a thickness of 3 mm, and the thickness is parameterized and adjusted according to the actual working conditions.

[0021] 2) Construct an electron radiation source model and calculate the relevant radiation parameters;

[0022] Program in Geant4 to construct an electron source and set the electron source parameters and incident electron parameters. Design the electron source as a plane electron source and make it incident vertically along the sample surface; the parameters of the incident electrons are the incident electron energy and the electron beam current density. The incident electron energy is directly programmed and set, and the electron beam current density is obtained by a conversion method; Geant4 uses the Monte Carlo method to simulate the interaction process between electrons and the medium. Only the number of incident electrons is set, and the charge deposition rate under the corresponding beam current density is converted through the number of deposited charges recorded by the detector.

[0023] Among them, the conversion method is as follows:

[0024] When the number of incident electrons is N; the incident electron beam current density is J0, A / m 2 ; the area of the electron source is A0, m 2 ; the charge deposition amount and energy deposition amount recorded by the Geant4 medium volume micro-element are E n and E g , then the virtual radiation time T is:

[0025] Unit s;

[0026] Among them, e q is the electron charge 1.6×10 -19 C.

[0027] The charge deposition rate ρ d in the medium corresponding to the actual beam current is:

[0028] Unit C / m 3 ·s;

[0029] The dose rate in the medium is:

[0030] Unit: rad / s.

[0031] 3) Calculate and export the radiation data;

[0032] Build the calculation models of the specimen, shield, and electron source in Geant4, set the number of incident electrons for simulation, and perform the simulation. After the calculation, save the recorded charge deposition amount E n and the energy deposition amount E g as a.txt file and export it to MATLAB, and convert the charge deposition rate ρ d and the dose rate

[0033] (2) Simulation of the radiation process of the medium in the real-space electron radiation environment

[0034] 1) Build the specimen model and the shield model;

[0035] Build the corresponding three-dimensional models of the specimen and the shield and the vacuum environment in Geant4 by programming according to the material, size of the medium specimen, the material, and thickness of the shield. Set the medium model as the detector and divide it into 100*100*10 volume micro-elements for detecting and recording the charge deposition and energy deposition at each position inside the medium.

[0036] 2) Build the electron radiation source model and calculate the relevant radiation parameters;

[0037] Build the electron source by programming in Geant4, and set the electron source parameters and the incident electron parameters. Design the electron source as a planar electron source, which is incident vertically along the sample surface. The parameters of the incident electrons are the incident electron energy and the electron beam current density, and the FLUMIC model is selected for the calculation.

[0038] The outer radiation belt model is as follows:

[0039] Taking into account the solar cycle and the annual variation, when the outer radiation belt L>2.5, the electron flux will be a function of fsc, foy, L, and E;

[0040] Function about the solar cycle:

[0041]

[0042] In the formula, fsc represents the normalized value of the solar activity cycle, which is 0 in the solar minimum year.

[0043] Function about the season:

[0044]

[0045] In the formula, foy represents the normalized value of the date in a year, with January 1st as the zero starting point.

[0046] Function regarding energy:

[0047] F(>E) = F(>2MeV) × exp[(2 - E) / E0];

[0048] Wherein,

[0049] Function regarding L:

[0050]

[0051] In the formula, L is the distance to the center of the Earth.

[0052] Calculate the electron radiation flux corresponding to different orbital heights through the FLUMIC3 model, convert it to the vertical direction to simulate the vertical incidence of electrons, and at the same time set it to the energy spectrum mode radiation in Geant4 according to the converted electron flux, and set the electron energy range.

[0053] The conversion method of the charge deposition rate and dose rate in the medium is as follows:

[0054] When the number of incident electrons is N; the incident electron beam current density is J0, A / m 2 , the electron source area is A0, m 2 ; the charge deposition amount and energy deposition amount recorded by the Geant4 medium volume microelement are E n and E g , then the virtual radiation time T is:

[0055] Unit s;

[0056] Wherein, e q is the electron charge of 1.6 × 10 -19 C.

[0057] Corresponding to the charge deposition rate ρ in the medium under the actual beam current d is:

[0058] Unit C / m 3 ·s;

[0059] The dose rate in the medium is:

[0060] Unit rad / s.

[0061] 3) Calculate and export the radiation data;

[0062] Build a computational model of the specimen, shield, and electron source in Geant4, set the number of incident electrons for simulation, and perform the simulation. After the calculation, save the recorded charge deposition amount \(E\) n and the energy deposition amount \(E\) g as a.txt file and export it to MATLAB, and convert it to the charge deposition rate \(\rho\) under the corresponding beam current density d and the dose rate

[0063] Furthermore, the determination of the working voltage simulation scheme in step two includes:

[0064] Analyze four voltage application conditions, namely A: \(V\) S -G, the radiation surface of the specimen is pressurized and the bottom surface is grounded; B: \(V\) S -S, the radiation surface of the specimen is pressurized and the bottom surface is neither pressurized nor grounded; C: \(S - V\) S , the radiation surface of the specimen is neither pressurized nor grounded and the bottom surface is pressurized; D: \(G - V\) S , the radiation surface of the specimen is grounded and the bottom surface is pressurized.

[0065] Ignore the thickness of the electrodes and the grounding plates in the calculation; set the working voltage range to 100V to 1000V, and select three voltage levels of 100V, 500V, and 1000V for calculation.

[0066] Furthermore, the determination of the grounding method simulation scheme in step three includes:

[0067] Construct the grounding methods and analyze the influence of the grounding methods on the electric field distribution in the medium; among them, the constructed grounding methods are respectively a: \(S - G\), the radiation surface is suspended, neither pressurized nor grounded, and the bottom surface is grounded; b: \(G - S\), the radiation surface is grounded and the bottom surface is suspended; c: \(G - G\), both the radiation surface and the bottom surface are grounded.

[0068] Furthermore, the comprehensive evaluation calculation in step four includes:

[0069] (1) Construction of the charge transport model

[0070] The selected charge transport equation is as follows:

[0071]

[0072] The charge transport equations are, from top to bottom, the Poisson equation, the current continuity equation, and Ohm's law. Among them, \(E\) is the electric field strength, V / m; \(\rho\) s is the net charge density in the medium, C / m 3 ; \(\varepsilon\) is the dielectric constant of the medium, F / m; \(J\) is the net current density, A / m 2 ; \(\rho\) d is the charge deposition rate in the medium, C / m 3·s.

[0073] σ E is the conductivity related to the electric field, with the unit of S / m;

[0074]

[0075]

[0076] In the formula, σ E is the Poole-Frenkel conductivity / S / m; σ0 is the initial conductivity of the medium, S / m; β F is the Frenkel coefficient; e is the electronic charge, C; ε0 is the vacuum permittivity, F / m; ε r is the relative permittivity.

[0077] σ RIc is the conductivity related to the electric field, with the unit of S / m;

[0078]

[0079] In the formula, is the radiation dose rate, rad / s; k RIC (T) is a proportionality coefficient, whose value is related to the material, with the unit of / S·s / m·rad; Δ(T) is an exponential coefficient, both of which are related to the material itself and vary with temperature; the value of Δ(T) ranges from 0.5 to 1, depending on the energy state distribution of the traps in the medium, and the preferred value is 0.5.

[0080] (2) Solve the charge transport model

[0081] The charge transport model is solved using the commercial finite element software COMSOL:

[0082] 1) In COMSOL, construct a corresponding three-dimensional medium model according to the size of the specimen;

[0083] 2) In COMSOL, construct a corresponding three-dimensional charge transport equation;

[0084] The partial differential equation is selected as the partial differential equation, and the structure of the partial differential equation is as follows:

[0085]

[0086]

[0087] Modify the coefficients of the partial differential equation one by one according to the charge transport model equation to obtain the set charge transport equation group.

[0088] 3) In COMSOL, introduce the set working voltage and grounding method;

[0089] Taking into account the factors of electron radiation, working voltage, and dielectric grounding method, where the working voltage and grounding method are set when solving the charge transport equations in COMSOL.

[0090] When solving the charge transport equations, the grounding state, grounding position of the dielectric, and the amplitude and application position of the working voltage correspond to the initial state and boundary conditions of the partial differential equations in COMSOL. In COMSOL, modify the initial conditions of the custom equations and add Dirichlet boundary conditions according to the set working conditions to complete the setting of various boundary conditions for the working voltage position, amplitude, and grounding method and position.

[0091] 4) Solve the charge transport equations;

[0092] In Geant4, complete the simulation of the electron radiation process according to the set radiation parameters, and after converting the two key parameters of the charge deposition rate and dose rate at each position in the sample obtained, import them into COMSOL by interpolation.

[0093] According to the actual working conditions of the sample, complete the setting of the grounding method, position, and the application position and amplitude of the working voltage; perform mesh division on the three-dimensional model of the dielectric, set the radiation time, and select the MUMPS type solver based on LU decomposition for solving calculations to obtain the internal electric field distribution of the sample within the set radiation time under actual working conditions.

[0094] (3) Dielectric electrostatic discharge risk assessment

[0095] 1) Experimentally determine the breakdown field strength of the dielectric;

[0096] 2) Calculate the internal electric field distribution of the dielectric under the set conditions and obtain the maximum electric field strength amplitude;

[0097] 3) Compare the dielectric breakdown field strength and the maximum electric field amplitude under the set radiation conditions to determine whether there is an electrostatic discharge risk. If the maximum electric field strength amplitude is greater than the measured breakdown field strength of the dielectric, there is an electrostatic discharge risk, and the greater the difference between the two, the higher the electrostatic discharge risk; if the maximum electric field strength amplitude is less than the measured breakdown field strength of the dielectric, there is no electrostatic discharge risk, and the greater the difference between the two, the lower the electrostatic discharge risk;

[0098] 4) Recalculate the maximum electric field amplitude by adjusting the shielding thickness to calibrate the minimum shielding thickness required, thereby adjusting the shielding design;

[0099] 5) Recalculate the maximum electric field amplitude by adjusting the grounding method and grounding position to select the optimal grounding method design.

[0100] Another object of the present invention is to provide a system for calculating and evaluating the risk of internal charging of a dielectric, which applies the method for calculating and evaluating the risk of internal charging of a dielectric. The system for calculating and evaluating the risk of internal charging of a dielectric includes:

[0101] An electron radiation simulation module, configured to determine an electron radiation simulation scheme by simulating the radiation process of the dielectric in a monoenergetic electron radiation environment and simulating the radiation process of the dielectric in a real-space electron radiation environment;

[0102] A working voltage simulation module, configured to analyze four voltage application conditions to determine a working voltage simulation scheme,

[0103] A grounding method simulation module, configured to analyze the influence of the grounding method on the electric field distribution in the dielectric by determining a grounding method simulation scheme;

[0104] A comprehensive evaluation calculation module, configured to comprehensively evaluate and calculate the risk of electrostatic discharge in the dielectric by constructing a charge transport model and then solving the charge transport model.

[0105] Another object of the present invention is to provide a computer device, which includes a memory and a processor. The memory stores a computer program. When the computer program is executed by the processor, the processor executes the steps of the method for calculating and evaluating the risk of internal charging of a dielectric.

[0106] Another object of the present invention is to provide a computer-readable storage medium, which stores a computer program. When the computer program is executed by the processor, the processor executes the steps of the method for calculating and evaluating the risk of internal charging of a dielectric.

[0107] Another object of the present invention is to provide an information data processing terminal, which is used to implement the system for calculating and evaluating the risk of internal charging of a dielectric.

[0108] Combined with the above technical solutions and the solved technical problems, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0109] First, aiming at the technical problems existing in the above-mentioned prior art and the difficulty of solving this problem, closely combining the technical solutions to be protected by the present invention and the results and data in the R & D process, etc., analyze in detail and deeply how the technical solutions of the present invention solve the technical problems and the creative technical effects brought after solving the problems. The specific description is as follows:

[0110] The present invention provides a feasible method for calculating and analyzing the internal charging characteristics of a dielectric and comprehensively evaluating the internal charging risk under the coupling of multiple factors such as electron radiation, shielding factor, working voltage, and grounding method, which can fully consider factors such as electron radiation, shielding factor, working voltage, and the grounding method of the dielectric to calculate and analyze the internal charging characteristics of the dielectric.

[0111] Second, considering the technical solution as a whole or from the perspective of the product, the technical effects and advantages of the technical solution to be protected by the present invention are described in detail as follows:

[0112] The method for calculating the internal charge characteristics of a dielectric and for risk assessment provided by the present invention is more scientific and reasonable, conforms to the actual working conditions of spacecraft dielectrics, and is suitable for analyzing the internal charge characteristics of thick insulating dielectrics on high-power, high-voltage spacecraft, and meets future development needs.

[0113] Third, as auxiliary evidence of the inventiveness of the claims of the present invention, it is also reflected in the following important aspects:

[0114] The expected benefits and commercial value of the technical solution of the present invention after transformation are as follows: a complete set of equipment can be further developed based on the present invention for risk assessment of charged spacecraft dielectrics with high power and high voltage. The target customers are aerospace research institutes, universities, and aerospace dielectric material research and development and production enterprises, etc., and the application prospects are broad. BRIEF DESCRIPTION OF THE DRAWINGS

[0115] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. 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 creative work.

[0116] Figure 1 is a flow chart of a method for calculating and assessing the risk of electrical discharge in a medium provided by an embodiment of the present invention;

[0117] Figure 2 It is a schematic diagram of the simulation of the medium electron radiation process in Geant4 provided by an embodiment of the present invention;

[0118] Figure 3 Schematic diagram of the dielectric working voltage application method under electron radiation provided by an embodiment of the present invention; A (V S -G); B(V S -S); C(SV S );D(GV S );

[0119] Figure 4 Schematic diagram of the grounding type of the sample under the actual working condition provided by the embodiment of the present invention; a (SG); b (GS); c (GG);

[0120] Figure 5 Schematic diagram of the relationship between the maximum value of the electric field in the PI and the grounding method and shielding thickness under the GEO environment provided by an embodiment of the present invention;

[0121] Figure 6 It is a schematic diagram showing the relationship between the maximum value of the internal electric field of PI, the working voltage, and the shielding thickness in the GEO environment provided by the embodiment of the present invention; in the figure, (a) without shielding; (b) 3 mm. Detailed implementation manners

[0122] In order to make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0123] Aiming at the problems existing in the prior art, the present invention provides a method, system, device, and terminal for calculating and evaluating the risk of charging in a medium. The present invention will be described in detail below with reference to the accompanying drawings.

[0124] I. Explanation of the embodiment. This part is an explanatory embodiment that expands and explains the technical solution of the claim in order to enable those skilled in the art to fully understand how the present invention is specifically implemented.

[0125] As Figure 1 shown, the method for calculating and evaluating the risk of charging in a medium provided by the embodiment of the present invention includes the following steps:

[0126] S101, determine whether to use a monoenergetic electron radiation environment simulation or a real-space electron radiation environment simulation according to the specific research object and actual working conditions, and correspondingly determine the electron radiation simulation scheme.

[0127] S102, determine the voltage application situation and grounding method according to the specific research object and actual working conditions, and determine the corresponding voltage and grounding method simulation scheme.

[0128] S103, construct a charge transport model according to the specific working conditions, and then solve this charge transport model to further realize the comprehensive evaluation and calculation of the risk of electrostatic discharge in the medium.

[0129] As a preferred embodiment, the method for calculating and evaluating the risk of charging in a medium provided by the embodiment of the present invention specifically includes the following steps:

[0130] 1. Electron radiation simulation scheme

[0131] First, it is necessary to simulate the electron radiation process, mainly to calculate and obtain two key parameters, namely the charge deposition rate and the dose rate inside the medium under the set electron radiation conditions. Among them, according to the differences in actual working conditions and test conditions, generally, the electron radiation simulation is divided into two situations:

[0132] 1: Simulate a monoenergetic electron radiation environment, which is mostly used in ground electron radiation tests. It can adjust factors such as the electron energy and beam current density of the incident electrons, but the electron energy corresponding to each radiation is single.

[0133] 2: Real-space electron radiation environment, which is mostly used to simulate the real spacecraft space radiation environment. At this time, the corresponding incident electron energy is a range, presenting an energy spectrum, and the beam current density corresponding to electrons of each energy is also different. Generally, the corresponding electron flux model is used for simulation. For example, the electron radiation environment in the geosynchronous orbit can generally be simulated and calculated using the FLUMIC model.

[0134] The specific scheme is as follows:

[0135] (1) Simulation of the radiation process of the medium under a monoenergetic electron radiation environment

[0136] The present invention selects the Monte Carlo method to simulate the interaction process between the medium and the incident electrons, and uses the open-source software Geant4 to write the corresponding electron radiation program for simulation:

[0137] Step 1: Construct a specimen model and a shielding layer model;

[0138] According to the material and size of the medium specimen and the material and thickness of the shielding layer, etc., program in Geant4 to construct the corresponding three-dimensional models of the specimen, shielding layer and vacuum environment. And set the medium model as a detector, divided into 100*100*10 volume micro-elements to detect and record the charge deposition and energy deposition at each position inside the medium.

[0139] An example of the simulation of the medium electron radiation process in Geant4 provided by the embodiment of the present invention is as Figure 2 shown.

[0140] The embodiment of the present invention constructs a disc specimen model with a diameter of 10 cm and a thickness of 1 mm according to the actual size of the polyimide (PI) specimen, and places the whole in a vacuum environment. Considering the actual situation, an aluminum shielding layer is constructed 10 cm to the left of the specimen, with a size of 15 cm×15 cm and a thickness of 3 mm, and the thickness can be parameterized and adjusted according to the actual working conditions.

[0141] Step 2: Construct an electron radiation source model and calculate relevant radiation parameters;

[0142] Programming to construct an electron source in Geant4 mainly involves setting the parameters of the electron source and the incident electrons. In this invention, considering that in actual ground electron radiation tests, the electron source is mostly located above the specimen and the electrons are incident vertically, the electron source is also designed as a planar electron source, incident vertically along the surface of the sample; the parameters of the incident electrons are mainly the incident electron energy and the electron beam current density. Among them, the incident electron energy can be directly programmed and set, and the electron beam current density needs to be obtained by conversion. This is because Geant4 uses the Monte Carlo method to simulate the interaction process between electrons and the medium. Only the number of incident electrons needs to be set, and then the charge deposition rate corresponding to the beam current density is obtained by converting the number of deposited charges recorded by the detector.

[0143] The conversion method is as follows:

[0144] Assume the number of incident electrons is N; the incident electron beam current density is J0, A / m 2 , the area of the electron source is A0, m 2 ; the charge deposition amount and energy deposition amount recorded by the Geant4 medium volume element are E n and E g , then the virtual radiation time T is:

[0145] (s)

[0146] where e q is the electron charge (1.6×10 -19 C).

[0147] The charge deposition rate ρ d in the medium corresponding to the actual beam current is:

[0148] (C / m 3 ·s)

[0149] The dose rate in the medium is:

[0150] (rad / s)

[0151] As Figure 2 shown, the planar electron source provided in the embodiment of the present invention is set as a circular planar source with a radius of 6 cm, placed 20 cm to the left of the specimen, incident vertically from left to right on the surface of the specimen. At the same time, the incident electron energy is set to 0.3 MeV, and the electron energy can be modified by modifying the program parameters; the number of simulated incident electrons: 3×10 6 pieces. During the electron radiation process, the red line represents the trajectory of the incident electrons, and the green line represents the trajectory of the photons excited during the collision process.

[0152] Step 3: Calculate and export radiation data

[0153] Construct calculation models such as specimens, shields, and electron sources in Geant4 according to the methods described in Step 1 and Step 2. Set the number of incident electrons for simulation and start the simulation. After the calculation is completed, save the recorded charge deposition amount E n and energy deposition amount E g as a.txt file and export it to MATLAB; convert to the charge deposition rate ρ d and dose rate

[0154] (2) Simulation of the radiation process of the medium in the real-space electron radiation environment

[0155] The simulation of the radiation process of the medium in the real-space electron radiation environment is also completed using a radiation program written in Geant4 software. The biggest difference from the simulation in the monoenergetic electron radiation environment lies in the different radiation source models of the two. Here, an electron flux model in the real-space environment needs to be selected for simulation, mainly in Step 2 being different.

[0156] Step 1: Construct the specimen model and the shield layer model;

[0157] Construct the specimen model and the shield layer. Similar to the monoenergetic electron case, program in Geant4 to construct the corresponding three-dimensional models of the specimen, shield layer, and vacuum environment according to the material, size of the medium specimen, and the material, thickness of the shield layer. And set the medium model as the detector, divided into 100*100*10 volume micro-elements to detect and record the charge deposition and energy deposition at each position inside the medium.

[0158] Step 2: Construct the electron radiation source model and calculate relevant radiation parameters;

[0159] Program to construct an electron source in Geant4, mainly setting the electron source parameters and the incident electron parameters. In the present invention, considering that in actual ground electron radiation experiments, the electron source is mostly located above the specimen and the electrons are vertically incident, the electron source is also designed as a planar electron source, vertically incident along the surface of the sample; the parameters of the incident electrons are mainly the incident electron energy and the electron beam current density. Since the electron energies are different and the beam current densities corresponding to electrons of different energies are also different in the real-space radiation environment, an electron flux model needs to be used for calculation here. The present invention selects the FLUMIC (Flux Model for Internal Charging) model for calculation:

[0160] FLUMIC3 updated the outer belt model based on the observational data of satellites such as GEOS / SEM and STRV-1b / REM, and modeled the inner radiation belt electron flux. It considered the seasonal and annual variations of the high-energy electron flux and introduced the high-energy electron flux enhancement events, making it the most accurate model to describe the electron flux in the GEO environment currently.

[0161] The specific model of the outer radiation belt is as follows:

[0162] Taking into account the solar cycle and annual variations, for the outer radiation belt (L>2.5), the electron flux will be a function of fsc, foy, L, and E:

[0163] Function regarding the solar cycle:

[0164]

[0165] In the formula, fsc represents the normalized value of the solar activity cycle, which is 0 at the solar minimum.

[0166] Function regarding seasons:

[0167]

[0168] In the formula, foy represents the normalized value of the date in a year, starting from zero on January 1st.

[0169] Function regarding energy:

[0170] F(>E) = F(>2MeV) × exp[(2 - E) / E0](3)

[0171] Among them,

[0172] Function regarding L:

[0173]

[0174] In the formula, L is the distance to the Earth's geocenter.

[0175] Through the FLUMIC3 model, the electron radiation flux corresponding to different orbital heights can be calculated, and then it can be converted to the vertical direction to simulate the vertical incidence of electrons. At the same time, the converted electron flux is set as the energy spectrum mode radiation in Geant4, and the electron energy range to be studied is set.

[0176] The conversion method of the charge deposition rate and dose rate in the medium is the same as that of the mono-energetic electron incidence method:

[0177] The conversion method is as follows:

[0178] Assume the number of incident electrons is N; the incident electron beam current density is J0, A / m2 , the area of the electron source is A0, m 2 ; the charge deposition amount and energy deposition amount recorded by the Geant4 medium volume element are E n and E g , then the virtual radiation time T is:

[0179] (s)

[0180] Among them, e q is the electron charge amount (1.6×10 -19 C).

[0181] Corresponding to the charge deposition rate ρ d in the medium under the actual beam current is:

[0182] (C / m 3 ·s)

[0183] The dose rate in the medium is:

[0184] (rad / s)

[0185] Step 3: Radiation data calculation and export

[0186] Construct calculation models such as specimens, shields, and electron sources in Geant4 according to the methods described in Step 1 and Step 2, set the number of incident electrons for simulation, and start the simulation. After the calculation is completed, save the recorded charge deposition amount E n and energy deposition amount E g as a.txt file and export it to MATLAB; convert the charge deposition rate ρ d and dose rate

[0187] 2. Working voltage simulation scheme

[0188] As Figure 3 shown, the present invention considers four voltage application conditions, namely A (V S -G), the radiation surface of the specimen is pressurized and the bottom surface is grounded; B (V S -S), the radiation surface of the specimen is pressurized and the bottom surface is neither pressurized nor grounded; C (S-V S ), the radiation surface of the specimen is neither pressurized nor grounded and the bottom surface is pressurized; D (G-V S ), the radiation surface of the specimen is grounded and the bottom surface is pressurized. The thickness of the electrode and the grounding plate are ignored in the calculation.

[0189] According to research, the current bus voltages of spacecraft are mostly 42V, 100V, 120V, etc. According to the "13th Five-Year" technology pre-research guidelines for civil space: the short-term power demand of geostationary orbit high-power high-resolution SAR satellites is expected to be 50 - 80kW, and the output power of nuclear-powered spacecraft is 100kW, with the designed bus voltage being 400 - 600V. Therefore, the research range of the working voltage set in this invention is 100V - 1000V, and three voltage levels of 100V, 500V, and 1000V are selected for analysis and calculation; it can also be set and simulated according to the actual working voltage of the spacecraft.

[0190] 3. Grounding method simulation scheme

[0191] The grounding method is an important part of the spacecraft shielding design, which determines the leakage path of charges in the medium and affects the distribution of the electric field in the medium. This invention constructs several common grounding methods to study the influence of the grounding method on the electric field distribution in the medium, such as Figure 4 shown, which are respectively a (S - G), the radiation surface is suspended (neither pressurized nor grounded), and the bottom surface is grounded; b (G - S), the radiation surface is grounded and the bottom surface is suspended; c (G - G), both the radiation surface and the bottom surface are grounded. The grounding method can be selected according to the actual working conditions of the spacecraft medium and simulated.

[0192] 4. Comprehensive evaluation calculation

[0193] (1) Construction of the charge transport model

[0194] In order to evaluate the risk of charging in the medium, it is necessary to calculate the distribution of the electric field strength in the medium under the corresponding working conditions, which requires solving the charge transport equation.

[0195] The charge transport equation selected in this invention is as follows:

[0196]

[0197] This system of equations is, from top to bottom, the Poisson equation, the current continuity equation, and Ohm's law. Among them, E is the electric field strength, V / m (to be solved); ρ s is the net charge density in the medium, C / m 3 , (to be solved); ε is the dielectric constant of the medium, F / m, (measured by experiment); J is the net current density, A / m 2 , (to be solved); ρ d is the charge deposition rate in the medium, C / m 3 ·s.

[0198] σ E is the conductivity related to the electric field, S / m.

[0199]

[0200]

[0201] Wherein, σ E is the Poole-Frenkel conductivity, S / m; σ0 is the initial conductivity of the medium, S / m (measured experimentally); β F —the Frenkel coefficient; e is the electronic charge, C; ε0 is the vacuum permittivity, F / m; ε r is the relative permittivity (measured experimentally).

[0202] σ RIC is the conductivity related to the electric field, S / m.

[0203]

[0204] Wherein, is the radiation dose rate, rad / s; k RIC (T) is a proportionality coefficient, the value of which is related to the material, with the unit of / S·s / m·rad; Δ(T) is the exponential coefficient, both of which are related to the material itself and vary with temperature; Δ(T) generally takes values between 0.5 and 1, depending on the energy state distribution of the traps in the medium. In the present invention, 0.5 is taken.

[0205] (2) Solve the charge transport model

[0206] The charge transport model is solved by the finite element method. In the present invention, the commercial finite element software COMSOL is selected for solving:

[0207] Step 1: Construct a corresponding three-dimensional medium model in COMSOL according to the size of the specimen;

[0208] Step 2: Construct a corresponding three-dimensional charge transport equation in COMSOL;

[0209] In the present invention, the partial differential equation interface in the mathematical module of COMSOL is not selected to customize and construct the above three-dimensional charge transport equation set.

[0210] The partial differential equation selects the partial differential equation in the general form, and its specific structure is as follows:

[0211]

[0212]

[0213] Modify the coefficients of this partial differential equation one by one according to the charge transport model equation to obtain the set charge transport equation set.

[0214] Step 3: Introduce the set working voltage and grounding method in COMSOL.

[0215] The present invention needs to comprehensively consider factors such as electron radiation factors, working voltage, and dielectric grounding method. When setting the working voltage and grounding method, they are set in COMSOL when solving the charge transport equations:

[0216] When solving the charge transport equations, factors such as the grounding state, grounding position of the dielectric, and the amplitude and application position of the working voltage correspond to the initial state and boundary conditions of the partial differential equations in COMSOL. In COMSOL, the initial conditions of the custom equations can be modified according to the set working conditions, and the Dirichlet boundary conditions can be added to complete the setting of various boundary conditions such as the position and amplitude of the working voltage and the grounding method and position.

[0217] Step 4: Solve the charge transport equations

[0218] First, it is necessary to complete the simulation of the electron radiation process in Geant4 according to the set radiation parameters, and convert the two key parameters of the charge deposition rate and dose rate at each position in the sample obtained and import them into COMSOL. The present invention uses the interpolation method to import them into COMSOL.

[0219] Then, according to the actual working conditions of the sample, complete the setting of the grounding method, position, and the application position and amplitude of the working voltage. Then, perform mesh division on the three-dimensional model of the dielectric, set the radiation time, and select the MUMPS type solver based on LU decomposition for solving calculations. Finally, the internal electric field distribution of the sample within the set radiation time under the actual working conditions can be obtained.

[0220] (3) Dielectric electrostatic discharge risk assessment

[0221] Step 1: Experimentally determine the breakdown field strength of the dielectric;

[0222] Step 2: Calculate the internal electric field distribution of the dielectric under the set conditions and find the maximum electric field strength amplitude;

[0223] Step 3: Compare the dielectric breakdown field strength and the maximum electric field amplitude under the set radiation conditions to determine whether there is an electrostatic discharge risk. If the maximum electric field strength amplitude is greater than the measured breakdown field strength of the dielectric, there is an electrostatic discharge risk, and the greater the gap between the two, the higher the electrostatic discharge risk; if the maximum electric field strength amplitude is less than the measured breakdown field strength of the dielectric, there is no electrostatic discharge risk, and the greater the gap between the two, the lower the electrostatic discharge risk.

[0224] Step 4: Calibrate the required minimum shielding thickness by recalculating the maximum electric field amplitude by adjusting the shielding thickness, so as to adjust the shielding design;

[0225] Step 5: Select the optimal grounding method design by recalculating the maximum electric field amplitude by adjusting the grounding method and grounding position.

[0226] The calculation results provided by the embodiments of the present invention are as Figures 5 to 6 shown.

[0227] The system for calculating and evaluating the risk of internal charging in the medium provided by the embodiments of the present invention includes:

[0228] An electron radiation simulation module, configured to determine an electron radiation simulation scheme by simulating the radiation process of the medium in a monoenergetic electron radiation environment and simulating the radiation process of the medium in a real-space electron radiation environment;

[0229] A working voltage simulation module, configured to analyze four voltage application conditions to determine a working voltage simulation scheme,

[0230] A grounding method simulation module, configured to analyze the influence of the grounding method on the internal electric field distribution of the medium by determining a grounding method simulation scheme;

[0231] A comprehensive evaluation calculation module, configured to comprehensively evaluate and calculate the risk of electrostatic discharge in the medium by constructing a charge transport model and then solving the charge transport model.

[0232] II. Evidence of related effects of the embodiments. Some positive effects have been achieved during the research and development or use of the embodiments of the present invention, and there are indeed great advantages compared with the prior art. The following content is described in combination with the data, charts, etc. of the test process.

[0233] In this example, the typical aerospace medium polyimide (PI) is used as the research object, and the geosynchronous orbit electron radiation environment is selected for analysis. According to the method provided by the present invention, first, the FLUMIC3 model is used to construct the geosynchronous orbit electron radiation environment according to the setting method of the real-space electron radiation environment; then, the charge transport equation is constructed, and the internal electric field characteristics of PI under different aluminum shielding layer thicknesses, different grounding methods and working voltages are calculated, and the discharge risk thereof is evaluated.

[0234] The calculation results are as Figure 5 As can be seen from the relationship between the maximum value of the internal electric field of PI in the GEO environment and the grounding method and the shielding thickness, under the three grounding methods, the maximum value of the internal electric field of the sample decreases with the increase of the aluminum shielding thickness. When the shielding thickness increases from 0 mm to 6 mm, when using the a-type grounding, the maximum value of the internal electric field of the sample decreases from 5.817×10 7 V / m to 1.556×10 6 V / m; when using the b-type grounding, it decreases from 5.116×10 7 V / m to 1.503×10 6 V / m; when using the c-type grounding, the maximum value of the internal electric field decreases from 4.196×10 7 V / m to 1.476×10 6V / m. At the same time, by comparing the maximum values of the internal electric fields corresponding to the three grounding types under the same shielding thickness, it can be obtained that when using type a grounding, the internal electric field strength is the largest, followed by type b, and the smallest is type c. The reason is that when using type c grounding, since both the irradiated surface and the bottom surface of the sample are grounded, the largest grounding area is conducive to the leakage of deposited charges, and the corresponding electric field strength is the smallest.

[0235] As Figure 6 shown, from the calculation results, it can be obtained that when the electrostatic discharge safety threshold is set to 2×10 7 V / m or the more stringent 1×10 7 V / m, the shielding thickness required for using type c grounding (both the irradiated surface and the bottom surface are grounded) is the smallest, only 1.216 mm and 2.612 mm respectively. When the thickness of the aluminum shielding layer is greater than this threshold, it can be considered that there is no risk of electrostatic discharge.

[0236] From the calculation results, it can be obtained that considering all voltage application methods and voltage amplitudes comprehensively, the maximum value of the internal electric field in the sample without shielding is 5.77×10 7 V / m, which is greater than the recommended electrostatic discharge threshold of 2×10 7 V / m; when the shielding thickness is 3 mm, the maximum value of the internal electric field in the sample is 1.37×10 7 V / m, which can meet the requirements of charged protection in the medium under general circumstances.

[0237] It should be noted that the embodiments of the present invention can be implemented through hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated designed hardware. Those of ordinary skill in the art can understand that the above-mentioned devices and methods can be implemented using computer-executable instructions and / or included in processor control code, for example, such code is provided on a carrier medium such as a disk, CD, or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and their modules of the present invention can be implemented by hardware circuits of programmable hardware devices such as very large scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable logic devices such as field programmable gate arrays, or can be implemented by software executed by various types of processors, or can be implemented by a combination of the above hardware circuits and software, such as firmware.

[0238] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for calculating and evaluating the risk of charge in a medium, characterized in that, The method for calculating and evaluating the risk of charging in a medium includes: simulating the radiation process of the medium in a monoenergetic electron radiation environment and the radiation process of the medium in a real-space electron radiation environment by constructing a specimen model and a shielding layer model, constructing an electron radiation source model and calculating relevant radiation parameters, and calculating and deriving radiation data; analyzing four voltage application conditions, setting the working voltage range as 100 - 1000V, and selecting three levels of voltages, 100V, 500V, and 1000V, for calculation; analyzing the influence of the grounding method on the electric field distribution in the medium by constructing a grounding method simulation scheme; constructing a charge transport model and solving it to achieve the risk assessment of electrostatic discharge in the medium; The method for calculating and evaluating the risk of charging in a medium includes the following steps: Step 1, determining the electron radiation simulation scheme through simulating the radiation process of the medium in a monoenergetic electron radiation environment and the radiation process of the medium in a real-space electron radiation environment; Step 2, analyzing four voltage application conditions to determine the working voltage simulation scheme; Step 3, determining the grounding method simulation scheme and analyzing the influence of the grounding method on the electric field distribution in the medium; Step 4, achieving the comprehensive assessment calculation of the risk of electrostatic discharge in the medium by constructing a charge transport model and then solving the charge transport model; The comprehensive assessment calculation in Step 4 includes: (1) Construction of the charge transport model The selected charge transport equation is as follows: The charge transport equations from top to bottom are the Poisson equation, the current continuity equation, and Ohm's law; where E is the electric field strength with the unit of V / m; ρ s is the net charge density in the medium with the unit of C / m 3 ; ε is the dielectric constant of the medium with the unit of F / m; J is the net current density with the unit of A / m 2 ; ρ d is the charge deposition rate in the medium with the unit of C / m 3 ·s; σ E is the conductivity related to the electric field, with the unit of S / m; where σ E is the Poole-Frenkel conductivity, with the unit of S / m; σ0 is the initial conductivity of the medium, with the unit of S / m; β F is the Frenkel coefficient; e is the electron charge amount, with the unit of C; ε0 is the vacuum permittivity, with the unit of F / m; ε r is the relative permittivity; σ RIC is the conductivity related to the electric field, with the unit of S / m; In the formula, is the radiation dose rate, rad / s; k RIC (T) is the proportionality coefficient, whose value is related to the material, with the unit of S·s / m·rad; Δ(T) is the exponential coefficient, both of which are related to the material itself and vary with temperature; the value of Δ(T) ranges from 0.5 to 1, depending on the energy state distribution of the traps in the medium; (2) Solving the charge transport model The charge transport model is solved using the commercial finite element software COMSOL: 1) Construct a corresponding three-dimensional medium model in COMSOL according to the size of the specimen; 2) Construct a corresponding three-dimensional charge transport equation in COMSOL; The structure of the partial differential equation is as follows: Modify the coefficients of the partial differential equation one by one according to the charge transport model equation to obtain the set charge transport equations; 3) Introduce the set working voltage and grounding method in COMSOL; Comprehensively consider the electron radiation factor, the working voltage, and the medium grounding method factor, where the working voltage and the grounding method are set when solving the charge transport equations in COMSOL; When solving the charge transport equations, the grounding state, grounding position of the medium, and the amplitude and application position of the working voltage correspond to the initial state and boundary conditions of the partial differential equation system in COMSOL; modify the initial conditions of the custom equation and add Dirichlet boundary conditions according to the set working conditions in COMSOL to complete the setting of various boundary conditions of the working voltage position, amplitude, and grounding method and position; 4) Solve the charge transport equations; Complete the simulation of the electron radiation process in Geant4 according to the set radiation parameters, and after converting the two key parameters of the charge deposition rate and dose rate at each position in the specimen obtained, import them into COMSOL by interpolation; Complete the setting of the grounding method, position, and the application position and amplitude of the working voltage according to the actual working conditions of the specimen; perform mesh division on the three-dimensional medium model, set the radiation time, and select the MUMPS type solver based on LU decomposition for solving calculation to obtain the internal electric field distribution of the specimen within the set radiation time under the actual working conditions; (3) Risk assessment of electrostatic discharge in the medium 1) Measure the breakdown field strength of the medium through experiments; 2) Calculate the electric field distribution in the medium under the set conditions and find the maximum electric field strength amplitude; 3) Compare the breakdown field strength of the medium and the maximum electric field amplitude under the set radiation conditions to determine whether there is a risk of electrostatic discharge. If the maximum electric field strength amplitude is greater than the measured breakdown field strength of the medium, there is a risk of electrostatic discharge, and the greater the difference between the two, the higher the risk of electrostatic discharge; if the maximum electric field strength amplitude is less than the measured breakdown field strength of the medium, there is no risk of electrostatic discharge, and the greater the difference between the two, the lower the risk of electrostatic discharge; 4) Recalculate the maximum electric field amplitude by adjusting the shielding thickness to calibrate the minimum shielding thickness required and thus adjust the shielding design; 5) Recalculate the maximum electric field amplitude by adjusting the grounding method and grounding position to select the optimal grounding method design.

2. The method for calculating and evaluating the risk of charged particles in the medium according to claim 1, wherein, The determination of the electron radiation simulation scheme in step one includes: (1) Simulation of the radiation process of the medium in a monoenergetic electron radiation environment Select the Monte Carlo method to simulate the interaction process between the medium and the incident electrons, and use the open-source software Geant4 to write the corresponding electron radiation program for simulation; 1) Construct the specimen model and the shielding layer model; Program in Geant4 to construct the corresponding three-dimensional models of the specimen and the shielding layer and the vacuum environment according to the material, size of the medium specimen, and the material and thickness of the shielding layer; set the medium model as the detector, divided into 100*100*10 volume micro-elements for detecting and recording the charge deposition and energy deposition at various positions inside the medium; Construct a circular specimen model with a diameter of 10 cm and a thickness of 1 mm according to the actual size of the polyimide specimen, and place it entirely in a vacuum environment; construct an aluminum shielding layer 10 cm to the left of the specimen, with dimensions of 15 cm×15 cm and a thickness of 3 mm, and the thickness is parameterized and adjusted according to the actual working conditions; 2) Construct the electron radiation source model and calculate the relevant radiation parameters; Program in Geant4 to construct an electron source, set the electron source parameters and the incident electron parameters; design the electron source as a planar electron source, incident perpendicular to the sample surface; the parameters of the incident electrons are the incident electron energy and the electron beam current density. The incident electron energy is directly programmed and set, and the electron beam current density is obtained by a conversion method; Geant4 uses the Monte Carlo method to simulate the interaction process between electrons and the medium, only setting the number of incident electrons simulated, and converting the deposition charge quantity recorded by the detector to the charge deposition rate under the corresponding beam current density; Among them, the conversion method is as follows: When the number of incident electrons is N; the incident electron beam current density is J0, with the unit of A / m 2 ; the area of the electron source is A0, with the unit of m 2 ; the amounts of charge deposition and energy deposition recorded by the Geant4 medium volume element are E n and E g , then the virtual radiation time T is: Unit s; where e q is the elementary charge of 1.6×10 -19 C; Corresponding to the charge deposition rate ρ in the medium under the actual beam current d is C / m 3 ·s; Dose rate in the medium is as follows: Unit: rad / s; 3) Calculate and export the radiation data; Build a computational model of the specimen, shield, and electron source in Geant4, set the number of incident electrons for simulation, and perform the simulation. After the calculation, save the recorded charge deposition E n and energy deposition E g as a.txt file and export it to MATLAB, and convert the charge deposition rate ρ d and dose rate (2) Simulation of the radiation process of the medium in a real-space electron radiation environment 1) Construct the specimen model and the shielding layer model; The construction of the specimen model and the shielding layer is the same as that in the monoenergetic electron case. Program in Geant4 to construct the corresponding three-dimensional models of the specimen and the shielding layer and the vacuum environment according to the material, size of the medium specimen, and the material and thickness of the shielding layer; set the medium model as the detector, divided into 100*100*10 volume micro-elements for detecting and recording the charge deposition and energy deposition at various positions inside the medium; 2) Construct the electron radiation source model and calculate the relevant radiation parameters; Program to construct an electron source in Geant4, set the parameters of the electron source and the incident electrons; design the electron source as a planar electron source, incident vertically along the sample surface; the parameters of the incident electrons are the incident electron energy and the electron beam current density, and the FLUMIC model is selected for calculation; The outer radiation belt model is as follows: Taking into account the solar cycle and annual variations, for the outer radiation belt with L>2.5, the electron flux will be a function of fsc, foy, L, and E; Function regarding the solar cycle: In the formula, fsc represents the normalized value of the solar activity cycle, which is 0 in the solar minimum year; Function regarding the season: In the formula, foy represents the normalized value of the date in a year, with January 1 as the zero starting point; Function regarding the energy: F(>E)=F(>2MeV)×exp[(2-E) / E0]; Among them, Function regarding L: In the formula, L is the distance to the center of the Earth; Calculate the electron radiation flux corresponding to different orbital heights through the FLUMIC3 model, convert it to the vertical direction to simulate the vertical incidence of electrons, and at the same time set it as the energy spectrum mode radiation in Geant4 according to the converted electron flux, and set the electron energy range; The conversion method of the charge deposition rate and dose rate in the medium is as follows: When the number of incident electrons is N; the incident electron beam current density is J0, with the unit of A / m 2 , the electron source area is A0, with the unit of m 2 ; the charge deposition and energy deposition recorded by the Geant4 medium volume element are E n and E g , then the virtual radiation time T is: Unit s; where e q is the electronic charge of 1.6×10 -19 C; Corresponding to the charge deposition rate ρ in the medium under the actual beam current d is as follows: C / m 3 ·s; Dose rate in the medium is as follows: Unit: rad / s; 3) Calculate and export the radiation data; Build a computational model of the specimen, shield, and electron source in Geant4, set the number of incident electrons for simulation, and perform the simulation. After the calculation, save the recorded charge deposition amount E n and the energy deposition amount E g as a.txt file and export it to MATLAB, and convert the charge deposition rate ρ d and the dose rate 3. The method for calculating and evaluating the risk of charging in a medium according to claim 1, wherein The determination of the working voltage simulation scheme in step two includes: Analyze four voltage application conditions, namely A: V S -G, with the radiation surface of the specimen pressurized and the bottom grounded; B: V S -S, with the radiation surface of the specimen pressurized and the bottom neither pressurized nor grounded; C: S-V S , with the radiation surface of the specimen neither pressurized nor grounded and the bottom pressurized; D: G-V S , with the radiation surface of the specimen grounded and the bottom pressurized; Ignore the thickness of the electrodes and the grounding plate during the calculation; set the working voltage range to 100V to 1000V, and select three levels of voltages, 100V, 500V, and 1000V, for calculation.

4. The method for calculating and evaluating the risk of charging in the medium according to claim 1, wherein, The determination of the grounding method simulation scheme in step three includes: Construct the grounding method and analyze the influence of the grounding method on the electric field distribution in the medium; among them, the constructed grounding methods are a: S-G, the radiation surface is suspended, neither pressurized nor grounded, and the bottom surface is grounded; b: G-S, the radiation surface is grounded and the bottom surface is suspended; c: G-G, both the radiation surface and the bottom surface are grounded.

5. A system for calculating and evaluating the risk of charge in a medium, which applies the method for calculating and evaluating the risk of charge in a medium according to any one of claims 1 to 4, is characterized in that The system for calculating and evaluating the charging risk in the medium includes: An electron radiation simulation module, which is used to determine the electron radiation simulation scheme through the simulation of the radiation process of the medium in a monoenergetic electron radiation environment and the simulation of the radiation process of the medium in a real-space electron radiation environment; A working voltage simulation module, which is used to analyze four voltage application conditions and determine the working voltage simulation scheme; A grounding method simulation module, which is used to analyze the influence of the grounding method on the electric field distribution in the medium by determining the grounding method simulation scheme; A comprehensive evaluation calculation module, which is used to realize the comprehensive evaluation calculation of the electrostatic discharge risk in the medium by constructing a charge transport model and then solving the charge transport model.

6. A computer device, characterized in that, The computer device includes a memory and a processor. When the computer program stored in the memory is executed by the processor, the processor executes the steps of the method for calculating and evaluating the charging risk in the medium as described in any one of claims 1 to 4.

7. A computer-readable storage medium stores a computer program. When the computer program is executed by the processor, the processor executes the steps of the method for calculating and evaluating the charging risk in the medium as described in any one of claims 1 to 4.

8. An information data processing terminal, characterized in that, The information data processing terminal is used to implement the system for calculating and evaluating the charging risk in the medium as described in claim 5.

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