Analysis and evaluation method for risk of single event upset of aerospace electronic device caused by solar proton event

Abstract

The invention discloses an analysis and evaluation method for the risk of single event upset of an aerospace electronic device caused by a solar proton event, and the method comprises the following steps: S1, building a target model of the aerospace electronic device, and calculating the relation between the SEU section of the target device and the proton energy; s2, analyzing on-orbit proton radiation environment elements of the spacecraft, acquiring detection data and calculating the radiation flux of the SPE; s3, calculating measurement parameters of device single event upset caused by the SPE generation process; and S4, evaluating and grading the SEU risk caused by the SPE according to a calculation result. The SEU cross section of the electronic device is calculated by adopting a Monte Carlo method, and an inelastic energy deposition event of a sensitive area of the device caused by monoenergetic protons can be accurately obtained. According to the method, a basis can be accurately and effectively provided for troubleshooting and information error correction of the spacecraft, and the method can be directly applied to an existing on-orbit spacecraft.

Description

Technical Field

[0001] The present invention relates to the technical field of risk assessment of aerospace electronic device anomalies caused by high-energy particle radiation in space weather services, and in particular to a method for calculating and analyzing and grading the risk of single particle upset effects of space electronic devices caused by solar proton events. Background Art

[0002] High-energy proton radiation during a solar proton event (SPE) can cause a series of single event effects (SEE) in integrated circuit electronic devices of on-orbit spacecraft, among which the single event upset (SEU) has a high incidence rate. SEU of aerospace electronic systems is one of the important causes of spacecraft anomalies and failures.

[0003] At present, in the sub-field of SEU risk assessment for electronic devices in space weather forecasting and warning services, the existing methods and standards are not sound enough. The main factors causing this situation include: the SEU phenomenon is the comprehensive result of the excitation, transfer and collection of electrons in the target material caused by space ionizing radiation, and the microscopic physical mechanism is relatively complex. The probability of SEU occurrence has obvious dependence on the device process structure, radiation environment and protection conditions. In addition, the detection and prediction of the local radiation energy spectrum of the spacecraft orbit and its data fusion technology still need to be developed.

[0004] In recent years, with the development of aerospace science and technology and electronic technology, the cost of satellite launch and operation has continued to decrease, and the number of satellites in orbit has greatly increased. The application of satellite and aerospace technology in remote sensing, navigation, communications and other fields is also becoming increasingly widespread. At the same time, satellite-borne and aerospace integrated circuits are developing in the direction of small size, low power consumption, large capacity, high transmission and operation speed. The single-bit state change of key electronic devices corresponds to a decrease in radiation energy and critical charge. The research on the ability of satellites to resist single-particle effects has become more important. On the basis of improving the observation level of high-energy particle radiation characteristics in solar activities and gradually and accurately calculating the laws of SEU of on-orbit electronic devices, the formation of SEU forecasting and early warning business capabilities for on-orbit electronic devices has become one of the important development directions of space weather services.

[0005] After a solar proton event occurs, according to the current industry classification standards for solar proton events, it is impossible to effectively assess the risk of single particle upset effects in aerospace electronic devices caused by it. Therefore, it is difficult to determine the extent to which troubleshooting and information correction should be performed on aerospace electronic devices after a solar proton event occurs. The industry urgently needs a solution that can effectively assess and alarm the risk of single particle upsets caused by solar proton events based on the specific energy spectrum of solar protons and the physical mechanism of device response. Summary of the invention

[0006] In view of the prior art and existing problems, the present invention provides a method for calculating, analyzing and risk assessing single particle upset effects of on-orbit aerospace electronic devices caused by solar proton events.

[0007] The present invention adopts the following technical solution: A method for analyzing and evaluating the risk of single-event upset of aerospace electronic devices caused by a solar proton event comprises the following steps: Step 1: Establish a device target material model based on the aerospace electronic device data parameters, including device structure, CAD information, material parameters, physical plane dimensions, storage capacity, and shielding conditions. Calculate the target device SEU cross section σ SEU and proton energy E P The relationship between SEU (E P ). Accumulate typical device information and establish a SEU cross-section database of conventional devices under standard protection.

[0008] Step 2: Obtain environmental factors, mainly including the orbital conditions of aerospace electronic devices and event parameters near the orbit. Analyze the proton radiation environmental factors of the device orbit when the solar proton event occurs. Based on the data of satellite detectors (such as ACE, GOES, SOHO) combined with ground neutron counting detection data, calculate the solar proton event radiation flux in the orbital environment and obtain the proton flux energy spectrum in a wide energy range.

[0009] Step 3: Based on the above device reaction cross section, proton flux spectrum, and device size and capacity parameters, calculate the metric parameters of the single particle upset of the target device caused by the solar proton event process.

[0010] Step 4: Based on the calculation results described in step 3, evaluate and analyze the SEU risk caused by solar proton events.

[0011] The measurement parameters of the single-particle upset of the target device in step 3 include: the maximum flip probability P of each bit caused by SPE TotMax , the maximum cumulative flip cross section Σ experienced by each bit of the device during the SPE process TotMax 、The maximum total number of flips experienced by the entire device N TotMax , device average SEU flip rate .

[0012] The risk assessment classification method described in step 4 is: based on the maximum SEU flip probability P of typical aerospace components TotMax Distribute the data and set the risk to four levels: L0: Low risk area. The corresponding single particle maximum flip probability threshold upper limit is P TotMax = ; The overturning probability in this region is close to the probability caused by the average GCR background radiation during the quiet solar activity period.

[0013] L1: Medium risk, yellow warning zone. The corresponding single particle maximum flip probability threshold upper limit is P TotMax = .

[0014] L2: High risk, orange warning zone. The corresponding single particle maximum flip probability upper limit is P TotMa = .

[0015] L3: Extreme risk, red warning zone. The corresponding single particle maximum flip probability exceeds P TotMax = At this point, the risk of a bit flipping in the device is higher than 10%. A high information error rate can cause the error correction mechanism to fail.

[0016] The method for calculating the relationship between the SEU cross section and the proton energy of the target device in step 1 is as follows: the Monte Carlo principle is used to simulate the interaction process between the monoenergetic proton and the device, and the energy deposition in the sensitive area of ​​the device is statistically analyzed based on a large number of simulation results. SEU (E P ) calculation formula is used to perform reaction judgment and cross-section calculation, so as to accurately calculate the relationship curve between proton energy and device reaction cross-section in a wide energy range.

[0017] Furthermore, the Monte Carlo principle calculation simulation method includes: using Geant4 and its expansion toolkit G4SEE to simulate a given energy region (such as E P The inelastic energy deposition in the sensitive area of ​​the device caused by monoenergetic protons with a voltage of less than 20 MeV is compared and verified with possible experimental results. The tracking and statistical tools provided by G4SEE are used to accurately simulate the reaction process in which the incident particles interact with the semiconductor material during the SEU process, deposit energy in the semiconductor sensitive area, and cause changes in the electron and hole concentrations and their recombination processes of the material, thereby causing the information state of the single bit storage location to flip.

[0018] Furthermore, the SEU cross-section calculation formula is: ,in, The energy is E P The number of incident protons, is the number of SEU events recorded in the simulation, To simulate the surface area of ​​the target, which is also the area of ​​the incident particle source in the simulation, is the number of bits corresponding to the target model.

[0019] The optimal method for calculating the radiation flux of the orbital environment in step 2 is: comprehensively process the flux records of proton detectors of satellites such as ACE, SOHO, and GOES, as well as the existing observation data obtained by ground-based neutron observatories, apply the parameterized double power law distribution function energy spectrum formula of SPE, and perform multi-parameter fitting to obtain proton flux energy spectrum data in a wide energy range. And match it with the proton energy range of the relationship curve of the device reaction cross section to achieve accurate calculation of the SEU reaction probability associated with the complete event.

[0020] Furthermore, the energy spectrum formula of the parameterized double power-law distribution function is: ,in, is the integrated flux or intensity of the particles, and E is the kinetic energy per nucleon of the particles. Four free parameters are used to describe the behavior of SPE spectral lines in a wide energy range. The four free parameters are obtained by fitting the double power law distribution function energy spectrum formula to satellite observation data. For the total energy spectrum of the calculated SPE event process, the flux is large enough to ignore the influence of the background environment (galactic cosmic rays).

[0021] Further, calculate the maximum flip probability P of each bit caused by SPE TotMax The formula is: .

[0022] Furthermore, the maximum cumulative flip cross section Σ experienced by each bit of the device during the SPE process is calculated. TotMax The formula is: ,in, It represents the average surface area of ​​1-bit device exposed to particles. It indicates the number of irradiated particles received by 1 bit. This metric parameter can reflect the SEU resistance of the device material to SPE and should be converted to this metric parameter when evaluating the performance of the device material.

[0023] Furthermore, the maximum total number of flips experienced by the entire device is calculated TotMax The formula is: ,in, is the total capacity of the device, is the energy range of SPE. This metric parameter can reflect the SEU impact of a specific device after it experiences a specific SPE, and should be converted to this metric parameter when assessing the SEU risk caused by SPE of a specific on-orbit aerospace electronic device.

[0024] Furthermore, the average SEU flip rate of the device is calculated The formula is: ,in, It is the time interval between the start and end of the SPE event. This metric parameter can reflect the average SEU impact of a specific SPE event on a device and should be converted to this metric parameter when evaluating the characteristics of an SPE event.

[0025] After adopting the above technical solution, the beneficial effects of the present invention are: 1. The present invention provides a Monte Carlo method for simulating and calculating the SEU cross section of a specific device based on Geant4, which can accurately simulate the single-particle upset effect of on-orbit electronic devices in a space proton radiation environment, and can be applied to various aerospace electronic devices with clear structures. Compared with experimental determination or other simulation methods, the method provided by the present invention can provide effective and low-cost upset cross section data when processing existing on-orbit spacecraft and future new aerospace devices.

[0026] 2. The present invention provides a method and program for fitting the SPE flux energy spectrum using SPE flux observation data, obtaining the behavior characteristics of the SPE spectral line in a sufficiently wide energy range, and facilitating batch processing of a large number of SPE events. Compared with directly using observation data, the method provided by the present invention can accurately and completely obtain the specific energy spectrum of solar protons.

[0027] 3. The present invention provides a method for calculating the metric parameters of the single-particle upset effect caused by SPE, and proposes the maximum flip probability P of each bit caused by SPE. TotMax As the main reference physical quantity for SEU risk assessment and classification of electronic devices, it can fully reflect the physical and probabilistic information of single-particle upset effects in on-orbit electronic devices, making it easy to convert measurement parameters. It can also establish parameters and classification standards that can be verified and easily compared for the statistical risk of single-particle upsets caused by SPE.

[0028] 4. The present invention proposes a reasonable risk classification scheme for single-particle upsets of aerospace electronic devices. Compared with the traditional method in the current industry that uses the solar proton event level as a reference, the classification of the present invention is more specific and reliable. Because there is no definite linear correspondence between the SEU risk level and the solar proton event level, the classification scheme for specific SEU measurement parameters proposed by the present invention is a significant improvement on the current risk assessment.

[0029] 5. The present invention provides a complete analysis and assessment method for the risk of single-particle upsets caused by SPE, which can accurately and effectively provide a basis for troubleshooting and information correction of aerospace devices. The method provided by the present invention can reduce the cost of coping with aerospace devices to interference from solar proton events, and can be directly applied to existing on-orbit spacecraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A flowchart illustrating a method for analyzing and evaluating the risk of single particle upset in aerospace electronic devices caused by a solar proton event provided by the present invention.

[0031] Figure 2 A diagram showing the calculation results of the single particle upset reaction cross section of an electronic device provided in an embodiment of the present invention.

[0032] Figure 3 This is a diagram of the solar proton event energy spectrum fitting results provided by an embodiment of the present invention.

[0033] Figure 4 The total probability calculation result of the single particle upset effect of aerospace electronic devices caused by a solar proton event provided in an embodiment of the present invention, and the risk assessment result diagram implemented according to the risk grading method provided by the present invention. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below with reference to the accompanying drawings and specific examples, but the embodiments of the present invention are not limited thereto: See also Figure 1 , is a flowchart of a method for analyzing and evaluating the risk of single-particle upset of aerospace electronic devices caused by a solar proton event provided by the present invention, comprising: Step 1: Establish a device target material model based on the aerospace electronic device data parameters, including device structure, CAD information, material parameters, physical plane dimensions, storage capacity, and shielding conditions. Calculate the target device SEU cross section σ SEU and proton energy E P The relationship between SEU (E P ).

[0035] The main reference device ISSI SRAM selected in this embodiment is manufactured by Integrated Silicon Solutions Inc using a 40nm process. Its physical plane size is 18.40mm×12.00mm, and its storage capacity is 32Mbit. In order to study the shielding effect of electronic devices at different positions in the spacecraft, this embodiment simulates two typical conditions for the ISSI SRAM device to be directly irradiated by protons (DR condition) and to be shielded by a 3mm thick Al layer (SR condition).

[0036] The method for calculating the relationship between the SEU cross section and the proton energy of the target device in step 1 is: using the Monte Carlo principle to simulate the interaction process between the monoenergetic proton and the device, statistically analyzing the energy deposition in the sensitive area of ​​the device based on a large number of simulation results, and using the energy criterion for SEU occurrence and the SEU cross section σ SEU (E P ) calculation formula is used to perform reaction judgment and cross-section calculation, so as to accurately calculate the relationship curve between proton energy and device reaction cross-section in a wide energy range.

[0037] The Monte Carlo calculation simulation method includes: using Geant4 and its expansion toolkit G4SEE to simulate the given energy range E P The inelastic energy deposition in the sensitive area of ​​the device caused by monoenergetic protons <20MeV is compared and verified with possible experimental results. Using the tracking statistics tool provided by G4SEE, the incident particles interact with the semiconductor material during the SEU process, depositing energy in the semiconductor sensitive area, causing changes in the electron and hole concentrations of the material and their recombination process, and then causing the single-bit storage location to flip the information state reaction process to be accurately simulated.

[0038] The SEU cross-section calculation formula is: .

[0039] See also Figure 2 , which is a simulation result diagram of the relationship between the SEU cross section and the proton energy of the on-orbit electronic device ISSI SRAM selected in this embodiment under direct radiation conditions and 3mmAl layer protection conditions. The two radiation conditions correspond to the two curves in the figure respectively.

[0040] Step 2: Obtain environmental factors and analyze the proton radiation environmental factors of aerospace devices on orbit. Based on the data of satellite detectors (such as ACE, GOES, SOHO) combined with ground neutron detection data, calculate the solar proton event radiation flux in the orbital environment and obtain the proton flux energy spectrum in a wide energy range.

[0041] The method for calculating the radiation flux of the orbital environment is: based on the existing observation data, fit the parameterized double power-law distribution function energy spectrum of the solar proton event to obtain the radiation conditions.

[0042] This embodiment selects satellite detectors: GOES in geosynchronous orbit; ACE and SOHO at L1. To avoid overlapping of energy zones, this embodiment arranges and selects energy channels.

[0043] This embodiment selects the ground-enhanced event among solar proton events to calculate the flux energy spectrum. Solar protons with energy exceeding 200 MeV enter the Earth's atmosphere and can interact with the atmosphere to produce abundant secondary particles, thereby effectively increasing the ground neutron flux. Such solar proton events that cause significant changes in ground neutron counts are called ground-enhanced events (GLE). There are currently 73 GLEs observed by humans. This example selects 39 ground-enhanced events with relatively complete and reliable observation data.

[0044] The energy spectrum formula of parameterized double power-law distribution function is: .

[0045] This function uses four free parameters to describe the behavior of SPE lines over a wide energy range. For the total energy spectrum of the calculated SPE event, the flux is large enough to ignore the influence of the background environment (cosmic rays).

[0046] See also Figure 3 , which is a diagram of the fitted energy spectra of 39 ground enhancement events selected in this embodiment. There are 39 curves in total, and each curve corresponds to a ground enhancement event.

[0047] Step 3: Combine the above reaction cross section, proton flux spectrum, and device size and capacity parameters to calculate the metric parameters of the single particle flip of the device accompanying the solar proton event process.

[0048] The measurement parameters of the single-particle upset of the device in step 3 include: the maximum flip probability P of each bit caused by SPE TotMax , the maximum cumulative flip cross section Σ experienced by each bit of the device during the SPE process TotMax 、The maximum total number of flips experienced by the entire device N TotMax , device average SEU flip rate .

[0049] Calculate the maximum flip probability P of each bit caused by SPE TotMax The formula is: .

[0050] Calculate the maximum cumulative flip cross section Σ experienced by each bit of the device during the SPE process TotMax The formula is: .

[0051] Calculate the maximum total number of flips N experienced by the entire device TotMax The formula is: .

[0052] Calculate the average SEU flip rate of the device The formula is: .

[0053] Step 4: Based on the measurement parameter calculation results of step 3, evaluate and grade the SEU risk caused by the solar proton event.

[0054] In this embodiment, the maximum flip probability P of each bit is caused by using SPE. TotMax As the main reference physical quantity for SEU risk assessment and classification of electronic devices, this parameter can centrally reflect the SEU probability characteristics based on the specific energy spectrum of solar protons and the physical mechanism of device response. At the same time, this parameter is easy to convert into other metric parameters to reflect the unit device effect (Σ TotMax ), total effect (N TotMax )、Unit Event Effect( ).

[0055] See also Figure 4 , the horizontal axis is the peak value of the proton flux intensity of SPE , whose unit is The two curves in the figure correspond to two radiation conditions, direct radiation conditions and 3mmAl layer protection. Each curve has 39 data points, corresponding to 39 ground enhancement events. The risk grading rules for SPE in the industry are currently used for grading on the horizontal axis, and the risk grading method for SEU risk assessment of aerospace electronic devices provided by the present invention is used for grading on the vertical axis, so as to clearly show the SEU risks of a series of solar proton events selected in this embodiment to the target device.

[0056] In order to facilitate the classification of the risk of SEU of electronic devices caused by solar proton events, this embodiment sets the risk to four levels according to the maximum SEU flip probability distribution data of a typical aerospace device ISSI SRAM (specific model: S61WV204816BLL-10TLI), where: L0: Low risk area. The flip probability in this area is close to the probability caused by the average GCR background radiation during the quiet solar activity period, and the corresponding single particle maximum flip probability threshold upper limit is P TotMax = .

[0057] L1: Medium risk, yellow warning zone. The corresponding single particle maximum flip probability threshold upper limit is P TotMax = Under DR conditions, half of the level 1 GLEs, level 2 non-GLE SPEs, and a small number of level 2 and 3 GLEs have SEU risks to ISSI SRAM in this area. Under 3mmAl protection, the SEU risk of most SPEs to ISSI SRAM is at this level.

[0058] L2: High risk, orange warning zone. The corresponding single-particle upset probability upper limit is P TotMa = For ISSI SRAM, under DR conditions, about 80% of GLEs will cause this high SEU risk, Level 1 and Level 2 GLEs (about 20% of total events) can cause the device to be in this high risk area, and the remaining GLEs can cause higher risks. Under SR conditions, only two Level 3 and one Level 4 GLEs will cause this level of SEU risk, accounting for less than 8% of the total events.

[0059] L3: Extreme risk, red warning zone. The corresponding single-particle upset probability upper limit exceeds P TotMa = . At this point, the risk of each bit flipping in the device is higher than 10%. A high information error rate can cause the error correction mechanism to fail. For ISSI SRAM, some level 2 and level 3 GLEs under DR conditions can cause such extreme risks. The device has low risk resistance under DR conditions, and 75% of the GLEs cause such extreme SEU risks.

Claims

1. A method for analyzing and evaluating the risk of single event upsets in aerospace electronic devices caused by solar proton events, characterized in that: The following steps are involved: S1. According to the data parameters of aerospace electronic devices, establish the device target material model and calculate the relationship between the target device SEU cross section σSEU and the proton energy EP σ SEU (E P ), establish the SEU cross-section library; S2. Analyze the proton radiation environment factors of aerospace devices on orbit, obtain detection data and calculate the proton radiation flux of the orbital radiation environment according to the location of the spacecraft during the SPE; S3. Combine the calculation results of S1 and S2 to calculate the measurement parameters of the single-particle upset of the device caused by the solar proton event; S4. Perform risk assessment and classification of SEU risks caused by solar proton events based on the metric parameters obtained in S3; The measurement parameters of single-particle upsets in S3 devices include the maximum flip probability P per bit caused by SPE. TotMax , the maximum cumulative flip cross section per bit of the device caused by the entire SPE process Σ TotMax 、The maximum total number of flips of the entire device N TotMax , device average SEU flip rate ; The risk assessment classification method in S4 is as follows: according to the maximum flip probability P per bit of the aerospace device TotMax Distribute data and set risk to four levels, where: L0： Low risk area, corresponding to the upper limit of the single particle maximum flip probability threshold is P TotMax = ; L1: Medium risk, yellow warning zone, corresponding to the upper limit of the single particle maximum flip probability threshold value P TotMax = ; L2: High risk, orange warning area, corresponding to the maximum SEU flip probability upper limit P TotMax = ; L3: Extreme risk, red warning zone, corresponding to the single particle upset probability upper limit exceeding P TotMax = .

2. The method for analyzing and evaluating the risk of single event upset of aerospace electronic devices caused by solar proton events according to claim 1, characterized in that: The method for calculating the relationship between the SEU cross section and the proton energy of the target device in S1 is: using a computational simulation method based on the Monte Carlo principle to simulate the interaction process between high-energy protons and the target device, and statistically analyzing the energy deposition in the sensitive area based on the simulation results, and calculating the relationship between the SEU cross section and the proton energy according to the energy criterion of SEU occurrence and the SEU cross section σ SEU The calculation formula is used to carry out calculation analysis; the SEU cross-section calculation formula is: 。 3. The method for analyzing and evaluating the risk of single event upset of aerospace electronic devices caused by solar proton events according to claim 2, characterized in that: The computational simulation method based on the Monte Carlo principle is as follows: Geant4 and its expansion toolkit G4SEE are used to simulate the inelastic energy deposition in the sensitive area of ​​the device caused by monoenergetic protons in a given energy range, and compared with the experimental results. During the simulation, the energy deposition of the reaction particles, the types of secondary particles and the momentum distribution are accurately tracked and counted within the micrometer-scale volume.

4. The method for analyzing and evaluating the risk of single event upset of aerospace electronic devices caused by solar proton events according to claim 1, characterized in that: The method for calculating the proton radiation flux of the orbital radiation environment in S2 is: based on satellite observation data, fit the parameterized double power-law distribution function energy spectrum of solar proton events. The energy spectrum distribution function uses four free parameters to describe the behavioral characteristics of solar proton spectral lines in a wide energy range.

5. The method for analyzing and evaluating the risk of single event upset of aerospace electronic devices caused by solar proton events according to claim 1, characterized in that: The parameterized double power-law distribution function energy spectrum formula is: ,in, is the integrated flux or intensity of the particle, E is the kinetic energy per nucleon of the particle, There are four free parameters that describe the behavior characteristics of SPE spectral lines in a wide energy range.

6. The method for analyzing and evaluating the risk of single event upset of aerospace electronic devices caused by solar proton events according to claim 1, characterized in that: Calculate the maximum flip probability P of each bit caused by SPE TotMax The formula is: 。 7. The method for analyzing and evaluating the risk of single event upset of aerospace electronic devices caused by solar proton events according to claim 1, characterized in that: Calculate the maximum cumulative flip cross section Σ experienced by each bit of the device during the SPE process TotMax The formula is: Among them, it means The average surface area of ​​each bit device exposed to particle irradiation, Indicates the number of irradiated particles received by 1 bit.

8. The method for analyzing and evaluating the risk of single event upset of aerospace electronic devices caused by solar proton events according to claim 1, characterized in that: Calculate the maximum total number of flips N experienced by the entire device TotMax The formula is: ,in, is the total capacity of the device, is the energy range of SPE.

9. The method for analyzing and evaluating the risk of single event upset of aerospace electronic devices caused by solar proton events according to claim 1, characterized in that: Calculate the average SEU flip rate of the device The formula is: ,in, is the start and end time interval of the SPE event.

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