A method for analyzing and evaluating the risk of single event upset of space electronic devices caused by a solar proton event

Abstract

The application discloses a kind of solar proton event causes the analysis and evaluation method of the risk of single event upset of spaceflight electronic device, comprising the following steps: S1. Establishing spaceflight electronic device target material model, calculating target device SEU cross section and proton energy relationship;S2. Analyzing the on-orbit proton radiation environment elements of spaceflight device, obtaining detection data and calculating the radiation flux of SPE;S3. The metric parameter of device single event upset caused by the occurrence process of SPE is calculated;S4. According to the calculation result, the SEU risk caused by SPE is evaluated and classified. The Monte Carlo method is used for SEU cross section calculation of electronic device, and the non-elastic energy deposition event of device sensitive area caused by single-energy proton can be accurately obtained. The present application can accurately and effectively provide basis for troubleshooting and information correction of spaceflight device, and can be directly applied to existing on-orbit spacecraft.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of risk assessment of high-energy particle radiation caused by space weather business abnormality of space electronic devices, and particularly relates to a calculation analysis and risk grading method of single event upset effect of space electronic devices caused by solar proton event. BACKGROUND

[0002] High-energy proton radiation during solar proton event (SPE) can cause a series of single event effects (SEE) of integrated circuit electronic devices of on-orbit spacecraft, among which the single event upset (SEU) occurrence rate is higher. SEU of space electronic system is one of the important reasons for causing spacecraft anomaly and failure.

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

[0004] In recent years, with the development of space science and technology and electronic technology, the cost of satellite launching and operation continues to decrease, and the number of on-orbit satellites has greatly increased. The application of satellite and space technology in the fields of remote sensing, navigation and communication is also increasingly widespread. At the same time, spaceborne and space integrated circuits are developing towards small size, low power consumption, large capacity, high transmission and operation speed, and the single-bit state change of key electronic devices has a certain decrease in corresponding radiation energy and critical charge amount, so the study of satellite anti-single event effect capability becomes more important. On the basis of improving the observation level of high-energy particle radiation characteristics in solar activity and gradually accurately calculating the SEU rule of on-orbit electronic devices caused by high-energy particle radiation, forming the on-orbit electronic device SEU forecasting and early warning business capability has become one of the important development directions of space weather business.

[0005] After the occurrence of solar proton event, according to the current industry classification standard of solar proton event, it is difficult to effectively evaluate the risk of single event upset effect of space electronic devices caused by solar proton event. Therefore, it is difficult to determine what degree of fault diagnosis and information correction should be performed on space electronic devices after a solar proton event occurs. The industry urgently needs a scheme that can effectively evaluate and alarm the risk of single event upset of devices caused by solar proton event from the specific energy spectrum of solar proton and the physical mechanism of device response. SUMMARY

[0006] Aiming at the prior art and the existing problems, the application provides a calculation analysis and risk assessment method for single event upset effect of on-orbit spaceflight electronic devices caused by solar proton events.

[0007] The application adopts the following technical scheme:

[0008] A kind of solar proton event causes the analysis and evaluation method of single event upset risk of spaceflight electronic device, comprising the following steps:

[0009] Step one: according to spaceflight electronic device data parameters, including: device structure, CAD information, material parameters, physical plane size, storage capacity and shielding conditions, device target material model is established.Calculation target device SEU cross section σ SEU With proton energy E P Relationship σ SEU (E P ) is accumulated. Accumulate typical device information, establish the SEU cross section database of conventional device under standard protection.

[0010] Step two: obtain environmental elements, mainly including the orbit conditions of spaceflight electronic devices and the event parameters near the orbit.Analyze the proton radiation environmental elements of device orbit when solar proton event occurs.Combined with ground neutron counting detection data, the solar proton event radiation flux of orbit environment is calculated according to satellite detector (such as ACE, GOES, SOHO) data, and the proton flux energy spectrum of a wide energy range is obtained.

[0011] Step three: combined with the above device reaction cross section, the flux energy spectrum of protons, and the size and capacity parameters of the device, the metric parameters of single event upset of target device caused by solar proton event process are calculated.

[0012] Step four: according to the calculation results of step three, the SEU risk caused by solar proton event is evaluated and analyzed.

[0013] The metric parameters of single event upset of target device in step three include: the maximum upset probability P TotMax experienced by SPE per bit, the maximum cumulative upset cross section Σ TotMax experienced by SPE process per 1bit of device, the maximum total upset number N TotMax experienced by the whole device, and the average SEU upset rate of device.

[0014] The risk assessment grading method in step four is: according to the maximum SEU upset probability P TotMax distribution data of typical space device, the risk is divided into four levels:

[0015] L0: low risk area. The upper limit of single particle maximum upset probability threshold is PTotMax = The flipping probability of this region is close to the probability caused by the average GCR background radiation in a quiet solar activity period.

[0016] L1: Medium risk, yellow alert zone. The upper threshold of the maximum single particle flipping probability is P TotMax = .

[0017] L2: High risk, orange alert zone. The upper threshold of the maximum single particle flipping probability is P TotMa = .

[0018] L3: Extremely high risk, red alert zone. The maximum single particle flipping probability exceeds P TotMax = At this time, the risk of each bit of the device flipping is higher than 10%. The high information error rate can cause the error correction mechanism to fail.

[0019] Preferably, the method for calculating the relationship between the SEU cross section of the target device and the proton energy in step one is: using a Monte Carlo principle calculation simulation method to simulate the interaction process of single-energy protons and the device, statistically analyzing the energy deposition of the sensitive region of the device according to a large number of simulation results, and using the energy criterion for SEU occurrence and the SEU cross section formula to calculate the reaction and cross section, so as to accurately calculate the relationship curve between the proton energy and the device reaction cross section in a wide energy range. SEU (E P ) calculation formula.

[0020] Further, the Monte Carlo principle calculation simulation method includes: using Geant4 and the extended toolkit G4SEE based thereon to simulate the non-elastic energy deposition of the sensitive region of the device caused by single-energy protons in a given energy range (such as E P <20 MeV), and compare and verify with possible experimental results. Using the tracking and statistical tools provided by G4SEE, the reaction process of the interaction between incident particles and semiconductor materials in the sensitive region of the semiconductor, the energy deposition, and the changes in the electron and hole concentration of the material and their recombination process, which further causes the information state of the single bit storage location to flip, is accurately simulated.

[0021] Further, the SEU cross section calculation formula is:

[0022] wherein, is the number of incident protons with energy E P , is the number of SEU events recorded in the simulation, is the surface area of the simulated target, which is also the area of the incident particle source in the simulation, is the number of bits corresponding to the target model.

[0023] Optionally, the method for calculating the radiation flux of the orbital environment in step two is as follows: comprehensive processing of the flux records of the proton detectors of satellites such as ACE, SOHO, and GOES, and the existing observation data obtained by the ground neutron observation station, application of the parameterized double-power-law distribution function spectrum formula of SPE, multi-parameter fitting to obtain the proton flux spectrum data in a wide energy range, and matching with the proton energy range of the relationship curve of the device reaction cross section to realize accurate calculation of the SEU reaction probability of the complete event.

[0024] Further, the parameterized double-power-law distribution function spectrum formula is as follows:

[0025] wherein, is the integral flux or intensity of the particles, and E is the kinetic energy per nucleon of the particles. are four free parameters for describing the behavior characteristics of the SPE spectrum line in a wide energy range, and the four free parameters are obtained by fitting the satellite observation data with the double-power-law distribution function spectrum formula. For the total spectrum in the process of calculating the SPE event, the flux is large enough, and the influence of the background environment (galactic cosmic rays) can be ignored.

[0026] Further, the formula for calculating the maximum flip probability P TotMax experienced by each bit in the SPE process is as follows:

[0027] .

[0028] Further, the formula for calculating the maximum cumulative flip cross section Σ TotMax experienced by each 1 bit of the device in the SPE process is as follows:

[0029] wherein, represents the average surface area of the 1 bit device receiving particle irradiation, and the number of irradiation particles received by 1 bit. This measurement parameter can reflect the SEU resistance of the device material to SPE, and should be converted into this measurement parameter when evaluating the performance of the device material.

[0030] Further, the formula for calculating the maximum total number of flips N TotMax experienced by the entire device is as follows:

[0031] wherein, is the total capacity of the device, is the energy interval of SPE. This metric parameter can reflect the SEU impact of a specific device after experiencing a specific SPE, and should be converted into this metric parameter when evaluating the SEU risk of a specific on-orbit space electronic device caused by SPE.

[0032] Further, the average SEU flip rate of the calculator device is calculated The formula is:

[0033] , wherein, is the start-end time interval of the SPE event. This metric parameter can reflect the average SEU impact of a specific SPE event on the device, and should be converted into this metric parameter when evaluating the characteristics of the SPE event.

[0034] After the above technical scheme is adopted, the beneficial effects of the present application are:

[0035] 1. The present application provides a Monte Carlo method for simulating the SEU cross section of a specific device based on Geant4, which can accurately simulate the single event upset effect of on-orbit electronic devices in the space proton radiation environment, and can be applied to various types of structure-specific space electronic devices. Compared with experimental determination or other simulation methods, the method provided by the present application can provide effective and low-cost flip cross section data when dealing with existing on-orbit spacecraft and future new space devices.

[0036] 2. The present application provides a method and program for fitting the SPE flux energy spectrum using SPE flux observation data, which obtains the behavior characteristics of the SPE spectrum in a wide enough energy range, and is convenient for batch processing a large number of SPE events. Compared with directly using observation data, the method provided by the present application can accurately and completely obtain the specific energy spectrum of solar protons.

[0037] 3. The present application provides a method for calculating the metric parameter of the single event upset effect caused by SPE, and proposes to use the maximum flip probability P TotMax as the main reference physical quantity for the SEU risk assessment classification of electronic devices. It can comprehensively reflect the physical and probabilistic information of the single event upset effect of on-orbit electronic devices, and is convenient for metric parameter conversion. Establish a parameter and grading standard for the statistical risk of single event upset caused by SPE, which can be calibrated and compared conveniently.

[0038] 4. The present application proposes a reasonable single event upset risk grading scheme for space electronic devices. Compared with the traditional method in the current industry which uses solar proton event level as a reference, the grading of the present application is more specific and reliable. Because there is no definite linear correspondence between the SEU risk level and the solar proton event level, the grading scheme proposed by the present application for specific SEU metric parameters is a significant improvement over the current risk assessment.

[0039] 5. The application provides a complete analysis and evaluation method of single event upset risk caused by SPE, which can accurately and effectively provide basis for failure troubleshooting and information correction of space devices. The method provided by the application can reduce the response cost of space devices to solar proton event interference, and can be directly applied to existing on-orbit space devices. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 A flowchart of a solar proton event caused space electronic device single event upset risk analysis and evaluation method provided by the application.

[0041] Figure 2 An electronic device single event upset reaction cross-section calculation result diagram provided by an embodiment of the application.

[0042] Figure 3 A solar proton event energy spectrum fitting result diagram provided by an embodiment of the application.

[0043] Figure 4 A solar proton event caused space electronic device single event upset effect total probability calculation result provided by an embodiment of the application, and a risk evaluation result diagram implemented according to a risk grading method provided by the application. DETAILED DESCRIPTION

[0044] The application will be further described in detail below in combination with the drawings and specific examples, but the embodiments of the application are not limited thereto:

[0045] Please refer to Figure 1 , which is a flowchart of a solar proton event caused space electronic device single event upset risk analysis and evaluation method provided by the application, including:

[0046] Step one: according to the data parameters of space electronic devices, including: device structure, CAD information, material parameters, physical plane size, storage capacity and shielding conditions, a device target material model is established. The SEU cross section σ of the target device is calculated SEU and the relationship σ (E) of proton energy E P . SEU P

[0047] ​​The main reference device ISSI SRAM selected in the embodiment is manufactured by Integrated Silicon Solutions Inc. using 40 nm process. The device physical plane size is 18.40 mm x 12.00 mm, and the storage capacity is 32 Mbit. In order to study the shielding effect of electronic devices in different positions of the spacecraft, the embodiment simulates two typical conditions of ISSI SRAM device directly receiving proton radiation (DR condition) and being shielded by a 3 mm thick Al layer (SR condition) for research.

[0048] The method for calculating the relationship between the SEU cross section of the target device and the proton energy in step one is: using the Monte Carlo principle calculation simulation method to simulate the interaction process of single-energy protons and the device, statistically analyzing the energy deposition of the sensitive area of the device according to 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 to determine the reaction and calculate the cross section, so as to accurately calculate the relationship curve between the proton energy and the device reaction cross section in a wide energy range.

[0049] The Monte Carlo principle calculation simulation method includes: using Geant4 and the extended toolkit G4SEE based thereon to simulate the interaction process of single-energy protons with the device in a given energy range E P <20 MeV. The non-elastic energy deposition in the sensitive area of the device caused by single-energy protons is compared with the possible experimental results for verification. Using the tracking and statistical tools provided by G4SEE, the interaction between incident particles and semiconductor materials in the SEU process is simulated accurately, the energy deposition in the sensitive area of the semiconductor is simulated accurately, and the changes in the electron and hole concentration of the material and their recombination process are simulated accurately, thereby causing the information state of a single bit storage location to flip.

[0050] The SEU cross section calculation formula is:

[0051] .

[0052] See Figure 2 , the simulation result graph of the SEU cross section of the ISSI SRAM selected in the embodiment in the on-orbit electronic device under the conditions of direct radiation and 3 mm Al layer protection, and the two curves in the graph correspond to the two radiation conditions respectively.

[0053] Step two: Obtain environmental factors and analyze the on-orbit proton radiation environment of the spacecraft device. According to the satellite detector (such as ACE, GOES, SOHO) data combined with the ground neutron detection data, the solar proton event radiation flux of the orbit environment is calculated, and the proton flux energy spectrum in a wide energy range is obtained.

[0054] The method for calculating the radiation flux of the orbit environment is as follows: according to the existing observation data, a parameterized double-power-law distribution function spectrum of a solar proton event is fitted to obtain the radiation condition.

[0055] In this embodiment, the satellite detectors are selected as: the geosynchronous orbit GOES, the L1 point ACE and SOHO. In order to avoid the overlapping of energy regions, the energy channels are arranged and selected.

[0056] In this embodiment, the flux spectrum of the ground enhancement event in the solar proton event is calculated. Solar protons with an energy of more than 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 counting are called ground enhancement events (GLE). There are currently 73 GLEs observed by humans. In this example, 39 ground enhancement events with relatively complete and reliable observation data are selected.

[0057] The formula of the parameterized double-power-law distribution function spectrum is:

[0058] .

[0059] The function uses four free parameters to describe the behavior characteristics of the SPE spectrum line in a wide energy range. For the total spectrum during the calculation of the SPE event, the flux is large enough, and the influence of the background environment (cosmic rays) can be ignored.

[0060] See Figure 3 , the fitting spectrum result graph of the 39 ground enhancement events selected in this embodiment. There are 39 curves in the graph, and each curve corresponds to a ground enhancement event.

[0061] Step three: combining the above reaction cross section, the flux spectrum of protons, and the size and capacity of the device and other parameters, the metric parameters of single event upset of the device accompanied by the solar proton event are calculated.

[0062] The metric parameters of single event upset of the device in step three include: the maximum flip probability P TotMax experienced by each bit caused by SPE, the maximum cumulative flip cross section Σ TotMax of each 1bit of the device accompanied by the SPE process, the maximum total flip number N TotMax experienced by the entire device, and the average SEU flip rate of the device. .

[0063] The formula for calculating the maximum flip probability P TotMax experienced by each bit caused by SPE is:

[0064] .

[0065] Maximum cumulative cross section per 1 bit of the device experienced during the SPE process TotMax The formula is:

[0066] .

[0067] Maximum total number of flips N experienced by the entire device TotMax The formula is:

[0068] .

[0069] Average SEU flip rate of the device The formula is:

[0070] .

[0071] Step four: according to the calculation results of the measurement parameters in step three, the SEU risk caused by the solar proton event is evaluated and classified.

[0072] In this embodiment, the maximum flip probability P experienced by each bit caused by SPE TotMax is used as the main reference physical quantity for the SEU risk evaluation classification of electronic devices. This parameter can comprehensively reflect the SEU probability characteristics from the specific energy spectrum of solar protons and the physical mechanism of device response. At the same time, this parameter is convenient for conversion into other measurement parameters to reflect the unit device effect (Σ TotMax ), total effect (N TotMax ), and unit event effect ( ).

[0073] Please refer to Figure 4 , the abscissa is the peak value of the proton flux of SPE , and the unit is . In the figure, the two curves correspond to the direct radiation condition and the 3mm Al layer protection radiation condition respectively, and each curve has 39 data points, corresponding to 39 cases of ground enhancement events. According to the current industry risk classification rules of SPE, the abscissa is classified, and according to the space electronic device SEU risk evaluation classification method provided by the present application, the ordinate is classified, so as to clearly show the SEU risk of a series of solar proton events on the target device selected in this embodiment.

[0074] In order to facilitate the classification of the risk of SEU caused by solar proton events on electronic devices, according to the maximum SEU flip probability distribution data of the typical space device ISSI SRAM (specific model: S61WV204816BLL-10TLI), the risk is divided into four levels, wherein:

[0075] L0: Low risk zone. The probability of a flip in this region is close to the probability of the average GCR background radiation during a quiet solar activity period, corresponding to a maximum single-event flip probability threshold of P TotMax = .

[0076] L1: Medium risk, yellow warning zone. Corresponding to a maximum single-event flip probability threshold of P TotMax = Under DR conditions, half of the 1 -class GLEs, 2-class non-GLE SPEs, and a small number of 2- and 3-class GLEs pose SEU risk to ISSI SRAM. Under 3 mm Al protection, the majority of SPEs that cause SEU risk to ISSI SRAM are in this category.

[0077] L2: High risk, orange warning zone. Corresponding to a maximum single-event flip probability threshold of P TotMa = . For ISSI SRAM, under DR conditions, approximately 80% of GLEs pose this high SEU risk, with 1 - and 2-class GLEs (approximately 20% of total events) causing the device to be in this high risk zone, and the rest of the GLEs causing even higher risk. Under SR conditions, only two 3-class and one 4-class GLEs pose this level of SEU risk, less than 8% of total events.

[0078] L3: Extreme risk, red warning zone. Corresponding to a maximum single-event flip probability threshold exceeding P TotMa = At this point, the risk of a flip in each bit of the device is higher than 10%. The high rate of information errors can cause the error correction mechanism to fail. For ISSI SRAM, some 2- and 3-class GLEs under DR conditions pose this extreme risk. The device has low resistance to risk under DR conditions, with 75% of GLEs causing this extreme SEU risk.

Claims

1. A method for analyzing and evaluating the risk of single event upset of space electronic devices caused by solar proton events, characterized in that, The method comprises the following steps: S1. According to the aerospace electronic device data parameters, the device target material model is established, and the relationship σ between the target device SEU cross section σSEU and the proton energy EP is calculated σ SEU (E P ), and the SEU cross section library is established; S2. Analyzing the on-orbit proton radiation environment elements of the spacecraft device, obtaining detection data, and calculating the proton radiation flux of the orbital radiation environment according to the location of the spacecraft during the occurrence of the SPE; S3. Calculating the metric parameter of the single event upset of the device caused by the occurrence of the solar proton event according to the calculation results of S1 and S2; S4. Classifying the risk of SEU caused by the solar proton event according to the metric parameter obtained in S3; The metric parameters of single event upset of the device in S3 include the maximum upset probability P per bit caused by SPE TotMax , the maximum accumulated upset cross section Σ per bit of the device caused by the whole process of SPE TotMax , the maximum total upset number N of the whole device TotMax , the average SEU upset rate of the device ; The method of risk assessment grading in S4 is: according to the maximum flip probability P of each bit of the spacecraft device TotMax The distribution data sets the risk into four levels, wherein: L0: Low risk zone, corresponding to an upper threshold of the maximum single event upset probability P TotMax = ; L1: Medium risk, yellow warning zone, corresponding to the upper threshold of the maximum single particle flip probability P TotMax = ; L2: High risk, orange warning zone, corresponding to the maximum SEU flip probability upper limit P TotMax = ; L3: extreme risk, red alert zone, corresponding to a single event upset probability upper limit exceeding P TotMax = ; The method for calculating the relationship between the SEU cross section of the target device and the proton energy in S1 is: using a calculation simulation method based on the Monte Carlo principle to simulate the interaction process of high-energy protons and the target device, and according to the simulation results, the energy deposition of the sensitive region is counted, and according to the energy criterion and the SEU cross section σ SEU The calculation formula is used to carry out calculation and analysis; and the SEU cross section calculation formula is: wherein, is the number of incident protons with energy E P is the number of SEU events recorded in the simulation, is the surface area of the simulated target, which is also the area of the source of incident particles in the simulation, is the number of bits corresponding to the target model.​ The method for calculating the proton radiation flux of the orbital radiation environment in S2 is as follows: according to the satellite observation data, a parameterized double-power-law distribution function spectrum of the solar proton event is fitted, and the spectrum distribution function uses four free parameters to describe the behavior characteristics of the solar proton spectrum in a wide energy range; The parameterized double-power-law distribution function spectrum formula is as follows: where, is the integral flux or intensity of the particles, E is the kinetic energy per nucleon of the particles, are four free parameters that characterize the behavior of the SPE line over a wide energy range.

2. The method for analyzing and assessing the risk of single-event upset in aerospace electronic devices caused by solar proton events according to claim 1, characterized in that, The calculation simulation method based on the Monte Carlo principle is as follows: Geant4 and the extended toolkit G4SEE based thereon are used to simulate the non-elastic energy deposition of the device sensitive area caused by the single-energy proton in a given energy region, and the simulation result is compared with the experimental result; in the simulation process, the energy deposition, the type of secondary particles and the momentum distribution of the reaction particles are accurately tracked and counted in a micrometer-level volume.

3. The method for analyzing and assessing the risk of single-event upset in aerospace electronic devices caused by solar proton events according to claim 1, characterized in that, The calculation of the SPE results in a maximum probability of flipping P experienced by each bit TotMax The formula is: 。 4. The method for analyzing and assessing the risk of single-event upset in aerospace electronic devices caused by solar proton events according to claim 1, characterized in that, The maximum cumulative flip cross section per bit, Σ, that a device undergoes during the SPE process TotMax The formula is: wherein, represents the average surface area of each bit device to receive particle irradiation, represents the number of irradiation particles received by 1 bit.

5. The method of claim 1, wherein the method further comprises: determining a solar proton event risk of a single event upset (SEU) of a space electronic device based on the solar proton event risk of the space electronic device. calculating the maximum total number of flips N experienced by the entire device TotMax The formula is: wherein, is the total capacity of the device, is the energy segment interval of the SPE.

6. The method of claim 1, wherein the method further comprises: determining a solar proton event risk of a single event upset (SEU) of a space electronic device based on the solar proton flux and the solar proton fluence. 6 Computer device average SEU flip rate The formula is: wherein, is the start-end time interval of the SPE event.

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