This part of IEC 62396 is intended to provide guidance on atmospheric radiation effects on avionics electronics used in aircraft operating at altitudes up to 60 000 feet (18,3 km). It defines the radiation environment, the effects of that environment on electronics and provides design considerations for the accommodation of those effects within avionics systems.<\/p>\n
This International Standard is intended to help aerospace equipment manufacturers and designers to standardise their approach to single event effects in avionics by providing guidance, leading to a standard methodology.<\/p>\n
Details of the radiation environment are provided together with identification of potential problems caused as a result of the atmospheric radiation received. Appropriate methods are given for quantifying single event effect (SEE) rates in electronic components. The overall system safety methodology should be expanded to accommodate the single event effects rates and to demonstrate the suitability of the electronics for the application at the component and system level.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 4<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 1 Scope 2 Normative references <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 4 Abbreviations and acronyms <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 5 Radiation environment of the atmosphere 5.1 Radiation generation 5.2 Effect of secondary particles on avionics 5.3 Atmospheric neutrons 5.3.1 General <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 5.3.2 Energy spectrum of atmospheric neutrons Figures Figure 1 \u2013 Energy spectrum of atmospheric neutrons at 40\u00a0000 feet (12\u00a0160\u00a0m), latitude 45 degrees <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 5.3.3 Altitude variation of atmospheric neutrons <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 5.3.4 Latitude variation of atmospheric neutrons Figure 2 \u2013 Model of the atmospheric neutron flux variation with altitude (see Annex D) <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | Figure 3 \u2013 Distribution of vertical rigidity cut-offs around the world Figure 4 \u2013 Model of atmospheric neutron flux variation with latitude <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 5.3.5 Thermal neutrons within aircraft 5.4 Secondary protons <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 5.5 Other particles Figure 5 \u2013 Energy spectrum of protons within the atmosphere <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 5.6 Solar enhancements 5.7 High altitudes greater than 60\u00a0000 feet (18\u00a0290 m) <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 6 Effects of atmospheric radiation on avionics 6.1 Types of radiation effects 6.2 Single event effects (SEE) 6.2.1 General <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 6.2.2 Single event upset (SEU) 6.2.3 Multiple bit upset (MBU) and multiple cell upset (MCU) <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | 6.2.4 Single effect transients (SET) 6.2.5 Single event latch-up (SEL) <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | 6.2.6 Single event functional interrupt (SEFI) 6.2.7 Single event burnout (SEB) 6.2.8 Single event gate rupture (SEGR) <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | 6.2.9 Single event induced hard error (SHE) 6.2.10 SEE potential risks based on future technology 6.3 Total ionising dose (TID) <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | 6.4 Displacement damage <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | 7 Guidance for system designs 7.1 Overview <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | Figure 6 \u2013 System safety assessment process <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | Tables Table 1 \u2013 Nomenclature cross reference <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | 7.2 System design Figure 7 \u2013 SEE in relation to system and LRU effect <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | 7.3 Hardware considerations <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | 7.4 Parts characterisation and control 7.4.1 Rigour and discipline 7.4.2 Level A systems <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | 7.4.3 Level B 7.4.4 Level C <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | 7.4.5 Levels D and E 8 Determination of avionics single event effects rates 8.1 Main single event effects 8.2 Single event effects with lower event rates 8.2.1 Single event burnout (SEB) and single event gate rupture (SEGR) <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | 8.2.2 Single event transient (SET) 8.2.3 Single event hard error (SHE) 8.2.4 Single event latch-up (SEL) <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | 8.3 Single event effects with higher event rates \u2013 Single event upset data 8.3.1 General 8.3.2 SEU cross-section 8.3.3 Proton and neutron beams for measuring SEU cross-sections <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | Figure 8 \u2013 Variation of RAM SEU cross-section as function of neutron\/proton energy <\/td>\n<\/tr>\n | ||||||
| 47<\/td>\n | Figure 9 \u2013 Neutron and proton SEU bit cross-section data <\/td>\n<\/tr>\n | ||||||
| 48<\/td>\n | 8.3.4 SEU per bit cross-section trends in SRAMs <\/td>\n<\/tr>\n | ||||||
| 49<\/td>\n | 8.3.5 SEU per bit cross-section trends and other SEE in DRAMs Figure 10 \u2013 SEU cross-section in SRAMs as function of manufacture date <\/td>\n<\/tr>\n | ||||||
| 50<\/td>\n | Figure 11 \u2013 SEU cross-section in DRAMs as function of manufacture date <\/td>\n<\/tr>\n | ||||||
| 51<\/td>\n | 8.4 Calculating SEE rates in avionics <\/td>\n<\/tr>\n | ||||||
| 52<\/td>\n | 8.5 Calculation of availability of full redundancy 8.5.1 General 8.5.2 SEU with mitigation and SET <\/td>\n<\/tr>\n | ||||||
| 53<\/td>\n | 8.5.3 Firm errors and faults 9 Considerations for SEE compliance 9.1 Compliance 9.2 Confirm the radiation environment for the avionics application 9.3 Identify system development assurance level 9.4 Assess preliminary electronic equipment design for SEE 9.4.1 Identify SEE-sensitive electronic components 9.4.2 Quantify SEE rates 9.5 Verify that the system development assurance level requirements are met for SEE 9.5.1 Combine SEE rates for entire system <\/td>\n<\/tr>\n | ||||||
| 54<\/td>\n | 9.5.2 Management of parts control and dependability 9.6 Corrective actions <\/td>\n<\/tr>\n | ||||||
| 55<\/td>\n | Annex A (informative) Thermal neutron assessment <\/td>\n<\/tr>\n | ||||||
| 56<\/td>\n | Annex B (informative) Methods of calculating SEE rates in avionics electronics <\/td>\n<\/tr>\n | ||||||
| 57<\/td>\n | Table B.1 \u2013 Sources of high energy proton or neutron SEU cross-section data <\/td>\n<\/tr>\n | ||||||
| 58<\/td>\n | Table B.2 \u2013 Some models for the use of heavy ion SEE data to calculate proton SEE data <\/td>\n<\/tr>\n | ||||||
| 62<\/td>\n | Annex C (informative) Review of test facility availability <\/td>\n<\/tr>\n | ||||||
| 70<\/td>\n | Annex D (informative) Tabular description of variation of atmospheric neutron fluxwith altitude and latitude Table D.1 \u2013 Variation of 1 MeV to 10\u00a0MeV neutron flux in the atmosphere with altitude Table D.2 \u2013 Variation of 1 MeV to 10\u00a0MeV neutron flux in the atmosphere with latitude <\/td>\n<\/tr>\n | ||||||
| 71<\/td>\n | Annex E (informative) Consideration of effects at higher altitudes <\/td>\n<\/tr>\n | ||||||
| 72<\/td>\n | Figure E.1 \u2013 Integral linear energy transfer spectra in siliconat 100\u00a0000 feet (30\u00a0480\u00a0m) for cut-off rigidities (R) from 0 GV to 17 GV Figure E.2 \u2013 Integral linear energy transfer spectra in siliconat 75\u00a0000 feet (22\u00a0860\u00a0m) for cut-off rigidities (R) from 0 to 17 GV <\/td>\n<\/tr>\n | ||||||
| 73<\/td>\n | Figure E.3 \u2013 Integral linear energy transfer spectra in siliconat 55\u00a0000 feet (16\u00a0760\u00a0m) for cut-off rigidities (R) from 0 GV to 17 GV Figure E.4 \u2013 The influence of solar modulation on integral linear energytransfer spectra in silicon at 150\u00a0000 feet (45\u00a0720\u00a0m) for cut-off rigidities (R) of 0 GV and 8 GV <\/td>\n<\/tr>\n | ||||||
| 74<\/td>\n | Figure E.5 \u2013 The influence of solar modulation on integral linear energy transferspectra in silicon at 55\u00a0000 feet (16\u00a0760\u00a0m) for cut-off rigidities (R) of 0 GV and 8 GV <\/td>\n<\/tr>\n | ||||||
| 75<\/td>\n | Figure E.6 \u2013 Calculated contributions from neutrons, protons and heavy ionsto the SEU rates of the Hitachi-A 4 Mbit SRAM as a function of altitude at a cut-off \u2013rigidity (R) of 0 GV Figure E.7 \u2013 Calculated contributions from neutrons, protons and heavy ionsto the SEU rates of the Hitachi-A 4 Mbit SRAM as a function of altitude at a cut-off rigidity (R) of 8 GV <\/td>\n<\/tr>\n | ||||||
| 76<\/td>\n | Annex F (informative) Prediction of SEE rates for ions <\/td>\n<\/tr>\n | ||||||
| 77<\/td>\n | Figure F.1 \u2013 Example differential LET spectrum Figure F.2 \u2013 Example integral chord length distributionfor isotropic particle environment <\/td>\n<\/tr>\n | ||||||
| 79<\/td>\n | Annex G (informative) Late news as of 2011 on SEE cross-sections applicable to the atmospheric neutron environment <\/td>\n<\/tr>\n | ||||||
| 81<\/td>\n | Figure G.1 \u2013 Variation of the high energy neutron SEU cross-sectionper bit as a function of device feature size for SRAMs and SRAM arraysin microprocessors and FPGAs <\/td>\n<\/tr>\n | ||||||
| 82<\/td>\n | Figure G.2 \u2013 Variation of the high energy neutron SEU cross-section per bitas a function of device feature size for DRAMs <\/td>\n<\/tr>\n | ||||||
| 83<\/td>\n | Figure G.3 \u2013 Variation of the high energy neutron SEU cross-section per device as a function of device feature size for NOR and NAND type flash memories <\/td>\n<\/tr>\n | ||||||
| 84<\/td>\n | Figure G.4 \u2013 Variation of the MCU\/SBU percentage as a function of feature size basedon data from many researchers in SRAMs [43, 45] <\/td>\n<\/tr>\n | ||||||
| 85<\/td>\n | Figure G.5 \u2013 Variation of the high energy neutron SEFI cross-section in DRAMsas a function of device feature size <\/td>\n<\/tr>\n | ||||||
| 86<\/td>\n | Figure G.6 \u2013 Variation of the high energy neutron SEFI cross-sectionin microprocessors and FPGAs as a function of device feature size <\/td>\n<\/tr>\n | ||||||
| 87<\/td>\n | Figure G.7 \u2013 Variation of the high energy neutron single event latch-up (SEL) cross-section in CMOS devices (SRAMs, processors) as a function of device feature size <\/td>\n<\/tr>\n | ||||||
| 88<\/td>\n | Figure G.8 \u2013 Single event burnout (SEB) cross-section in power devices (400\u00a0V\u20131\u00a0200\u00a0V)as a function of drain-source voltage (VDS) Table G.1 \u2013 Information relevant to neutron-induced SET <\/td>\n<\/tr>\n | ||||||
| 90<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Process management for avionics. Atmospheric radiation effects – Accommodation of atmospheric radiation effects via single event effects within avionics electronic equipment<\/b><\/p>\n |