Neutron Radiation Environment and Resulting Single Event Effects Prediction in Near Spaceormalsize

Neutron radiation environment in near space is analyzed by Space Radiation 7.0 toolkit. It is found that neutron flux decreases by several orders as altitude increases, low-energy neutron flux increases sharply at solar maximum condition, neutron flux increases constantly as latitude ascends. The inner reasons are further investigated. Based on the results, a prediction technique of atmospheric-neutron induced Real-Time Soft Error Rate (RTSER) using Monte-Carlo method is proposed. Taking Field Programmable Gate Array (FPGA), critical Integrated Circuit (IC) used in avionics system, as an example, the RTSERs of Single Event Upset (SEU) sensitive modules (including Configurable Memory (CM), Block Random Access Memory (BRAM) and user Flip-Flops (FF)) and Single Event Functional Interrupt (SEFI) sensitive modules (including Power-On-Reset (POR), SelectMAP etc.) are predicted. The results show that SEUs in CM accounted for 77% of the total SEU rate in the FPGA. Both POR and SelectMAP SEFIs accounted for 36% of the total SEFI rate respectively. According to the failure levels of flight system in RTCA DO-254, the FPGA can not be employed in key positions of avionics.