临近空间中子辐射环境分析及其引起的单粒子效应预计研究

使用Space Radiation 7.0工具分析临近空间中子辐射环境，研究其与海拔高度、太阳活动和经纬度的关系及内在原因.在此基础上，提出了一种基于蒙特卡罗方法的大气中子实时错误率预计方法，并以航空电子系统关键集成电路FPGA为例，预计其单粒子翻转敏感模块包括配置存储器、块存储器和用户触发器，单粒子功能中断敏感模块包括上电复位电路、SelectMAP接口等的实时飞行错误率.结果表明，配置存储器中发生的单粒子翻转达到总单粒子翻转率的77%，而上电复位电路和SelectMAP接口中发生的单粒子功能中断各占总单粒子功能中断率的36%.根据RTCA DO-254对飞行系统失效等级的划分，该FPGA器件不可用于航空电子系统关键位置. 

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.