Research On The Effects That Solar Activity Has On The Single Event Effect For Space Instrument

A large number of energetic particles are released when solar activity is frequent.They have a big influence on the terrestrial space radiation environment and do serious harm to human space activities,for example,radiation damages,Single Event Upsets(SEU),and so on.It is important to avoid the potential damage of solar activities on spacecraft,guarantee the normal operation of on-orbit space instruments,and accomplish space missions safely and reliably.Thus,it is significant to do some research on the influence of solar activities on the Single Event Effect(SEE)of space instruments.This work collected the SEU telemetry data of the 48 on-orbit instruments distributing in three different low orbits,and analyzed the on-orbit SEU in the 24 th solar cycle and during the Solar Proton Events(SPE).After analyzing the pertinence between SEU and the variation of Sunspot number,it is discovered that the SEU number during solar quiet periods is higher than active periods,and,the SEU rate variation curve during solar active periods has a strong correlation with the variation curve of Sunspot number if delayed a period of time.After statistical analysis of the SEU situations before and after SPE,it is discovered that SPE could arouse the increasing of the SEU number of space instruments in low orbit,and SPE could constantly influence the variation of SEU number during days later.It is discovered that South Atlantic Anomaly(SAA)has a large influence on the SEU of space instruments in low orbits after analyzing the spatial distribution of on-orbit SEU.Then the influence of SAA is eliminated from SEU data.After analyzing the relationship between Sunspot number and SPE in new data,it is discovered that the maximum positive correlation coefficients between SEE and SPE in 500 km and 700 km orbits are bigger than before generally,and,the corresponding delay time is longer generally.Thus,the correlation between the long-term variation of solar activities and SEU is affirmed further.And it is concluded that phenomenon of the influence of the long-term variation of solar activities on SEE is weakened because of the disturbance of SAA.And the influence of the SPE on the SEU of satellites in low orbits such as 700 km and 1100 km is more evident than before.This paper researched the influence of the variation of solar activities on SEE via a great deal of actually measured on-orbit data for the first time in China.Contributions are expected to be made on the radiation hardening techniques for the aerospace of homeland via these researches.