From satellite ion flux data to SEU rate estimation

During a solar particle event (SPE) a spacecraft can suffer a large number of single event effect (SEE) anomalies due to the enhanced energetic ion environment. Throughout satellite design, simulations can be made to estimate the mission single event upset (SEU) rate. One of the most used models to predict in-orbit SEU rate is cosmic ray effects on microelectronics (CREME96). CREME96 treats solar particle events on the basis of a specific event-October 1989. Some engineering applications require evaluation of expected SEU behavior in a range of SPE types. In addition, comparison cannot be made directly between in-flight SEU behavior during SPEs and the CREME96 prediction. To address these issues, we examine the feasibility of using available environmental datasets; to derive linear energy transfer (LET) spectra. We find serious problems with many datasets, particularly with availability of data during the most significant SPEs. It is also difficult to derive data on SEU behavior of systems. Where comparisons are possible, we find that shielding plays a significant role. Again, obtaining shielding data concerning a part proves difficult. Recommendations are made with respect to environmental data sources, analysis methods and engineering procedures to safeguard "lessons learned" type exercises/comparison of prediction. Three different SPEs [November 6, 1997, July 14, 2000, and November 9, 2000] have been evaluated. As target device, The Solar and Heliospheric Observatory solid state recorder is analyzed.