Predictions and observations of SEU rates in space

This paper summarizes the available data on the observation and prediction of SEU rates in space. It considers three questions: 1. How good can a prediction be? 2. How bad can a prediction be? 3. How does the quality of the prediction depend on the type of orbit? The paper considers one hundred and twenty-six reports of predicted and observed rates. These include updated predictions for the CRRES devices. The analysis then excludes solar particle events, single event burnout, cases with poor statistics, and cases that are essentially duplicates; leaving 77 comparisons. The heavy ion predictions based on the CREME environments and the proton predictions based on the AP8 environments are both very successful for their basic environments, but are less accurate for low earth orbits (LEO). The quality of the results depends strongly on whether the predictions are based on tests with flight parts or with generic parts. The quality also depends on the use of the proper shielding around the part. The results appear consistent with suggested modifications in these environments based on recent space measurements. The methods that are used for upset rate predictions appear to be adequate for the current generation of devices.