SEE data from the APEX Cosmic Ray Upset experiment: predicting the performance of commercial devices in space

This paper presents additional results from the CRUX experiment on the US Air Force APEX satellite. The experiment monitors single event effects on 256 Kbit and 1 Mbit SRAMs. It is shown that trapped protons dominate the single event upset rates, as evidenced by correlation with measured proton flux peaks and with flux contours calculated with the AP8 model. The responses of some part type lots were surprising because of the wide variation exhibited in upset rates from device to device within a part type, and because of a wide disparity in upset rates, depending on logic state. The use of generic ground test data in error rate predictions for a mission may be acceptable, but may also result in answers whose inaccuracies are unknown and could be unacceptably large.