Total dose effect on soft error rate for dynamic metal-oxide-semiconductor memory cells

A simple model for the soft error rate for dynamic metal-oxide-semiconductor random access memories due to normal galactic radiation was devised and then used to calculate the rate of decrease of the single-event-upset rate with total radiation dose. The computation shows that the decrease in the soft error rate is less than 10% per day if the shielding is 0.5 g/cm2 and the spacecraft is in a geosynchronous orbit. The decrease is considerably less in a polar orbiting device.