Single-event upsets (SEUs) are random errors in semiconductor memory that occur at a much higher rate in space than on the ground. They are non-destructive, but can cause a loss of data if left uncorrected. SEUs are often associated with heavy ions from the galactic cosmic radiation.

SEUs are caused by passage of energetic charged particles through sensitive regions of a chip. Depending on their energy and angle of impact, individual particles can cause a large current impulse sufficient to change the state of a bistable circuit element. This package consists of four modules that compute SEU rates in space using standard SEU rate models ¹ and Space Radiation environments.²

Heavy-Ion SEU

These SEUs occur directly when a heavy ion passes through a semiconductor memory element. The standard models take into account the size, shape, and charge sensitivity of the memory element; and the energy, angle, and impact parameter of the incident particle. Four different methods are included depending on what SEU test data you have available.

• Empirical: LET threshold, SEU cross section, depth, funnel (optional)
• Model: Critical charge, sensitive volume dimensions, funnel (optional)
• File: Text file containing SEU cross section as a function of LET, depth, funnel (optional)
• Weibull: Empirical parameters, Weibull width and shape