Satellite Single-Event-Effect Rate

CREME96 IRPP method: the device Weibull SEE cross-section convolved with the orbit galactic-cosmic-ray LET spectrum. A parametric order-of-magnitude screen for part selection + EDAC sizing - run CREME96 / CREME-MC in SPENVIS for the design value.

This single-event upset (SEU) rate calculator convolves the device's Weibull cross-section - the four parameters a JEDEC JESD57 heavy-ion test produces - with the orbit's galactic-cosmic-ray linear-energy-transfer (LET) spectrum, following the CREME96 integral rectangular-parallelepiped (IRPP) method (Tylka et al. 1997). It reports upsets per bit-day, upsets per device-day, and the mean time between upsets (MTBU), with altitude, inclination, and solar-cycle scaling of the environment built in. A parametric order-of-magnitude screen for part selection and error-correction sizing - the design value comes from CREME96 / CREME-MC run in SPENVIS.

A single-event effect is caused by one energetic particle: a heavy ion (or a proton, via a nuclear reaction) passes through a sensitive node and deposits enough charge to flip a memory bit (single-event upset, SEU), trip a latch-up (SEL), or inject a transient. Unlike total ionizing dose, which accumulates, an SEE is a rate - so what matters is the flux of ionizing particles, not how long the mission runs. This tool estimates that rate.

The device is characterised by its Weibull cross-section: the LET threshold L₀ below which no ion can upset it (the single most important hardness number), the saturation cross-section (the geometric sensitive area once every strike upsets), and the width and exponent that shape the turn-on. The environment is the orbit's integral galactic-cosmic-ray (GCR) LET spectrum - a high flux of low-LET ions falling steeply to an iron "knee" around 25-30 MeV·cm²/mg and a hard cutoff past relativistic iron. The IRPP method (Integral Rectangular Parallelepiped, as implemented in CREME96) convolves the two: the rate is the integral of the differential ion flux times the cross-section over LET.

Three environment facts drive the answer. The GCR flux is highest at GEO and interplanetary (full exposure), lower in MEO, and strongly suppressed in low-inclination LEO where Earth's magnetic field deflects the ions; polar orbits let GCR pour in at the poles. Counter-intuitively the rate peaks at solar minimum - at solar max the stronger heliospheric field modulates the incoming galactic ions (the opposite of the total-dose story). And shielding barely helps: the iron-group ions that cause most upsets are so penetrating that practical aluminum only trims the low-LET tail. The real mitigations are a higher LET threshold (rad-hard-by-design), EDAC/memory scrubbing, and redundancy.

What this tool does not do: it is a parametric analytic model of the IRPP convolution, tuned to CREME96-class magnitudes - an order-of-magnitude screen, not a physics-first sensitive- volume transport code. Real prediction uses CREME96 or CREME-MC (in SPENVIS) with the device's measured sensitive-volume geometry and the specific orbit-integrated spectrum. It models only heavy-ion direct ionization; proton-direct and proton-nuclear SEE - which dominate for very-low-threshold parts inside the proton belts - are not included, nor are SEL/SET/SEFI severity, angle-of-incidence path-length distributions, or single-event burnout in power devices.