SBAK021 December   2024 AFE7950-SP

 

  1.   1
  2.   2
  3.   Trademarks
  4. 1Introduction
  5. 2Single-Event Effects
  6. 3Device and Test Board Information
  7. 4Irradiation Facility and Setup
  8. 5Test Setup and Procedures
  9. 6Destructive Single-Event Effects (DSEE)
  10. 7Single-Event Effects (SEE)
  11. 8Event Rate Calculations
  12. 9References

8 Event Rate Calculations

Event rates were calculated for LEO (ISS) and GEO environments by combining CREME96 orbital integral flux estimations and simplified SEE cross-sections according to methods described in Heavy Ion Orbital Environment Single-Event Effects Estimations. A minimum shielding configuration of 100 mils (2.54mm) of aluminum, and worst-week solar activity (this is similar to a 99% upper bound for the environment) is assumed. Using the 95% upper-bounds for the SEL and SET, the event rates for SEU and SEFIs are shown in Table 8-1 andTable 8-2. For SEU event rate calculations, the total fluence of each run was integrated to come up with cross section levels at each LET. Plots for corresponding Weibull curve are found below. For this particular device, even at the lower LETs of 9.75 Mev, both SEFIs and SEUs are occurring. For the MTBF calculations, an onset of one was used to be conservative.

Table 8-1 SET Event Rate Calculations of SEUs for Worst-Week LEO and GEO Orbits
Orbit Type Onset LETEFF (MeV-cm2/mg) σSAT (cm2) Event Rate (/day) Event Rate (FIT) MTBE (Years)
LEO (ISS) 1 1.31 × 10–4 2.57 × 10–4 1.07 × 104 1.07 × 101
GEO 2.18 × 10–3 9.09 × 104 1.26
Table 8-2 SET Event Rate Calculations of SEFIs for Worst-Week LEO and GEO Orbits
Orbit Type Onset LETEFF (MeV-cm2/mg) σSAT (cm2) Event Rate (/day) Event Rate (FIT) MTBE (Years)
LEO (ISS) 1 2.33 × 10–5 9.48 × 10–5 3.95 × 103 2.89 × 101
GEO 8.29 × 10–4 3.45 × 103 3.30
AFE7950-SP Weibull Curve Characterizing SEUs Figure 8-1 Weibull Curve Characterizing SEUs
AFE7950-SP Weibull Curve Characterizing SEFIs Figure 8-2 Weibull Curve Characterizing SEFIs