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The importance of including secondary particles in particle environments for single event effects (SEE) simulations is examined by comparing total error rates with and without secondary alpha particles as a result of target fragmentation. Previous experimental single-event tests have demonstrated importance of short-range, high-LET secondary particles, produced by target fragmentation near to device. However, current error rate prediction workflows, based on tools such as CREME96 and SPENVIS, do not account for these secondary particles from target fragmentation. Reevaluating those practices shows that the impact of secondary alpha particles on total error rates is negligible for the environments, devices, and aluminum shielding explored. To compare the broader issue of nuclear reactions in overlaying materials, energy deposition simulations were done in MRED, which indicate that the composition and sequence of overlying materials need to be considered with regard to secondary particle production.

Device-level failure probabilities derived from historical, similar radiation datasets can be inputted into a system-level radiation reliability model to provide insight into that system’s failure probability. A linear voltage regulator reliability model that utilizes historical total ionizing dose (TID) [< 100 krad(SiO2)] and displacement damage dose (DDD) measurements ( $ &lt; 9\times 10^{11}$ equivalent 1-MeV neutrons/cm2) is used as a demonstration system. This methodology aims to reduce engineering uncertainty at early design stages before radiation test data are available or on quick turn-around projects without radiation test budgets.

Silicon carbide (SiC) power devices may exhibit step increases in leakage current when exposed to heavy ions while biased in the OFF state. Estimating the magnitude of this phenomenon over time in the variable solar energetic particle environment represents a challenge, as the probability of occurrence and step sizes are widely variable. The Prediction of Solar particle Yields for Characterizing Integrating Circuits (PSYCHIC) code is used to generate potential environmental flux spectra. Using an existing method, leakage current increases during broad-beam irradiation are characterized by frequency and magnitude. In this article, these characterizations are applied to various environmental flux spectra to generate a range of cumulative leakage current increases. This process is repeated to produce distributions of leakage current increases that account for environmental variability and step size variability. Comparing the results for various operating voltages, mission durations, and shielding, it is shown that shielding thickness and operating voltage have a significant influence on the potential cumulative leakage current increase.