Proton Proxy Risk Tool

Residual heavy-ion SEE risk after a proton-only test campaign. Recoil LET-equivalent coverage and Weibull model-grid rate bounding after Ladbury & Lauenstein, IEEE TNS 2016, and Ladbury, Lauenstein & Hayes, IEEE TNS 2015; recoil spectra after Hiemstra & Blackmore, IEEE TNS 2003.
This tool is provided as a free community resource. Results should be verified independently. See Help & User Guide

Proton Test

Device & SEE Mode

Mission

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What the paired data say: proton versus heavy-ion SEL in the combined test corpus

Every part in the corpus with both heavy-ion and proton SEL records (95 parts, 92 from published REDW/RADECS/GSFC sources; internal reports counted in aggregate only). Heavy-ion onset = LET@10⁻⁸ from the Poisson-Weibull fit where available, else the author-stated threshold. Full per-part table and case studies: Proton vs. Heavy-Ion Case Studies.

P(proton SEL observed | heavy-ion onset)

Bars: fraction of parts in each heavy-ion onset bin that showed proton SEL, counting proton-SEL parts plus parts with an adequate null test (≥ 50 MeV, ≥ 10¹⁰ p/cm²). Error bars: 90% credible interval on that fraction (Jeffreys/Beta method, which stays sensible for small counts and for 0-of-n or n-of-n bins). n below each bar; weaker nulls are not counted.

Heavy-ion onset of parts that did vs. did not latch under protons

Each dot is one part, placed at its heavy-ion onset (MeV·cm²/mg). Parts with proton SEL cluster below LET 5; parts with a null proton test span the whole range, and the low-onset ones are the residual risk this tool quantifies.
Methodology, calibration and provenance

Method

A null (or N-event) proton test constrains heavy-ion susceptibility only through the nuclear-reaction recoils the protons generate, about 1 per 289,000 at 200 MeV. The recoil population is described as an integral fluence vs. equivalent LET (LETEQ = Edep/ρd), which collapses toward low LET as the sensitive-volume depth grows, because short-range recoils cannot deposit their full LET across a deep volume. For each candidate Weibull σ(LETEQ) model on the published grid (onset 0.5–6.5, width 5–25, shape 0.5–2.5), the expected test event count per unit limiting cross section is μ₁ = ∫F(>L)dW; the Poisson upper limit on the observed count then bounds σsat ≤ μUL/μ₁. Models with σUL < τ are "meaningfully bounded"; the bounded worst case is the max mission rate among them, computed by full CREME96 spectral integration. Models the test cannot bound are evaluated at the die-area geometric cap, the residual worst case. Mission exposure uses the same environment tables and episodic-flare model as the SEL Test-LET tool.

Emulator calibration

The recoil fluence-vs-LETEQ family is a piecewise-linear emulator of the published CRÈME-MC results (2016 Fig 5 depth family; Hiemstra 2003 shallow spectra), with energy scaling (counts ×0.6–1.4, spectral hardness) and a maximum-recoil-energy cap Er,max/(ρd). Validation against the papers: worst-case bounded rate at ISS, 10-µm SV, 10¹⁰ 200-MeV p/cm² reproduces the published power-law to ×1.04; the %-unbounded matrix (2016 Fig 9) matches within ~±8 points across 50–400 MeV; at 10¹² p/cm² the bound runs up to ~×4 conservative. High-Z package option adds the p+Au fission component (~2,250 events/cm² per 10¹⁰ at 200 MeV, LETEQ to ~38 shallow, collapsing with depth per 2016 Fig 10).

References

R. Ladbury and J.-M. Lauenstein, "Evaluating Constraints on Heavy-Ion SEE Susceptibility Imposed by Proton SEE Testing and Other Mixed Environments," IEEE Trans. Nucl. Sci. vol. 64, no. 1, pp. 301–308, 2016.
R. Ladbury, J.-M. Lauenstein and K. P. Hayes, "Use of Proton SEE Data as a Proxy for Bounding Heavy-Ion SEE Susceptibility," IEEE Trans. Nucl. Sci. vol. 62, no. 6, pp. 2505–2510, 2015.
D. M. Hiemstra and E. W. Blackmore, "LET Spectra of Proton Energy Levels From 50 to 500 MeV and Their Effectiveness for Single Event Effects Characterization of Microelectronics," IEEE Trans. Nucl. Sci. vol. 50, no. 6, pp. 2245–2249, 2003.
T. L. Turflinger et al. "RHA Implications of Proton on Gold-Plated Package Structures in SEE Evaluations," IEEE Trans. Nucl. Sci. vol. 62, no. 6, pp. 2468–2475, 2015.