Atmospheric Neutron SEE and Avionics
Cosmic rays create a neutron flux in the atmosphere that upsets airborne and high-altitude electronics; ground testing reproduces that hazard.
Neutrons from the sky
Cosmic rays striking the upper atmosphere produce showers of secondary particles, and at aircraft altitudes the neutron component of that shower is a leading cause of electronic upsets. The flux rises with altitude and latitude. For avionics and high-altitude platforms, atmospheric-neutron soft errors are a design driver, not a rare curiosity.
Reproducing the hazard on the ground
The atmospheric neutron spectrum extends to high energies, and its damaging tail overlaps the 14 MeV region. A controlled 14 MeV beam lets engineers accumulate upset statistics quickly and characterize how avionics respond to the hard part of the spectrum, which real-time flight exposure would take a very long time to reveal.
- Flux increases with altitude and toward the poles
- The high-energy tail drives the most severe upsets
- Ground testing compresses years of flight exposure
Outcome
The result is a soft-error-rate estimate for the platform's operating envelope, supporting design margins and certification arguments. Kronos frames this as part of its neutron-service offering.
Beyond aircraft
The atmospheric neutron hazard is not confined to aviation. High-altitude platforms, mountaintop installations, and even ground-level systems with very large device counts accumulate enough exposure to matter. As electronics grow denser and more numerous in every platform, the aggregate soft-error rate rises even where any single device is robust. Characterizing parts against a representative neutron spectrum lets designers budget for that aggregate reliability across a whole system, not just one board.
This is a public overview only. It contains no classified information, no operational detail, and no weapons-design content.