Cosmic-ray neutrons on the ground and in the atmosphere

Neutrons from collisions of, cosmic rays with the nuclei of atoms in the are an irremovable external radiation that causes single-event upsets in microelectronic devices. Predicting soft error rates requires knowledge of the flux and energy distribution of the cosmic-ray-induced neutrons. This article reviews cosmic-ray neutrons in e atmosphere and on the ground, the,factors that determine their intensity, and recent calculations and state-of-the-art measurements of neutron spectra cove-ring 2 decades of energy, from the thermal energy range up to 10 GeV.