Calculations have been carried out to determine the neutron flux induced in the earth's atmosphere by galactic protons and alpha particles at solar minimum for a geomagnetic latitude of 42°N. Neutron flux spectra in the energy range from ~ 10-8 to ~ 105 MeV at various depths in the atmo-sphere were calculated using Monte Carlo and discrete ordinates methods, and various comparisons with experimental data are presented. The magnitude and shape of the calculated neutron-leakage spectrum at the particular latitude considered support the theory that the cosmic-ray-albedo-neutron-decay (CRAND) meachanism is the source of the protons and electrons trapped in the Van Allen belts.
展开▼
