Numerical calculations of cosmic ray cascade in the Earth's atmosphere - Results for nucleon spectra

The interaction of primary cosmic rays with Earth's atmosphere is investigated using the simulation toolkit Geant4. The yield functions of atmospheric nucleon fluxes are computed for the energy of primary cosmic ray particles ranging from 0.1 to 10(4) GeV. The model is presented that enables to calculate differential particle fluxes in the atmosphere for given level of solar modulation and geomagnetic latitude. The accuracy of the computations is verified by experimental data taken under various conditions. The calculated particle fluxes can be employed for estimation of the production rates of cosmogenic nuclides in the atmosphere and Earth's surface, for calculations of cosmic ray exposure dose for the public and soft-error failure rates in the microelectronics. (C) 2012 Elsevier B.V. All rights reserved.