Monte Carlo calculations of nuclear cascades and associated Čerenkov radiation in extensive air showers

Abstract

We present a Monte Carlo calculation, with observed cross sections and multiplicities, of the nuclear component of small extensive air showers (EAS) with primary energies ${E}_{0}\ensuremath{\ge}{10}^{3}$ GeV. The simulations were completely three-dimensional and were initiated by cosmic rays sampled from both their primary energy and mass spectra. Resulting particle spectra sampled at 564 g ${\mathrm{cm}}^{\ensuremath{-}2}$ agree with extrapolations from observations of EAS with ${E}_{0}>{10}^{4\ensuremath{-}6}$ GeV. The optical \ifmmode \check{C}\else \v{C}\fi{}erenkov radiation calculated for the nuclear-active particles and muons in these EAS is found to be comparable to that expected from the electrons and distinguishable for particular detector configurations. Implications for EAS observations of cosmic $\ensuremath{\gamma}$ rays and cosmic-ray composition are mentioned.