Bursts in NaI(Tl) near Sea Level

Abstract

The spectrum of cosmic-ray events induced in a NaI(Tl) scintillation spectrometer has been observed near sea level. The high-energy bursts so observed are interpreted as due mainly to nuclear interactions in the crystal with an energy distribution given by the power law $N(E)\mathrm{dE}\ensuremath{\propto}{E}^{\ensuremath{-}3.6}\mathrm{dE}$. The attenuation length for the star-producing component in concrete is found to be 200\ifmmode\pm\else\textpm\fi{}25 g/${\mathrm{cm}}^{2}$.