LAUSR

Abstract A detailed simulation of showers with various zenith angles in atmosphere produced by different primary particles including gamma, proton, carbon, and iron at Alborz-I observatory level ( 35 ∘ 43 ′ N, 51 ∘ 20 ′ E, 1200 m a.s.l= 890 gcm − 2 ), in the energy range 3 × 1013 eV–3 × 1015 eV, has been performed by means of the CORSIKA Monte Carlo code. The aim of this study is to examine the time structure of secondary particles in Extensive Air Showers (EAS) produced by the different primary particles. For each primary particle, the distribution of the mean values of the time delays of secondary particles relative to the first particle hitting the ground level in each EAS, τ i > = t i − t p > , and the distribution of their mean standard deviations, in terms of distance from the shower core are obtained. The mean thickness and profile of showers as a function of their energy, primary mass, and zenith angle is described.