WHAT WE CAN INFER ABOUT THE NUCLEAR COSMIC-RAY COMPOSITION FROM THE EAS LONGITUDINAL DEVELOPMENT

Results from a detailed Monte Carlo simulation for electromagnetic and hadronic cascades in the atmosphere, generated by primary gamma-rays, p, O and Fe are provided in the primary energy range 10(12)-10(16) eV for vertical incident showers. In the simulation of the Extensive Air Showers (EAS) development, the CORSIKA. (COsmic Ray SImulator for KAs cade) code has been used to perform a full simulation of the electroma gnetic and hadronic interactions. The main aims of this simulation are to obtain accurate information on the longitudinal development of the electromagnetic component, for both pure electromagnetic and hadronic cascades, for different primary cosmic rays. Results on the dependenc e of the shower size and the photon number with primary energy are obt ained. Ratios between the maximum development depth parameter and prim ary particle energy or the shower size have been studied and predicted values for the electron and photon content and fluctuations on these parameters have been determined at the maximum development depth of th e EAS and at mountain altitude (X = 800 g cm(-2)). We also seek to pro vide relations to interpret the experimental data, for those who do no t have detailed simulation calculations available and also to provide material for a full and deep comparison of air shower Monte Carlo code s. (C) 1997 Elsevier Science B.V.