VALIDITY OF THE SUPERPOSITION MODEL FOR EXTENSIVE AIR SHOWERS

The VENUS model of relativistic nucleus-nucleus collisions is used to study interactions of various nuclei with N-14 in view of their influe nce on the development of extensive air showers initiated by cosmic ra y nuclei in the atmosphere. As is well known, only some of the project ile nucleons take part in the interaction (participants) whereas the o thers (spectators) do not lose an appreciable amount of energy, Our ma in result is that the nucleus-nucleus collision, at the high energies of interest. can be described to a good approximation by the superposi tion of N(p) nucleon-nucleus collisions where N(p) is the number of pa rticipant projectile nucleons. Therefore the superposition model frequ ently employed in the calculation of air shower development in the atm osphere should represent a rather good approximation. This is in disag reement with some statements in the literature but is corroborated by simulation calculations of extensive air showers employing the VENUS p rogram. Possible reasons for this discrepancy are discussed.