Monte Carlo simulation of air shower development for the study of cosmic ray composition

We have developed a Monte Carlo program to simulate the extensive air showe rs (EASs) in short computing time and to study the chemical composition of cosmic rays at the knee region. This code is particularly applied to the Ce renkov experiment that measures the time structure of Cerenkov light from t he EAS. There are many EAS programs available for public use. However, they are not adequate for simulating large number of air shower, since they dea l with the very complex interaction algorithm and consume a lot of time. Th erefore much faster program should be developed adequately for our purpose. In this report, we discuss the interaction model used in our Monte Carlo c ode and make a comparison with the accelerator data and the widely used Mon te Carlo code, CORSIKA. In addition, we propose a parameterization method t hat describes the fluctuation of air shower development. Using this method, we can calculate air shower development 10(6) times faster than the CORSIK A simulation code. (C) 2001 Elsevier Science B.V. All rights reserved.