Analysis of the Cherenkov time profile as a technique to distinguish the primary particle

In this paper, we discuss the possibility of excluding the cosmic ray background in gamma ray telescope experiments using the Cherenkov photons arrival time. A method to distinguish proton and iron from gamma induced showers of energies around 50 TeV is presented. A total number of 300 simulated showers are analysed one by one and a distinction method is developed. The simulations were performed with the program CORSIKA and a detailed simulation of the telescope is applied to the surviving Cherenkov photons. Two different shapes of telescopes are tested: parabolic and Davies-Cotton, and the superiority of the parabolic mirrors concerning time information is illustrated