Cosmic-ray mass composition investigations through atmospheric Cerenkov technique - a simulation study

Abstract

The 4-element TACTIC Cerenkov telescope array at Mt. Abu comprises a central Imaging Element equipped with a 349- pixel Cerenkov imaging camera and three Vertex Elements, each of which is equipped with a special duplex detector array for recording spectral, temporal and polarization characteristics of the atmospheric Cerenkov pulses initiated by primary gamma-rays and cosmic-ray hadrons. It is proposed to use the array for cosmic-ray mass-composition studies above 10 TeV energy during partially moonlit conditions. In order to assess the capability of the TACTIC array for these studies, detailed Monte Carlo simulations, using the CORSIKA code, are being carried out for four primary species (gamma-rays, protons, Neon and Iron), in the energy range ~ 10 - 400 TeV, to estimate the spectral parameters like UV (? ~ 250 - 310 nm) to Visible (? ~ 310 - 600 nm) intensity ratio, energy dependence of U / V ratio for each species and the lateral distribution of Cerenkov light for primaries of different energies.