Estimation of the Chemical Composition of Charged Cosmic Rays between eV and eV with the HEGRA Arrays

Data of the HEGRA scintillator and AIROBICC arrays are used to determine the coarse chemical composition of charged cosmic rays in the energy range between eV and eV. Especially the wide angle integrating ˇ Cerenkov counters (AIROBICC) allow to measure the penetration depth of the shower maximum, a parameter which is correlated with the energy per nucleon. By analyzing the distribution of penetration depths in six energy intervals the coarse chemical composition of cosmic rays can be derived. The results are achieved using a primary mass independent method to determine the energy.