Simulation of proton-induced and iron-induced extensive air showers at extreme energies

The development of extensive air showers at extreme energies is studied using a simulation model much simpler and cruder, but also more transparent and flexible, than existing sophisticated codes. Evidence for its satisfactory performance is presented. As an illustration, shower elongation rates are evaluated in the 10181018 to 10201020 eV region and compared with recently published data. Lateral distribution functions of both muons and electrons/photons are also briefly discussed. Reliable results are obtained in the comparison between proton-induced and iron-induced showers.

► A simple shower development model using parameterized sub-showers has been developed.
► It gives reasonable predictions in the 10181018–10201020 energy range in spite of its crudeness.
► It shows the robustness of relative predictions such as elongation rates and Fe/p ratios.
► It does not have the ambition to compete with existing sophisticated models.
► It illustrates difficulty to reproduce observations without change in mass composition.