Primary energy spectra of cosmic rays selected by mass groups in the knee region

The KASCADE experiment measures the electron and muon number of extensive air showers in the knee region with high precision. From these data shower size spectra for electrons and muons are constructed. An analysis is presented in which electron and muon size spectra in three different zenith angle bins are analysed simultaneously. With a four component assumption for the mass composition of primary cosmic rays (hydrogen, helium, carbon and iron) and using unfolding methods taking into account shower fluctuations and experimental effects energy spectra of these mass groups in the range between 10(15) and 10(17) eV are reconstructed. Each energy spectrum shows a steepening of the index of the resulting power law with a knee-like structure. The positions of the individual knees suggest a rigidity dependence.