Untersuchungen zum primären Energiespektrum der kosmischen Strahlung im PeV-Bereich mit dem KASCADE-Experiment

Abstract

The energy spectrum of cosmic rays follows over a wide rang a simple power law with a change of the spectral index at about 4 . 10 1 5 eV. This break is usually referred to as the knee in the spectrum of cosmic rays. There exists a large number of theories on the origin of the knee but only few of them could have been confirmed or falsified. To make a clear statement it is necessary to determine the energy spectra of individual primary particles. In this work the correlated frequency distribution of electron and muon numbers of extensive air showers measured by the KASCADE experiment was used. By application of different unfolding techniques it was possible to deconvolute the flux spectra of 5 primary particles (H, He, C, Si, Fe) representing different mass groups. The applied unfolding procedures were tested by simulations and found to be suitable for the analysis of air shower data. For this analysis the two different high energy hadronic interaction models QGSJet and SIBYLL were used. For each model it was possible to obtain the individual energy spectra. Although the description of the measured data is not fully consistent for both interaction models some basic properties of the individual energy spectra could have been derived which are probably independent of the interaction models. Additionally the shortfall of the data description occurs in different regions of the measuring range which makes it possible to specify the discrepancies of the model predictions.