Analyse der KASCADE-Messdaten anhand statistischer Klassifikationsverfahren zur Bestimmung der Energie und Teilchenart der kosmischen Strahlung

The experiment KASCADE is able to measure simultaneously the muonic, electromagnetic and hadronic component of air showers. The 200x200 m"2 detector array, the iron sampling calorimeter (#approx#1000 g/cm"2) and the two layers of multiwire proportional chambers installed below, allow the reconstruction of different observables for the determination of energy and mass of the primary cosmic radiation. To estimate systematic effects of different hadronic interaction models (made available by the air shower simulation code CORSIKA) simulated distributions using the models QGSJet, VENUS and Sibyll, including a simulation of the detector response, are compared with measured ones. While the models QGSjet and VENUS can reproduce the measurements, the model Sibyll shows systematic deviations. By applying nonparametric analysis methods, which use simulated air showers as input pattern, mass and energy of air showers are reconstructed. Proof is given for the existence of the knee in the energy spectrum. In the case of the model QGSJet (VENUS) the resulting spectral indices of the reconstructed energy spectrum are #gamma#_1=2.72#+-#0.003 (#gamma#_1=2.87#+-#0.003) below and #gamma#_2=3.22#+-#0.05 (#gamma#_2=3.25#+-#0.04) above the knee. The position of the knee is almost model-independently estimated to 6.39#+-#0.14x10"6 GeV (6.22#+-#0.27x10"6 GeV). The systematic deviations of the results are studied in detail. The analysis of the relative abundances of the chemical composition of the cosmic radiation results in a lighter composition below the knee and becomes heavier above. The results of the composition analysis are differently pronounced depending on the model. (orig.)Available from TIB Hannover: ZA 5141(6262) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Proceedings of the workshop ANI 98 Current topics of cosmoic ray research with EAS observations

The following topics were dealt with: EAS signatures, cosmic ray mass composition in the PeV region, KASCADE experiment, cosmic ray energy composition, cosmic ray elemental composition, EAS analysis by nonparametric methods, soft EAS component, hadronic EAS component, GAMMA array measurements, EAS muon characteristics, muon detector response studies with the simulation program ARES, GAMMA array measurement accuracy, EAS charged particle component, EAS size spectrum, MAKET installation, EAS size spectra in the knee region, cosmic ray background flux at Aragat, EAS selection, muon arrival time, muon angle of incidence distributions, EAS simulations, GAMMA muon underground detectors, superhigh energy hadron production, high energy hadron interaction models, KORSICA code verification, charge ratio of cosmic ray muonsAvailable from TIB Hannover: ZA 5141(6215) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

A compact detector for the measurement of the cosmic ray muon charge ratio

A compact sampling calorimeter is developed and used to measure the ratio between positive and negative muons in the cosmic ray flux at momenta below 1 GeV/c. The delayed coincidence method is used, based on the reduced mean life time of negative muons due to nuclear capture in matter. It is shown that aluminum is a good choice as capture medium for negative muons and suitable for a simple detector set-up. The muon charge ratio is found to be 1.30 #+-# 0.05 for a mean momentum of 0.86 GeV/c and over a zenith angle acceptance with #THETA#_m_e_a_n = 26 . (orig.)47 refs.Available from TIB Hannover: ZA 5141(6071) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Core structure of extensive air showers at primary energies around the knee by a multifractal moments analysis

A system of large-area position-sensitive multiwire proportional chambers (MWPC), installed below the hadron calorimeter of the central detector of the KASCADE (Karlsruhe shower core and array detector) experiment is able to observe the density distributions of high-energy muons and of the high-energy tails of the hadron spectrum in the core of extensive air showers (EAS). Applying a classification by multifractal moments of the observed patterns allows to explore the information on mass composition of cosmic rays in the studied energy region. Additionally correlating with the shower size and the number of reconstructed muons in the core region, an artificial neural net analysis leads to probability distributions for associating single showers to particular primary masses. The classification can serve as basis of a more detailed shower specification considering further measured shower parameters. (orig.)26 refs.Available from TIB Hannover: ZA 5141(6105) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman