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  • 1
    Publication Date: 2020-10-07
    Description: In cosmic ray experiments the arrival directions, among other properties, of cosmic ray particles from detected air shower events are reconstructed. The question of uniformity in the distribution of arrival directions is of large importance for models that try to explain cosmic radiation. In this thesis, methods for the reconstruction of parameters of a dipole-like flux distribution of cosmic rays from a set of recorded air shower events are studied. Different methods are presented and examined by means of detailed Monte Carlo simulations. Particular focus is put on the implications of spurious experimental effects. Modifications of existing methods and new methods are proposed. The main goal of this thesis is the development of the horizontal Rayleigh analysis method. Unlike other methods, this method is based on the analysis of local viewing directions instead of global sidereal directions. As a result, the symmetries of the experimental setup can be better utilised. The calculation of the sky coverage (exposure function) is not necessary in this analysis. The performance of the method is tested by means of further Monte Carlo simulations. The new method performs similarly good or only marginally worse than established methods in case of ideal measurement conditions. However, the simulation of certain experimental effects can cause substantial misestimations of the dipole parameters by the established methods, whereas the new method produces no systematic deviations. The invulnerability to certain effects offers additional advantages, as certain data selection cuts become dispensable.
    Description: thesis
    Keywords: 523 ; TFE 000 ; Kosmische Elektrodynamik {Astrophysik}
    Language: English
    Type: monograph , publishedVersion
    Format: 177 S.
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  • 2
    Publication Date: 2021-03-29
    Description: thesis
    Keywords: 523 ; TCE 500 ; TFE 000 ; TVM 610 ; TVB 420 ; Sonstige Instrumente {Astronomische Instrumente} ; Kosmische Elektrodynamik {Astrophysik} ; Luftelektrische Beobachtungs- und Meßverfahren {Meteorologie} ; Aeronomie {Meteorologie}
    Language: English
    Type: monograph , publishedVersion
    Format: 165 S.
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  • 3
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    Univ. Siegen
    Publication Date: 2021-03-29
    Description: The CosmoALEPH experiment, located underground at the LEP e+e? storage ring at CERN at a depth of 320 m water equivalent, was used to study the chemical composition of primary cosmic rays up to 10 PeV energies from the measurement of high energy muons, created in extensive air showers by interactions of primary nuclei in the atmosphere. The Time Projection Chamber (TPC) and the Hadron Calorimeter of the ALEPH detector and six scintillator stations located at distances up to 1 km from each other were used to analyse the decoherence curve, multiplicity and transverse momentum distributions of energetic cosmic muons. The experimental data were compared with predictions from different Monte Carlo (MC) models and mass composition approaches. From a comparison between the measured decoherence distribution with CosmoALEPH and the MC predicted decoherence curves for proton, helium and iron, a primary composition of (77±11) % protons and (23±11) % iron nuclei with a ?2 - probability of 84 % was determined, based on the predictions of the VENUS model with the constant mass composition approach. The analysis of the decoherence curve, with consideration of correlations between the measured CosmoALEPH parameters, leads to a composition of (88 ± 8) % protons and (12 ± 8) % iron nuclei for cosmic rays with a ?2 -probability of 53 % ...
    Description: thesis
    Keywords: 523 ; TFE 000 ; Kosmische Elektrodynamik {Astrophysik}
    Language: English
    Type: monograph , publishedVersion
    Format: 191 S.
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  • 4
    Publication Date: 2021-03-29
    Description: Extensive air showers measured by the KASCADE-Grande experiment at the Forschungszentrum Karlsruhe are studied with respect to the arrival times of electrons and muons at observation level. KASCADE-Grande is a ground based detector array to study extensive air showers generated by primary cosmic ray particles in the energy range from 10^14 eV to 10^18 eV. Approximately 290,000 air showers measured between January 2005 and Febuary 2006 are used to generate arrival time distributions of electrons and muons for 13 intervals of the distance R to the shower center. The particle arrival times are reconstructed by unfolding detector signal pulses sampled by a Flash-ADC based data acquisition system connected to the electron and muon detectors of eight detector stations of the KASCADE detector array. For distances R〉200 m particles of the a muonic shower component arrive on average earlier at observation level than particles of the electromagnetic shower component. This difference in arrival time is used to determine a cut on the particle arrival time as a function of the distance from the shower center. This cut is intended to be used by experiments with time resolving detectors for the separation of electrons and muons according to their arrival times relative to the arrival time of the shower core. Particles with arrival times smaller than the cut are considered as muons. Due to the large spread of the arrival time distributions the number of muons reconstructed in this way will contain a contribution from the electromagnetic shower component ...
    Description: thesis
    Keywords: 539.7223 ; 523 ; 550 ; TFE 000 ; TVM 000 ; Kosmische Elektrodynamik {Astrophysik} ; Verschiedene Phänomene und Einflüsse {Meteorologie}
    Language: English
    Type: monograph , publishedVersion
    Format: 162 S.
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