[en] In the present thesis the experiment of the CDHS collaboration on the search for inclusive muon-neutrino oscillations is described. The event rates of ν_μ reactions via charged currents was simultaneously measured in two detectors which were 130 m and 885 m away from the beam origin. The data contain no hints for oscillation effects. At maximal mixing mass differences of the contributing eigenstates are excluded in a range 0.26 ≤ Δm² ≤ 90 eV² with 90% confidence. The best sensitivity was reached for Δm²=2.5 eV² and allows there a maximal mixing parameter sin²2 ≤ 0.053. From the CDHS data the hitherto best limits on oscillation parameters resulted. From a common analysis of different oscillation experiments the allowed parameters for the case of simultaneous transitions between electron, muon, and tau neutrinos could be obtained. Regarding systematic uncertainties also here no evidence for oscillations exists. (orig./HSI)

No abstract available

[en] The present volume is a compilation of the contributions of Institutes of Forschungszentrum Karlsruhe and University Karlsruhe to the 30th International Cosmic Ray Conference (ICRC), held in Merida, Mexico from July 3 to 11, 2007. The collection of contributions provides an up-to-date review of the current activities and research projects related to cosmic rays that are pursued in Karlsruhe. The articles compiled in this report are sorted according to the main research foci of the Karlsruhe groups. These include the physics of the knee in the cosmic ray spectrum, the transition between galactic and extra-galactic cosmic rays, and extragalactic cosmic rays of the highest energies. Important contributions presented at the conference include the investigation of the influence of thunderstorms on the measured field strength and the measurement of showers with large zenith angles as well as significant progress in the modelling of the emission processes of the radio signals during the shower development. The Auger results represented the highlights of the conference. Due to the indirect character of cosmic ray measurements with air showers, all analyses discussed above depend on the detailed simulation of cosmic ray interactions and extensive air showers. Recent progress in this field is summarized in the contributions related to the CORSIKA (Cosmic Ray Simulations for KASCADE and Auger) simulation package, the measurement of the characteristics of hadronic interactions, and air shower simulation studies. Other contributions to the conference in Merida include the measurement of the fluorescence light yield with the AIRLIGHT experiment in Karlsruhe, the direct measurement of cosmic rays at lower energy with the balloon borne instrument TRACER (Transition Radiation Array for Cosmic Energetic Radiation) and possible theoretical interpretations, and the search for signals from dark matter annihilation. (orig.)

[en] This volume is a compilation of the contributions of the Forschungszentrum Karlsruhe, Institut fuer Kernphysik and Karlsruhe University, Institut fuer Experimentelle Kernphysik to the biannual International Cosmic Ray Conference 2003 (ICRC 2003). It gives an up-to-date summary of the corresponding scientific activities of the aforementioned institutes, focussing on two experiments, KASCADE-Grande and the Pierre Auger Observatory, the physics of air showers and their simulation using CORSIKA, and cosmic ray phenomenology. Many of the contributions are the product of close collaboration with other national (e.g. Siegen, Wuppertal, Bonn) and international (e.g. from Poland, Italy, Romania, Russia, Great Britain, US) universities and institutes. (orig.)

[en] This report is a compilation of contributions of institutes of the Forschungszentrum Karlsruhe and University Karlsruhe to the International Cosmic Ray Conference (ICRC) held in Pune, India this year. These contributions have been made in close collaboration with many national and international universities and institutes. The compilation provides a review of the corresponding scientific activities of the issuing institutes. It also gives an overview of the status and scientific results of the air shower experiments KASCADE-Grande, the Pierre Auger Project, and the new radio antenna array LOPES, which is complemented by a number of articles on related physics subjects such as air shower simulation and direct cosmic ray measurements. (orig.)

[en] The Pierre Auger Observatory is now being constructed to understand the nature and origin of cosmic rays at ultra-high energies (> 10¹⁹ eV). It will be the largest cosmic ray detector ever built, covering 3000 square kilometers in both hemispheres in its full configuration. First data show a very good performance of the apparatus. (author)

[en] Motivated by the importance of the measurement of p+C and π+C interactions for hadronic interaction models used in extensive air shower simulations we analyze the pion production in p+C and π+C reactions at 12 GeV/c in the fixed target experiment HARP at CERN-PS. We present momentum spectra of positive and negative pions within a momentum range from 0.5 GeV/c to 8.0 GeV/c and an angular range from 30 mrad to 210 mrad. Systematic and statistical uncertainties are discussed and the results are compared with model predictions. Finally a Sanford-Wang function is used to parameterize the obverse spectra. (orig.)

[en] An apparatus is described to measure drift velocities of electrons in gas mixtures. Free electrons are liberated in the gas by laser ionization and the drift time is measured with a two-beam differential method. Drift velocities in various xenon-methane mixtures have been investigated systematically with a xenon content from 0% to 95% in steps of 5%. In addition, drift velocities of electrons in an argon-methane (90:10) mixture are given. The measured velocities are compared with predictions of the Magboltz code

No abstract available

[en] In this paper, we will discuss the prospects of deducing the proton-air cross section from fluorescence telescope measurements of extensive air showers. As it is not possible to observe the point of first interaction, X₁, directly, other observables closely linked to X₁ must be inferred from the longitudinal profiles. This introduces a dependence on the models used to describe the shower development. The most straightforward candidate for a good correlation to X₁ is the depth of shower maximum X_max. We will discuss the sensitivity of an X_max-based analysis on σ_p-air and quantify the systematic uncertainties arising from the model dependence, parameters of the reconstruction method itself and a possible non-proton contamination of the selected shower sample