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A. Haungs

Publications and source records attributed to A. Haungs.

At least 127 records · Page 7Linked to original sources
arXiv2010

The KASCADE-Grande experiment: measurements of the all-particle energy spectrum of cosmic rays

The all-particle energy spectrum as measured by the KASCADE-Grande experiment for E = 10^{16} - 10^{18} eV is presented within the framework of the QGSJET II/FLUKA hadronic interaction models. Three different methods were applied based on the muon size and the total number of charged particles individually and in combination. From the study it is found that the spectrum cannot be completely described by a smooth power law due to the presence of characteristic features.

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arXiv2010

On noise treatment in radio measurements of cosmic ray air showers

Precise measurements of the radio emission by cosmic ray air showers require an adequate treatment of noise. Unlike to usual experiments in particle physics, where noise always adds to the signal, radio noise can in principle decrease or increase the signal if it interferes by chance destructively or constructively. Consequently, noise cannot simply be subtracted from the signal, and its influence on amplitude and time measurement of radio pulses must be studied with care. First, noise has to be determined consistently with the definition of the radio signal which typically is the maximum field strength of the radio pulse. Second, the average impact of noise on radio pulse measurements at individual antennas is studied for LOPES. It is shown that a correct treatment of noise is especially important at low signal-to-noise ratios: noise can be the dominant source of uncertainty for pulse height and time measurements, and it can systematically flatten the slope of lateral distributions. The presented method can also be transfered to other experiments in radio and acoustic detection of cosmic rays and neutrinos.

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arXiv2010

New method for the time calibration of an interferometric radio antenna array

Digital radio antenna arrays, like LOPES (LOFAR PrototypE Station), detect high-energy cosmic rays via the radio emission from atmospheric extensive air showers. LOPES is an array of dipole antennas placed within and triggered by the KASCADE-Grande experiment on site of the Karlsruhe Institute of Technology, Germany. The antennas are digitally combined to build a radio interferometer by forming a beam into the air shower arrival direction which allows measurements even at low signal-to-noise ratios in individual antennas. This technique requires a precise time calibration. A combination of several calibration steps is used to achieve the necessary timing accuracy of about 1 ns. The group delays of the setup are measured, the frequency dependence of these delays (dispersion) is corrected in the subsequent data analysis, and variations of the delays with time are monitored. We use a transmitting reference antenna, a beacon, which continuously emits sine waves at known frequencies. Variations of the relative delays between the antennas can be detected and corrected for at each recorded event by measuring the phases at the beacon frequencies.

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arXiv2009

The Cosmic Ray Energy Spectrum Measured with KASCADE-Grande

KASCADE-Grande is a multi-detector experiment at Forschungszentrum Karlsruhe, Germany for measuring extensive air showers in the primary energy range of 100 TeV to 1 EeV. This contribution attempts to provide a synopsis of the current results of the experiment. In particular, the reconstruction of the all-particle energy spectrum in the range of 10 PeV to 1 EeV based on four different methods with partly different sources of systematic uncertainties is presented. Since the calibration of the observables in terms of the primary energy and mass depends on Monte Carlo simulations, we compare the results of various methods applied to the same sample of measured data. In addition, first investigations on the elemental composition of the cosmic particles as well as on tests of hadronic interaction models underlying the analyses are discussed.

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arXiv2009

Lateral Distribution of the Radio Signal in Extensive Air Showers Measured with LOPES

The antenna array LOPES is set up at the location of the KASCADE-Grande extensive air shower experiment in Karlsruhe, Germany and aims to measure and investigate radio pulses from Extensive Air Showers. The coincident measurements allow us to reconstruct the electric field strength at observation level in dependence of general EAS parameters. In the present work, the lateral distribution of the radio signal in air showers is studied in detail. It is found that the lateral distributions of the electric field strengths in individual EAS can be described by an exponential function. For about 20% of the events a flattening towards the shower axis is observed, preferentially for showers with large inclination angle. The estimated scale parameters R0 describing the slope of the lateral profiles range between 100 and 200 m. No evidence for a direct correlation of R0 with shower parameters like azimuth angle, geomagnetic angle, or primary energy can be found. This indicates that the lateral profile is an intrinsic property of the radio emission during the shower development which makes the radio detection technique suitable for large scale applications.

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arXiv2009

Influence of Low Energy Hadronic Interactions on Air-shower Simulations

Experiments measuring cosmic rays above an energy of 10^14 eV deduce the energy and mass of the primary cosmic ray particles from air-shower simulations. We investigate the importance of hadronic interactions at low and high energies on the distributions of muons and electrons in showers on ground. In air shower simulation programs, hadronic interactions below an energy threshold in the range from 80 GeV to 500 GeV are simulated by low energy interaction models, like Fluka or Gheisha, and above that energy by high energy interaction models, e.g. Sibyll or QGJSJet. We find that the impact on shower development obtained by switching the transition energy from 80 GeV to 500 GeV is comparable to the difference obtained by switching between Fluka and Gheisha.

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arXiv2008

Air Shower Measurements with the LOPES Radio Antenna Array

LOPES is set up at the location of the KASCADE-Grande extensive air shower experiment in Karlsruhe, Germany and aims to measure and investigate radio pulses from Extensive Air Showers. Since radio waves suffer very little attenuation, radio measurements allow the detection of very distant or highly inclined showers. These waves can be recorded day and night, and provide a bolometric measure of the leptonic shower component. LOPES is designed as a digital radio interferometer using high bandwidths and fast data processing and profits from the reconstructed air shower observables of KASCADE-Grande. The LOPES antennas are absolutely amplitude calibrated allowing to reconstruct the electric field strength which can be compared with predictions from detailed Monte Carlo simulations. We report about the analysis of correlations present in the radio signals measured by the LOPES 30 antenna array. Additionally, LOPES operates antennas of a different type (LOPES-STAR) which are optimized for an application at the Pierre Auger Observatory. Status, recent results of the data analysis and further perspectives of LOPES and the possible large scale application of this new detection technique are discussed.

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arXiv2008

The muon charge ratio in cosmic ray air showers

The muon charge ratio of the lateral muon density distributions in single EAS is studied by simulations, in context of recent proposals to measure this observable in coincidence with EAS observations. While effects of the hadronic interaction do not lead to significant differences of the total muon plus and muon minus content, the differences of the azimuthal variation of the muon densities of opposite charges and the azimuthal variation of the muon charge ratio appear to be very much pronounced, dependent on the direction of EAS incidence. This is due to the influence of the geomagnetic field which induces related effects in radio emission from extended air showers.

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arXiv2008

Applying Shower Development Universality to KASCADE Data

On basis of the theorem of a universal shower development stating that a hadronically generated extensive air shower is completely described by the primary energy, the position of the shower maximum and a parameter related to the total muon number, the so-called correlation curve method is developed and applied to KASCADE data. Correlation information of the muon and electron content of showers measured by the KASCADE experiment are used for the reconstruction of energy and mass of primary cosmic rays. Systematic uncertainties of the method and the results are discussed in detail. It is shown that by this method general tendencies in spectrum and composition indeed can be revealed, but the absolute normalization in energy and mass scale requires much more detailed simulations.

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arXiv2008

Amplitude calibration of a digital radio antenna array for measuring cosmic ray air showers

Radio pulses are emitted during the development of air showers, where air showers are generated by ultra-high energy cosmic rays entering the Earth's atmosphere. These nanosecond short pulses are presently investigated by various experiments for the purpose of using them as a new detection technique for cosmic particles. For an array of 30 digital radio antennas (LOPES experiment) an absolute amplitude calibration of the radio antennas including the full electronic chain of the data acquisition system is performed, in order to estimate absolute values of the electric field strength for these short radio pulses. This is mandatory, because the measured radio signals in the MHz frequency range have to be compared with theoretical estimates and with predictions from Monte Carlo simulations to reconstruct features of the primary cosmic particle. A commercial reference radio emitter is used to estimate frequency dependent correction factors for each single antenna of the radio antenna array. The expected received power is related to the power recorded by the full electronic chain. Systematic uncertainties due to different environmental conditions and the described calibration procedure are of order 20%.

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arXiv2006

New p+C data in fixed target experiments and the muon component in extensive air showers

The interpretation of extensive air shower (EAS) measurements is strongly dependent on the hadronic interaction models used for simulating reference showers. We study the importance of low-energy hadronic interactions in simulated air showers, generated with the simulation package CORSIKA, for the observed characteristics of extensive air showers. In particular we investigate in detail the energy and the phase space regions of secondary particle production which are most important for muon production. This phase space region is covered by fixed target experiments at CERN. In the second part of this work we present preliminary momentum spectra of secondary pi+ and pi- in p+C collisions at 12 GeV/c measured with the HARP spectrometer at the PS accelerator at CERN. In addition we use the new p+C NA49 data at 158 GeV/c to check the reliability of hadronic interaction models for muon production in EAS. Finally, possibilities to measure relevant quantities of hadron production in existing and planned accelerator experiments are discussed.

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arXiv2005

Muon production in extensive air showers and its relation to hadronic interactions

In this work, the relation between muon production in extensive air showers and features of hadronic multiparticle production at low energies is studied. Using CORSIKA, we determine typical energies and phase space regions of secondary particles which are important for muon production in extensive air showers and confront the results with existing fixed target measurements. Furthermore possibilities to measure relevant quantities of hadron production in existing and planned accelerator experiments are discussed.

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arXiv2005

Combined LOPES and KASCADE-Grande Data Analysis

First analyses of coincident data of the LOPES (LOfar PrototypE Station) radio antennas with the particle air shower experiment KASCADE-Grande show basic correlations in the observed shower parameters, like the strength of the radio signal and the particle number, or comparing the estimated shower directions. In addition, an improvement of the experimental resolution of the shower parameters reconstructed by KASCADE-Grande can be obtained by including the data of the radio antennas. This important feature will be shown in this article explicitely by an example event.

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arXiv2005

Hadronic multiparticle production in extensive air showers and accelerator experiments

Using CORSIKA for simulating extensive air showers, we study the relation between the shower characteristics and features of hadronic multiparticle production at low energies. We report about investigations of typical energies and phase space regions of secondary particles which are important for muon production in extensive air showers. Possibilities to measure relevant quantities of hadron production in existing and planned accelerator experiments are discussed.

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arXiv2004

KASCADE: Astrophysical results and tests of hadronic interaction models

KASCADE is a multi-detector setup to get redundant information on single air shower basis. The information is used to perform multiparameter analyses to solve the threefold problem of the reconstruction of (i)the unknown primary energy, (ii) the primary mass, and (iii) to quantify the characteristics of the hadronic interactions in the air-shower development. In this talk recent results of the KASCADE data analyses are summarized concerning cosmic ray anisotropy studies, determination of flux spectra for different primary mass groups, and approaches to test hadronic interaction models. Neither large scale anisotropies nor point sources were found in the KASCADE data set. The energy spectra of the light element groups result in a knee-like bending and a steepening above the knee. The topology of the individual knee positions shows a dependency on the primary particle. Though no hadronic interaction model is fully able to describe the multi-parameter data of KASCADE consistently, the more recent models or improved versions of older models reproduce the data better than few years ago.

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arXiv2002

Features of Muon Arrival Time Distributions of High Energy EAS at Large Distances From the Shower Axis

In view of the current efforts to extend the KASCADE experiment (KASCADE-Grande) for observations of Extensive Air Showers (EAS) of primary energies up to 1 EeV, the features of muon arrival time distributions and their correlations with other observable EAS quantities have been scrutinised on basis of high-energy EAS, simulated with the Monte Carlo code CORSIKA and using in general the QGSJET model as generator. Methodically various correlations of adequately defined arrival time parameters with other EAS parameters have been investigated by invoking non-parametric methods for the analysis of multivariate distributions, studying the classification and misclassification probabilities of various observable sets. It turns out that adding the arrival time information and the multiplicity of muons spanning the observed time distributions has distinct effects improving the mass discrimination. A further outcome of the studies is the feature that for the considered ranges of primary energies and of distances from the shower axis the discrimination power of global arrival time distributions referring to the arrival time of the shower core is only marginally enhanced as compared to local distributions referring to the arrival of the locally first muon.

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arXiv2002

Energy Spectrum and Mass Composition around the Knee by EAS Measurements

Primary cosmic ray particles above energies of about 100 TeV are investigated by large-area ground based detector installations, observing various components of the development of extensive air-showers (EAS). By such an indirect access to the primary cosmic ray spectrum a steepening of the power-law falls off at around 3-5 PeV, known as the {\em knee} has been identified. Different experimental techniques are used to deduce mass- and energy-sensitive observables of EAS experiments. The experiments involve measurements of secondary particle distributions at various observation levels and of muons deep underground as well as of observables reconstructed by measuring the air Cherenkov light emitted with the shower development in the atmosphere. Recently methods for analysing multidimensional distributions get favoured since they are able to take into account the correlations between different observables and the influence of large intrinsic fluctuations of the air-shower development. Additionally the use of a larger set of observables provides the possibility to test simultaneously the consistency of the Monte-Carlo models underlying the reconstruction procedures. By many experiments the existence of the knee in the primary energy spectrum is confirmed and a tendency of an increasing mean mass above the knee energy is indicated. Recent results show that the knee originates from a decrease of the flux of light primary particles, whereas heavy cosmic ray particles seem to miss a kink in the energy range of 1 and 10 PeV.

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