Showing papers by "M. Petcu published in 2013"
TL;DR: In this article, the KASCADE-Grande air-shower data was used to reconstruct the energy spectra of different mass groups by unfolding methods over an energy range where the detector is fully efficient.
178 citations
TL;DR: In this paper, the authors present an update of the KASCADE-Grande analysis by using data with increased statistics, originating both from a larger data set including more recent measurements and by using a larger fiducial area.
Abstract: Recent results of the KASCADE-Grande experiment provided evidence for a mild knee-like structure in the all-particle spectrum of cosmic rays at $E={10}^{16.92\ifmmode\pm\else\textpm\fi{}0.10}\text{ }\text{ }\mathrm{eV}$, which was found to be due to a steepening in the flux of heavy primary particles. The spectrum of the combined components of light and intermediate masses was found to be compatible with a single power law in the energy range from ${10}^{16.3}$ to ${10}^{18}\text{ }\text{ }\mathrm{eV}$. In this paper, we present an update of this analysis by using data with increased statistics, originating both from a larger data set including more recent measurements and by using a larger fiducial area. In addition, optimized selection criteria for enhancing light primaries are applied. We find a spectral feature for light elements, namely, a hardening at $E={10}^{17.08\ifmmode\pm\else\textpm\fi{}0.08}\text{ }\text{ }\mathrm{eV}$ with a change of the power law index from $\ensuremath{-}3.25\ifmmode\pm\else\textpm\fi{}0.05$ to $\ensuremath{-}2.79\ifmmode\pm\else\textpm\fi{}0.08$.
133 citations
TL;DR: In this paper, a mobile detector for cosmic muon flux measurements has been set up at IFIN-HH, Romania, where the detector is composed of two 1m2 scintillator plates, each viewed by wave length shifters and read out by two Photomultiplier Tubes (PMTs).
Abstract: Precise measurements of the muon flux are important for different practical applications, both in environmental studies and for the estimation of the water equivalent depths of underground sites. A mobile detector for cosmic muon flux measurements has been set up at IFIN-HH, Romania. The device is used to measure the muon flux on different locations at the surface and underground. Its first configuration, not used in the present, has been composed of two 1 m2 scintillator plates, each viewed by wave length shifters and read out by two Photomultiplier Tubes (PMTs). A more recent configuration, consists of two 1 m2 detection layers, each one including four 1 · 0,25 m2 large scintillator plates. The light output in each plate is collected by twelve optical fibers and then read out by one PMT. Comparative results were obtained with both configurations.
8 citations
01 Jun 2013
TL;DR: In this article, predictions of the muon content of EAS from QGSJET II-2, SIBYLL 2.1 and EPOS 1.99 are confronted with the experimental measurements performed with the KASCADE-Grande experiment in order to test the validity of these hadronic models commonly used in EAS simulations.
Abstract: KASCADE-Grande is an air-shower observatory devoted for the detection of cosmic rays with energies in the interval of 10 14 − 10 18 eV, where the Grande array is responsible for the higher energy range. The experiment comprises different detection systems which allow precise measurements of the charged, elec- tron and muon numbers of extensive air-showers (EAS). These data is employed not only to reconstruct the properties of the primary cosmic-ray particle but also to test hadronic interaction models at high energies. In this contribution, predictions of the muon content of EAS from QGSJET II-2, SIBYLL 2.1 and EPOS 1.99 are confronted with the experimental measurements performed with the KASCADE-Grande experiment in order to test the validity of these hadronic models commonly used in EAS simulations.
6 citations
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TL;DR: The KASCADE-Grande detector as discussed by the authors is an air-shower array composed of different particle detector systems suitable for the detailed study of the properties of Extensive Air Showers developed by cosmic rays in the atmosphere.
Abstract: The KASCADE-Grande detector is an air-shower array devoted to the study of primary cosmic rays with very high-energies (E = 10^{16} - 10^{18} eV). The instrument is composed of different particle detector systems suitable for the detailed study of the properties of Extensive Air Showers (EAS) developed by cosmic rays in the atmosphere. Among the EAS observables studied with the detector, the charged number of particles, the muon content (at different energy thresholds), and the number of electrons are found. By comparing the measurements of these air-shower parameters with the expectations from MC simulations, different hadronic interaction models can be tested at the high-energy regime with the KASCADE-Grande experiment. In this work, the results of a study on the evolution of the muon content of EAS with zenith angle, performed with the KASCADE-Grande instrument, is presented. Measurements are compared with predictions from MC simulations based on the QGSJET II, QGSJET II-04, SIBYLL 2.1 and EPOS 1.99 hadronic interaction models. A mismatch between experiment and simulations is observed. A similar problem is found for the evolution of the lateral distribution function of muons in the atmosphere.
6 citations
01 Feb 2013
TL;DR: In this article, a composition analysis using the air shower size ratio lgNμ/lgNch, corrected for attenuation in the atmosphere, is described, where an energy independent cut on the shower ratio can be chosen in order to separate the cosmic ray events into light and heavy mass groups.
Abstract: KASCADE-Grande is an air-shower observatory devoted to the study of cosmic rays with energies in the range 1016 – 1018 eV. In KASCADE-Grande, different detector systems allow independent measurements of the number of muons (Nμ) and charged particles (Nch) of air showers, which are the basis for several energy and composition studies of cosmic rays. In this contribution, a composition analysis using the shower size ratio lgNμ/lgNch, corrected for attenuation in the atmosphere, is described. Using QGSJET II-based simulations of different primaries, it is shown that an energy independent cut on the shower ratio can be chosen in order to separate the cosmic ray events into light and heavy mass groups. The analysis is applied to the KASCADE-Grande data. The energy spectra derived from the analysis are presented.
5 citations
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TL;DR: In this paper, the detection of high-energy cosmic rays above a few hundred TeV is realized by the observation of extensive air-showers using the multi-detector setup of KASCADE-Grande.
Abstract: The detection of high-energy cosmic rays above a few hundred TeV is realized by the observation of extensive air-showers. By using the multi-detector setup of KASCADE-Grande, energy spectrum, elemental composition, and anisotropies of high-energy cosmic rays in the energy range from below the knee up to 2 EeV are investigated. In addition, the large high-quality data set permits distinct tests of the validity of hadronic interaction models used in interpreting air-shower measurements. After more than 16 years, the KASCADE-Grande experiment terminated measurements end of 2012. This contribution will give an overview of the main results of the data analysis achieved so far, and will report about the status of KCDC, the KASCADE Cosmic-ray Data Center, where via a web-based interface the data will be made available for the interested public.
4 citations
01 Feb 2013
TL;DR: The detection of high-energy cosmic rays above a few hundred TeV by using the multi-detector setup of KASCADE-Grande is realized by the observation of extensive air-showers as discussed by the authors.
Abstract: The detection of high-energy cosmic rays above a few hundred TeV is realized by the observation of extensive air-showers. By using the multi-detector setup of KASCADE-Grande, and here in particular the detectors of the large Grande array, the energy spectrum and the elemental composition of high-energy cosmic rays in the energy range from 10 PeV to 1 EeV are investigated. The estimation of energy and mass of the high-energy primary particles is based on the combined analysis of the total number of charged particles and the total number of muons measured by the detector arrays of Grande and KASCADE, respectively. The latest analysis results have shown that in the all-particle spectrum two features are present: a hardening of the spectrum at energies around 20 PeV and a steepening, i.e. a knee-like structure, at 80-90 PeV. The latter one was found to be due to a decrease of flux of the heavy mass component.
2 citations
01 Feb 2013
TL;DR: In this paper, the reconstruction of the all-particle energy spectrum is based on the size spectra of the charged particle component and the energy is calibrated by using Monte Carlo simulations performed with CORSIKA and high-energy interaction models QGSJet, EPOS and SIBYLL.
Abstract: KASCADE-Grande is a large detector array for observations of the energy spectrum as well as the chemical composition of cosmic ray air showers up to primary energies of 1 EeV. The multi-detector arrangement allows to measure the electromagnetic and muonic components for individual air showers. In this analysis, the reconstruction of the all-particle energy spectrum is based on the size spectra of the charged particle component. The energy is calibrated by using Monte Carlo simulations performed with CORSIKA and high-energy interaction models QGSJet, EPOS and SIBYLL. In all cases FLUKA has been used as low-energy interaction model. In this contribution the resulting spectra by means of different hadronic interaction models will be compared and discussed.
2 citations
TL;DR: In this article, a multi-detector system is used to reconstruct charged particles, electron and muon numbers for individual air showers with high accuracies based on the spectrum of the charged particle component, where attenuation effects in the atmosphere are corrected by applying the constant intensity cut method.
Abstract: KASCADE-Grande is dedicated for investigations of cosmic-ray air showers in the primary energy range from 10 PeV to 1 EeV. The multi-detector system allows us to reconstruct charged particles, electron and muon numbers for individual air showers with high accuracies. Based on the shower size ($N_{ch}$) spectra of the charged particle component, the all-particle energy spectrum of cosmic rays is reconstructed, where attenuation effects in the atmosphere are corrected by applying the constant intensity cut method. The energy calibration is performed by using CORSIKA simulations with high-energy interaction models QGSJET-II-2, QGSJET-II-4, EPOS 1.99 and SIBYLL 2.1, where FLUKA has been used as low-energy interaction model for all cases. In the different hadronic models, different abundances for shower particles are predicted. Such model differences in the observables will be compared and discussed in this contribution. Furthermore, by using data with increasing statistics, the updated energy spectra by means of different interaction models will be presented.
2 citations
Posted Content•
TL;DR: In this article, the KASCADE-Grande Muon Tracking Detector enables with high accuracy the measurement of directions of EAS muons with energy above 0.8 GeV and up to 700 m distance from the shower centre.
Abstract: The KASCADE-Grande Muon Tracking Detector enables with high accuracy the measurement of directions of EAS muons with energy above 0.8 GeV and up to 700 m distance from the shower centre. Reconstructed muon tracks are used to investigate muon pseudorapidity (eta) distributions. These distributions are nearly identical to the pseudorapidity distributions of their parent mesons produced in hadronic interactions. Comparison of the eta distributions from measured and simulated showers can be used to test the quality of the high energy hadronic interaction models. In this context a comparison of the QGSJet-II-2 and QGSJet-II-4 model will be shown. The pseudorapidity distributions reflect the longitudinal development of EAS and, as such, are sensitive to the mass of the cosmic rays primary particles. With various parameters of the eta distribution, obtained from the MTD data, it is possible to calculate the mean logarithmic mass of CRs. The results of the analysis in the primary energy range 10^{16} eV - 10^{17} eV with the 1st quartile (Q1) of eta distribution will be presented.
01 Jan 2013
01 Jan 2013
TL;DR: In this article, a multi-detector system is used to reconstruct charged particles, electron and muon numbers for individual air showers with high accuracies based on the shower size (Nch) spectra of the charged particle component.
Abstract: KASCADE-Grande is dedicated for investigations of cosmic-ray air showers in the primary energy range from 10 PeV to 1 EeV. The multi-detector system allows us to reconstruct charged particles, electron and muon numbers for individual air showers with high accuracies. Based on the shower size (Nch) spectra of the charged particle component, the all-particle energy spect rum of cosmic rays is reconstructed, where attenuation effects in the atmosphere are corrected by applying the constant intensity cut method. The energy calibration is performed by using CORSIKA simulations with high-energy interaction models QGSJET-II-2, QGSJET-II-4, EPOS 1.99 and SIBYLL 2.1, where FLUKA has been used as low-energy interaction model for all cases. In the different hadronic models, different abundances for shower particles are predicted. Such model differences in the observables will be compared and discussed in this contribution. Furthermore, by using data with increasing statistics, the updated energy spectra by means of differen t interaction models will be presented.
Posted Content•
TL;DR: In this paper, the authors present the investigation of possible structures in the spectrum of light primaries with increased statistics both from a larger data set including more recent measurements and by using a larger fiducial area than in the previous study.
Abstract: Data of the Grande extension of the KASCADE experiment allows us to study extensive air showers induced by primary cosmic rays with energies above 10^{16} eV. The energy of an event is estimated in terms of the number of charged particles (Nch ) and the number of muons (N{\mu} ) measured at an altitude of 110 m a.s.l. While a combination of the two numbers is used for the energy, the ratio defines the primary mass (group). The spectrum of the combined light and medium mass components, recently measured with KASCADE-Grande, was found to be compatible with both a single power-law and a broken power-law in the energy range between 10^{16.3} and 10^{18} eV. In this contribution we will present the investigation of possible structures in the spectrum of light primaries with increased statistics both from a larger data set including more recent measurements and by using a larger fiducial area than in the previous study. With the better statistical accuracy and with optimized selection criteria for enhancing light primaries we have found evidence for a hardening (ankle) of the spectrum of the light component at an energy of 10^{17.08+-0.08} eV.
08 Aug 2013
TL;DR: In this article, the authors present the investigation of possible structures in the spectrum of light primaries with increased statistics both from a larger data set including more recent measurements and by using a larger fiducial area than in the previous study.
Abstract: Data of the Grande extension of the KASCADE experiment allows us to study extensive air showers induced by primary cosmic rays with energies above 10^{16} eV. The energy of an event is estimated in terms of the number of charged particles (Nch ) and the number of muons (N{\mu} ) measured at an altitude of 110 m a.s.l. While a combination of the two numbers is used for the energy, the ratio defines the primary mass (group). The spectrum of the combined light and medium mass components, recently measured with KASCADE-Grande, was found to be compatible with both a single power-law and a broken power-law in the energy range between 10^{16.3} and 10^{18} eV. In this contribution we will present the investigation of possible structures in the spectrum of light primaries with increased statistics both from a larger data set including more recent measurements and by using a larger fiducial area than in the previous study. With the better statistical accuracy and with optimized selection criteria for enhancing light primaries we have found evidence for a hardening (ankle) of the spectrum of the light component at an energy of 10^{17.08+-0.08} eV.