KASCADE, together with its extension KASCADE-Grande measured individual air showers of cosmic rays in the primary energy range of 100 TeV to 1 EeV. The data collection was fully completed at the end ...of 2013 and the experiment was dismantled. However, the data analysis is still in progress. Recently, we published a new result on upper limits to the flux of ultra-high energy gamma rays, which set constraints on some fundamental astrophysical models. We also use the data to investigate the validity of the new hadronic interactions models like SIBYLL version 2.3c or EPOS-LHC. In addition, we updated and improved the webbased platform of the KASCADE Cosmic Ray Data Centre (KCDC), where now the data from KASCADE and KASCADE-Grande of more than 20 years measurements is available, including corresponding Monte-Carlo simulated events based on three different hadronic interaction models. In this contribution, recent results from KASCADE-Grande and the update of KCDC is briefly discussed.
•We compare LOPES radio lateral distributions of air showers with simulations.•Absolute amplitude is reproduced by REAS 3.11 simulations, but lower for CoREAS.•Slope of measured lateral distributions ...is reproduced by both simulation programs.•Rarely measured rising lateral distributions are likely due to refractive index of air.•The lateral distribution is sensitive to energy and mass of the primary particle.
Cosmic ray air showers emit radio pulses at MHz frequencies, which can be measured with radio antenna arrays – like LOPES at the Karlsruhe Institute of Technology in Germany. To improve the understanding of the radio emission, we test theoretical descriptions with measured data. The observables used for these tests are the absolute amplitude of the radio signal, and the shape of the radio lateral distribution. We compare lateral distributions of more than 500 LOPES events with two recent and public Monte Carlo simulation codes, REAS 3.11 and CoREAS (v 1.0). The absolute radio amplitudes predicted by REAS 3.11 are in good agreement with the LOPES measurements. The amplitudes predicted by CoREAS are lower by a factor of two, and marginally compatible with the LOPES measurements within the systematic scale uncertainties. In contrast to any previous versions of REAS, REAS 3.11 and CoREAS now reproduce the shape of the measured lateral distributions correctly. This reflects a remarkable progress compared to the situation a few years ago, and it seems that the main processes for the radio emission of air showers are now understood: The emission is mainly due to the geomagnetic deflection of the electrons and positrons in the shower. Less important but not negligible is the Askaryan effect (net charge variation). Moreover, we confirm that the refractive index of the air plays an important role, since it changes the coherence conditions for the emission: Only the new simulations including the refractive index can reproduce rising lateral distributions which we observe in a few LOPES events. Finally, we show that the lateral distribution is sensitive to the energy and the mass of the primary cosmic ray particles.
KASCADE-Grande is an air-shower observatory devoted to the detection of cosmic rays with energies in the range of 1016 to 1018 eV. This energy region is of particular interest for the cosmic ray ...astrophysics, since it is the place where some models predict the existence of a transition from galactic to extragalactic origin of cosmic rays and the presence of a break in the flux of its heavy component. The detection of these features requires detailed and simultaneous measurements of the energy and composition of cosmic rays with sufficient statistics. These kinds of studies are possible for the first time in KASCADE-Grande due to the accurate measurements of several air-shower observables, i.e., the number of charged particles, electrons and muons in the shower, using the different detector systems of the observatory. In this contribution, a detailed look into the composition of 1016 - 1018 eV cosmic rays with KASCADE-Grande is presented.
In this work, we report measurements on the muon content (E
th
> 230 MeV) of extensive air showers (EAS) induced by cosmic rays with primary energy from 10 PeV up to 1 EeV performed with the ...KASCADE-Grande experiment. The measurements are confronted with SIBYLL 2.3. The results are focused on the dependence of the total muon number and the lateral density distribution of muons in EAS on the zenith angle and the total number of charged particles in the shower. We also present updated results of a detailed study of the attenuation length of shower muons, which reveal a deviation between the measured data and the predictions of the post-LHC hadronic interaction models SIBYLL 2.3, QGSJET-II-04 and EPOS-LHC.
The Cherenkov Telescope Array (CTA) will be the next generation ground-based gamma-ray observatory. CTA consists of different telescope types of which the largest ones (Large-Sized Telescopes, LSTs) ...cover the lower energy range, between 20GeV and 200GeV. The first LST is currently being commissioned at the Roque de los Muchachos Observatory, La Palma, Canary Islands. Its camera has 1855 photomultipliers (PMTs) with 1.5 inch cathodes. Silicon Photomultipliers (SiPMs) are increasingly becoming valid alternatives to PMTs also in gamma-ray astronomy. In the context of the LST project, there is an effort to study a novel Advanced Camera, equipped with SiPMs and a completely redesigned electronics based on a fully digital approach. To study and develop solutions on the sensors of these camera, we built a prototype camera module with a fully re-designed pre-amplifying stage and sensor bias control while re-using the digitizing and triggering stages of the existing LST camera module. We report on the design choices made to achieve the highest performance in terms of timing and charge resolution and the laboratory measurements validating those choices.
► Using muon tracking we study muon production heights in cosmic ray air showers. ► The sensitivity of this quantity to the primary particle mass and energy is shown. ► The validity of hadronic ...interaction models used in simulations is discussed. ► An estimate of the cosmic ray mass composition in the studied energy range is given
A large area (128
m
2) muon tracking detector, located within the KASCADE experiment, has been built with the aim to identify muons (
E
μ
>
0.8
GeV) and their angular correlation in extensive air showers by track measurements under 18 r.l. shielding. Orientation of the muon track with respect to the shower axis is expressed in terms of the radial and tangential angles, which are the basic tools for all muon investigations with the tracking detector. By means of triangulation the muon production height is determined. Distributions of measured production heights are compared to CORSIKA shower simulations. Analysis of these heights reveals a transition from light to heavy cosmic ray primary particles with increasing shower energy in the energy region of the ‘Knee’ of the cosmic ray spectrum
KASCADE-Grande was an air-shower experiment designed to study cosmic rays between 1016 and 1018 eV. The instrument was located at the site of the Karlsruhe Institute of Technology, Germany at an ...altitude of 110 m a.s.l. and covered an area of 0.5 km2. KASCADE-Grande consisted of several detector systems dedicated to measure different components of the EAS generated by the primary cosmic rays, i.e., the muon and the electron contents of the air-shower. With such a number of EAS observables and the precision of the measurements, the KASCADE-Grande data can be used to not only study in detail the properties of cosmic rays but also to test the predictions of hadronic-interaction models. In this work, in particular, the attenuation lengths of the muon number and the charged number of particles of EAS in the atmosphere were extracted from the KASCADE-Grande data and the results were compared with the predictions of the new EPOS-LHC hadronic-interaction model.
Relativistic, charged particles present in extensive air showers (EAS) lead to a coherent emission of radio pulses which are measured to identify the shower initiating high-energy cosmic rays. ...Especially during thunderstorms, there are additional strong electric fields in the atmosphere, which can lead to further multiplication and acceleration of the charged particles and thus have influence on the form and strength of the radio emission. For a reliable energy reconstruction of the primary cosmic ray by means of the measured radio signal it is very important to understand how electric fields affect the radio emission. In addition, lightning strikes are a prominent source of broadband radio emissions that are visible over very long distances. This, on the one hand, causes difficulties in the detection of the much lower signal of the air shower. On the other hand the recorded signals can be used to study features of the lightning development. The detection of cosmic rays via the radio emission and the influence of strong electric fields on this detection technique is investigated with the LOPES experiment in Karlsruhe, Germany. The important question if a lightning is initiated by the high electron density given at the maximum of a high-energy cosmic-ray air shower is also investigated, but could not be answered by LOPES. But, these investigations exhibit the capabilities of EAS radio antenna arrays for lightning studies. We report about the studies of LOPES measured radio signals of air showers taken during thunderstorms and give a short outlook to new measurements dedicated to search for correlations of lightning and cosmic rays.
The KASCADE-Grande experiment has significantly contributed to the current knowledge about the energy spectrum and composition of cosmic rays for energies between the knee and the ankle. Meanwhile, ...post-LHC versions of the hadronic interaction models are available and used to interpret the entire data set of KASCADE-Grande. In addition, a new, combined analysis of both arrays, KASCADE and Grande, was developed significantly increasing the accuracy of the shower observables. First results of the new analysis with the entire data set of the KASCADE-Grande experiment will be the focus of this contribution.
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