F. Di Pierro

Comparison of lopes measurements with coreas and reas 3.11 simulations

In the previous years, LOPES emerged as a very successful experiment measuring the radio emission from air showers in the MHz frequency range. In parallel, the theoretical description of radio emission was developed further and REAS became a widely used simulation Monte Carlo code. REAS 3 as well as CoREAS are based on the endpoint formalism, i.e. they calculate the emission of the air-shower without assuming specific emission mechanisms. While REAS 3 is based on histograms derived from CORSIKA simulations, CoREAS is directly implemented into CORSIKA without loss of information due to histogramming of the particle distributions. In contrast to the earlier versions of REAS, the newest version REAS 3.11 and CoREAS take into account a realistic atmospheric refractive index. To improve the understanding of the emission processes and judge the quality of the simulations, we compare their predictions with high-quality events measured by LOPES. We present results concerning the lateral distribution measured with...

LOPES — Recent Results and Open Questions on the Radio Detection of Air Showers

LOPES was a digital antenna array operating for approximately 10 years until spring 2013 at the Karlsruhe Institute of Technology (KIT). Triggered by the co-located KASCADE-Grande air-shower experiment, it measured the radio signal of around 1000 cosmic-ray air showers with energies E 1017 eV in an effective band of 43 – 74 MHz. Using the interferometric technique of cross-correlation beamforming, LOPES could reconstruct the shower direction with an accuracy < 0.7°, the shower energy with a precision < 20%, and the atmospheric depth of the shower maximum, Xmax, with a precision < 95g/cm2. In particular the reconstruction of the shower maximum suffers from significant measurement uncertainties due to the radio-loud environment of the site. This article summarizes our latest results on the reconstruction of the shower maximum, using two independent methods: the steepness of the hyperbolic radio wavefront and the slope of the lateral distribution of the radio amplitude. Moreover, we show vectorial measurements of the electric field with the tripole antennas of the latest LOPES setup. Finally, we discuss open questions as well as the potential impact of the lessons learned at LOPES for future antenna arrays.

Measurement of radio emission from extensive air showers with LOPES

Abstract A new method is explored to detect extensive air showers: the measurement of radio waves emitted during the propagation of the electromagnetic shower component in the magnetic field of the Earth. Recent results of the pioneering experiment LOPES are discussed. It registers radio signals in the frequency range between 40 and 80xa0MHz. The intensity of the measured radio emission is investigated as a function of different shower parameters, such as shower energy, angle of incidence, and distance to shower axis. In addition, new antenna types are developed in the framework of LOPES star and new methods are explored to realize a radio self-trigger algorithm in real time.

The KASCADE-Grande observatory and the composition of very high-energy cosmic rays

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.

Separation of the light and heavy mass groups of 1016 – 1018 eV cosmic rays by studying the ratio muon size to shower size of KASCADE-Grande data

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.

Effects of the new hadronic interaction models on the reconstruction of KASCADE-Grande observables

A. Gherghel-Lascu∗5, W.D. Apel1, J.C. Arteaga-Velázquez2, K. Bekk1, M. Bertaina3, J. Blümer1,4, H. Bozdog1, I.M. Brancus5, E. Cantoni3,6, A. Chiavassa3, F. Cossavella4, K. Daumiller1, V. de Souza7, F. Di Pierro3, P. Doll1, R. Engel1, D. Fuhrmann8, H.J. Gils1, R. Glasstetter8, C. Grupen9, A. Haungs1, D. Heck1, J.R. Hörandel10, D. Huber4, T. Huege1, K.-H. Kampert8, D. Kang4, H.O. Klages1, K. Link4, P. Łuczak11, H.J. Mathes1, H.J. Mayer1, J. Milke1, B. Mitrica5, C. Morello6, J. Oehlschläger1, S. Ostapchenko12, N. Palmieri4, T. Pierog1, H. Rebel1, M. Roth1, H. Schieler1,S. Schoo1, F.G. Schröder1, O. Sima13, G. Toma5, G.C. Trinchero6, H. Ulrich1, A. Weindl1, J. Wochele1, J. Zabierowski11 KASCADE-Grande

Investigation of the Properties of Galactic Cosmic Rays with the KASCADE-Grande Experiment

Abstract The properties of galactic cosmic rays are investigated with the KASCADE-Grande experiment in the energy range between 10 14 and 10 18 xa0eV. Recent results are discussed. They concern mainly the all-particle energy spectrum and the elemental composition of cosmic rays.

Primary Energy Reconstruction from the Charged Particle Densities Recorded with the KASCADE‐Grande Detector at 500 m Distance from Shower Core

Previous EAS investigations have shown that for a fixed primary energy the charged particle density becomes independent of the primary mass at certain (fixed) distances from the shower core. This feature can be used as an estimator for the primary energy. We present results on the reconstruction of the primary energy spectrum of cosmic rays from the experimentally recorded S(500) observable (the density of charged particles at 500 m distance to the shower core) using the KASCADE‐Grande detector array. The KASCADE‐Grande experiment is hosted by the Karlsruhe Institute for Technology—Campus North, Karlsruhe, Germany, and operated by an international collaboration. The constant intensity cut (CIC) method is applied to evaluate the attenuation of the S(500) observable with the zenith angle and is corrected for. A calibration of S(500) values with the primary energy has been worked out by simulations and was applied to the data to obtain the primary energy spectrum (in the energy range log10[E0/GeV]∈[7.5,9]). ...

The knee of cosmic rays — news from KASCADE

The energy spectrum of cosmic rays, following over large energy ranges a simple power law, steepens at energies around 4 PeV. This so‐called knee is believed to be an imprint of corresponding steepenings or even cut‐offs in the energy spectra of single cosmic ray elements, thus implying a change of composition in the range between 1 PeV and 100 PeV. One of the sophisticated experiments aiming at detailed measurements in the knee region is the KASCADE experiment and its successor, KASCADE‐Grande. In the following, existing data on the knee and their limitations are briefly discussed. Concluding, an update on the KASCADE composition analysis is presented.

Measurements of the muon content of EAS in KASCADE-Grande compared with SIBYLL 2.3 predictions

The KASCADE-Grande observatory was a ground-based air shower array ndevoted to the study of the energy and composition of cosmic rays with energies nfrom