[en] To better understand the radio signal emitted by extensive air-showers and to further develop the radio detection technique of high-energy cosmic rays, the LOPES experiment was reconfigured to LOPES-3D. LOPES-3D is able to measure all three vectorial components of the electric field of radio emission from cosmic ray air showers. The additional measurement of the vertical component ought to increase the reconstruction accuracy of primary cosmic ray parameters like direction and energy, provides an improved sensitivity to inclined showers, and will help to validate simulation of the emission mechanisms in the atmosphere. LOPES-3D will evaluate the feasibility of vectorial measurements for large scale applications. In order to measure all three electric field components directly, a tailor-made antenna type (tripoles) was deployed. The change of the antenna type necessitated new pre-amplifiers and an overall recalibration. The reconfiguration and the recalibration procedure are presented and the operationality of LOPES-3D is demonstrated.

[en] The KASCADE-Grande experiment, located at Forschungszentrum Karlsruhe (Germany), is a multi-component extensive air-shower experiment to study cosmic rays and their interactions at primary energies 10¹⁴-10¹⁸ eV. After detailed investigations of the knee in the spectrum with KASCADE and EAS-TOP experiments, the main goal of KASCADE-Grande is to provide conclusive results on the knee region by detecting the expected iron knee in the spectrum at around 10¹⁷ eV, and measuring the composition in the possible transition region between galactic and extragalactic components. Due to its multi-component characteristics, basically the former KASCADE experiment enriched by two new arrays of scintillator detectors (Grande and Piccolo), with the aim of providing a large acceptance area (0.5 km²) and prompt trigger signal, KASCADE-Grande is a suitable array to provide refined measurements in the 10¹⁶-10¹⁸ eV region. In the following, we briefly report on the characteristics of the detector, its performance, and first results based on 2 years of data taking

[en] 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.

[en] The LOPES experiment at the Karlsruhe Institute of Technology has been taking radio data in the frequency range from 40 to 80 MHz in coincidence with the KASCADE-Grande air shower detector since 2003. Various experimental configurations have been employed to study aspects such as the energy scaling, geomagnetic dependence, lateral distribution, and polarization of the radio emission from cosmic rays. The high quality per-event air shower information provided by KASCADE-Grande has been the key to many of these studies and has even allowed us to perform detailed per-event comparisons with simulations of the radio emission. In this article, we give an overview of results obtained by LOPES, and present the status and perspectives of the ever-evolving experiment.

[en] 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 transferred to other experiments in radio and acoustic detection of cosmic rays and neutrinos.

[en] We report in this paper on an analysis of 20 months of data taken with LOPES. LOPES is radio antenna array set-up in coincidence with the Grande array, both located at the Karlsruhe Institute of Technology, Germany. The data used in this analysis were taken with an antenna configuration composed of 30 inverted V-shape dipole antennas. We have restricted the analysis to a special selection of inclined showers - with zenith angle θ>40^∘. These inclined showers are of particular interest because they are the events with the largest geomagnetic angles and are therefore suitable to test emission models based on geomagnetic effects.The reconstruction procedure of the emitted radio signal in EAS uses as one ingredient the frequency-dependent antenna gain pattern which is obtained from simulations. Effects of the applied antenna model in the calibration procedure of LOPES are studied. In particular, we have focused on one component of the antenna, a metal pedestal, which generates a resonance effect, a peak in the amplification pattern where it is the most affecting high zenith angles, i.e. inclined showers. In addition, polarization characteristics of inclined showers were studied in detail and compared with the features of more vertical showers for the two cases of antenna models, with and without the pedestal.

[en] The KASCADE-Grande experiment measures extensive air showers induced by cosmic rays in the energy range between 0.5 PeV and 1 EeV - the so-called knee region. Principal task of the experiment is to measure with high accuracy the energy and composition of primary cosmic rays to shed light on the nature of the knee. The data of the former KASCADE experiment have been used in a composition analysis showing the knee at 3-5 PeV to be caused by a steepening in the light-element spectra. In the following, an update on these analyses will be given. In addition, the status of the experimental extension - the Grande array - together with first results will be briefly discussed

[en] In the present study, we analyze the radio signal from inclined air showers recorded by LOPES-30 in coincidence with KASCADE-Grande. LOPES-30 consists of 30 East-West oriented digital antennas, which are amplitude calibrated by an external source. Radio emission from air showers is considered a geomagnetic effect. Inclined events provide a larger range of values for geomagnetic angle (angle between shower axis and geomagnetic field direction) than vertical showers and thus more information on the emission processes can be gathered. In order to have the geometry of the air shower we use the reconstruction provided by the KASCADE-Grande particle detectors array. Analyzing events observed by both LOPES and the extended part of the KASCADE array, Grande, gives the possibility to test in particular the capability and efficiency of radio detection of more distant events. The results are compared with a previous analysis of inclined events recorded by the initial 10 antenna set-up, LOPES-10, in coincidence with the Grande array.

[en] KASCADE-Grande is a multi detector setup for the investigation of extensive air showers in the primary energy range of the knee including energies around the so-called second knee. With the data of the 700 . 700 m² large Grande array shower core position, shower direction, and the total number of electrons are reconstructed for events with primary energy above 10^16.5 eV. In addition, the experiment consists of different detector setups for measuring muons at various energy thresholds between 230 MeV and 2.4 GeV. These information are used to estimate the muon shower size as well as observables sensitive to differences of hadronic interaction models embedded in shower simulation codes. We report the goals and the status of the different muon measurements at KASCADE-Grande

[en] LOPES is a radio antenna array co-located with the Karlsruhe Shower Core and Array DEtector, KASCADE-Grande in Forschungszentrum Karlsruhe, Germany, which provides well-calibrated trigger information and air shower parameters for primary energies up to 10¹⁸eV. By the end of 2006, the radio antennas were re-configured to perform polarization measurements of the radio signal of cosmic ray air showers, recording in the same time both, the East-West and North-South polarization directions of the radio emission. The main goal of these measurements is to reconstruct the polarization characteristics of the emitted signal. This will allow a detailed comparison with theoretical predictions. The current status of these measurements is reported here.