[en] Previous EAS investigations have shown that the particle density becomes independent of the primary mass at certain distances from the shower core and can be used as an estimator for the primary energy. In the context of the KASCADE-grande experiment, the particular distance at which this effect takes place is around 500 m, hence the notation S(500). It has been shown that S(500) has a primary energy-like spectrum. We present results of further investigations in this direction. A correction function can be derived from the S(500) attenuation with the EAS angle of incidence thus allowing us to build an all event S(500) spectrum. Previously, the study relied on a three parameter Linsley parameterization for the lateral particle density distribution. Further tests have been performed now using a similar Linsley form in which one of the shape parameters has been considered fixed

[en] It has been shown that the charged particle density becomes independent of the primary mass at large but fixed distances from the shower core. This makes it possible to use the charged particle density as an estimator for the primary energy. In the case of the KASCADE-Grande experiment simulations have indicated that the particular radial distance from the shower axis where this effect takes place is around 500 m. Therefore a notation S(500) is used for the charged particle density at this specific distance. We present the reconstruction of the primary energy spectrum of cosmic rays from the experimentally recorded S(500) observable using the KASCADE-Grande detector. The constant intensity cut (CIC) method is applied to evaluate the attenuation of the S(500) observable with the zenith angle. A correction is subsequently applied to correct all recorded S(500) values for attenuation. Each corrected S(500) value is converted into the corresponding primary energy value by means of a simulation-derived calibration of S(500) with the primary energy (in the energy range accessible to the KASCADE-Grande array, 10¹⁶-10¹⁸ eV). The effect of fluctuations on the shape of the reconstructed primary energy spectrum is evaluated by the use of a response matrix. The systematic uncertainties induced by different factors are also evaluated.

[en] Studies have shown that for a particular EAS detector array the charged particle density at a given distance from shower core becomes independent of the primary mass and thus it can be used as a primary energy estimator. The particular distance for which this effect takes place is a characteristic of the array and in the case of the KASCADE-Grande it was shown to be 500 m. A Linsley parameterization has been used to describe the lateral particle density distribution of detected showers and to estimate the charged particle density at 500 m distance from shower core - S(500). The Constant Intensity Cut (CIC) method was applied to correct S(500) for attenuation. A calibration of S(500) with primary energy has been derived from simulated studies and used to construct a preliminary primary energy spectrum from the S(500) spectrum.

[en] A key topic in international safeguards is the work in preventing the further spread of nuclear weapon technology and nuclear materials. High performance analyses play an important role in enabling the detection of undeclared nuclear activities. Such analyses require comparison between different producers of analytical results. Within the European Commission Support Programme, the JRC Karlsruhe has been demonstrating that the technical competences in safeguards laboratories are to the benefit to IAEA. It will be shown that direct contact between inspectors and applied nuclear scientists brings scientific excellence at the working level. Furthermore, frequent and informal contacts between inspectors and R&D staff are essential to enhance scientific/technical capabilities for the IAEA and the safeguards community. Specific examples include:  Participation in inter-laboratory exercises, provided by the IAEA, allowing the safeguards community to gain confidence in the results produced by different laboratories.  Reference materials produced by the IAEA, known as Large Size Dried (LSD) spikes, are verified by JRC Karlsruhe and other laboratories to offer assurance for U and Pu content analyses.  The experience gained from operating the Euratom safeguards on-site laboratories OSL/LSS since 1999. This activity has provided sustainable information and experience, which fed into the on-site laboratory at the Rokkasho Reprocessing Plant in Japan.  The COMPUCEA technique, which was developed in Karlsruhe for in-field measurement in support of inspections, was transferred to the IAEA and is now a Class A method used in international safeguards. Furthermore, such collaborations facilitate non-conventional combinations of measurement techniques, used in safeguards and nuclear forensics to obtain more comprehensive safeguards information. (author)

[en] We present a study on simulated air showers with relevance for the AERA experiment at the Pierre Auger Observatory. Investigating the radio component of air showers requires good knowledge of the geometrical properties of the shower, like for example the position of the shower core and the arrival direction of the shower. At the Pierre Auger Observatory the geometrical observables of the detected events are reconstructed with the help of the FD and SD components (the Infill array playing the major role in the shower core reconstruction for AERA). We investigate the possibility to increase the quality of the shower core reconstruction by increasing the density of surface detectors in an area close the the position of the radio antennas. From the technical point of view, extending the surface array by adding new SD stations to the Infill is not a straight forward job so simulation studies can be used to test various configurations for the additional stations. We present the effects induced on the reconstruction quality, for several geometrical configurations.

[en] It has been shown that the particle density becomes independent of the primary mass at detector-specific and fixed distances from shower core and can be used as an estimator for the primary energy. This property of the density has been used by various experiments to infer the primary energy from the recorded particle density. In the context of the KASCADE-grande experiment, the particular distance at which this effect takes place is around 500 m, hence the notation S(500) for the particle density a this specific range. The primary energy spectrum has been obtained from the recorded S(500) data using a simulation-derived dependence of primary energy with the S(500). A response matrix is used to account for the effects of fluctuations on the spectral index of the reconstructed energy spectrum.

[en] The primary energy of cosmic rays is inferred at KASCADE-Grande using two independently applied methods that are based on different EAS observables. A standard method is based on the correlation between the total charged particle content and the muon content of the shower, while the other method is based on the S(500) energy estimator. S(500) is a notation for the charged particle density in the air shower at 500 m distance from the shower axis and for the case of the KASCADE-Grande detector this observable was shown to be independent of the primary mass. The results of the two methods are compared when analyzing recorded data and we observe a systematic shift between the results. This does not happen when analyzing simulated events. We explain this feature as an effect of the interaction model that describes differently EAS observables such as the total charged particle content and the shape of the lateral particle density distribution.

[en] The KASCADE-Grande detector hosted by the KIT Campus North Karlsruhe, Germany, is designed to record air showers in the 10¹⁶-10¹⁸ eV energy range. The primary energy spectrum of cosmic rays as reconstructed by KASCADE-Grande based on the N_μ-N_ch correlation has been recently published. We present results of an alternative technique that is applied to the KASCADE-Grande data in order to reconstruct the primary energy. In the described method we use the charged particle density at 500 m from the shower axis, S(500) as a primary energy estimator practically independent from the primary mass. We account for the attenuation of S(500) in the atmosphere by applying the constant intensity cut method. With the help of a simulation-derived calibration curve we convert the recorded S(500) to energy. The final result is discussed in comparison with the recent results published by KASCADE-Grande.

[en] The reconstruction of high-energy air showers (EAS) on the basis of ground level particle detectors is based on the characteristics of observables like particle lateral density (PLD), arrival time signals etc. Lateral densities, inferred from detector data, are usually parameterized by applying various lateral distribution functions (LDF). Typical LDFs anticipate azimuthal symmetry of PLD around the shower axis. The deviations from symmetry are important in the case of arrays like Grande, which only sample a small part of the azimuthal dependence. In this contribution we discuss the origin of the asymmetry, its magnitude and propose procedures to incorporate it in the shower reconstruction. Geometric and attenuation effects (for inclined showers) and the earth magnetic field contribute to the asymmetry. The azimuth dependence of the energy deposit per particle does not impact on the real PLD, but affects the reconstructed PLD. Based on studies of CORSIKA simulations we propose procedures for minimizing the effects of the azimuthal asymmetry of PLD in shower reconstruction

[en] The KASCADE-Grande experiment at the Karlsruhe research center measures Extensive Air Showers by detecting the secondary particles created in the atmosphere and arriving the ground level. The main goal of this work is to determine the Lateral Energy Correction Function (LECF) which is required for converting the energy deposit measured by the GRANDE detectors (without discrimination of any particle types) into particle densities. In a first step, detailed energy deposition patterns for all the secondary particles of interest (electrons, muons, photons, protons and neutrons) were computed with GEANT 3.21 for a grid of energies and incidence angles. Then the energy deposition spectra were fitted to a superposition of distribution functions which can be sampled much faster than using GEANT. Next the parameters of these distribution functions as a function of energy and angle were obtained for each type of particle. Finally the fast procedure proposed for the computation of the energy deposition was applied to the distribution of the secondary EAS particles simulated with CORSIKA for obtaining realistic LECF.