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The experiment KASCADE observes simultaneously the electron–photon, muon, and hadron components of high-energy extensive air showers (EAS). The analysis of EAS observables for an estimate of energy and mass of the primary particle invokes extensive Monte Carlo simulations of the EAS development for preparing reference patterns. The present studies utilize the air shower simulation code corsika with the hadronic interaction models VENUS, QGSJet and Sibyll, including simulations of the detector response and efficiency. By applying non-parametric techniques the measured data have been analyzed in an event-by-event mode and the mass and energy of the EAS inducing particles are reconstructed. Special emphasis is given to methodical limitations and the dependence of the results on the hadronic interaction model used. The results obtained from KASCADE data reproduce the knee in the primary spectrum, but reveal a strong model dependence. Owing to the systematic uncertainties introduced by the hadronic interaction models no strong change of chemical composition can be claimed in the energy range around the knee.

KASCADE (KArlsruhe Shower Core and Array DEtector) is a multi-detector setup to observe the electromagnetic, muonic and hadronic air shower components simultaneously in the energy region around the “knee” of the primary spectrum. Its main aim is to determine energy spectrum and composition of hadrons in primary cosmic rays. This is attempted by registring a large number of observables for each EAS including measurements of electrons, muons and hadrons. This contribution gives a short description of the experiment and then presents some results on the lateral distributions of various particle types and on the spectrum of hadrons. The status of our analyses to determine mass composition is presented in an accompanying contribution by A. Haungs.

KASCADE (KArlsruhe Shower Core and Array DEtector) is a multi-detector setup to observe the electromagnetic, muonic and hadronic air shower components simultaneously at primary energies in the region of the “knee”. A large number of observables per single shower are registered. The main aims of the experiment are the determination of the primary energy spectrum around the “knee” and the energy variation of the chemical composition. The measurements reveal an increasing mean mass of the primary cosmic rays above the observed kink, and a sharper knee for the light primary component than for the all-particle spectrum, and the absence of a knee for the heavy component between 1 and 10 PeV.

Based on the KASCADE multi-detector system with its large hadron calorimeter and using the CORSIKA simulation program with the implemented high-energy hadronic interaction models QGSJET, VENUS, DPMJET, SIBYLL, and HDPM, a method for the test of models by comparing el ent rates is described. Preliminary results show differences of the model predictions both among each other and when confronted with measurements. The rates are strongly influenced by the inelastic cross sections and the elasticity, especially by the contribution of diffractive dissociation. The discrepancy to measurements at primary energies below similar or equal to 3 (.) 10(13) eV can be reduced by increasing the non-diffractive inelastic cross section.

CaCl2 undergoes a second-order proper ferroelastic phase transition from the tetragonal rutile type to the orthorhombic calcium-chloride type structure atT c ≈490 K. The transition is of the optical type and induced by an order parameter ofB 1g symmetry. An underdamped soft mode exists above and belowT c , the frequency and intensity of which have been measured by Raman spectroscopy. Due to a strong coupling to strain the softening is incomplete and a transverse acoustical mode is predicted to become soft. The frequency of the optical soft mode, ωs, exhibits a classical Landau behavior in a remarkably large temperature range. The unusual value of the ratio of ∂ω s 2 /∂ below and aboveT c of about −6.5 can be accounted for by appropriate terms of the thermodynamical potential. The Raman active hard modes show no significant anomaly atT c .

Measurements of electron, muon, and hadron lateral distributions of extensive air showers as recorded by the KASCADE experiment are presented. The data cover the energy range from about 5x10^14 eV up to almost 10^17 eV and extend from the inner core region to distances of 200 m. The electron and muon distributions are corrected for mutual contaminations by taking into account the detector properties in the experiment. All distributions are well described by NKG-functions. The scale radii describing the electron and hadron data best are approx. 30 m and 10 m, respectively. We discuss the correlation between scale radii and `age' parameter as well as their dependence on shower size, zenith angle, and particle energy threshold., Comment: 28 pages, 14 figures, Accepted for publication in Astroparticle Physics

The temporal structure of the extensive air shower (EAS) muon component (E-thres = 2.4 GeV) is studied at sea level by measurements of the muon arrival time distributions using the muon detection facilities of the KASCADE central detector. Data have been analysed for EAS core distances up to 110 m for primary energies around the knee region. The time structure of the EAS muon component is represented by the distributions of the mean, median, first quartile and the third quartile of the muon arrival time distributions relative to the foremost muon. The EAS time profiles (variation with the distance from the EAS center) are studied along their dependencies on the angle of incidence and the energy-indicative muon number N-mu(tr). Effects of the fluctuation of the arrival time of the first registered muon are scrutinised and corrected. The experimental results are compared with EAS Monte Carlo (CORSIKA-GEANT) simulations, fully including the detector responses and illustrating the phenomenological features. The comparisons, though generally in fair global agreement, revealed that the simulations underestimate the shower thickness and show nearly no dependence on the mass composition if the time resolution of the apparatus is realistically taken into account. (C) 2001 Elsevier Science B.V. All rights reserved.

The experimental results of the KASCADE Extensive Air Shower experiment have been searched for events which might be attributed to high energy primary gamma rays. The observed data are compared with simulated gamma showers. Events with a very low muon to electron ratio, a smooth lateral electron distribution and an age characteristic of gamma induced events are selected. This contribution describes the applied methods. So far only a very small fraction of the KASCADE results has been studied and no positive identification can yet be claimed.

The main goals of the KASCADE (KArlsruhe Shower Core and Array DEtector) experiment are the determination of the energy spectrum and elemental composition of the charged cosmic rays in the energy range around the knee at ca. 5 PeV. Due to the large number of measured observables per single shower a variety of different approaches are applied to the data, preferably on an event-by-event basis. First results are presented and the influence of the high-energy interaction models underlying the analyses is discussed., 3 pages, 3 figures included, to appear in the TAUP 99 Proceedings, Nucl. Phys. B (Proc. Suppl.), ed. by M. Froissart, J. Dumarchez and D. Vignaud

An electronically guided mechanism permits the "unbloody" measurement of the horny layer (HL) thickness in vivo.If a steel needle is driven by a constant speed electrode through the HL from the exterior, it is possible to measure and catalogue specific resistance variations by means of synchronic recording following derivation from the alternating current circuit against an indifferent electrode per needle electrode through the HL, i.e. from the point of skin surface contact to that of the living "ell layer of the epidermis.The mechanical construction consists of a hydraulic trust with a measuring head which is affixed by subpressure to the skin surface. The electronic device of plug-in design constains: 1. a constant voltage generator for the analogous and digital electronic, 2. a high Ohm test amplifier as well as threshold value switch, and measuring area transformer, 3. a digital measuring value indicator, hydraulic-guidance logistics, inclusive of respective operational parts. Measuring values, made available by electronic output, are being transmitted numerically via code transformer to a teletypewriter and simultaneously transferred on an electronic data processing tape. Presented are measuring data for the calibration of the device as well as a series of results of HL-thickness measurements. Methodological errors are being discussed, just as the applicability of the device for research and practical usage.

A new extensive air shower (EAS) experiment has been installed at the laboratory site of the Forschungszentrum Karlsruhe. The main aim of the KASCADE [1] project is the determination of the chemical composition in the energy range around and above the knee of the primary cosmic ray spectrum. The main advantage of the new installation is the simultaneous measurement of a large number of observables for each individual event. This is achieved by the combination of various advanced detection techniques for the electromagnetic, the muonic, and the hadronic component of the extensive air showers. Data taking with a large part of the experiment has started at the end of 1995. The estimated accuracy of air shower data is discussed for the various detector components of KASCADE and first very preliminary results are presented.