He 1.2.27 Estimation of the Cosmic Ray Composition with the Kascade

  • Published 1997


The hadron calorimeter of the KASCADE experiment is used to study extensive air shower cores corresponding to primary energies in the "knee" region. The hadronic component carries per se a signiicant amount of information about the primary particle type, and allows to deduce its mass from the hadron distribution within the core. Several observables are presented which are useful to determine the primary's mass. Their dependence on diierent models of high energy hadronic interactions is discussed and compared with measured data. INTRODUCTION The experiment KASCADE (Klages et al., 1997) has in its centre a large iron calorimeter to study the hadronic core of extensive air showers (EAS) in the energy region around the "knee". The development of EAS in the earth's atmosphere is determined by the primary's energy and mass. In the following, observables are presented which allow to draw conclusions about the mass composition from the particle distribution in the hadronic core. When deriving and discussing such parameters, one commonly relies on simulations. A correct modeling of the hadronic interaction is important, which has to be extrapolated from collider results to higher energies. During the past years several models of hadronic interactions have been developed and adapted to experimental results using diierent theoretical ideas and computing techniques. Five models widely used for high energy nuclear reactions and EAS calculations are implemented in the air shower program CORSIKA (Heck et al., 1997). In order to study the innuence of the diierent models on the analysis of measured data, extensive simulations have been performed and their results are compared with measured data obtained with the KASCADE experiment. EXPERIMENTAL SETUP AND MEASUREMENTS KASCADE measures all three components of EAS simultaneously, i.e. the electromagnetic, the muonic and the hadronic part. The latter is studied with a large iron sampling{calorimeter, which is 11 interaction lengths deep and interspersed with eight layers of active detectors, consisting of liquid ionisation chambers lled with tetramethylsilane and tetramethylpentane. The ionisation chambers have nely segmented electrodes of 25 25 cm 2 size matched to the mean lateral spread of hadronic cascades allowing to resolve single hadrons in the core of large EAS. For all hadrons of an energy larger than 50 GeV, impact point and direction are reconstructed. Details of the calorimeter performance are given by (Milke et al., 1997). For the investigations presented below, events with the following conditions have been selected: at least three hadrons had to …

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@inproceedings{CALORIMETER1997He1E, title={He 1.2.27 Estimation of the Cosmic Ray Composition with the Kascade}, author={HADRON CALORIMETER}, year={1997} }