•Alexandru Bercuci¹ und Torsten Antoni² für die KASCADE-Kollaboration
¹Forschungszentrum Karlsruhe, Institut für Kernphysik, 76021 Karlsruhe
²Institut für Experimentelle Kernphysik, Universität Karlsruhe, 76021 Karlsruhe

The punctual information on mass and energy of the primary Cosmic Rays (CR) is heavily dissipated when Extensive Air Showers (EAS) are measured with a ground based experiment. The KASCADE experiment is designed to gather redundant information, by a large set of observable, for individual EAS in order to compensate this loss. The showers hitting with their core the central sensitive area ( » 300m²) of KASCADE - central showers - provide the highest redundancy as they are registered with a 7-fold detection system. They are the subject of this analysis. The data are processed at 2 levels. The individual detector -first level- results are used as "likelihood CR spectra" for a common bayesian framework. The most probable CR energy spectrum and mass composition are then deduced. Recently a system of Limited Streamer Tubes (LST) was installed in the central detection area. The benefits and limitations of this extention are pointed out.