Simultaneous observation of air shower cores at sea level and under 800 g/cm2 of shielding

Abstract

Using a 14-m² neon hodoscope installed under 800 g/cm² of concrete and vertically below the 32-m² neon hodoscope, observations have been made on the strongly interacting and the muon component in air shower cores. A preliminary analysis has yielded the following results: (a) The energy spectrum of strongly interacting particles in air shower cores has been obtained in the energy range from 1 to 10 TeV, yielding an exponent of ~ −1.2 for the integral spectrum. (b) The lateral distribution of muons exhibits a distribution as steep as r^{−0.9 ± 0.1} down to distances of the order of 1 m from the air shower axis. However, at the present state of evaluation contamination of muon data, due to unrecognized cascades, cannot be ruled out completely.