High-energy nuclear interactions of cosmic rays (> 10¹² eV) observed at 5 200 m above sea level

Abstract

The shielded 60-m2 scintillation detector in the center of the Chacaltaya air shower array was used to observe large bursts of size greater than 3 000 particles. These bursts are produced mainly by nuclear interactions in the absorber above the scintiUator of nuclear-active particles with energy greater than 3 X 1012 eV. The majority of these bursts are accompanied by extensive air showers, which were detected by the BASJE array. However, there are some events which are not accompanied by air showers and are considered to be due to residual primary nucleons. Some features of the data and results of preliminary analysis of these events will be presented.