Determination of parameters of cascade showers in the water calorimeter using 3D-distribution of Cherenkov light

Abstract

Results of investigations of cascade showers produced by muons in Cherenkov water calorimeter (CWC) NEVOD with a dense lattice of quasi-spherical measuring modules are presented. The spatial distribution of the Cherenkov radiation from the cascades is obtained. It represents the dependence of the radiation intensity on the depth of the shower development and on the distance from its axis with a step of 0.5 meter in both directions. The obtained results allowed to develop methods for selecting the cascades among the events with a high energy release and for estimating the parameters of cascades on the basis of the CWC data. The accuracy of such estimations is considered. The zenith angular distribution of experimental events with cascades is presented, and the problem of separation of cascades produced by hadrons and by muons is discussed. The energy spectrum of showers with energies from 100 GeV to 15 TeV generated by muons is measured.