Investigating Cherenkov radiation from electromagnetic cascades in a water calorimeter

Abstract

Results from investigating electromagnetic cascade showers in the NEVOD Cherenkov water calorimeter (CWC) with a dense lattice of quasi-spherical detecting modules are presented. The spatial distribution of the Cherenkov radiation from the cascades is measured, and the dependence of radiation intensity on the depth of shower development and on the distance from its axis with a step of 0.5 meter in both directions is obtained. Experimental results are compared to calculations based on different models of angular distribution of cascade particles. Basing on the obtained results the algorithm of iterative reconstruction of parameters of showers on the basis of CWC data is proposed and the energy spectrum of showers with energies from 100 GeV to 20 TeV is measured.