Simulation of Positron Flux in Cascades of Runaway Electrons Generated by Cosmic Rays in Thunderstorm Atmosphere

Probabilities for positrons in cascades of runaway electrons produced by secondary cosmic rays in the strong electric field of thunderclouds to become runaway particles in the direction opposite to that of acceleration of electrons are calculated using modified GEANT4 code. Different electric field strengths and primary energies of electrons generating cascades are investigated.