Angular and energy distributions of charged particles in electron-photon cascades in air

Monte-Carlo simulations of the development of 100 GeV photon-initiated cascades in the atmosphere have been used to predict the energy spectra and angular distributions of charged particles in electron-photon showers as a function of shower age. The lateral spread of the particles and their spread in time were also studied, in rather less detail, and a track length integral which measures the angular deflections produced by a magnetic field is given. Approximate formulae are given to describe these distributions. Particles of energy below about 15 MeV are not included in the distributions, as the main intended application is to the study of Cerenkov radiation from cosmic-ray showers, although particles were actually followed down to 0.05 MeV.