Cerenkov radiation of electron-photon showers developing in water

The Cerenkov radiation lateral distributions (CRLD) are calculated using the electron angular distribution function valid up to pi, since for the DUMAND experiment it is necessary to estimate the backward flux of the emitted photons (less than 7% of the total flux) relative to the direction of primary particle motion. In addition, Cerenkov radiation characteristics at distances much greater than shower length are determined with fixed luminous point approximations, while at small distances and for angles close to the theta sub c, the finite cascade length was taken into account. The CRLD obtained using the approximate theta function given differed by less than 10% from the exact theta function for the case of theta sub 0 within 0.2 of theta sub c