The angular distribution function of electrons in a shower with arbitrary boundary conditions

A solution of the equations of electromagnetic cascade theory in the small angle approximation of multiple scattering with arbitrary bound­ ary conditions is described. The cross sections of the basic processes of retarded radiation and pair formation are taken in the Bethe-Heitler form, and the polarization of the medium is taken into account. The solution for the primary electron is examined and justified for finite values of the ratio E/E0.