ABSTRACT
We consider passage through matter of electrons with energies of 0.01-0.1 MeV and more, and it means that we can neglect binding of electrons with nuclei and consider them as free particles in their impact with incoming fast electrons. Electromagnetic interaction between incoming relativistic electrons and the Coulomb field of nuclei leads to radiation of electromagnetic waves, and, therefore, electrons lose in medium their primary energy by ionization and radiative processes.
