Contribution of nuclear-reaction products into the formation of simple defects in silicon irradiated with electrons and γ-quanta

Using the Monte Carlo method, a detailed calculation of the number of simple defects and of the absorbed energy in a silicon sample irradiated by electrons and γ - quanta at energies in the range up 0.5 to 100 MeV has been performed. The program used makes allowance for the following processes: ionization losses; bremsstrahlung; delta -electron production; electron Coulomb multiple scattering; photoeffect; γ -quanta Compton scattering; electron-positron pair production; positron annihilation; γ -quanta elastic scattering on nuclei, and photonuclear reactions. The contribution from nuclear reaction products in the above values has been estimated. It has been shown that at γ -quanta energys above 10 MeV the contribution from ''nuclear'' defects is significant; it becomes predominant in the energy range from 20 to 30 MeV due to the dipole giant resonance. For electron irradiation the above contribution does not exceed 5%. The dose from the charged products of nuclear reactions is not greater than 10% of the total dose absorbed. The distributions of the defect number and the absorbed energy over the sample thickness along the direction of incidence of γ -quanta and electron beams are presented and their characters are discussed