Migration kinetic of primary radiation defects at nonuniform irradiation

The migration of interstitial atoms and vacancies under nonuniform irradiation is theoretically studied. The possibility of the formation of regions with increased concentration of point defects of certain kind in crystalls with low concentration of dislocatios at the surface and at Bragg peak is demonstrated. The region of the penetration of interstitials beyond the irradiated area is estimated. It might be of order of 0.02 sm at the dislocation density 104 cm-2. The difference of the flows of interstitials and vacancies changes its sign in process of irradiation which can lead to different processes of macroscopic defect formation at the imitial stages of irradiation and in the stationary state

Effect of interaction between electronic excitations on luminescence from fast charged particle’s track’s region

The paper studies the effect of the interaction between the electronic excitations (excitons) on the light emission yield of the high energy charged particle in the dielectric medium. It is assumed that after being created in the track, the excitons diffuse from its core. Exciton annihilation and the non-radiative part of its lifetime contribute to the losses that manifest themselves as the decrease of the luminescence intensity. The dependence of the losses on the direction of propagation of the high energy charged particle with respect to the crystal axes for crystals with the exciton diffusion anisotropy is calculated. Dynamic interaction between excitons leads to the changes of their motion, affects the inter-exciton distance, and, hence, causes losses due to annihilation. The estimates of the losses are made depending on the interaction: an increase for the exciton attraction, a decrease for the repulsion. The possibility of the exciton condensation in the track region in the inorganic semiconductors is evaluated