Particle track phenomena and radiation power effects at the formation of radiation defects in ionic crystals

The mechanisms of the radiation defect formation in alkali halide crystals are studied in an extremely wide range of the absorbed radiation dose rate (10 1-10 12 Gy/s). It is found that the power dependence of color centers accumulation is described by a curve with a maximum at a dose rate of about 10 10 Gy/s. The electron and proton track parameters for ionic crystals are calculated in the context of the theory of ionization losses of charged-particle energy. Proceeding from the concept of the charged-particle track overlap, the theoretical relations are obtained that explain the radiation power effect in all dielectric materials including alkali halide crystals. The suppression of color center accumulation in these crystals under high-power electron irradiation is due to a more regular topography of the radiation defect formation. © 2007 Springer Science+Business Media, Inc.