Influence of γ irradiation on the absorption coefficient of alkali halide crystals at the CO2 laser radiation wavelength

An investigation was made of the influence of thermal and photothermal treatment on the ultraviolet, visible, and infrared absorption spectra in order to establish the relationship between the appearance of color centers and an increase in the bulk absorption (α) at 10.6 µ in γ-irradiated NaCl and KCl crystals. It is postulated that the presence of isolated electron and hole color centers and also of interstitial-induced dislocation loops has no influence on α, whereas complex F aggregate centers and alkali metal colloids can increase α.