Influence of irradiation with $\gamma$-ray photons on the photoluminescence of Cd$_{0.9}$Zn$_{0.1}$ crystals preliminarily subjected to the intense radiation of a neodymium laser

The effect of the preliminary treatment of Cd$_{0.9}$Zn$_{0.1}$ crystals with high-power pulses of neodymium laser radiation (the power density is $\le$ 1.8 MW/cm$^2$, at a wavelength of 532 nm) on the low-temperature (5 K) photoluminescence induced by $\gamma$-ray radiation (the dose was $\Phi_{\gamma}$ = 5 kGy) is studied. The luminescence bands are related to radiation-stimulated donor-acceptor pairs, which include shallow neutral donors and neutral cadmium vacancies stimulated by $\gamma$-ray irradiation, the transition of free electrons to neutral cadmium vacancies formed by radiation, and the annihilation of excitons bound to the above vacancies. It is shown that, in the crystals preliminarily treated with laser radiation, the intensity of the $\gamma$-ray-stimulated luminescence bands is significantly lower than in crystals not subjected to laser radiation. This fact is accounted for by a decrease in the concentration of cadmium vacancies generated by the $\gamma$-ray radiation as a result of their annihilation during the course of their interaction with laser-stimulated defects, in particular, as a consequence of their recombination at laser-stimulated interstitial cadmium atoms.