Ti and Ge substitute for Si and form diamagnetic precursors [TiO4]0 and [GeO4]0 in quartz structure. Under irradiation they may capture an additional electron, being transformed into paramagnetic centers: [TiO4 -/M+]0 and [GeO4 -/M+]0, where M+ is a charge compensating ion (H+, Li+, Na+). The dependence of the concentration of paramagnetic centers on accumulated dose is non-monotonic. At low doses the concentration increases and at doses of about (1.5-2)·104 Gy for Ti and (3-5)·103 Gy for Ge reach its maximum. At further increase of the dose the concentration decreases and may reach undetectable for EPR spectroscopy value. This effect is called radiation decay. Nonmonotonic dose response curves may be explained by the remove of an additional electron or by capturing of second electron which transforms [TiO4 -/M+]0 and [GeO4 -/M+]0 centers into the form which is not recorded with EPR spectroscopy - radiation modified (RM) centers [TiO4 -/M+]rm and [GeO4 -/M+]rm. The compensation of an extra negative charge may be completed by additional ion M+ for which there are two non equivalent positions in channels of quartz structure. In the frames of this model dose-response curves may be simulated with   formula    where Cp is the concentration of precursors, f1 – efficiency of the formation of paramagnetic centers from precursors, f2 – efficiency of the transformation of paramagnetic centers into RM states, d – accumulated dose. This equation satisfactory simulates experimental data and shows that f2 is always higher than f1. Paramagnetic and RM centers are metastable and may be annihilated at elevated temperatures. The loose of one electron by RM centers transforms them into paramagnetic state. In this case the concentration of paramagnetic centers is determined by the difference between the rate of their thermal annealing and the rate of their formation from RM centers. To study this effect a series of annealing of irradiated with big doses quartz samples were done. For most samples increase of concentration of paramagnetic [TiO4 -/M+]0 and [GeO4 -/M+]0 centers was recorded at first steps of annealing. To simulate annealing data for [GeO4 -/Li+]0 centers following equation was used:   formula    where k1 is the recombination rate of RM centers at given temperature, k2 - recombination rate of paramagnetic centers at given temperature and concentration, A – initial concentration of RM centers, t – time. For [TiO4 -/Li+]0 to achieve better correspondence experimental data it was necessary to assume existence of two types of [TiO4 -/M+]rm centers in quartz structure:   formula   where k3 is the recombination rate of RM centers of second type at given temperature, B – initial concentration of RM centers of second type. Obtained results indicate that capture of second electron by paramagnetic centers is the cause of non-monotonic dose response curves. That should be taken into account for different materials which are subjected to ionizing radiation. At the same time the results explain why first or second order kinetics can`t simulate annealing processes correctly.