[en] In this work nonlinear effects of light scattering in the one crystalline modification silica: alpha-quartz (α-CS) at neutron-activated phase transition was studied. As a results of the high fluxes of fast neutrons bombardment the alpha-phase transformed into another crystalline phase. This process of radiation damage of crystalline structure and defect formation has been studied by spectroscopic methods: Raman light scattering for receiving the information about character of a kinetics of this processes, about a volume effect of radiation spectroscopy. The Raman spectra were measured before and after irradiation with the fluxes (F) of a samples. The influence of radiation on spectral characteristics of α-CS crystalline lattice of main vibrations: a intensity (R), a frequency (ν), a width (δ) in region a frequencies 100-1400 cm^-1 was studied. It is shown that neutron irradiation of α-CS to integrated fluxes from 1·10¹⁹ cm^-2 to 2·10²⁰ cm^-2 strongly influences on their Raman spectra. Radiation effect on the parameters R, ν, δ of row a series of lines in region a frequencies 128, 265, 357, 396, 466, 697, 796, 1162 cm^-1 was determined. For example dose dependencies of spectral characteristics for the 'sort' modes at 128 cm^-1 are investigated. It can be seen from this curves that at the initial stage of irradiation these parameters changes little. A noticeable changes of functions ν(F) and δ(F) occurs for F>10¹⁹ cm^-2, when a rapid phase transition take place. It is found that an the both dose dependencies exhibit breaks and then near of some critical point (F_c=7·10¹⁹ cm^-2) these parameters is no registered, at this there are nonlinear changed these curves. It was seen from the series determined Raman light scattering spectra that at this critical point spectroscopic parameters of lines highly transformed and lot of bands was disappearance (for instance 128, 207, 357 cm^-1). A kinetics change of radiation effects in dependence of F for the intensity (R₎, frequency (R_ν) width (R_δ) of a another 'soft' modes - 207 cm^-1 in Raman spectra was studied. It can be seen that a curves R_j(F) to very non monotonically changed in the dose range, where according to XRD data the phase of α-β transition occurs. The results on both lines (128, 207 cm^-1) and for other lines of scattering are analyzed in comparison with the Raman spectra of the single crystal quartz temperature dependence. It is supposed that in α-CS samples irradiated to fluxes near F_c the β-CS like structure is formed. As a result, it is discovered that dose dependence was changed of character the light scattering of very nonlinearly from some modes in Raman spectra. Basing from approximation products changed the parameters of the valent degeneration and deformations full symmetrical vibrations Si-O-bonds and 'steam chink' theory, a conception of percolation mechanism of radiation-induced the phase transition in α-CS is proposed