THE INFLUENCE OF RADIATION-INDUCED DISTORTIONS OF DIELECTRICAL AND MECHANICAL CHARACTERISTICS OF OPTICAL MATERIALS ON THE IMAGE STRUCTURE

The influence of the radiation-induced change in the properties of optical materials on the characteristics of optical systems is discussed. Physical mechanisms are considered that lead to the changes in dielectrical and mechanical characteristics of optical materials exposed to high-energy particles of ionizing radiation. An estimation of the efficiency of ionizing radiation action is based upon the use of the concept of dose coefficients. It is shown that the main contribution to the processes of radiation-induced formation of defects is given by the ionization scattering. On this basis the dose coefficients of the refractive index of linear expansion were evaluated taking into account the change both of dielectric and mechanical characteristics of optical materials. The radiation-induced changes in the characteristics of optical materials are shown to be significant at dose loads typical for optical systems exposed to ionizing radiations in circumterraneous outer space. 12 refs., 3 figs., 1 tab.