Radiation-induced Changes in Refractive Index and Absorption Coefficient for Several Optical Materials

An experiment was performed to determine the change in refractive index and absorptivity upon x radiation of several optical materials. Exposure to a radiation dose of 10(5) rad produced measurable changes at lambda = 0.5330 microm in the index of refraction and at lambda = 0.5000, microm in the absorption coefficient of ~5.8 x 10(-6) and ~0.1 cm(-1) for calcium fluoride. Optical glasses exhibited changes of ~5.8 x 10(-6) and ~1.1 cm(-1) for LaK 8, ~4.3 x 10(-6) and ~1.7 cm(-1) for PSK 53, ~5.1 x 10(-6) and ~1.4 cm(-1) for FK 50, and ~6.0 x 10(-6) and ~1.0 cm(-1) for SF 8. A change in the absorption coefficient of the optical glass KzFS 5 of ~0.52 cm(-1) was measured. Changes induced in an SiO(2) (Suprasil 2B) control sample were below measurement capability.