Transient optical transmission changes induced by pulsed electron radiation in commercial crown silicate glasses

摘要

We report on results of time-resolved induced optical absorption measurements in commercial crown silicate glass K8 (similar to Schott BK7 glass) and its radiation-resistant counterpart K108 under 0.25-MeV pulsed electron radiation. The spectra have been obtained in a wavelength range 280-1100 nm on a time interval 10 ns-1 s after the end of a 20-ns pulse. In contrast to behavior of stable defects, the efficiency of non-stationary color centers' generation in the long-wavelength spectrum range is similar for both standard and radiation-resistant glasses. The characteristic time for transmission recovery in the visible range at room temperature was found to be about 100 μs. Based on the Kramers-Kroenig relations we have estimated transient refractive index changes. For the same radiation dose such changes can be two orders of magnitude higher than those observed in stationary conditions.