Luminescence properties of pure silica core optical fibers (OFs) with a high-OH group content are studied in the visible region at different doses and dose rates of 60Co γ-radiation. It is shown that the γ-induced light emission (GLE) spectra consist of Cherenkov emission along the luminescence bands. Different increase rates of the luminescence bands at 450 and 650nm and the absorption band at 610nm with increasing γ-radiation dose are observed. The 450nm luminescence band is caused by the recombination of holes with the trapped electrons of E0-centers. The dose dependence of the 650nm luminescence band, caused by the nonbridging oxygen hole center (NBOHC), does not coincide with that of the 610nm absorption band related to this center. It is shown that a considerable part of NBOHC participates in nonradiative relaxation. Also, there is an absorption band caused by color centers different from NBOHC, that contributes to the formation of the 610nm absorption band. A linear dependence of GLE intensity (at wavelengths of 450 and 650 nm) on the dose rate increase is observed. Such a dependence is caused by a substantial increase in the Cherenkov emission intensity and comparatively small increases in luminescence band intensities at 450 and 650 nm.
ASJC Scopus subject areas
- Physics and Astronomy(all)