Dose and Dose Rate Dependency of Radiationinduced Transient Absorption in Pure Silica Optical Fibers Under Gamma Irradiation
Annotatsiya
The optical losses spectra in 300-800 nm region of silica core fibers with high and low OH-group content is measured in-situ and after 10 minutes of irradiation by γ-rays of <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">60</sup> Co source. In-situ optical losses are separated to fast annealing (transient) and residual (stable) parts in order to analyze behavior of transient color centers with the change of dose and dose rate. The linear dependence of the magnitude of transient absorption caused by transient color centers is observed as a function of dose and its saturation at the dose ~5·10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> Rad in silica core silica clad fiber is achieved. The saturation of transient color centers in silica core polymer clad fibers is achieved at ~10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> Rad. The dependence of radiation-induced optical losses on dose rate is linear within the observed values 6-360 R/s. It's supposed that creation mechanism and concentration of transient color centers depend on OH-group content as well as core diameter and preliminary defects in fibers.