Sol–gel derived copper-doped silica glass as a sensitive material for X-ray beam dosimetry
Résumé
The light emission from a sol–gel-derived Cu-doped silica glass was studied under 10 keV X-ray irradiation
using a fibered setup. Both radioluminescence (RL) and optically stimulated luminescence (OSL)
were analyzed at different high dose rates up to 50 Gy/s and for different exposure times, yielding accumulated
doses up to 50 kGy (in SiO2). Even if a darkening effect appears at this dose level, the material
remains X-sensitive after exposure to several kGy. At low dose rate, the scintillation mechanisms are similar
to photoluminescence, involving the Cu+ ions electronic levels, contrary to the nonlinear domain (for
dose rates higher than 30 Gy/s). This RL, as well as the OSL, could be exploited in their linear domain to
measure doses as high as 3 kGy. A thorough study of the OSL signal has shown that it must be employed
with caution in order to take the fading phenomenon and the response dependency on stimulation source
intensity into consideration.