Optically stimulated luminescence in Tm-doped calcium fluoride phosphor crystal for application to a novel passive type dosimeter

Abstract

An intense optically stimulated luminescence (OSL) with four emission bands in the wavelength range from 290 to 420 nm is observed for the first time in X-ray-irradiated Tm-doped CaF 2 (CaF 2 :Tm) phosphor crystal. The OSL intensity increases almost linearly with increasing X-ray absorbed dose. Thermally stimulated luminescence (TSL) glow curves with four peaks are also observed in X-ray-irradiated CaF 2 :Tm phosphor crystal. It is confirmed that the shape of the TSL glow curve in X-ray-irradiated CaF 2 :Tm phosphor crystal is the same as that of a commercially available dosimeter (TLD-300). An OSL emission and stimulation mechanism of X-ray-irradiated CaF 2 :Tm phosphor crystal is proposed.