Spectroscopy and optically stimulated luminescence of $Al2O3:C$ using time-resolved measurements

This paper reports the observation of ultraviolet (UV) emission at $335nm$ in the optically stimulated luminescence (OSL) of carbon-doped aluminum oxide $(Al2O3:C)$ and presents results on the investigation of the OSL properties of this band, including its dose response, time dependence after irradiation, and dependence of the OSL signal on the type of radiation. Time-resolved OSL measurements were used to separate the UV emission band from the dominant OSL emission band of $Al2O3:C$⁠, namely, the $F$-center luminescence at $420nm$⁠. A comparison of the OSL properties of the UV and $F$-center emission bands is important for various dosimetric applications because the relative contribution of the UV and $F$-center emissions to the OSL signal varies with readout technique and optical filters used in the readout equipment. The UV emission band is found to show an ionization density dependence that is different from the dependence observed for the $F$-center emission, and an increase in intensity with time elapsed after beta irradiation. These results are relevant for OSL dosimetry of radiation fields containing heavy charged particles, such as the space radiation field and the secondary fields created by interactions of matter with energetic neutrons, as well as for understanding of the basic OSL mechanism in $Al2O3:C$⁠.