Radiophotoluminescence properties of Al2O3:C,Mg crystals

The objective of this study is to characterize the radiophotoluminescence (RPL) properties of Al2O3:C,Mg detectors, including the dependence of the photoluminescence (PL) emission spectrum on excitation wavelength after optical bleaching and irradiation, and the dose response. We also measure the sensitivity and background for samples from various crystal growth processes. The results confirm that the detectors can be efficiently bleached with a N2 laser and the RPL signal exhibits a linear dose response using either UV or red excitation. However, red excitation yields higher background (relative to the signal after irradiation) compared to UV excitation. Using red excitation, the emission spectrum is dominated by an unknown emission centered >800 nm at low doses. The main obstacles for dosimetry application are the signal increase over time, observed after bleaching and irradiation, and the background after optical bleaching.

► RPL signal exhibits linear dose response using 335 nm and 615 nm excitation.
► Al2O3:C,Mg RPL detectors can be efficiently bleached with a N2 laser.
► UV (335 nm) excitation results in higher signal-to-background ratios.
► Transient signal is observed due to the stimulation of trapped charges.
► Main obstacle for dosimetry is the background after bleaching.