Dose response features of quenched and reconstructed, TL and deconvolved OSL signals in BeO

Despite the fact that Beryllium oxide (BeO) has been suggested by several research groups as an alternative passive radiation detector and dosimetric material, various concerns about supralinear dose response features were raised for both thermoluminescence (TL) and optically stimulated luminescence (OSL) signals of this material. This paper presents a detailed dose response study on BeO, for two different experimental conditions, namely for (i) the TL signal following irradiation at room temperature (RT), 125 and 200 °C and (ii) the CW – OSL signal measured at three different measurement temperatures (RT, 100 and 220 °C), following two different preheating temperatures (Tpre = 100 and 220 °C). The selection of these temperatures is based on the TL glow curve structure for BeO. The analysis was performed using (a) the actual experimental luminescence signals which suffer thermal quenching, and (b) by using the reconstructed luminescence signals, after correcting for thermal quenching. Deconvolution was performed only for the OSL signals. Intense supralinearity features for both TL peaks and OSL components are reported. Reconstruction affects greatly the dose response features of all TL signals, enhancing supralinearity. The dose response linearity coefficient μ of the dominant OSL component C1 is found to be independent of the preheating temperature. This provides a strong argument for the fact that the charge associated with this component originates mainly from the trap responsible for the TL peak 3 in BeO with Tm beyond 300 °C. Based on our experimental results, the supralinearity features of BeO are attributed to competition for free electrons by electron traps. The results of the present study suggest that competition takes place during both the irradiation and heating stages of a dose response experiment in BeO. Finally, preheating at 220 °C and subsequent OSL measurement at 100 °C is highly recommended as the optimum configuration for BeO, not only for roughly linear dose response but also in order to minimize transfer effects.