Afterglow based detection and dosimetry of beta particle irradiated ZrO2.

In this work, we report on the afterglow (AG) response characterization of commercially available ZrO2. Pellet shaped samples previously annealed in air at 1000°C during 24h were exposed to beta particle irradiation in the dose range from 0.5 up to 128Gy and their AG decay curves recorded during 600s after irradiation exposure. The characteristic glow curves of beta particle irradiated ZrO2 show two maxima located around 80°C and 150°C. The first one rapidly vanishes at room temperature, giving rise to AG. The integrated AG signal increases as dose increases from 0.5 to 128Gy, with a linear dependence from 0.5 up to ca. 32Gy. Excellent reproducibility of the AG response was observed in 10 irradiation - AG readout cycles, showing that the studied ZrO2 samples are reusable. The results here presented show that ZrO2 is a promising material for use as a radiation dosimeter based on the AG phenomenon.

Afterglow dosimetry performance of beta particle irradiated lithium zirconate.

In this work, we report for the very first time on the thermoluminescence (TL) and afterglow (AG) properties of Li2ZrO3. The ternary oxide Li2ZrO3 was synthesized by solid state reaction of a mixture of Li2CO3 and ZrO2 subjected to thermal annealing at 400°C for 2h and 1000°C during 24h in air. The characteristic glow curves of beta particle irradiated samples exhibit an intense TL emission located around 150°C. From the shape of the TL curve, a 0.4 form factor was determined, suggesting that first order kinetics processes are involved. The afterglow decay curves were recorded after exposure to beta particle irradiation in the dose range from 0.5 up to 2kGy. The AG integrated in the time interval from 510 to 600s after radiation exposure shows a linear dependence as a function of the irradiation dose from 0.5 up to 256Gy. A method is proposed to compute the lower detection limit and the AG sensitivity and applied to the studied phosphors. Structural and morphological characterization were carried out by X-ray diffraction and Scanning Electron Microscopy, respectively. From the results presented, it is concluded that the AG response of the synthesized Li2ZrO3 presents features suitable to develop radiation detectors and dosimeters.