The removal of anomalous fading in zircon

Three techniques which seek to separate the stable from the fading TL component are reported. In the first we looked at anomalous fading as a function of TL wavelength and found that it occurred equally at all wavelengths (300 to 650 nm). Holding irradiated zircons at elevated temperatures, however, was found to accelerate the fading rate and to remove the fading component without thermally draining the stable component. The results for storage at 21, 125 and 175 C over periods up to 100 days demonstrate this. Similarly exposure of irradiated zircons to long wavelength light (greater than 550 nm in this work) produces an acceleration in the fading rate. As illustration the bleaching as a function of time is compared to the room temperature fading. (author)