Anomalous behaviour of thermoluminescence from quartz: A case of glow peaks from a Nigerian quartz

Anomalous behaviour displayed by a thermoluminescence (TL) glow peak as radiation dose increases in a Nigerian quartz is presented. The glow curves of the phosphor have four clear glow peaks. The peak temperatures of the first three glow peaks were found to be constant with change in radiation dose at 82, 148 and 200∘C for the sample readout at a heating rate of 1∘Cs-1. The peak temperature of the fourth peak, which is at around 320∘C for a sample irradiated to a dose of 63 Gy and heated at 1∘Cs-1, displays anomalous behaviour with increase in dose relative to the first three peaks. The temperature at which this peak occurs increases with dose to about 335∘C for 177 Gy and then decreases thereafter as dose is further increased. The change is explained on the assumption that the peak may be complex consisting of several overlapping first-order glow peaks each with different TL behaviour.