Thermoluminescence study of the natural radiation damage in zircon

The effects of natural radiation damage on gamma-ray induced thermoluminescence (TL) in gem-quality zircons from Ceylon has been examined before and after annealing at 950°C for 20 hours in a nitrogen atmosphere. Natural radiation damage is shown to reduce the TL output by a factor of 105, whereas annealing restores the TL. The restoration is α-dose dependent, and can be accounted for by the breakdown of the crystal structure by α-recoil damage and recovery of the crystallinity after annealing. The data are used to develop a qualitative model of the process of α-recoil damage based on that suggested by Pellas [1965].