Lifetime estimation of thermoluminescence traps in granitic quartz

Thermoluminescence (TL) traps in granitic quartz are potential geochronometers for ages of up to billions years. TL sensitivity is believed to be a measure of the population of TL traps. Their lifetimes can be roughly estimated either by isothermal annealing or by an empirical approach. The former is applicable to radiation sensitive traps corresponding to > 200 degrees C TL when first order kinetics is assumed. The lifetimes are found to be several orders longer than those of trapped electrons. The lifetimes of thermally sensitive traps (< 200 degrees C TL) are estimated from empirical curves that are constructed from data from granitic quartz of known age. It is found that the lifetime increases with the trap depth.