Instability of luminescence responses in feldspar-and quartz-based paleo-dosimeters

It is shown that repeated cycles of laboratory irradiation/heating, being a component part of the majority of luminescent dating protocols, cause a change in sensitivity of quartz and feldspars. As a rule, these changes relax within one month and the sensitivity tends toward its initial value. The analysis of experimental data confirms that these phenomena are caused by thermo-and radiation-induced ionic processes and cannot be connected to tunneling. In addition, ionic processes cause an increase in the sensitivity of quartz on heating to temperatures approaching that of the phase transition in quartz (573°C). The dose sensitivity (stored or liberated light sum per unit absorbed dose) of quartz starts growing even when it is moderately heated (to about 300°C), which is typical of dating procedures.