Modeling the charge deposition in quartz grains during natural irradiation and its influence on the optically stimulated luminescence signal

The rate of charge deposition in quartz grains irradiated in natural conditions is computed by radiation transport modeling. Quartz luminescence models are modified with the addition of the resulting charge deposition term, and the influence of this process on the optically stimulated luminescence (OSL) signal is analyzed. The results indicate that the charge deposition occurring in the quartz grain during the time of residence within rock could lead to the depletion of trapped holes in the recombination centres. For the two different quartz models investigated here, complete depletion is expected to occur for rock ages between 500 Ma and 1100 Ma. It is predicted that for sedimentary quartz derived from such rocks, the OSL signal is dominated by the slow component. It was also found that the shape and saturation level of the natural sensitivity-corrected dose response curve (DRC) of quartz is affected by the charge deposition; specifically, a linear reduction of the saturation level with the age of the rock is observed.

Automated summary

The study shows that the charge deposition in quartz grains under natural conditions significantly affects the optically stimulated luminescence signal, potentially depleting trapped holes in recombination centers. For quartz grains residing in rocks for extended periods, charge deposition may lead to complete depletion expected between 500 Ma and 1100 Ma. It is also observed that the shape and saturation level of the dose response curve of quartz is linearly reduced with rock age due to charge deposition.