Optically Stimulated Luminescence (OSL) Dosemetry Characteristics of Quartz Grains Extracted from Some Sediments from Chad Basin, N.E. Nigeria

The Single Aliquot Regenerative dose (SAR) protocol has received popular application in Optically Stimulated Luminescence (OSL) dosemetry due to its ability to correct for numerous sensitivity changes that result during equivalent dose measurements. The basic luminescence dosemetry characteristics and SAR performance evaluation tests have been applied on quartz grains collected from the Chad basin using Risoe TL/OSL reader. The outcome shows that the measured equivalent Doses (De) are independent of thermal pre-treatment and charge recuperation, thermal transfer of charges and repeatability of measurements are all negligible within operational conditions. The dose recovery quality of the grains are within acceptable recommendations. Heterogeneous exposure of grains has been observed to have prevailed throughout transport and deposition of sediments and the mean of <5% of measured De have been used as dose estimates from the grains. None of the two deposition environments studied (aeolian and fluvial) showed any evidence of homogeneous resetting of luminescence signal in quartz grains during transport and deposition.