Reproducibility of optically stimulated luminescence measurements from single grains of Al₂O_3: C and annealed quartz

We have measured some aspects concerning the performance of a new instrument for the measurement of optically stimulated luminescence (OSL) from single sand-sized grains. The instrument uses a solid-state laser to stimulate OSL from each grain individually. These grains are placed in a regular grid of nine-by-nine holes, which are drilled in the sample disc. We report on tests carried out to determine the precision with which the laser beam can be directed at individual grains in these holes. Single grains of aluminium oxide (Al2O3:C) (90–180 μm) and annealed quartz (90–120 μm) were used to test the reproducibility with which the OSL signal can be measured. These experiments suggest that the laser beam can be positioned to within 30 μm and that the reproducibility of OSL measurement is 3.5% on an average.