Developments in Optically Stimulated Luminescence Techniques for Dating and Retrospective Dosimetry

Abstract

Optically stimulated luminescence signals from natural quartz and feldspar are now used routinely in dating geological and archaeological materials. More recently they have also been employed in accident dosimetry, i.e. the retrospective assessment of doses received as a result of a nuclear accident. Since 1990, the exploration of this wide variety of applications has driven an intensive investigation and development programme at Risø in measurement facilities and techniques. This paper reviews some of the outcomes of this programme, including (i) optimisation of stimulation and emission windows, and detection sensitivity, (ii) experience with various stimulation light sources, including filtered incandescent lamps and high intensity light emitting diodes and laser diodes (infrared at 830-850 nm, blue-green at 420-550 nm and blue at 470 nm). Also discussed are recently developed high-precision single-aliquot measurement protocols. These offer exciting possibilities in dating and accident dosimetry, and are already leading to new demands on measurement techniques and facilities.