OSL response to proton irradiation in some natural dosemeters: Implications for martian sediment dating

The knowledge of environmental dose rate on Mars is crucial for in situ Optically Stimulated Luminescence (OSL) dating of martian sediments. Protons are the dominant source of dose rate on Mars. The efficiency of OSL production after proton irradiation depends on the protonʹs Linear Energy Transfer (LET). Since the absorbed dose estimates are usually derived using a low LET reference radiation (e.g. gamma rays, X-rays or beta particles), it is important to know the correct weighting factors to account for the changes in OSL efficiency for proton irradiation. Here, we present and discuss new results on OSL efficiency for protons for two martian analogue materials (feldspar and a basaltic rock sample) and one laboratory standard (quartz).