Assessments of environmental dose rates in luminescence readers using α-Al2O3:C

Environmental dose rates can be recorded in standard luminescence readers using alpha-Al2O3:C after appropriate attenuation of the built-in radioactive source. Increasing the sample to source distance and reducing the active area of the source by interposing a system of disks between the source and sample results in a dose rate that is convenient for measuring doses of the order of 0.2 mu Gy or less. The set-up allows one to exploit the high sensitivity of alpha-Al2O3:C, and thereby reduces the time of field exposure to a few weeks. The effect of bremsstrahlung either in the form of leakage or crosstalk radiation in this set-up was found not to conflict with the requirements of routine measurements of environmental dose rates for luminescence dating. The changes are inexpensive compared to the acquisition of low activity radioactive sources including housing. (c) 2005 Elsevier Ltd. All rights reserved.