The dose rate of beta sources for optical dating applications: A comparison between fine silt and fine sand quartz

Abstract

This note reports on the determination of the dose rates of beta sources used for optical dating. Equipment and targets used for the experiments were chosen according to dating application requirements: sand-sized and silt-sized quartz mounted on aluminium and stainless-steel discs were measured in two Risø readers using a single aliquot regeneration dose protocol. The experiments show that backscattering due to disc substrate accounts for ~ 16% of the dose rate. Charge build-up and attenuation associated with the grain size of the target accounts for ~ 11% of the dose rate. The total uncertainty of the dose rates is ~ 2% or less depending on the accuracy of the primary gamma-source. The excellent agreement between our values and those reported by Armitage and Bailey (2005) indicate that factors determined can be adopted by other laboratories.