Cross-calibration between beta and gamma sources using quartz OSL: Consequences of the use of the SAR protocol in optical dating

The radiation dose delivered by the ⁹⁰Sr beta source of a TL-OSL reader and the one delivered by a ¹³⁷Cs gamma source were compared using OSL dating techniques and tools. Three sets of quartz of different origins (rock, sediment and loess) were studied and measured by the SAR protocol (Single aliquot regenerative dose protocol) after irradiations carried out either by the ⁹⁰Sr source or by a ¹³⁷Cs source. Measurements show that the values obtained by the SAR protocol must be corrected in order to provide an acceptable cross-calibration of the beta and gamma source. Once applied, measurement sets become self-consistent and compatible with expected values. The consequences of the above mentioned observations on the methodology of OSL dating are discussed and suggest that a mixed protocol be used including both the SAR protocol and an added dose techniques close to the SARA protocol (Single aliquot regenerative and added dose protocol). - Highlights: • We study OSL properties of 4 quartz fine grain sample from Loess. • These study show how these samples can be used for comparing a beta and a gamma source. • We study 13 quartz coarse grain sample from quartzite and sediments. • This confirms the SAR protocol can be used for cross-calibration of sources. • This must be achieved applying individual corrections to the SAR protocol results