Influence of self-absorption corrections in the quantification of 210Pb and 241Am for sediment dating

Abstract The nuclides 210 Pb and 241 Am are used in geochronological studies. In this work, we examine the influence of the sediment chemical composition on the self-attenuation corrections needed for the accurate determination of specific activities for 210 Pb and 241 Am used for sediment dating. A theoretical exercise was carried out evaluating the relative bias obtained by four different analytical laboratories in the quantification of the 210 Pb and 241 Am activity concentration by gamma-ray spectrometry. The laboratories considered the same density for the sediment sample, but each one used a different chemical composition in the Monte Carlo calculations, and six different HPGe detectors (including n and p-types). An estimate of the impact that would have the relative biases found in the estimation of the 210 Pb sediment ages, applying the Constant Rate of Supply (CRS) dating model, is also given. In addition, the performance scores that the laboratories would have obtained in a hypothetical IAEA proficiency test are also presented.