How reliable are our beta-source calibrations?

International audienceThe calibration of any artificial-source attached to a luminescence reader is fundamental for the accuracy of luminescence dating results. Here, we present calibration results obtained for a-source attached to a single grain Risø reader in Bordeaux using a series of quartz of different origins. The quartz was irradiated with three different-irradiators. An unexpected variability of the apparent dose rates was observed and our results suggest that the-irradiation is the main reason for this variability. Further work is needed to clarify the underlying reasons

Luminescence age calculation through Bayesian convolution of equivalent dose and dose-rate distributions:The De_Dr model

In nature, each mineral grain (quartz or feldspar) receives a dose rate (Dr) specific to its environment. The dose-rate distribution, therefore, reflects the micro-dosimetric context of grains of similar size. If all the grains were well bleached at deposition, this distribution is assumed to correspond, within uncertainties, with the distribution of equivalent doses (De). The combination of the De and Dr distributions in the De_Dr model proposed here would then al- low calculation of the true depositional age. If grains whose De values are not representative of this age (hereafter called “outliers”) are present in the De distribution, this model al- lows them to be identified before the age is calculated, en- abling their exclusion. As the De_Dr approach relies only on the Dr distribution to describe the De distribution, the model avoids any assumption about the shape of the De distribu- tion, which can be difficult to justify. Herein, we outline the mathematical concepts of the De_Dr approach (more details are given in Galharret et al., 2021) and the exploitation of this Bayesian modelling based on an R code available in the R package “Luminescence”. We also present a series of tests using simulated Dr and De distributions with and without outliers and show that the De_Dr approach can be an alter- native to available models for interpreting De distributions.Using the world in ancient societies : processes and forms of appropriation of space in Long TimeCREDit - Chronological REference Datasets and Sites (CREDit) towards improved accuracy and precision in luminescence-based chronologie

Morts en œuvre

"Les livres sont carnassiers. Ils se nourrissent de chair, de larmes, ils se frottent de mort, ils prennent leur source au cimetière, c’est tout su, sur mon père j’ai bâti une œuvre, en dot j’ai reçu ses ossements, ses deuils, ses peaux, ses lettres, une fortune de terreur et d’inconsolation." Hélène CIXOUS. Les subjectums Travaillant le concept d’informe, comme une catégorie de la forme, s’opposant historiquement à la figure dans sa formulation bourgeoise type début de siècle, en s’articulan..

Dose-rate estimation using α-Al2O3:C chips: aftermath

We present additional experiments for α-Al2O3:C chips used to estimate in situ g-dose rates. Our contribution supplements the article by Kreutzer et al. (2018) and presents results from previously announced follow-up experiments. (1) We investigate the divergent g-dose rate results we obtained from cross-check experiments for one reference site. (2) We discuss the origin of encountered large inter-aliquot scatter using results from low-level background and calibration measurements. (3) We show that the chip geometries vary considerably, which may partly contribute to additional inter-aliquot scatter, regardless of an overall good reproducibility of results. (4) We report new source-calibration results after replacing the b-source housing of our measurement system, which resulted in an increase of the source dose rate at the sample position by ca 37%. GEANT4 simulations show that the increased dose rate is likely caused by an unfortunate fabrication tolerance of the shutter in front of the b-source, which, in combination with the chip geometry, significantly contributes to the observed inter-aliquot scatter. (5) Finally, we introduce a newly developed shiny application we use at the IRAMAT-CRP2A to analyse α-Al2O3:C measurements. The application is open-source and freely available

Environmental dose rate determination using a passive dosimeter: Techniques and workflow for α-Al2O3:C chips

International audienc

Bayesian statistics in luminescence dating: The ’baSAR’-model and its implementation in the R package ’Luminescence’

International audienceA function named analyse baSAR() was writtenusing the statistical programming languageR and its code is now available within the Rpackage ’Luminescence’. The function allowsthe application of the Bayesian hierarchicalmodel ’baSAR’ proposed by Comb`es et al.(2015) and comes with additional features toanalyse luminescence data in a straight forwardway. Example scripts are provided showing thepossible numerical and graphical outputs

Absorbed dose, equivalent dose, measured dose rates, and implications for OSL age estimates: Introducing the Average Dose Model

International audienc

Received dose, equivalent dose, measured dose rates, and implications for OSL age estimates: introducing the Mean Dose Model

International audienc