Study of non-linear luminescence-dose growth curves for the estimation of paleodose in luminescence dating: results of Monte Carlo simulations

Abstract

In luminescence dating applications, non-linear luminescence versus dose growth curves are often observed. An experimental data scatter of 5-15% is commonplace and this causes difficulties in estimating the equivalent dose D_c and the error on the equivalent dose δ_De. Two aspects need consideration: (a) What configuration of experimental parameters (such as maximum radiation dose and radiation dose intervals) should be chosen so as to minimize δ_De? and (b) How accurate are the estimates D_e and δ_De given by the non-linear parameter estimation procedure? To address these aspects, Monte Carlo simulations of a large number of saturating exponential growth curves were carried out for the three principal experimental methods commonly used for the estimation of equivalent dose, i.e. additive dose method, the regeneration or slide method and the partial bleach method. Additionally, third-order polynomial growth curves (as seen in some quartz) were also examined. In these studies, the influence of various experimental parameters such as the maximum irradiation dose D_max, the number of data points N_dat and the spacing of dose on D_e and δ_De were studied. Based on a synthesis of the simulation results, optimal values for the experimental parameters for the different methods are suggested.