Monte Carlo simulation of beta depth dose distributions in LiF

The accurate measurement of weakly penetrating radiation is usually difficult due to the attenuation of the radiation in the detector. The aim of this work is to estimate by means of Monte Carlo techniques beta depth-dose distributions in LiF dosemeters of different thicknesses. The new Monte Carlo code for electron-photon simulation, PENELOPE, developed at the University of Barcelona, is used in this study. The Amersham/Buchler beta secondary standard usually used for the calibration of beta dosemeters is simulated. The irradiation unit and geometries are taken into account for the calculations. Depth dose distributions in 105 mg.cm(-2) and 240 mg.cm(-2) thick detectors produced by Tl-204 and Sr-90-Y-90 reference sources at a surface-source distance of 30 cm are calculated. Subsequently, detector responses are evaluated for the two detector thicknesses and the two beta sources and compared with experimental data. Results agree within estimated uncertainties (+/-10%).