Calibration of a CeBr3 based γ-spectrometer for onsite and laboratory radioactivity measurements in sediment samples

The calibration of an underwater spectrometer, consisting of a CeBr3 crystal, is performed for sediment sample measurements, via experimental data and Monte Carlo simulations. The system was implemented for activity concentration measurements in marine sediment samples in the laboratory. The results were compared with corresponding high resolution measurements and showed that the system provides accurate results, but relatively high uncertainties. Different measurement geometries are theoretically studied via Monte Carlo simulations in order to improve the system performance for such measurements. •Application of a CeBr3 crystal for measurements in the laboratory and in the field.•Calibration for sediment samples measurements combining experimental and simulation data.•The measurement geometry is optimized using a Marinelli beaker.•A valid MC model is developed for the efficiency estimation in different geometries.