Scintillation and detection characteristics of high-sensitivity CeBr3 gamma-ray spectrometers

Crystal growth and detector fabrication technologies have reached such a state of maturity that high-quality large-volume CeBr3 scintillators can now be produced with dimensions of 2′′×2′′ and well above. We present a study of CeBr3 samples of various dimensions and show that they have a number of advantages over equivalently sized LaBr3:5%Ce for gamma-ray spectroscopy applications requiring high detection sensitivity. At the present time, the achieved energy resolution of CeBr3 is about 4% FWHM at 662 keV, i.e. 25% worse than that of LaBr3:5%Ce. However, thanks to the drastically reduced intrinsic activity, CeBr3 gamma-ray detection sensitivity is about 1 order of magnitude better than that of LaBr3:5%Ce at energies of 1461 keV and 2614.5 keV, which are relevant for the detection of 40 K and 208 Tl ( 232 Th), respectively. In this communication, we report on several aspects of CeBr3 gamma-ray spectrometers, such as scintillation characteristics, non-proportionality of the response, gamma-ray detection performances up to 3 MeV and radiation tolerance.