High energy resolution scintillation spectrometers

We report on cerium doped scintillator - LaBr₃:Ce for gamma ray spectroscopy. Crystals of this scintillator have been grown using the Bridgman process. This material when doped with cerium has high light output (>60,000 photons/MeV) and fast principal decay constant (<30 ns). The peak of LaBr₃:Ce emission is at 360 nm. LaBr₃:Ce shows excellent energy resolution for gamma ray detection. For 662 keV gamma rays (¹³⁷Cs source), energy resolution of 2.7% (FWHM) has been recorded at room temperature for LaBr₃:Ce crystals coupled to a photomultiplier. This energy resolution is over two times better than that of NaI(TI) scintillators. Analysis of the energy resolution of LaBr₃:Ce scintillators is presented and the performance of this scintillator at other gamma ray energies is covered. Energy resolution of LaBr₃:Ce crystals coupled to silicon avalanche photodiodes is discussed. Potential applications of this material are addressed.