Scintillation properties of LaBr3:Ce3+ crystals:: fast, efficient and high-energy-resolution scintillators

The scintillation properties of LaBr3 doped with different Ce concentrations, studied by means of optical, X-ray, and gamma-ray excitation are presented. Under optical and gamma-ray excitation, Ce3+ emission is observed peaking at 356 and 387mn. For pure LaBr3 and LaBr3 doped with 0.5%, 2%, 4% and 10% Ce3+ we measured a light yield of 17,000 +/- 2000, 61,000 +/- 5000, 48,000 +/- 5000, 48,000 +/- 5000 and 45,000 +/- 5000 photons per MeV (ph/MeV) of absorbed gamma-ray energy, respectively. The scintillation decay curve of LaBr3:Ce3+ can be described by a single exponential decay function with a decay time of 30 +/- 5 ns. It represents over 90% of the total light yield. An energy resolution (FWHM over peak position) for the 662 keV full energy peak of, respectively, 2.9 +/- 0.1%, 3.8 +/- 0.4%, 3.5 +/- 0.4% and 3.9 +/- 0.4% was observed for LaBr3:0.5%, 2%, 4% and 10% Ce3+. (C) 2002 Elsevier Science B.V. All rights reserved.