Optical and scintillation properties of cerium-doped LaCl3, LuBr3 and LuCl3

The optical and scintillation properties of LaCl3 : 0.57% Ce, LuBr3 : 0.021%, 0.46%, 0.76% Ce and LuCl3 : 0.45 % Ce are studied under optical, X- and gamma-ray excitation. The highest light yield of 40000 +/- 4000 photons per MeV (ph/MeV) of absorbed gamma-ray energy was measured for LaCl3:0.57% Ce. An energy resolution (FWHM over peak position) of, respectively, 7.0 +/- 0.5%, 6.0 +/- 0.1%, 7.8 +/- 0.3%, 6.5 +/- 0.5% and 18.0 +/- 0.5% was observed for the 662 keV full absorption peak. The scintillation decay curves can be described with three components: 20 +/- 2, 330 +/- 30 ns and 2.2 +/- 0.2 mu s for LaCl3:0.57%; 32 +/- 3, 450-550 ns and > 5 mu s for LuBr3:0.76%; 50 +/- 5, 250-350 ns and > 4 mu s for LuCl3:0.45%. (C) 1999 Elsevier Science B.V. All rights reserved.