Spectroscopic and scintillation properties of cerium-doped LuF3 single crystal

Lutetium based fluoride crystals doped with trivalent cerium ions, due to their high density, are good candidates as heavy fast scintillators. Optical absorption, emission, excitation spectra and lifetime measurements of Ce3+ doped LuF3 are presented. The experiments were performed on a crystal which was grown by Czochralski technique. Excitation and absorption spectra were recorded at T=10K and room temperature. They both show the characteristic five bands structure of Ce3+ doped materials. UV and X-ray excitations of LuF3:Ce reveal a broad emission band centred at 310 nm. Two components are clearly seen at T=5K and even at room temperature. The photon yield of LuF3 is about 8000 photons/Mev under X-ray excitation which is a quite high value compared to other fluoride crystals. The emission decay time was measured with the single photon counting technique under excitation ranging from 5.2 eV up to 40 eV. A fast component of 23 ns followed by a slow one of few micro-seconds was measured. Several transfer mechanisms are proposed to explain the scintillation properties and the fluorescence dynamics of LuF3:Ce3+.