Scintillation properties of LaCl3:Ce3+ crystals:: Fast, efficient, and high-energy resolution scintillators

The scintillation properties of LaCl3 doped with different Ce3+ 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 330 and 352 mn. For LaCl3 doped with 2%, 4%, 10%, and 30% Ce3+ and pure CeCl3, we measured a light yield of 46 000 +/- 3000 photons per MeV of absorbed gamma -ray energy. The scintillation decay curve can be described by three decay components: short (tau = 25 ns), intermediate (tau = 200 - 800 ns), and long (tau = 0.8-14 mus). The contribution of the short decay component to the total light yield increases with Ce3+ concentration: ranging from 10% for LaCl3: 2 % Ce3+ to 69 % for pure CeCl3. An energy resolution (full-width half-maximum over peak position) for the 662-keV full energy peak of 3.5 +/- 0.4 %, 3.5 +/- 0.4 %, 3.1 +/- 0.3 %, 3.3 +/- 0.3 %, and 3.4 +/- 0.3%, respectively, was observed for LaCl3: 2%, 4%, 10%, 30% Ce3+ and pure CeCl3.