Scintillation properties of LaCl/sub 3/:Ce/sup 3+/ crystals: fast, efficient, and high-energy resolution scintillators

The scintillation properties of LaCl/sub 3/ doped with different Ce/sup 3+/ concentrations studied by means of optical, X-ray, and /spl gamma/-ray excitation are presented. Under optical and /spl gamma/-ray excitation, Ce/sup 3+/ emission is observed peaking at 330 and 352 nm. For LaCl/sub 3/ doped with 2%, 4%, 10%, and 30% Ce/sup 3+/ and pure CeCl/sub 3/, we measured a light yield of 46 000/spl plusmn/3000 photons per MeV of absorbed /spl gamma/-ray energy. The scintillation decay curve can be described by three decay components: short (/spl tau/=25 ns), intermediate (/spl tau/=200-800 ns), and long (/spl tau/=0.8-14 /spl mu/s). The contribution of the short decay component to the total light yield increases with Ce/sup 3+/ concentration: ranging from 10% for LaCl/sub 3/: 2% Ce/sup 3+/ to 69% for pure CeCl/sub 3/. An energy resolution (full-width half-maximum over peak position) for the 662-keV full energy peak of 3.5/spl plusmn/0.4%, 3.5/spl plusmn/0.4%, 3.1/spl plusmn/0.3%, 3.3/spl plusmn/0.3%, and 3.4/spl plusmn/ 0.3%, respectively, was observed for LaCl/sub 3/: 2%, 4%, 10%, 30% Ce/sup 3+/ and pure CeCl/sub 3/.