Radiation response of transition metals-doped lithium aluminate crystals

Basic radiation response properties of lithium aluminate LiAlO2 crystals activated with transition metals like Ti, Mn and Cu were examined. When X-ray excited the crystals, intense emission peaks were observed at visible wavelength regions, they are ascribed to the Ti4+ charge transfer (Ti-doped), Mn2+ 3d(5)-3d(5) (Mn-doped) and Cu+ 3d(9)4s-3d(10) (Cu-doped) transitions. The scintillation decay times were estimated to be about 1.8 mu s (93 %) and 9.9 mu s (7 %) for the Ti-doped crystal, 310 mu s (96 %) and 2220 mu s (4 %) for Mn-doped one, and 3.6 mu s (52 %) and 19.6 mu s (48 %) for Cu-doped one, respectively. In the Cf-252 neutron irradiated pulse height spectra, Ti- and Cu-doped crystals showed higher light yield in comparison to that of GS20 commercial scintillator.