Optical and scintillation properties of Tl-doped CsBr transparent ceramics produced by spark plasma sintering

We have developed CsBr transparent ceramics doped with various concentrations of Tl (0.01, 0.1, 0.2, 0.3 and 0.5 mol%) by spark plasma sintering and then investigated for scintillator applications. Regarding the scintillation properties, all the samples showed emission peaking around 360 nm due to P-3(1) -> S-1(0) transitions of Tl+ ion. In addition, all the samples showed emission due to off-center self-trap exciton, which appeared around 490 nm. Among the present samples, the 0.2% Tl-doped sample showed the highest light yield (22,000 photons/MeV) under Cs-137 exposure. Moreover, the scintillation response demonstrated a good linearity with gamma-ray energies of Cd-109, Co-57, Ba-133, Na-22 and Cs-137 sources.