Tl-concentration dependence of scintillation properties in Tl-doped CsBr single crystals

Abstract

Abstract Photoluminescence and scintillation properties of CsBr single crystals with various concentrations of Tl (0.1%, 0.2%, 0.3%, 0.5% and 1%) were examined. Under an excitation at 260–280 nm and X-ray excitation, all the samples exhibited emission peaking around 360 and 510 nm with the decay time constants of μs order. The former emission would be due to 3P1 → 1S0 transitions of Tl+ ion associated with tetragonal structures, and the latter one was due to off-center configurations of self-trapped excitons localized near Tl+ ions at trigonal structures. The pulse height analysis under 137Cs γ-ray (662 keV) irradiation indicated that the 0.3%Tl-doped sample possessed the highest scintillation output among the prepared samples. From the results under various γ-ray irradiation, we confirmed that the scintillation output showed a good proportional response against γ-ray energy up to 1274 keV.