Scintillation properties of Eu-doped CsCl and CsBr crystals

Eu-doped CsCl and CsBr crystals were grown by the vertical Bridgman-Stockbarger method and the scintillation properties of the crystals were investigated. The radioluminescence (RL) bands of CsCl:Eu were observed at 245-270 nm and 450 nm. The former bands are attributed to Auger-free luminescence, and the latter band is attributed to Eu2+ 5d-4f transitions. CsBr:Eu showed an RL band at 435 nm, and this broad band is attributed to Eu2+ 5d-4f transitions. The scintillation decay-time constants of the slow components for CsCl:Eu and CsBr:Eu were 0.38 and 2.8 μs, respectively. Based on the pulse-height spectra for 662 keV gamma ray from 137Cs, the light yield of CsCl:Eu and CsBr:Eu are estimated to be 1700 and 2500 photons/MeV, respectively.