Concentration Effects in Eu Doped SrI $_{2}$

This study reports on effects of dopant concentration and crystal size on some of the scintillation properties of SrI₂:Eu²⁺. For example, the emission shifts to longer wavelengths as the dopant concentration is increased. It also results in scintillation decays getting slower: a 620 ns decay time constant observed for a small 0.5% Eu sample increases to 1650 ns for a 10% Eu sample. Similar changes in the time constant values were also observed when the crystal size was being increased. It also appears that larger samples yielded somewhat less light. These effects are attributed to radiation trapping, in which the scintillation light is multiple time absorbed and consequently emitted by the dopant.