Non-proportionality components in co-doped CsI:Tl,Ce and GAGG

CsI:Tl scintillators are still among the world's leading detection materials. Growing applications of CsI(Tl) trigger researchers to grow crystals with improved energy resolution, non-proportionality, and reduced afterglow. Another attractive material is GAGG:Ce, the brightest of the oxide scintillators. This work presents newly developed CsI(Tl) co-doped with Ce, the other CsI(Tl) sample with improved energy resolution, and three GAGG samples exhibiting different LY and time profiles. The preliminary study of non-proportionality characteristics extracted separately for fast and slower components of scintillation light showed that fast and slow scintillation components exhibit opposite trends versus deposited energies. Moreover, the fast component follows the non-proportionality curves of CsI(Tl) and GAGG while slower ones have an opposite trend. The scintillation decay times as a function of deposited energy can be measured with the pulse digitization method using a gated fast oscilloscope, and at low gamma-ray energies (below 50 keV) are measured with a coincidence set-up reducing electronic noise's impact on the pulse shape.