Gamma-ray and electron response in doped alkali halide scintillators

The wide angle Compton coincidence technique was used to study non-proportionality of light yield and intrinsic resolution of doped alkali halides. The tested scintillators were 1 inch × 1 inch cylindrical crystals of NaI:Tl, CsI:Na and CsI:Tl. The experimental setup comprised a High Purity Germanium detector and the tested samples coupled to a photomultiplier. The results obtained for Compton electrons are compared with the response of the tested scintillators to γ-rays. In this study we pointed out the correlation between non-proportionality at low energy range and intrinsic energy resolution measured for Compton electrons and γ-rays. Substantial difference in intrinsic resolution of doped NaI and CsI crystals was observed.