“…The non-proportionality of the undoped oxide crystals, as BGO (Moszyń ski et al, 2004) and CWO (Moszyń ski et al, 2005a), represents the fundamental properties of the scintillator materials. In case of doped crystals, one observes variation of the non-proportionality characteristic depending on doping agents, particularly for halide crystals (Moszyń ski et al, 2009(Moszyń ski et al, , 2005c. Moreover, the pure, undoped halide crystals, as NaI and CsI, are very sensitive to the impurities, which affect the non-proportionality curves (Moszyń ski et al, 2009).…”