The non-proportional dependence of a scintillator's light yield on primary particle energy is believed to be influenced crucially by the interplay of non-linear kinetic terms in the radiative and non-radiative decay of excitations versus locally deposited excitation density. A calculation of energy deposition, -dE/dx, along the electron track for NaI is presented for an energy range from several electron-volt to 1 MeV. Such results can be used to specify an initial excitation distribution, if diffusion is neglected. An exactly solvable two-channel (exciton and hole(electron)) model containing 1st and 2nd order kinetic terms is constructed and used to illustrate important features seen in non-proportional light-yield curves, including a dependence on pulse shaping (detection gate width). � 2009 Elsevier B.V.
BIZARRI, G., Moses, W., Singh, J., VASILEV, A., & Williams, R. T. (2009). The role of different linear and non-linear channels of relaxation in scintillator non-proportionality. Journal of Luminescence, 129(12), 1790-1793. https://doi.org/10.1016/j.jlumin.2008.12.024