On the Constitutive Assumptions for a Continuum Model of Scintillating Crystals

For inorganic scintillating crystals, we show how the evolution equation for the charge carriers densities can be obtained by modeling the crystal as a continuum with structure. The resulting equation is a Reaction-Diffusion-Drift one. We deal with various hypotheses on the reaction/recombination term which are induced by two different choices for the associated entropy, namely those based either on the Gibbs-Boltzmann or Fermi–Dirac statistics.