Scintillation process in NaI(Tl): Comparison with scintillation models

The scintillation efficiency of NaI(Tl) crystals, containing Tl concentrati on of 0.01, 0.07 and 0.22 mole%, has been measured under electron, alpha pa rticle and fission fragment excitations. The purpose of this program was to provide a critical test of previously proposed models of the scintillation process in activated alkali halides. It is found that the shape of the sci ntillation efficiency versus dE/dx: for the three different Tl concentratio ns is dependent on Tl concentration. The measured scintillation efficiency is compared with the scintillation models for thallium-activated alkali hal ides proposed by Birks, and Murray and Meyer.