Scintillation Response of Activated Ionic Crystals to Charged Particles

Experimental studies of the response of thallium-activated alkali iodides to various charged particles indicate decreasing scintillation efficiency with increasing particle mass and a non-linearity in pulse height vs energy for heavier particles. The scintillation efficiency to electrons, however, is found to be anomalously low, less than that to protons and deuterons. This paper represents an effort to synthesize the results of various experiments and to provide a model for understanding the observed behavior. The model adopted treats the formation of energy carriers and the transport of energy by the diffusion of these carriers from the path of the incoming particle to the activator sites. Results of calculations based on this model are found to be generally consistent with experiment.