The Long-Lived Phosphorescent Components of Thallium-Activated Sodium Iodide

Abstract

Using a cobalt-60 source as a means of primary irradiation, the long-lived phosphorescent decay of thallium-activated sodium iodide crystal has been studied at several crystal temperatures. The results have been interpreted assuming that the different trap levels act independently of each other and that each trap decays according to the monomolecular process. Values for the experimental trap depths and vibrational frequency factors are given.