The saga of the thermoluminescence (TL) mechanisms and dosimetric characteristics of LiF:Mg,Ti (TLD-100)

This review summarizes the efforts of the TL research community over the past few decades, and in particular the efforts of the “Needle in the Haystack” group at the Sami Shamoon College of Engineering and the Ben Gurion University of the Negev, in the unraveling of some of the complex, inter-related and competing mechanisms controlling the production of TL photons in LiF:Mg,Ti. Considerable progress has been achieved, especially in the role of spatially correlated trapping centers (TCs) and luminescent centers (LCs) and their impact on many TL characteristics, but especially on the linear/supralinear behaviour of the dose response observed in many TL materials. This progress has been made possible due to the development of computerized analysis techniques which are capable of deconvoluting the very complex LiF:Mg,Ti glow curve into its component glow peaks – each glow peak arising from a distinct physical system. Glow curve analysis has allowed the successful simulation of dose response using nanodosimetric concepts in the framework of the Unified Interaction Model and solid state conduction band valence band models incorporating both localized and delocalized recombination. The investigations include combined measurements of TL, optical absorption, optical excitation and their inter-relationship. An essential requirement for future investigations of TL mechanisms.