The current state of knowledge concerning the effects of ionization density (ID) in the thermoluminescence (TL) of LiF:Mg, Ti - possibly the most prominent passive TL dosemeter in world-wide use - is reviewed. Other materials touched upon and demonstrating ID dependent characteristics are CaF2:Tm in its application as a linear-energy-transfer discriminator. Mechanisms discussed in depth in LiF:Mg, Ti are the preferential population of a nano-sized trapping center-luminescent center (TC/LC) complex following high-ionization density (HID) relative to low-ionization density (LID) irradiation. The presence of these TC/LC complexes leads to important changes in the relative efficiency of TL production for various types of radiation and levels of dose. The most dramatic example is the linear/supralinear dose response observed in many TL materials which is now recognized as the signature of spatially correlated TCs and LCs. The linear/supralinear dose response is modeled in the framework of a nanoscopic TC/LC model - the Unified Interaction Model (UNIM). Kinetic analyses based on conduction band/valence band charge carrier migration and spatially correlated TCs/LCs are also shown to be capable of simulating many of the effects of ID on efficiency, but only with the addition of hitherto relatively unknown radiation mechanisms in TL phenomena. Even though the focus of this chapter is on LiF:Mg, Ti, the discussion is of relevance to most other TL materials, since ID-dependent behavior is a common phenomenon observed in many materials.
|Title of host publication||Advances in Physics and Applications of Optically and Thermally Stimulated Luminescence|
|Publisher||World Scientific Publishing Co.|
|Number of pages||47|
|State||Published - 1 Jan 2019|
ASJC Scopus subject areas
- Physics and Astronomy (all)