Microdosimetry and Thermoluminescence

Abstract

The mechanism for production of light from a thermoluminescent phosphor requires the combination of a trapped electron and hole at a luminescent center. The kinetics is that of a second-order process. Accordingly one may expect a similarity in the formalism for describing thermoluminescent emission (TL) and the theory of dual radiation action in radiobiology (TDRA). The TDRA was developed to provide a framework for describing the effects of ionizing radiation on biological systems. It requires the interaction of two primary units of radiation damage called "sublesions" to form a "lesion" which may then be expressed as a biological effect. The physical parameters used in the TDRA come from microdosimetry, which deals with the deposition of energy by ionizing radiation in domains whose dimensions are of the order of micrometers. This paper explores the relationships between microdosimetric concepts and a description of TL properties, such as TL dose-response curves and TL LET dependence. This is then compared with similar quantities in biology to determine the possible relevance of TL as a biological model.