Evaluation of the relative TL efficiency of the thermoluminescent detectors to heavy charged particles

: The relative thermoluminescence efficiency, η, is in general not constant but depends on ionisation density. Evaluation of the η is therefore important especially for correct interpretation of measurements of densely ionising radiation doses in proton radiotherapy or in space dosimetry. The correct determination of the η is not always straightforward especially when more strongly ionising radiation is to be measured. In the present work, the process of calculation of the η based on two kinds of heavy charged particles was studied. Several factors which may influence the value of the η and their significance for the final result were discussed. These include for example non-uniform deposition of the dose within the detector volume, self-attenuation of thermoluminescent light, choice of the reference radiation, etc. The presented approach was applied to the experimental results of η of LiF:Mg,Ti detectors irradiated with two kinds of heavy charged particles, protons and alpha particles.