The influence of the dose assessment method on the LET dependence of the relative luminescence efficiency of LiF:Mg,Ti and LiF:Mg,Cu,P

Thermoluminescent detectors (TLDs) are solid state detectors commonly used for dose monitoring and dose mapping in many earth and space applications. Among all the crystals available, the ones based on lithium fluoride (LiF) are the most widely spread and studied around the world. In the last years the use of these TLDs in complex heavy charged particles (HCPs) fields, as in spacecraft or in radiotherapy beams, has grown rapidly leading to the necessity of an accurate characterization of the detectors’ response in these radiation environments.
In this work, 6LiF:Mg,Ti, 7LiF:Mg,Ti, 6LiF:Mg,Cu,P and 7LiF:Mg,Cu,P detectors were exposed to different radiation qualities in order to investigate the dependence of their relative luminescence efficiency on the linear energy transfer (LET) of the incident particles. The measured efficiencies were in good agreement
with literature.
In relation to this issue, different dose assessment methods, i.e. peak height, signal integration over different regions of interest (ROIs) and glow curve deconvolution, were compared and their influence on the measured relative luminescence efficiency values was assessed. For both LiF:Mg,Ti and LiF:Mg,Cu,P
detectors, no relevant differences were found in the relative luminescence efficiency evaluated by means of main peak height, main peak ROI and main peak deconvolution. On the other hand, if the integration of the signal is extended to the high temperature zone (248e310 C) of LiF:Mg,Ti or the low temperature
zone (125e185 C) of LiF:Mg,Cu,P, significant deviations were found.