Optimisation of LiF:Mg,Ti detectors for dosimetry in proton radiotherapy

Miniature LiF:Mg,Ti (MTS-N) pellets, of diameter 1-2 mm and thickness 0.5 mm, specially designed for dosimetry in proton radiotherapy, have been produced at the Institute of Nuclear Physics in Krakow, Poland. The influence of dopant composition, activation method and cooling rate on the dose-LET response of these TL detectors was tested. It appears that these dosimetric characteristics are governed mainly by the Mg-dopant - supralinearity and efficiency for high LET radiation are highest for samples with the lowest content of magnesium. The cooling rate after high temperature anneal is another significant factor. The new miniature MTS-N detectors can be applied for in vitro phantom dosimetry in proton beams, e.g, for ocular radiotherapy.