  The high-temperature ratio (HTR) is a parameter quantifying changes of the
shape of the high-temperature part of the LiF:Mg,Ti glow-curve after exposure
to densely ionizing radiation. It was introduced in order to estimate the
effective LET of an unknown radiation field and to correct the decreased
relative TL efficiency for high Linear Energy Transfer (LET) radiation. In the
present work the dependence of HTR on proton energy (14.5 to 58 MeV) and dose
(0.5 to 30 Gy) was investigated. All measured HTR values were at the level of
1.2 or higher, therefore significantly different from the respective value for
gamma rays (HTR is equal to 1), but HTR was found to be insensitive to changes
of proton energy above 20 MeV. As a result the relationship between HTR and
relative TL efficiency is not unequivocal. The HTR was found to be dependent on
absorbed dose even for the lowest studied doses.
