Dependence of the thermoluminescent high-temperature ratio (HTR) of LiF:Mg,Ti detectors on proton energy and dose

TL;DR

This study investigates how the high-temperature ratio (HTR) of LiF:Mg,Ti detectors varies with proton energy and dose, revealing insensitivity to proton energies above 20 MeV and dose dependence at low doses, impacting radiation field characterization.

Contribution

It provides new insights into the dependence of HTR on proton energy and dose, clarifying its limitations for radiation quality assessment.

Findings

HTR values are above 1.2 for proton irradiation.

HTR is insensitive to proton energies above 20 MeV.

HTR depends on absorbed dose even at low doses.

Abstract

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.