engleski

Using TL and PTTL of LiF:Mg, Ti detectors for mixed field dosimetry

Phototransfered thermoluminescence (PTTL) refers to thermoluminescence (TL) induced by light as a result of photo transfer of charge carriers from one or more kind of traps to other kind of traps. Usually this transfer takes place from high temperature (deep) traps which have been filled earlier by irradiation, to lower temperature (shallow) traps which have been emptied thermally, leaving the deep traps filled. In radiation dosimetry, PTTL found its use for dose reassessment. After the dose has first been evaluated by a normal TL measurement, the same dosimeter is subjected to the PTTL dose reassessment procedure with the intention of obtaining a new estimation by a completely independent measurement procedure. Recently, some experimental data indicated that PTTL could be used as a tool for dose discrimination in a mixed field using single TL detector. In this work, the short overview of the use of LiF:Mg, Ti based TL detectors in mixed field dosimetry is presented. Also, the experimental data of the use TL and subsequent PTTL in different mixed, neutron + gamma ray fields, are presented and discussed. LiF detectors with different Li isotopes were used. The results show that, in principle, it is possible to determine separately gamma and neutron dose components with a single detector due to different sensitivities of TL and subsequent PTTL to neutrons in comparison to gamma rays. The main disadvantage, the low sensitivity of both, TL and PTTL, to neutrons restricts the use only for the case of radiation accident. The further investigation of the sensitivity improvement is recommended.

TL; PTTL; LiF:Mg; Ti; mixed field dosimetry

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