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. 2020 Dec 30;192(2):165-177.
doi: 10.1093/rpd/ncaa211.

MICRODOSIMETRIC UNDERSTANDING OF DOSE RESPONSE AND RELATIVE EFFICIENCY OF THERMOLUMINESCENCE DETECTORS

Paweł Olko  1 , Paweł Bilski  1
Affiliations

MICRODOSIMETRIC UNDERSTANDING OF DOSE RESPONSE AND RELATIVE EFFICIENCY OF THERMOLUMINESCENCE DETECTORS

Paweł Olko et al. Radiat Prot Dosimetry. .

Abstract

LiF:Mg,Ti detectors show relative efficiency η for heavy charged particles significantly lower than one. It was for a long time not recognised that η varies also for electron energies and, as a consequence for photons. For LiF:Mg,Cu,P detectors measured photon energy response was named 'anomalous' because it differed significantly from the ratio of photon absorption coefficients. The decrease of η was explained as a microdosimetric effect due to local saturation of trapping centres around the electron track. For TLD-100 it was noticed by Horowitz that the measured photon energy response disagrees with the ratio of absorption coefficient by about 10%. It was demonstrated that a fraction of the TL signal in LiF:Mg,Ti is generated in the supralinear dose-response range, due to the high local doses generated by photon-induced tracks. Prediction of TL efficiency is particularly important in space dosimetry and in dosimetry of therapeutic beams like protons or carbon ions.

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Figures

Figure 1
Figure 1
Relative TL efficiency of LiF:Mg,Ti for different ion species vs. LET in water (all collected data).
Figure 2
Figure 2
Relative TL efficiency of LiF:Mg,Ti for selected ion species. Solid lines represent empirical fits (see Table 3).
Figure 3
Figure 3
Relative TL efficiency of LiF:Mg,Cu,P for different ion species vs. LET in water (all collected data). Solid lines represent empirical fits (see Table 4).
Figure 4
Figure 4
Relative TL efficiency of LiF:Mg,Cu,P vs. LET in water, with indication of origin of the datasets.
Figure 5
Figure 5
Dose response of LiF;Mg,Ti detectors normalised do linearity index f(D) after doses of Co-60 γ-rays. Adopted from publications of Majborn et al.(28), Horowitz et al.(29) and Bilski(30).
Figure 6
Figure 6
Linearity index for MCP-N detectors after exposure of 137Cs or 60Co γ-rays. The solid line corresponds to dose response described by the formula f(D) = const (1-exp(−D/D0))/D, where D0=233 Gy.
Figure 7
Figure 7
Relative photon energy response of MTS-N detectors after exposure of γ-rays and narrow beams of X-rays.
Figure 8
Figure 8
Relative photon energy response of MCP-N detectors after exposure of MCP-N detectors in different calibration laboratories (GUM- Główny Urząd Miar, Warsaw, CIEMAT –Madrid, KfK Karlsruhe) using γ-rays and narrow beams of X-rays.
Figure 9
Figure 9
Relative photon energy response of MCP-N (LiF:Mg,Cu,P) detectors [4]. The solid line represents the result of model calculation. The local minimum of response at about 100 keV corresponds to local minimum of relative TL efficiency ηcal for secondary electrons produced by photons of the given energy.
Figure 10
Figure 10
Relative TL efficiency of MTS-N detectors after narrow filtered beams of X-rays. Squares represent our experimental results, solid line model calculation for d = 20 nm. Different colours correspond to experiments with two batches of MTS-N detectors.
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References

    1. Horowitz Y. S. Thermoluminescence and Thermoluminescent Dosimetry. ( Boca Raton, FL, USA: CRC Press; ) (1984).
    1. Attix F. H. Introduction to Radiological Physics and Radiation Dosimetry. ( New York: John Wiley & Sons; ) (1986).
    1. Nakajima T., Murayama Y., Matsuzawa T. and Koyano A. Development of a highly sensitive LiF thermoluminescence dosimeter and its applications. Nucl. Instr. Meth. 157, 155–162 (1978).
    1. Olko P., Bilski P., Ryba E. and Niewiadomski T. Microdosimetric interpretation of the anomalous photon energy response of ultra sensitive LiF:Mg,Cu,P TL Dosemeters. Radiat. Prot. Dosim. 47, 31–35 (1993).
    1. Olko P. The microdosimetric one-hit detector model for calculating the response of solid state detectores. Radiat. Meas. 35, 255–267 (2002). - PubMed