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95
ST 1.2 –
Dosimetría externa
THE OSL RESPONSE OF THE CaF2:Dy AND THE CaF2:Mn
Medeiros, Beatriz; Alencar, Marcus
Instituto de Radioproteção e Dosimetria - IRD/CNEN. Brasil.
* Responsible author, email:
vallim@ird.gov.br
The OSL dosimetry has become, in recent years, a successful technique in personal and
environmental dosimetry due to high luminescence efficiency, excellent reproducibility, fast
readout of signal and repeated and successive OSL measurements of the same dosimeter.
Another factor that contributes to the increased use of OSL dosimetry is the use of the Al2O3:C
as dosimeter. Developed initially as thermoluminescent dosimeter, the Al2O3:C has an
excellent OSL sensitivity, high efficiency, good linearity, low fading and excellent stability with
respect to environmental conditions. However, the use of only one type of dosimeter tends to
create limitations on the use of OSL dosimetry because of the characteristics of this dosimeter,
such as the OSL dose response for Al2O3:C to be linear only for low doses. For intermediate
doses (doses in radiotherapy), the response is supralinear. Furthermore, the degree of
supralinearity and the saturation value vary from sample to sample (~ 30-300 Gy). The objective
of this work is the study of the OSL properties of other dosimetric materials. The dosimetric
materials used in this work are the CaF2:Dy and the CaF2:Mn produced by Harshaw and known
commercially as TLD-200 and TLD-400 respectively. The results demonstrate that both the
CaF2:Dy as the CaF2:Mn have OSL signal and the OSL dose responses are linear from 10 Gy
to 250 Gy for the CaF2:Dy, and from 3 Gy to 120 Gy for the CaF2:Mn. Therefore, the OSL
dosimetry with these dosimeters can be used in the evaluation of doses of the order of grays to
hundreds of grays.