Characterization and application of CaSO4:Dy TL pellets for the dosimetry of concave beta applicators

摘要

Thermoluminescent (TLD) dosimeters are widely utilized for radiation detection in manyapplications where small dimensions are required. In the case of the dosimetry of 90Sr+90Y applicators, theutilization of TLD is important mostly for the concave plaques, once the planes could be accurately calibratedagainst a plane extrapolation chamber. Besides the small size, the TLD could be very thin, which is necessaryfor beta dosimetry. Three kinds of CaSO4:Dy pellets are produced at IPEN, Brazil: conventional (0.8 mmthick), thin (0.2 mm thick), and doped with carbon (0.2 mm thick). The feasibility of thin CaSO4:Dy pellets forthe calibration of concave 90Sr+90Y applicators was already discussed. The aim of the present work was tocompare the performance of the three kinds of CaSO4:Dy pellets for the calibration of this kind of source. Themain dosimetric characteristics of the pellets were obtained, and a concave 90Sr+90Y applicator was calibrated.