Assessment of the effectiveness of attenuation of Pb aprons by using TLD dosimetry and Monte Carlo calculations

We developed an experimental set-up by using a continuous emission X-ray (Pantak DXT-3000) and three types of Pb aprons, with thicknesses of 0.25, 0.5, and 0.75 mm, coated with Mylar fiber on their surface. Aprons were placed at a distance of 2.5 m from the focus. Aluminum filtration was performed at the beam output to reproduce the qualities of narrow beams, N40 (Eeffective =33 keV), N80 (Eeffective =65 keV), and N100 (Eeffective =83 keV), according to the ISO standard 4037 (1-3). Each apron was fixed with 10 thermoluminescent dosimeters (TLDs) over its surface, five dosimeters before and five dosimeters after irradiation with X-rays. Dosimeter readings were noted, and the attenuation coefficients for each effective energy were calculated. To confirm the method of effective energy of ISO-4037 and evaluate the effectiveness of aprons according to the energy range required for different medical practices, a Monte Carlo simulation using GEANT4 code was performed. Thus, the fluence and the absorbed dose in each of the dosimeters were determined, and then the coefficients of linear attenuation were calculated and compared with the experimental data and with those reported by the National Institute of Standards and Technology. Results were consistent between theoretical calculations and experimental measures. This work will serve to make assessments for other personalized radiation protectors made of Pb.