The Future of Radiological Protection


Calibration of a Dosimetric System in Hp (3) Using a Cylindrical Phantom

Author(s): Andrea Castillo, Josselyn Mendoza, Norma Roas, Freddy Somarriba
(Laboratorio de Física de Radiaciones y Metrología (LAF-RAM), Universidad Nacional Autónoma de Nicaragua-Managua (UNAN), Managua, Nicaragua)


In Nicaragua the Laboratory of Radiation Physics and Metrology (LAF-RAM) has currently the only external dosimetry service provider at national level. During the last meeting between LAF-RAM and stakeholders it was agreed to provide monitoring of dose in the lens of the eye in Hp(3) which is in accordance to the recommendations of ICRP 118. This paper highlights the process and results of the LAF-RAM to achieved the characterization of the dosimetry system in this quantity.

Some measurements and comparisons where performed between the type of thermoluminescent materials, conversion coefficients and standards and type of phantom. The first approach was using MCP-N detectors using a conversion coefficient for Hp (3) of 1,226 Sv/Gy described in ISO 12794 for 137Cs and slab phantom for irradiations. The second approach was using the same conditions for calibration as the first one except that TLD-100 material was used.

For the last characterization MCP-N and cylindrical phantom locally manufactured with the technical specifications proposed in ISO 4037-3: 2019 was used and the conversion coefficient of 1,18 Sv/Gy for 137Cs. During the calibration of the dosimetry system comparison of the doses of Hp(3) was carried out with dosimeters irradiated with the slab phantom and with the cylindrical phantom, finding a relative percent error of 6,1 % and 3,6 % respectively with respect to the reference value.

Keywords: Calibration; Conversion coefficient; Cylindrical phantom