Characterization of minerals for luminescent dosimetry of ionizing radiations

Abstract

The project provides for the study of Brazilian minerals for application in radiation dosimetry. Because of the natural samples, the determination of the optical absorption spectrum (OA) is important to allow a correlation between the absorption ions present in the mineral and the effects observed before and after irradiation. Therefore, this project suggests the acquisition of an Optical Absorption Spectrometer in the UV-Vis region. In this project, in addition to the investigations proposed by spectroscopic measurements, usual laboratory techniques such as Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) will be used. The first material of interest is alexandrite (BeAl2O4: Cr3 +), chrysoberyl variety widely found in Brazil; however, it is still a little known gem as to its physical properties. In general, the objective of this work is to investigate the presence of Cr3 + and Fe3 + ions in alexandrite, in addition to other elements and phases, and how much they influence the optical properties, mainly regarding optical absorption and luminescent response; and the feasibility for dosimetric material. Recently, the investigation of natural minerals of alexandrite showed that the TL and OSL signal increases linearly as a function of the dose (ionizing radiation beta), therefore, alexandrite has shown potential for use in dosimetry. Still considering its luminescent properties, and that Brazil is currently the world's largest producer of alexandrite, this project also proposes the characterization of detectors in the format of pellets containing alexandrite and a binder. The research will be conducted in collaboration with the University of São Paulo. (AU)