Development of an optically stimulated luminescent detector for personal and medical dosimetry

Abstract

The main tool for controlling exposures to ionizing radiation in the industrial and medical areas is the individual monitoring of workers and the monitoring of radiation levels in the work areas through the use of radiation detectors, the dosimeters. The most commonly used dosimeters for individual monitoring are those using the thermoluminescence (TL) principle. However, optically stimulated luminescence (OSL) dosimeters are rapidly gaining ground in the world market and in some cases replacing TL dosimeters because of its several advantages.In Phase 1 of the project, investigations were focused on verifying the viability of a OSL-based ionizing radiation detector from magnesium oxide as a proof of concept and consisted of several steps: synthesis; characterization of the main properties of the materials, luminescent and physical of the material; and the development of a technique for encapsulating the polycrystalline material in a polymer matrix. The results demonstrate, unequivocally, the great potentiality of the new material as a promising dosimeter.In Phase 2, in addition of pursuing the investigations initiated in Phase 1, an investigation is going to be carry out to solve other challenges. For example: i) enhancing the sensitivity of the detector and/or of the reader; ii) improve the synthesis method, and thus have a greater reproducibility among the synthesized samples; iii) increases the automation in the process by which the substance is deposited on the substrate and thus, improve the homogeneity of the film; iv) to investigate the annealing treatment protocols that optimize the sensitivity of the dosimeter. Finally, we going to perform a complete and rigorous characterization of the detector/dosimeter, measuring all the relevant properties, including, angular dependence, energy dependence of the detector, resilience to humidity, thermal stability of the signal, signal fading, dose limits, etc.With this project, we intend to develop and then industrialize a product of compulsory use for a large number of direct users. The research will be essential to ensure the insertion of the product in the market. Above all, a research will be responsible for improving the technological characteristics of the dosimeter, in order to guarantee the success of the company in the field of dosimetry using optically stimulated luminescence.As the team and institutions involved in the project maintains several scientific, national and international agreements (CIDRA & HCFMRP & CNEN, HCFMRP & IRD & IAEA, etc.), it is also intending to generate human resources, so that universities, hospitals, radiology clinics, of radioprotection, will benefit from technological and academic improvement. Finally, it is expected that the new technology provides the market with a product of good quality and thus, with the increase of the installed capacity and the optimization of the production process, not only satisfy the existing demand, but also fulfill the Latin American market needs, with a competitive product. It is also expected that the new dosimeters will have other positive impact on society, due to the availability, in the domestic market, at a competitive price, which will be an incentive to control the working conditions of the places and people who use radiations, to besides the rules and regulation. Another important market branch is the academic and applied research that can use these dosimeters in their projects, avoiding spending on imported materials. (AU)