CONICET | Buscador de Institutos y Recursos Humanos

The fluorescence of silver nanoparticles or ions can be used for in situ detection and dose enhancement purposes in X-ray irradiation applications. This study is focused on the full integration of the chemical synthesis of silver nanoparticles suitable for dosimetry and radiology purposes with characteristics that can be exploited in radiotherapy and radiodiagnosis [1]. A narrow size distribution and a compatible stabilizing agent is often desired in order to obtain homogeneous behaviors in nanoparticle suspension. With the method proposed in this study, nanoparticles ranging from 5 to 20 nm were obtained. The fluorescence of aqueous suspensions of silver nanoparticles has been measured experimentally and simulated with the Monte Carlo PENELOPE code for different silver concentrations and geometrical configurations. Finally, the feasibility of using these nanoparticles for the elaboration of Fricke gel dosimeters has been tested obtaining a dose enhancement when compared with the same material irradiated below the silver K-edge. Besides, characterization results obtained from different X-ray based analytic techniques used are reported, assessing the presence of silver nanoparticles in gel dosimeters along with shape and size obtained from electronic microscopy, and silver nanoparticle concentration within sample was correlated with fluorescence signal and effective mass absorption coefficient was evaluated from high resolution micro-computed tomography. Comparisons with Monte Carlo simulations based on the PENELOPE main code [2] indicated overall good agreement with experimental data.[1] F. Mattea, J. Vedelago, F. Malano, C. Gómez, M. Strumia, M. Valente, Radiation Physics and Chemistry 130, 2017, 442-450.[2] F. Salvat, J. Fernández-Varea, J. Sempau, PENELOPE-2008: A Code System for Monte Carlo Simulation of Electron and Photon Transport, NEA France, 2008.