New article published in 12(4A) - ENAN / INAC 2024

Parameters for Validating a Spectrometric System with Itinerant NaI(Tl) in the Ativimeter’s Calibration

Abstract: In radiopharmaceutical production centers and nuclear medicine services, short half-life radionuclides are essential. They have been used as radiotracers since their use increased significantly and aroused the interest of national metrology laboratories, which are responsible for providing traceability to radioactive standards. Therefore, knowledge of the activity of administered radiopharmaceuticals must be obtained accurately. However, their short half-lives prevent the provision of traceability. To overcome these obstacles, an itinerant system based on a NaI(Tl)-type scintillator detector is being developed at the National Laboratory for Ionizing Radiation Metrology (LNMRI). This work aims to show the schematic arrangement of the system developed to calibrate activimeters, as well as the tests and experimental comparisons carried out in this study using performance indicator parameters to characterize and validate the itinerant NaI(Tl) detection system in the calibration of activimeters. Read full article

Paraloid Resins with Polymeric Monomers Cured by Gamma Radiation for Consolidation of Porous Wood

Abstract: Preservation consists of an action that aims to guarantee the integrity and perpetuity of something, such as a cultural asset. One of the preservation instruments is restoration, an intervention that aims to definitively secure a product of human activity. Cultural heritage presents an extensive diversity of wooden objects, which can be affected by insect attacks, causing severe damage to their structures. To recover this damage, compatible materials are needed to maintain their integrity. Therefore, we propose to study the obtaining of polymeric resins cured by gamma radiation without the use of catalysts for consolidation or restoration of wooden objects. A series of formulations were developed with polymeric resins based on paraloid B72 and polymeric monomers cured by gamma radiation from a cobalt-60 source. These resins were characterized by physicochemical analyses, and the results presented were surprising in terms of reversibility. Gamma radiation replaced the catalyst, curing the resin 100%, indicating new resin options for restoration and/or consolidation in porous wood. Read full article