National Nuclear Energy Commission

About: National Nuclear Energy Commission is a government organization based out in Rio de Janeiro, Brazil. It is known for research contribution in the topics: Dosimetry & Laser. The organization has 3816 authors who have published 4694 publications receiving 59951 citations.

Dependence of scintillation characteristics in the CsI(Tl) crystal on Tl/sup +/ concentrations under electron and alpha particles excitations

Abstract: This paper reports the emission spectra, pulse heights, and decay curves of CsI(TI) crystals with a Tl/sup +/ concentration ranging from 10/sup -6/ to 10/sup -2/ mol under electron and alpha particle excitations. Larger pulse heights from the crystals with Tl/sup +/ concentration of more than 10/sup -3/ mol were observed for a higher ionization density of alpha particle excitation compared with those of electron excitation. This enhancement may be explained in terms of the higher scintillation efficiency for higher Tl/sup +/ concentration. Decay curves under electron and alpha particle excitations were compared with the decay curve under pulsed UV excitation. The observed decay curves were explained in terms of the sum of the three energy transfer processes to create excited states (Tl/sup +/)*: the prompt process, the V/sub k/ diffusion process to Tl/sup 0/, and the electron release process from Tl/sup 0/ to Tl/sup ++/. Here, Tl/sup 0/ and Tl/sup ++/ were produced through (Tl/sup +/+electron)/spl rarr/Tl/sup 0/ and [Tl/sup +/+hole (or V/sub k/)]/spl rarr/Tl/sup ++/.

Studies of Cs retention in the human body related to body parameters and Prussian blue administration

Abstract: Using the in-vivo monitoring data from the individuals that suffered internal contamination in the Goiânia accident, a preliminary study on the elimination of Cs from their body was conducted. It was concluded that elimination follows a first-order linear kinetic pattern, both with and without Prussian Blue treatment. Cesium half-lives for both sexes were shown to be influenced mainly by the weight of each individual. In general, Prussian Blue seems to reduce the half-life by 32%. At the time our study was conducted, patients who were under treatment with the drug were receiving 3 g d-1, 6 g d-1, or 10 g d-1 of the medication. Our results suggest that there is an optimum dosage for a certain weight range to achieve this reduction in half-life, but one would need more data to statistically prove this assumption.