Carbon-based thin films as a suitable alternative to metallized films for the preparation of radioactive sources.

A new method for radionuclide labeling by the use of graphene thin films was previously presented. In this work, a comparison among low energy radioactive sources supported on carbonaceous thin films on polyvinyl chloride-polyvinyl acetate copolymer (VYNS), based on the use of aqueous solutions is investigated as a feasible alternative to the traditional metallized films avoiding the downside of the loss of many broken films. Graphene-based materials were prepared by both oxidation-exfoliation-reduction and direct graphite exfoliation routes.

Standardization of Ra solutions with descendants by 4παβ LSC counting.

In this work, a method to standardize Ra solutions with descendants by 4παβ liquid scintillation counting (LSC) has been used. The standardization can be carried out provided that the equilibrium state of Ra solutions, the counting efficiency of short-lived Po and/or the counter dead time are known. Procedures to obtain these requirements have been set up.

Standardization of non-equilibrium Pb solutions by LSC and 2πα counting.

A procedure for the standardization of Pb solutions in radioactive disequilibrium, or incompletely purified from its descendants, has been set up and successfully validated. The method, based on joint measurements of Po by alpha-particle spectrometry (2πα counting) with grid ionization chamber and liquid scintillation counting for overall activity estimation, is presented as an alternative to Pb measurement by LSC with α/β discrimination.

Design and optimization of a proportional counter for the absolute determination of low-energy x-ray emission rates.

We recently presented the construction of a proportional counter for the absolute measurement of low-energy x-ray emission rates. Its main features were presented in a previous study, along with the testing of its performance as an absolute technique. Full details on its design, construction, and characterization processes are given in this paper.

Absolute determination of low-energy X-ray emission rates with a proportional counter.

A defined-solid-angle proportional counter has been designed for the absolute determination of X-ray emission rates between 2 keV and 10 keV. The main features of the counter are described in this work, and spectra of two radionuclides with low-energy X-ray emissions are presented. The activity concentration of an Fe solution was determined by measuring the emission rate of three samples and using tabulated emission probabilities.