Determination of the neutron spectrum shape parameter alpha in k0 NAA methodology using covariance analysis
Mauro S Dias1, Vanderlei Cardoso, Marina F Koskinas
1Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN/SP), Centro do Reator de Pesquisas-CRPq, São Paulo-SP, Brazil. msdias@ipen.br
Abstract:
The k(0) method for quantitative reactor neutron activation analysis (NAA) has been applied in several laboratories for the determination of multi-elemental concentrations in different materials. The general formula that yields the concentration value can be divided in two parts: one involving detection parameters and the other involving irradiation parameters. A rigorous uncertainty calculation must take into account the correlations between each of these parameters. The Nuclear Metrology Laboratory at IPEN has a research program intended to develop a methodology applying covariance analysis in order to obtain the overall uncertainty in the concentrations of different elements in a given sample, and the correlation between each pair of them. The present paper concentrates in the determination of the neutron spectrum shape factor alpha by two methods: Cd-covered and Cd-ratio, using experimental data obtained in the IEA-R1 research reactor. The final values for alpha were: (0.001+/-0.018) and (0.001+/-0.019) for the Cd-covered and Cd-ratio methods, respectively, in good agreement with each other.
More Related Videos
Related Concept Videos
Atomic Absorption Spectroscopy: Overview
When irradiated by EMR of a particular wavelength, these...
Atomic Absorption Spectroscopy: Lab
Solutions containing organic solvents, such as low-molecular-mass alcohols, esters, or ketones, enhance absorbances by increasing nebulizer...
Atomic Emission Spectroscopy: Overview
Atomic Emission Spectroscopy: Lab
Atomic Emission Spectroscopy: Instrumentation
One-Compartment Open Model: Wagner-Nelson and Loo Riegelman Method for ka Estimation
On...


