Spatial distribution of neutron flux in geological larger sample analysis at CDTN/CNEN, Brazil
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Iron monitor wire was used to evaluate the neutron flux gradients inside 5 g-geological sample during irradiation. The spatial distribution for thermal flux was about 2 %/cm for radial and axial gradients and about 5 %/cm for radial and 2.5 %/cm for axial gradients for fast neutrons. The results were evaluated using reference material IAEA-SOIL-7 analysed as small and larger samples and tested with calculating E n numbers. This test pointed out that all results were consistent within a 95 % confidence interval. The contribution of the neutron flux gradients may be reduced for larger sample using the standard procedure of the k 0-instrumental neutron activation analysis.
KeywordsNeutron activation analysis k0-instrumental neutron activation analysis Larger sample Neutron flux gradients
This work was partially supported by the International Atomic Energy Agency under Grant BRA-14798, by the Foundation for Research Support of Minas Gerais, FAPEMIG, under Grant APQ-01259-09 and by financial support from the Slovenian Research Agency (ARRS) through programme P1-0143.
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