An investigation is made of the importance of (n,γ,n,γ,β -) second-order reaction interferences in reactor neutron activation analysis (NAA), in addition to the commonly considered (n,γ,β -; n,γ) interferences. The algorithms for the calculation of the interference are derived from the Bateman-Rubinson equation, taking into account the formation of all m- and g-states involved, burn-up effects, and the growth of the interfering radionuclide after irradiation due to a mother-daughter relationship. The following practical cases are examined in detail: 138Ba → 140La (determination of La in presence of excess Ba), 139La → 141Ce (Ce in La), 164Dy → 166Ho (Ho in Dy), 186W → 188Re (Re in W) and 192Os → 194Ir (Ir in Os). A computer search was done for the nuclear data involved in the computation. For 139La[(n,γ; n,γ; β -) + (n,γ; β -; n,γ)] 141Ce, and 164Dy[(n,γ; n,γ; β -) + (n,γ; β -; n,γ)] 166Ho, experimental checks were performed in the Budapest Research Reactor, which confirmed the calculations showing that the (n,γ; n,γ; β -) interference gives the largest contribution to the apparent concentration of Ce in La and of Ho in Dy, respectively.
ASJC Scopus subject areas
- Analytical Chemistry
- Nuclear Energy and Engineering
- Radiology Nuclear Medicine and imaging
- Public Health, Environmental and Occupational Health
- Health, Toxicology and Mutagenesis