A simplified method to replace the Westcott formalism in k 0-NAA using non-1/v nuclides

The Westcott formalism was developed to accurately describe the activation of nuclides whose neutron capture cross-sections do not follow the 1/v-law and it was incorporated in the k ₀-method about 20 years ago. However, its implementation in the original fashion is not easy, requiring the use of a different formalism for the non-1/v nuclides, with a g(T _n) factor for the thermal neutron activation and an s ₀ factor for epithermal activation, the measurement of the neutron spectral index of the irradiation channel and the irradiation of a temperature monitor with each batch of samples as well. In this work we investigated the accuracy of maintaining the simpler formula of the Høgdahl convention for all nuclides and introducing the g(T _n) factor for the thermal neutron activation for non-1/v nuclides. The epithermal activation is calculated using a Q ₀-value estimated from the measured s ₀-value for non-1/v nuclides. This new approach has been shown, by calculations with the parameters of the neutron spectra of five irradiation channels, not to give a significant loss of accuracy relative to the Westcott formalism.