Is the k₀ method accurate for elements with high Q₀ values?

Abstract

With a SLOWPOKE reactor, activation by epithermal neutrons is more important than for most other reactors. It was therefore undertaken to verify the accuracy of the k ₀ method for all elements with high Q ₀ values. Accurate standards of 40 elements were prepared and irradiated in the inner and outer irradiation sites of the Ecole Polytechnique SLOWPOKE reactor and then counted 10 cm from a 29% germanium detector and the amount of element in each case was calculated from the gamma-ray spectrum using the k ₀ method. For 13 nuclides with high Q ₀ values the results differed from the expected amounts by more than 5%, which suggests that measurements of new k ₀ and Q ₀ values are needed.