Optimised k0-instrumental neutron activation method using Triga Mark I IPR-R1 reactor at CDTN/CNEN, Belo Horizonte, Brazil

Abstract

The Nuclear Technology Development Centre/Brazilian Commission for Nuclear Energy, CDTN/CNEN, is the only Brazilian Institution to apply the k0-standardisation method of instrumental neutron activation technique determining elements using its own nuclear reactor, TRIGA MARK I IPR-R1. After changes in the reactor core configuration, the reactor neutron flux distribution in typical irradiation channels had to be updated, as well as the parameters f and a, needed to apply the k0-method of neutron activation analysis. The neutron flux distribution in the rotary rack was evaluated through the specific count rate of 198Au and the parameters f and a, were determined in five selected channels applying the ''Cd-ratio for multi-monitor'' method, using a set of Al-(0.1 percent) Au and Zr (99.8 percent) monitors. Several reference materials were analysed, indicating the effectiveness of the improved method