Measurements of epithermal neutron properties of ITU Triga Mark II research reactor

Abstract

The k₀ standardization method is one of the most commonly used neutron activation analyses to determine the concentrations of elements in the sample. To perform this method, it is required to know the neutron spectrum parameters such as epithermal neutron flux shape factor (α) and thermal to epithermal neutron flux ratio (f). In this study, the α and f parameters were determined using the Cd-ratio dual monitor method and bare triple monitor method. In both methods, irradiation studies were performed in the central thimble at the ITU Triga Mark II research reactor. A gamma-ray counting system (HpGe detector) was used for measuring foil activation values. The selected monitors were ¹⁹⁷Au and ⁹⁴Zr for the Cd-ratio dual monitor method and ¹⁹⁷Au/⁹⁴Zr/⁹⁶Zr for the bare triple monitor method. The α and f parameters were -0.221 ± 0.018 and 41.826 ± 4.701 for ¹⁹⁷Au/⁹⁴Zr (724 keV) monitors, -0.231 ± 0.019 and 42.626 ± 4.791 for ¹⁹⁷Au/⁹⁴Zr (756 keV) monitors, 0.228 ± 0.025 and 43.917 ± 3.596 for ¹⁹⁷Au/⁹⁴Zr/⁹⁶Zr monitors, respectively.

Keywords: Alpha shape factor; Flux ratio; Neutron activation analysis.