Defining “kf-factors” for threshold reactions

• Published in: Journal of radioanalytical and nuclear chemistry 2023-06, Vol.332 (6), p.1835-1840
• Main Authors: van Sluijs, R., Blaauw, M.
• Format: Article
• Language: English
• Subjects: Activation analysis; Chemistry; Chemistry and Materials Science; Diagnostic Radiology; Energy distribution; Hadrons; Heat transmission; Heavy Ions; Inorganic Chemistry; Neutron activation analysis; Neutrons; Nuclear Chemistry; Nuclear cross sections; Nuclear Physics; Nuclear reactions; Optimization; Physical Chemistry
• ISSN: 0236-5731; 1588-2780
• DOI: 10.1007/s10967-023-08871-y

The k 0 -method (De Corte in The k 0 -standardization method: move to the optimization of neutron activation analysis. Habil. Thesis, Ghent University, Belgium, 1987) was developed solely for the use of (n, γ) nuclear reactions in neutron activation analysis. For this, a definition of only the thermal and epi-thermal flux was needed. The fast flux of the fission neutrons was not taken into account although it was considered for primary interferences by De Corte 0 . The energy distribution of the fission neutrons can be rather well described by a Watt distribution but is reactor dependent. To complicate things, the activation cross-section behaviour is nuclide dependent. In order to incorporate threshold reactions in the k 0 -method we propose to use predefined k f -factors, measuring the fast flux using a Ni-58 monitor, and to introduce an h -factor that accounts for all deviations for a specific reaction and irradiation facility. It is shown, based on data from Verheijke, that there are useful correlations for Ni-58, Ti-47 and Ti-48. Activation cross section functions indicate that there are possible more relations that might allow h -factors to be predicted.