Determination of the reactor neutron cross section of nickel-63

Ni62(n,γ) andNi<

“…In fact, the thermal cross section obtained with the two choices is 16.2 barn for γ = 2.7 meV, but only 12.8 barn for γ = 2.4 meV. Previous measurements of the thermal cross section result in reported values between 14.0 and 21 barn [43][44][45][46][47][48][49][50], with the majority of values grouped around 14.5 barn [43,45,46,48,49]. Because of this large spread, these previous measurements cannot give us a hint on the correct γ value.…”

Neutron Capture Cross Section of UnstableNi63: Implications for Stellar Nucleosynthesis

“…1, we show the neutron capture path in the Ni-Cu-Zn region during He core and at high neutron density during C shell burning. Up to now the stellar cross section of 63 Niðn; Þ 64 Ni relied on calculations or extrapolations of experimental values at thermal neutron energies (0.025 eV) [10][11][12]. Theoretical predictions for the Maxwellian averaged cross section (MACS) at kT ¼ 30 keV are ranging from 24 to 54 mb [13][14][15][16][17].…”

Neutron-induced reactions for the s-process, and the case of Fe and Ni isotopes

“…Up to now, cross sections for the reaction 63 Ni(n, γ) were measured only at thermal neutron energies (0.025 eV) [4,5,6]. Hence, calculations of s process abundances rely on theoretical predictions of the cross section at stellar neutron energies.…”