Threshold Reaction Cross Sections of Nickel Isotopes, Averaged Over a ²³⁵U Fission Neutron Spectrum

We have measured, for nickel isotopes, several threshold reaction cross sections averaged over a ²³⁵U fission neutron spectrum. The measured reactions, and corresponding averaged cross sections found, are the following: ⁶⁰Ni(n,p)^60mCo, 1.499 ± 0.083 mb; ⁶¹Ni(n,p)⁶¹Co, 1.632 ± 0.096 mb; ⁵⁸Ni(n,2n)⁵⁷Ni, 4.72 ± 0.26 b; ⁵⁸Ni(n, d+np+pn)⁵⁷Co, 275 ± 15 b; ⁵⁸Ni(n,p)^58gCo, 74.8 ± 2.3 mb; and ⁵⁸Ni(n,p)^58mCo, 36.6 ± 1.2 mb; all referred to the well-known standard of 111 ± 3 mb for the ⁵⁸Ni(n,p)^58m+gCo-averaged cross section. The measured cross sections are of interest in nuclear engineering for the characterization of the fast neutron component in the energy distribution of reactor neutrons.