Evaluation of 27Al(n,α)24Na, 27Al(n,p)27Mg and 58Ni(n,p)58Co cross sections

The evaluation of the 27Al(n,α)24Na, 27Al(n,p)27Mg and 58Ni(n,p)58Co cross sections were performed in the neutron energies up to 20MeV. The original experimental data were examined with respect to the measuring procedures and the data analyses, and some data were modified by using the recent data of the standard cross sections and the decay data. The evaluation procedures are described, and the evaluated excitation curves for these three reactions are shown. The present values for the 27Al(n,α)24Na cross section are close to the recent other data. The evaluated values for the 27Al(n,p)27Mg and 58Ni(n,p)58Co cross sections are somewhat lower than those of ENDF/B-IV around the maxima of the excitation curves. The 235U fission-neutron average cross-sections calculated from the present evaluated values are compared with the corresponding values from the other evaluations and with the recent experimental data. (author)