Measurement and covariance analysis of ⁵⁹Co(n, 2n)⁵⁸Co reaction cross sections at the effective neutron energies of 11.98 and 15.75 MeV

The ⁵⁹Co(n, 2n)⁵⁸Co reaction cross sections relative to the cross sections of the ¹¹⁵In(n, n′)^115mIn reaction have been measured at the effective neutron energies of 11.98 and 15.75 MeV by using activation and off-line γ-ray spectrometric technique. Neutron beam used in the present experiment was generated from the ⁷Li(p, n)⁷Be reaction with the proton energies of 14 and 18 MeV at the 14UD BARC-TIFR Pelletron facility, Mumbai. We also present the covariance information by taking into account the sources of error and the correlations between the attributes influencing the measurements. The ⁵⁹Co(n, 2n)⁵⁸Co reaction cross sections from the present work are then compared with the values from different evaluated nuclear data libraries. The micro-correlation technique suggested by Smith was modified to generate the covariance matrix for the measurements of reaction cross sections as the efficiencies of detector for the sample and monitor are correlated.