Precise measurement of cross sections for the reactions⁵⁹Co(n,2n)^58m+gCo and⁵⁹Co(n,p)⁵⁹Fe around 14 MeV

Abstract

The cross sections for the reactions 59Co(n,2n)58m+gCo and 59Co(n,p)59Fe were measured at neutron energies of 13.5, 13.9, 14.5 and 14.8 MeV relative to the well known cross sections for the reaction 27Al(n, alpha )24Na using the activation technique. The accuracies achieved were approximately 2% and approximately 5% for the 59Co(n,2n) and the 59Co(n,p) reactions, respectively. Activity measurements were carried out using a 12.7*12.7 cm2 NaI(Tl) well-type detector and a Ge(Li) detector. Knowledge of the ratio of the 59Co(n,2n) and 59Co(n,p) cross sections was essential to evaluate the activity measurements precisely. The (n,2n) isomeric cross-section ratio was measured at the energy 13.9 MeV by following the ground-state gamma-ray activity of 58Co. The experimental results were compared with nuclear model calculations. Using the new precise cross-section values makes the 59Co(n,2n)58m+gCo reaction well suited as a reliable and handy fluence monitor for long-term 14 MeV neutron experiments.