Determination of thermal neutron capture cross-section of cerium isotopes

The thermal neutron capture cross-section of cerium isotopes \(^{140}\)Ce and \(^{142}\)Ce, were measured with detailed covariance analysis using naturally occurring cerium oxide samples. We conducted irradiation with an Am–Be neutron source at the Manipal Institute of Technology and performed offline gamma-ray measurements via High Purity Germanium (HPGe) Detector. The neutron spectrum from the irradiation location was obtained by employing multiple foil activation techniques and spectrum unfolding methods. The present results provide precise thermal neutron capture cross-section data with detailed covariance analysis. The measured cross sections, \( 0.54 \pm 0.03 \) barns for \(^{140}\)Ce and \(0.83 \pm 0.04\) barns for cerium-142, are compared with previous measurements and with the latest available evaluated nuclear libraries. It is observed that the presently measured thermal cross-section values of \(^{140}\)Ce and \(^{142}\)Ce are lower than the evaluated data but have higher accuracy compared to the previous measurements with larger uncertainties. Further, the measured thermal neutron capture cross-section values of \(^{140}\)Ce and \(^{142}\)Ce isotopes are in good agreement with the previous measurements than the evaluations. Thus, the current state of nuclear data evaluation requires improvement for cerium isotopes.