First results on the neutron-induced fission cross-section of 231Pa for incident neutron energies En > 17 MeV

Abstract

First results on the neutron-induced fission cross-section of 231Pa for incident neutron energies En>17MeV are presented. The experiments were carried out with quasi mono-energetic neutrons produced in the reaction T(d, n)4He. Corrections for low-energy neutron background produced in this reaction at incident deuteron energies Ed>2MeV are taken into account and based on experimental data obtained by two different techniques. Despite the relatively large error bars at the higher neutron energies, the new cross-section values meet the accuracy requirements set by the IAEA and will allow to remove the hitherto existing large spread between different previously published data. Recent cross-section calculations describe well the new experimental results, which are in consistency with cross-section values obtained in a particle-transfer reaction at excitation energies corresponding to neutron energies En<10MeV.