Prompt Fission Neutron Multiplicity and Spectrum Calculations for Thermal and Fast Neutron Induced Reactions on 233,231Pa Nuclei

摘要

The prompt fission neutron multiplicity and spectra of 233Pa(n, f) and 231Pa(n, f) were calculated for incident neutron energies up to50 MeV and 30 MeV, respectively using refined neutron evaporation models. Those models have been already successfully applied tocalculate the prompt neutron multiplicities and spectra for many actinides.The unique experimental data concerning the fission fragment mass distribution and total kinetic energy for the 234,233,232Pa fissioningnuclei were exploited in the frame of the Point-by-Point treatment. The total average prompt neutron multiplicity, the fission fragmentpair multiplicity and the multiplicity dependence on fragment mass (sawtooth) for the reactions 233,232,231Pa(nth, f) and the average values of the model parameters for 234-232Pa fissioning nuclei were calculated. For the other Pa fissioning nuclei involved in the studied reactions relevant parameters were established following systematic trends.Due to a total lack of experimental prompt fission neutron multiplicity and spectrum data for Pa isotopes, the present results werecompared with systematic trends following from neighboring actinides. The calculated prompt fission neutron multiplicity as well as theprompt c-ray energy of the 233,231Pa(n, f) reactions are obtained in very good agreement with all systematic trends.