Neutron cross sections of 239Pu in the energy range 0.01-6 MeV

Complete, selfconsistent calculations of neutron cross sections for 239pu in the energy range 0.01-6 MeV are presented. The direct calculations are made within the coupled channel method using a deformed optical potential defined by regional parameters. For the compound nucleus calculation a new HR TW version of the statistical model extended by us to describe fission at sub barrier energies is used. The parameters adopted for the fundamental fission barrier and the excitation energies at the saddle points of the discrete transition states are deduced from analyses of sub barrier fission probabilities. To describe the continuous part of the transition state spectrum analytical expressions have been established. The calculated neutron cross sections are in good agreement with the experimental data.