Abstract
An evaluation of fast neutron induced reactions on 235U is performed in the 2.25 keV–30 MeV incident energyrangewiththecodeEMPIRE–3.2Malta,combinedwithselectedexperimentaldata.Thereactionmodelincludes a dispersive optical model potential (RIPL 2408) that couples seven levels of the ground-state rotational band and a triple-humped fission barrier with absorption in the wells described within the optical model for fission. EGSM nuclear level densities are used in Hauser-Feshbach calculations of the compound-nuclear decay. The starting values for the modelparameters are retrievedfrom the RIPL-3 data-base. Excellentagreementis achievedwithavailable experimental data for neutron emission, neutron capture and fission, which gives confidence that the quantities for which there is no experimental information are also predicted accurately. In the fast neutron region of the evaluated file, the fission cross section is taken from Neutron Standards, and neutron capture includes fluctuations observed in recent experiments. Other channels are taken directly from model calculations. New evaluation is validated against ICSBEP criticality benchmarks with fast neutron spectra with excellent results.
