Cross sections of fast neutron elastic and inelastic scattering by 54Fe nuclei

Differential cross sections of neutron elastic and inelastic scattering are measured at an electrostatic accelerator in the 5-7 MeV energy range with the time-of-flight spectrometer for 54Fe nucleus during excitation of the first 2+-level (E=1.408 MeV) as well as the cross section of total inelastic scattering during excitation of the second 4+-level (E=2.538 MeV) and the third 0+-level (E=2.561 MeV). The neutrons obtained in the D(d,n)3He reaction are scattered by a cylindrical 54Fe sample placed at the distance of 10 cm from the target. Sample mass is 78.53 g enrichment in 54Fe-89.5%. The spectra of scattered neutrons are measured by a scintillation detector at a flight distance of 2.7 m for 13 different angles in the 20-150 deg range. Cross sections of elastic scattering are obtained by normalization to a neutron flux at an angle equalling 0.The analysis of data obtained within the framework of opticostatic approach permits to conclude on the relative role of direct and compound mecanisms in the neutron scattering by 54Fe nucleus.The role of the direct echanism is significant in neutron elastic and inelastic scattering with the excitation of the first 2+-level. It increasess with the rise in neutron energy and becomes dominating in the end of investigated range. The compound mechanism dominates in cross sections with excitation of the secondand higher levels