Photofission Cross Sections for ²³⁷Np in the Energy Interval from 5.27 to 10.83 MeV

Photofission cross sections for ²³⁷Np have been measured as a function of energy, in the interval from 5.27 to 10.83 MeV. The gamma-ray spectra were those produced by thermal neutron capture, in 30 different target materials, at a tangential beam hole of the Instituto de Pesquisas Energéticas e Nucleares IEA-R1 2-MW research reactor. The set of experimental data has been unfolded employing least-squares methods and the covariance matrix methodology. The determined photofission cross sections for ²³⁷Np, together with the complete correlation matrix for the involved errors, are presented and are compared with previous measurements reported in the literature. A statistical calculation for the ²³⁷Np photofission cross sections was performed, and the results are compared with the experimental data.