Angular distributions and anisotropy of fragments from the neutron-induced fission of $^{237}$Np in the energy range of 1–200 MeV: measurement data and model calculations

The experimental data on the angular distributions of fragments from the fission of $^{237}$Np nuclei induced by 1–200 MeV neutrons have been presented. Such measurements for neutron energies above 16 MeV have been performed for the first time. These distributions have been analyzed and the angular anisotropy in the center-of-mass of fragments has been determined in the entire energy range under study. A method involvng the complex dynamics of the formation and decay of highly excited nuclei and based on the TALYS program has been proposed to calculate the angular distributions of fission fragments in a wide energy range for the collision of nuclei with neutrons. It has been shown that the developed model describes well the main features of the energy dependence of the angular anisotropy for the $^{237}$Np target nuclei and can be used to extract new information on the reaction and fission process.