Angular Distribution and Anisotropy of Fission Fragments in Reactions Induced by Neutrons with Intermediate Energies of 1 to 200 MeV

Abstract

Experimental data on the angular distributions of ²³²Th, ²³³U, ²³⁵U, ²³⁸U, ^natPb, and ²⁰⁹Bi fission fragments in reactions induced by neutrons with intermediate energies of up to 200 MeV are presented. Measurements are made using the GNEIS time-of-flight (TOF) spectrometer with the neutron source based on the 1-GeV proton synchrocyclotron of the Petersburg Nuclear Physics Institute. Angular distributions and the anisotropy of fission fragments W(0°)/W(90°) calculated from these distributions are given together with the results of other authors. The disagreement between the results obtained in different works is discussed. The data presented in this work for the anisotropy of ^natPb and ²⁰⁹Bi fission fragments in reactions induced by neutrons with energies ranging from the fission threshold to 200 MeV are obtained for the first time.