Angular distribution of photoneutrons from deuterium
Evwaraye, Andrew Oteku
A photon beam of EÎ³max = 125 MeV, produced by the Saskatchewan electron linear accelerator, was used to irradiate a deuteron target. The deuteron target was viewed simultaneously by five neutron detectors located respectively at 30Â°, 60Â°:, 90Â°, 112Â° and 142Â° to the incident photon beam. The measured angular distributions were compared with the theoretical calculations using Hamada- Johnston and Boundary Condition Model potentials. The results of this experiment were also compared with previous measurements where they overlap. Good agreement was found between the present measurements and theoretical predictions in the energy region of EÎ³â‰¤40 MeV. The shape of the angular distributions in this energy region is approximately sin 2Î˜ as expected. There is no strict agreement between the present measurements and the theoretical predictions at EÎ³â‰¤55 MeV. Though the non-phenomenological potential, the Boundary Condition model potential, appears to give better predictions of the angular distributions than the Hamada- Johnson potential. The apparent disagreement between the present work and previous experiments at backward angles is interpreted to be due to the large uncertainties in the background subtraction in the forward proton angles, as all previous workers detected in the outgoing protons in the reaction D (Î³, p) n. The large isotropic contribution observed is interpreted to be due to tensor forces both in the ground and final states as well as spin-orbit forces in the final state.