Neutron-Induced Gamma-Ray Production in Lead-208 for Incident-Neutron Energies Between 4.9 and 8.0 MeV and in Bismuth-209 for an Incident-Neutron Energy of 5.4 MeV

Abstract

Interactions of neutrons with 208Pb have been studied by measuring photon production cross sections. Gamma-ray spectra were obtained at incidentneutron energies of 4.9, 5.4, 6.4, 6.95, 7.45, and 8.0 MeV with a gamma-ray detector system utilizing a 48-cm3 Ge(Li) detector. Nearly monoenergetic neutrons were obtained from the D(d, n) reaction using deuterons obtained from the (pulsed) Oak Ridge National Laboratory 5-MV Van de Graaff accelerator. Time-of-flight was used to discriminate against pulses due to neutrons and background radiation. Extracted differential and total inelastic cross sections have been compared with previous measurements and with data from the ENDF/B evaluation with generally satisfactory results. New information on the level structure of 208Pb is reported.Data were also obtained at En = 5.4 MeV for a sample of natural bismuth, and new information on the level structure of 209Bi was obtained. Differential gamma-ray production cross sections were obtained, and the total inelastic cross section at En = 5.4 MeV was deduced from these data.