Neutron Scattering at 2.45 Mev by a Time-of-Flight Method

Results have been obtained by a pulsed-beam time-of-flight method for the cross sections for excitation of various levels in many nuclides by inelastic scattering at 90 degrees. The incident neutrons had a mean energy of 2.45 Mev and a spread of plus and minus 100 kev. Detailed angular distributions are given for the neutrons of inelastic scattering, for the accompanying de-excitation gamma rays, and for the elastically scattered neutrons for iron, nickel, and titanium. Such results are also given for iron and titanium for a mean incident energy of 2.25 Mev. The angular distributions indicate that for these nuclides and excitations the statistical assumption is not applicable to states in the compound nucleus. Results on the spectrum of neutrons inelastically scattered by gold may be fitted over a limited range by an effective nuclear temperature of 0.3\ifmmode\pm\else\textpm\fi{}0.03 Mev. The same temperature describes the data on uranium 238 after subtraction of a fission neutron spectrum.