Neutron capture gamma-rays

Two-dimensional coincidence spectra have been obtained for the 23Na(n,γ)24Na reaction and branching ratios determined. The 56Fe(n,γ)57Fe and 58Fe(n,γ)59Fe reactions have been studied with thermal reactions in order to obtain more accurate excitation energies and branching ratios. The (n,γ) reactions on 138Ba, 140Ce and 142Ce have been studied both with polarized and unpolarized thermal neutrons and the spins of ten states unambiguously determined. The circular polarization of the γ-radiation produced by the capture of polarized thermal neutrons in 31P has been measured for 11 primary and 9 secondary transitions. (C.F.)