Nuclear Energy Levels Excited by Fast Neutrons

Abstract

Fast-neutron inelastic scattering has been studied in a number of elements by observation of the deexcitation gamma rays with a single-crystal NaI(Tl) spectrometer. Neutrons of energy 4.4±0.1 Mev were used to bombard isotopically enriched scatterers of Ti, Cr, Ni, Zn, Ge, and W, and normal scatterers of Cl, Sr, Nb, Nd, Sm, and Gd. The low-lying levels in ${\mathrm{Ti}}^{47}$, I, and W are studied using neutron energies between 0.50 Mev and 1.45 Mev. Energies and relative yields of the gamma rays are given, and their assignment to various excited states is discussed. Previously unknown states were found in ${\mathrm{Ti}}^{48}$, ${\mathrm{Cr}}^{50}$, ${\mathrm{Zn}}^{64}$, ${\mathrm{Zn}}^{66}$, and ${\mathrm{Ge}}^{74}$.