Oxygen Differential Neutron Scattering and Phenomenological Nuclear Potentials

The neutron differential elastic scattering cross section of ${\mathrm{O}}^{16}$ has been measured at and in the vicinity of the 1-Mev resonance as well as at higher nonresonant energies. A phase-shift analysis of the results gives the $s_{\frac{1}{2}}$, $p_{\frac{1}{2}}$, $p_{\frac{3}{2}}$, and $d_{\frac{3}{2}}$ phase shifts up to 2.4-Mev neutron bombarding energy. The bound single-particle states of ${\mathrm{O}}^{17}$, as well as the $s$- and $d$-wave phase shifts, determine the parameters of a phenomenological potential well which describes the average interaction of the neutron with the ${\mathrm{O}}^{16}$ core. This potential has a depth around 40-45 Mev, which varies slightly for different single-particle configurations, and has a diffuse boundary with a Thomas-type spin-orbit energy term. It is consistent with the potentials which in other work are found to fit data of much higher mass.