Elastic Scattering of Protons by Single Isotopes

Abstract

Differential cross sections for the elastic scattering of 22.2-Mev protons were measured for 20 targets of predominantly single isotopic composition at ∼2½-deg intervals over the angular range of 20°-150°. The targets ranged from ${\mathrm{Mg}}^{24}$ to ${\mathrm{U}}^{238}$ and included three pairs of isobars. Cross sections for elastic scattering of 16.4- and 9.5-Mev protons were also measured for ${\mathrm{Ni}}^{64}$ and ${\mathrm{Zn}}^{64}$ at ∼2½-deg intervals over the angular range of 25°-120°. The 9.5-Mev data for ${\mathrm{Ni}}^{64}$ and ${\mathrm{Zn}}^{64}$ show differences in the positions of maxima and minima of the elastic scattering angular distributions that are consistent with a dependence of real nuclear potential well depth on the nuclear symmetry parameter $\frac{\mathrm{}(N-Z)\mathrm{}}{A}$. The 22.2-Mev data indicate that the positions of minima and maxima of the elastic scattering angular distributions are not appreciably influenced by closed nucleon shells nor by variation of $\frac{\mathrm{}(N-Z)\mathrm{}}{A}$. The 22.4-Mev data indicate that elastic scattering at large angles is influenced by nuclear deformation.