Co59(O16,O16)Co59elastic scattering

Abstract

Differential cross sections for the $^{59}\mathrm{Co}$($^{16}\mathrm{O}$, $^{16}\mathrm{O}$)$^{59}\mathrm{Co}$ elastic scattering have been measured at laboratory energies 36, 40, 45.5, 49, 52, and 56 MeV. The angular range was 15\ifmmode^\circ\else\textdegree\fi{}-170\ifmmode^\circ\else\textdegree\fi{} (lab) in 5\ifmmode^\circ\else\textdegree\fi{} steps at lower energies. At higher energies detailed angular distributions were carried out in 1\ifmmode^\circ\else\textdegree\fi{} steps until the ratio to Rutherford was ${10}^{\ensuremath{-}3}$ with sample measurements at larger angles to assure that the differential cross sections were less than ${10}^{\ensuremath{-}4}$ ratio to Rutherford. The data have been analyzed with a four parameter optical model and the continuous ambiguities in this model are discussed. Strong absorption radii and the values of the nuclear potentials at these points are determined. Good fits to the data have been obtained using a $G$-matrix double-folding model with double-folded or Woods-Saxon forms for the imaginary potential. The required normalization of the real double-folded potential is near unity for all energies. Total reaction cross sections have been obtained by the optical model, quarter-point, "half partial-wave," and the sum of differences methods. The sum of differences method gives slightly larger total reaction cross sections than do the other methods by an amount consistent with estimates of the Coulomb excitation cross section. Estimates of the errors in the sum of differences values are computed by applying the optical theorem and are shown to be negligibly small.NUCLEAR REACTIONS: $^{59}\mathrm{Co}$($^{16}\mathrm{O}$, $^{16}\mathrm{O}$) $^{59}\mathrm{Co}$; measured $\ensuremath{\sigma}(\ensuremath{\theta}, E)$, ${E}_{\mathrm{lab}}=36, 40, 45.5, 49, 52, \mathrm{and} 56$ MeV; measured total reaction cross sections.