Neutron Transfer and the Tunneling Mechanism in the Bombardment of Gold by Nitrogen

Measurements have been made of the angular distributions of ${\mathrm{N}}^{13}$ nuclei produced in the neutron-transfer reaction ${\mathrm{Au}}^{197}$(${\mathrm{N}}^{14}$,${\mathrm{N}}^{13}$)${\mathrm{Au}}^{198}$. Fifteen different bombarding energies were studied. It is found that the results can be described in terms of the transfer of a neutron from an ${\mathrm{N}}^{14}$ nucleus moving along a classical trajectory. In particular, it is found that ${\mathrm{N}}^{14}$ trajectories with distances of closest approach of (12.7\ifmmode\pm\else\textpm\fi{}0.5)\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}13}$ cm give the largest contribution to the transfer process. Further, both the angular and energy dependence of the ${\mathrm{N}}^{13}$ production have been compared with the dependences predicted by the tunneling theory of Breit and Ebel; both experimental dependences have been found to be in agreement with this theory.