Shell-Structure Effect on Elastic<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>α</mml:mi></mml:math>Scattering

Abstract

Back-angle enhancements of elastic $\ensuremath{\alpha}$-scattering cross sections have been observed for nuclei at the ends of the $1p$, $2s\ensuremath{-}1d$, and ${f}_{\frac{7}{2}}$ shells. Strong reduction of this enhancement occurs if excess neutrons enter the next open major shell. The results are discussed in terms of intermediate $\ensuremath{\alpha}$ structure.