Elastic alpha scattering experiments and the alpha-nucleus optical potential at low energies

TL;DR

This study provides high-precision elastic scattering data for various nuclei at energies near the Coulomb barrier, enabling the development of a new systematic alpha-nucleus optical potential that predicts total reaction cross sections.

Contribution

It introduces a new systematic alpha-nucleus potential derived from local potentials, improving the prediction of total reaction cross sections across multiple nuclei.

Findings

High-precision angular distribution data for multiple nuclei.

A new systematic alpha-nucleus potential with few parameters.

The potential accurately predicts total reaction cross sections.

Abstract

High precision angular distribution data of ($\alpha$,$\alpha$) elastic scattering are presented for the nuclei $^{89}$Y, $^{92}$Mo, $^{106,110,116}$Cd, $^{112,124}$Sn, and $^{144}$Sm at energies around the Coulomb barrier. Such data with small experimental uncertainties over the full angular range (20-170 degrees) are the indispensable prerequisite for the extraction of local optical potentials and for the determination of the total reaction cross section $\sigma_{\rm{reac}}$. A systematic fitting procedure was applied to the presented experimental scattering data to obtain comprehensive local potential parameter sets which are composed of a real folding potential and an imaginary potential of Woods-Saxon surface type. The obtained potential parameters were used in turn to construct a new systematic $\alpha$-nucleus potential with very few parameters. Although this new potential cannot reproduce the angular distributions with the same small deviations as the local potential, the new potential is able to predict the total reaction cross sections for all cases under study.