Fusion excitation function revisited

TL;DR

This paper provides a comprehensive analysis of fusion cross sections across various nuclear systems and energies, revealing system-dependent behaviors and the potential role of geometrical effects at high energies.

Contribution

It offers the first extensive systematic study of fusion excitation functions over a wide energy range for diverse systems, highlighting the non-universality and geometrical influences.

Findings

Fusion cross sections do not follow a universal pattern across all systems.

Light and near-symmetric systems have well-characterized fusion excitation functions.

Incomplete fusion persists at energies up to 155A.MeV, possibly due to geometrical effects.

Abstract

We report on a comprehensive systematics of fusion-evaporation and/or fusion-fission cross sections for a very large variety of systems over an energy range 4-155 A.MeV. Scaled by the reaction cross sections, fusion cross sections do not show a universal behavior valid for all systems although a high degree of correlation is present when data are ordered by the system mass asymmetry.For the rather light and close to mass-symmetric systems the main characteristics of the complete and incomplete fusion excitation functions can be precisely determined. Despite an evident lack of data above 15A.MeV for all heavy systems the available data suggests that geometrical effects could explain the persistence of incomplete fusion at incident energies as high as 155A.MeV.