Fusion, elastic and total reaction cross sections in the collision6Li+64Zn

D Torresi,A Musumarra,M Zadro,D Santonocito,M Fisichella,M.G Pellegriti,C Maiolino,V Scuderi,M Lattuada,E Strano,P Figuera,A Di Pietro

doi:10.1051/epjconf/20111716018

Abstract

The structure of the weakly bound nuclei is expected to influence the fusion mechanism at energies around and below the Coulomb barrier. In fact direct channels may be favoured with respect to fusion by the low binding energies, while Coupling of the break-up channel can be responsible for a fusion cross-section enhancement. In this context the {sup 6}Li+{sup 64}Zn collision has been studied at several energies around the Coulomb barrier. The fusion cross section was measured by using an activation technique where the radioactive evaporation residues produced in the reaction were identified by the X-ray emission which follows their electron capture decay. The elastic scattering angular distributions were analyzed within the Optical Model and total reaction cross-sections were deduced from optical model calculations. (authors)

Highlights

Bound nuclei are nuclear systems with the ground state energy very close to the particle emission threshold
From a static point of view, a diffused mass distribution affects the projectile-target potential lowering the Coulomb barrier and increasing the fusion cross section; from a dynamical point of view, it is known that the strong coupling of the entrance channel with inelastic excitation or other reaction channels like break-up may lead to an enhancement of the fusion cross section with respect to single barrier penetration model
Detecting the atomic X-ray emitted after the electron capture (EC) decay it is possible to estimate the ammount of evaporation residues produced during the activation and the total fusion cross-section

Summary

Introduction

Bound nuclei are nuclear systems with the ground state energy very close to the particle emission threshold. For this reason we want to measure the 6,7Li+64Zn total fusion excitation functions down to energies far below the Coulomb barrier. Detecting the atomic X-ray emitted after the EC decay it is possible to estimate the ammount of evaporation residues produced during the activation and the total fusion cross-section. For each element the activity curve is obtained by fitting the measured activity experimental points by using a sum of several exponential functions with different decay time, one for each isotopes.

Results

Conclusion