Probing the fusion of neutron-rich nuclei with re-accelerated radioactive beams

Abstract

We report the first measurement of the fusion excitation functions for 39,47 K + 28 Si at nearbarrier energies. Evaporation residues resulting from the fusion process were identified by direct measurement of their energy and time-of-flight with high geometric efficiency. At the lowest incident energy, the cross-section measured for the neutron-rich 47 K induced reaction is ∼6 times larger than that of the β-stable system. This experimental approach, both in measurement and analysis, demonstrates how to efficiently measure fusion with low-intensity, re-accelerated radioactive beams, establishing the framework for future studies.

Horizons: Nuclear Astrophysics in the 2020s and Beyond

“…Nuclear masses play a key role in determining which processes may occur and how much energy they can generate, and significant experimental and theoretical progress has been achieved. In contrast, predicting the rates of the reactions has been a challenge [440,438] and only a few dedicated experiments have been performed to date [441,442].…”

Proton and neutron exchange as a prelude to fusion at near-barrier energies

“…The re-accelerated beam was transported to the experimental setup where it impinged upon the 28 Si target. Details on the experimental setup have been previously published [19].…”

“…Contaminants in the radioactive beam were identified and rejected on a particle-by-particle basis by performing a ∆E-TOF measurement [18,19]. The target composition was characterized using Rutherford Backscattering measurement (RBS) and confirmed using X-ray Photoelectron spectroscopy [20].…”

Extracting dynamics in the fusion of neutron-rich light nuclei

“…Fusion reactions provide a powerful means to assess the response of neutron-rich nuclei to perturbation. As fusion involves the interplay of the repulsive Coulomb and attractive nuclear potentials, by examining fusion for an isotopic chain one probes the neutron density distribution and how that density distribution evolves as the two nuclei approach and overlap [5][6][7]. In the following manuscript we propose a novel perspective for investigating the role of collective dynamics in fusion.…”