Recent direct reaction experimental studies with radioactive tin beams

TL;DR

This paper reviews recent experimental studies using radioactive tin beams to investigate nuclear structure near shell closures, employing direct reaction techniques to understand nucleosynthesis impacts.

Contribution

It presents new experimental results on exotic tin isotopes using direct reactions with radioactive beams, highlighting the importance of gamma-ray detection in these studies.

Findings

Studied states in 131Sn across the N=82 shell closure.

Performed one-neutron knockout reactions on 106,108Sn.

Demonstrated the effectiveness of gamma-ray coincidence measurements.

Abstract

Direct reaction techniques are powerful tools to study the single-particle nature of nuclei. Performing direct reactions on short-lived nuclei requires radioactive ion beams produced either via fragmentation or the Isotope Separation OnLine (ISOL) method. Some of the most interesting regions to study with direct reactions are close to the magic numbers where changes in shell structure can be tracked. These changes can impact the final abundances of explosive nucleosynthesis. The structure of the chain of tin isotopes is strongly influenced by the Z=50 proton shell closure, as well as the neutron shell closures lying in the neutron-rich, N=82, and neutron-deficient, N=50, regions. Here we present two examples of direct reactions on exotic tin isotopes. The first uses a one-neutron transfer reaction and a low-energy reaccelerated ISOL beam to study states in 131Sn from across the N=82 shell closure. The second example utilizes a one-neutron knockout reaction on fragmentation beams of neutron-deficient 106,108Sn. In both cases, measurements of gamma rays in coincidence with charged particles proved to be invaluable.